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Mahony MJ, Bertozzi T, Guzinski J, Hines HB, Donnellan SC. A new species of barred frog, Mixophyes (Anura: Myobatrachidae) from south-eastern Australia identified by molecular genetic analyses. Zootaxa 2023; 5297:301-336. [PMID: 37518792 DOI: 10.11646/zootaxa.5297.3.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Indexed: 08/01/2023]
Abstract
Mixophyes are large ground-dwelling myobatrachid frogs from eastern Australia and New Guinea. Several of the species found in mid-eastern and south-eastern Australia are listed as threatened, due largely to declines presumably caused by the amphibian disease chytridiomycosis. Given the wide distribution of several of these species and that their distributions cross well-known biogeographic boundaries that often correspond to deep genetic breaks or species boundaries among closely related vertebrates, we undertook a molecular genetic assessment of population structure across the range of each species to determine the presence of undescribed species. Of the four species of Mixophyes subject to molecular population genetic analyses, one, the Stuttering Frog (Mixophyes balbus), showed a level of diversity consistent with the presence of two species. Morphometric, meristic and bioacoustic analyses corroborate these distinctions, and a new species is described for the populations south of the Macleay River valley in mid-eastern New South Wales to east Gippsland in Victoria. Applying the IUCN Red List threat criteria the new species meets the conservation status assessment criteria for Endangered 2B1a,b because its extent of occupancy and area of occupancy are below the threshold value and it has declined and disappeared from the southern two thirds of its distribution over the past 30 years.
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Affiliation(s)
- Michael J Mahony
- School of Environmental and Life Sciences, University of Newcastle, University Drive, Callaghan 2308, Australia.
| | - Terry Bertozzi
- South Australian Museum, North Terrace, Adelaide 5000, Australia. School of Biological Sciences, University of Adelaide, North Terrace, Adelaide 5005, Australia..
| | - Jaro Guzinski
- South Australian Museum, North Terrace, Adelaide 5000, Australia.
| | - Harry B Hines
- Queensland Parks and Wildlife Service and Partnerships, Department of Environment and Science, PO Box 64, Bellbowrie, Qld 4070 and Honorary Research Fellow, Biodiversity, Queensland Museum, PO Box 3300, South Brisbane, Qld 4101.
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Callen A, Pizzatto L, Stockwell MP, Clulow S, Clulow J, Mahony MJ. The effect of salt dosing for chytrid mitigation on tadpoles of a threatened frog, Litoria aurea. J Comp Physiol B 2023; 193:239-247. [PMID: 36811723 PMCID: PMC9992028 DOI: 10.1007/s00360-023-01479-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 01/10/2023] [Accepted: 02/09/2023] [Indexed: 02/24/2023]
Abstract
The novel fungal pathogen Batrachochytrium dendrobatidis (chytrid) is one of the greatest threats to amphibians worldwide. Small increases in water salinity (up to ca. 4 ppt) have been shown to limit chytrid transmission between frogs, potentially providing a way to create environmental refugia to reduce its impact at a landscape scale. However, the effect of increasing water salinity on tadpoles, a life stage confined to water, is highly variable. Increased water salinity can lead to reduced size and altered growth patterns in some species, with flow-on effects to vital rates such as survival and reproduction. It is thus important to assess potential trade-offs caused by increasing salinity as a tool to mitigate chytrid in susceptible frogs. We conducted laboratory experiments to examine the effects of salinity on the survival and development of tadpoles of a threatened frog (Litoria aurea), previously demonstrated as a suitable candidate for trialling landscape manipulations to mitigate chytrid. We exposed tadpoles to salinity ranging from 1 to 6 ppt and measured survival, time to metamorphosis, body mass and locomotor performance of post-metamorphic frogs as a measure of fitness. Survival and time to metamorphosis did not differ between salinity treatments or controls reared in rainwater. Body mass was positively associated with increasing salinity in the first 14 days. Juvenile frogs from three salinity treatments also showed the same or better locomotor performance compared to rainwater controls, confirming that environmental salinity may influence life history traits in the larval stage, potentially as a hormetic response. Our research suggests that salt concentrations in the range previously shown to improve survival of frogs in the presence of chytrid are unlikely to impact larval development of our candidate threatened species. Our study lends support to the idea of manipulating salinity to create environmental refugia from chytrid for at least some salt-tolerant species.
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Affiliation(s)
- Alex Callen
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia.
| | - Ligia Pizzatto
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Michelle P Stockwell
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Simon Clulow
- Centre for Conservation Ecology and Genomics, Institute for Applied Ecology, University of Canberra, Bruce, ACT, 2617, Australia
| | - John Clulow
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Michael J Mahony
- Conservation Science Research Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia
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Garnham JI, Bower DS, Stockwell MP, Pickett EJ, Pollard CJ, Clulow J, Mahony MJ. Seasonal variation in the prevalence of a fungal pathogen and unexpected clearance from infection in a susceptible frog species. Dis Aquat Organ 2022; 148:1-11. [PMID: 35142293 DOI: 10.3354/dao03628] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) causes the disease chytridiomycosis, which is a primary driver for amphibian population declines and extinctions worldwide. For highly susceptible species, such as the green and golden bell frog Litoria aurea, large numbers of Bd-related mortalities are thought to occur during the colder season (winter), when low temperatures favour the growth of the pathogen. However, extant L. aurea populations are persisting with Bd. We measured Bd prevalence and infection levels of wild L. aurea using capture-mark-recapture and radio-tracking methods. Using this information, we sought to determine host and environmental correlates of Bd prevalence and infection load. Mean ± SE infection load was higher in frogs sampled in autumn (431.5 ± 310.4 genomic equivalents; GE) and winter (1147.5 ± 735.8 GE), compared to spring (21.8 ± 19.3 GE) and summer (0.9 ± 0.8 GE). Furthermore, prevalence of Bd infection in L. aurea was highest in winter (43.6%; 95% CI 33.1-54.7%) and lowest in summer (11.2%; 95% CI 6.8-17.9%). Both prevalence and infection load decreased with increasing temperature. Seven frogs cleared their fungal infection during the coolest months when Bd prevalence was highest; however, these clearances were not permanent, as 5 frogs became infected again. Understanding the factors that allow amphibians to clear their Bd infections when temperatures are optimal for Bd growth presents the potential for manipulating such factors and provides an important step in future research.
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Affiliation(s)
- James I Garnham
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales 2308, Australia
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Rowley JJL, Mahony MJ, Hines HB, Myers S, Price LC, Shea GM, Donnellan SC. Two new frog species from the Litoria rubella species group from eastern Australia. Zootaxa 2021; 5071:1-41. [PMID: 34810683 DOI: 10.11646/zootaxa.5071.1.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Indexed: 11/04/2022]
Abstract
The bleating tree frog (Litoria dentata) is one of the more prominent pelodryadid frogs of eastern Australia by virtue of its extremely loud, piercing, male advertisement call. A member of the Litoria rubella species group, L. dentata has a broad latitudinal distribution and is widespread from coastal and subcoastal lowlands through to montane areas. A recent mitochondrial DNA analysis showed a deep phylogeographic break between populations of L. dentata on the mid-north coast of New South Wales. Here we extended the mitochondrial survey with more geographically comprehensive sampling and tested the systematic implications of our findings with nuclear genome wide single-nucleotide polymorphism, morphological and male advertisement call datasets. While similar in appearance and in male advertisement call, our integrative analysis demonstrates the presence of three species which replace each other in a north-south series. We redescribe Litoria dentata, which is restricted to coastal north-eastern New South Wales, and formally describe Litoria balatus sp. nov., from south-eastern Queensland, and Litoria quiritatus sp. nov., from the mid-coast of New South Wales to north-eastern Victoria.
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Affiliation(s)
- J J L Rowley
- Australian Museum Research Institute, Australian Museum, 1 William St, Sydney 2010, Australia. Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia..
| | - M J Mahony
- School of Environmental and Life Sciences, The University of Newcastle, University Drive, Callaghan, 2308, Australia. .
| | - H B Hines
- Department of Environment and Science, PO Box 64, Bellbowrie, Qld, 4070, Australia. Honorary Research Fellow, Biodiversity, Queensland Museum, PO Box 3300, South Brisbane, QLD 4101..
| | - S Myers
- South Australian Museum, North Terrace, Adelaide, Adelaide, 5000, Australia. ALS Water Resources Group, 22 Dalmore Drive, Scoresby, Victoria, 3179, Australia..
| | - L C Price
- School of Biological Sciences, University of Adelaide, 5005, Australia..
| | - G M Shea
- Australian Museum Research Institute, Australian Museum, 1 William St, Sydney 2010, Australia. Sydney School of Veterinary Science B01, University of Sydney, NSW 2006, Australia. .
| | - S C Donnellan
- South Australian Museum, North Terrace, Adelaide, Adelaide, 5000, Australia. .
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Mahony MJ, Hines HB, Mahony SV, Moses B, Catalano SR, Myers S, Donnellan SC. A new hip-pocket frog from mid-eastern Australia (Anura: Myobatrachidae: Assa). Zootaxa 2021; 5057:451-486. [PMID: 34811197 DOI: 10.11646/zootaxa.5057.4.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Indexed: 11/04/2022]
Abstract
The hip-pocket frog (Assa darlingtoni), a small terrestrial myobatrachid frog found in mid-eastern Australia, has a highly derived, unusual, reproductive mode involving a unique form of male parental care. Males have subcutaneous pouches that open near the hip, and the developing tadpoles are carried in these pouches to post metamorphosis. It is found on several isolated mountain ranges in closed forest habitats, associated with high rainfall and temperate or sub-tropical climates. We established genetic relationships among specimens sampled across the range using phylogenetic analyses of thousands of single nucleotide polymorphisms (SNPs) from the nuclear genome and mitochondrial ND2 gene nucleotide sequences. These analyses uncovered two lineages that are genetically distinct in both nDNA and mtDNA analyses and that have low levels of divergence in male advertisement calls and are morphologically cryptic. Our data support separate species status for each lineage, based on the molecular genetic data. The first, which we name as a new species, Assa wollumbin sp. nov., is restricted to a single mountain, Wollumbin (= Mount Warning), the eroded cone of an ancient shield volcanothe Tweed Volcano. The second, the nominal species A. darlingtoni, has a wider distribution in five geographically disjunct subpopulations along 430 km of the Great Dividing Range in south-eastern Queensland and north-eastern New South Wales. The distributions of the two species closely approach within 15 km of each other on the central plug and rim of the caldera of the Tweed Volcano. Assa wollumbin sp. nov. meets the conservation criteria for Critically Endangered [A3(e), B2(a,b)]. When all subpopulations of A. darlingtoni are combined the conservation assessment is Endangered [A3(e), B2(a,b)]. Because of the fragmented nature of the distribution of A. darlingtoni, combined with the genetic evidence of concordant sub-structuring, we also conducted a conservation assessment on the five subpopulations. Two were assessed as Critically Endangered (DAguilar Range and Conondale/Blackall Ranges), and the remainder as Endangered (Dorrigo Plateau, McPherson Ranges, and Gibraltar Ranges/Washpool).
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Affiliation(s)
- Michael J Mahony
- School of Environmental and Life Sciences, University of Newcastle, University Drive, Callaghan NSW 2308, Australia .
| | - Harry B Hines
- Department of National Parks, Sport and Racing, GPO Box 2454, Brisbane Qld 4001, Australia .
| | | | - Bede Moses
- School of Environmental and Life Sciences, University of Newcastle, University Drive, Callaghan NSW 2308, Australia.
| | - Sarah R Catalano
- South Australian Museum, North Terrace, Adelaide SA 5000, Australia.
| | - Steven Myers
- South Australian Museum, North Terrace, Adelaide SA 5000, Australia.
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Mahony MJ, Penman T, Bertozzi T, Lemckert F, Bilney R, Donnellan SC. Taxonomic revision of south-eastern Australian giant burrowing frogs (Anura: Limnodynastidae: Heleioporus Gray). Zootaxa 2021; 5016:451-489. [PMID: 34810435 DOI: 10.11646/zootaxa.5016.4.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Indexed: 11/04/2022]
Abstract
The rarely encountered giant burrowing frog, Heleioporus australiacus, is distributed widely in a variety of sclerophyll forest habitats east of the Great Dividing Range in south-eastern Australia. Analyses of variation in nucleotide sequences of the mitochondrial ND4 gene and thousands of nuclear gene SNPs revealed the presence of two deeply divergent lineages. Multivariate morphological comparisons show the two lineages differ in body proportions with > 91% of individuals being correctly classified in DFA. The two lineages differ in the number and size of spots on the lateral surfaces and the degree by which the cloaca is surrounded by colour patches. The mating calls are significantly different in number of pulses in the note. The presence of a F2 hybrid in the area where the distribution of the two taxa come into closest proximity leads us to assign subspecies status to the lineages, as we have not been able to assess the extent of potential genetic introgression. In our sampling, the F2 hybrid sample sits within an otherwise unsampled gap of ~90km between the distributions of the two lineages. The nominate northern sub-species is restricted to the Sydney Basin bioregion, while the newly recognised southern subspecies occurs from south of the Kangaroo Valley in the mid-southern coast of New South Wales to near Walhalla in central Gippsland in Victoria. The habitat of the two subspecies is remarkably similar. Adults spend large portions of their lives on the forest floor where they forage and burrow in a variety of vegetation communities. The southern subspecies occurs most commonly in dry sclerophyll forests with an open understory in the south and in open forest and heath communities with a dense understory in the north of its distribution. The northern subspecies is also found in dry open forests and heaths in association with eroded sandstone landscapes in the Sydney Basin bioregion. Males of both taxa call from both constructed burrows and open positions on small streams, differing from the five Western Australian species of Heleioporus where males call only from constructed burrows. Using the IUCN Red List process, we found that the extent of occupancy and area of occupancy along with evidence of decline for both subspecies are consistent with the criteria for Endangered (A2(c)B2(a)(b)).
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Affiliation(s)
- Michael J Mahony
- Department of Biological Sciences, The University of Newcastle, University Drive, Callaghan, NSW 2308, Australia. .
| | - Trent Penman
- Research and Development Division, Forests New South Wales, P.O Box 100 Beecroft, NSW 2119, Australia. 3Current address: Department of Forest and Ecosystem Science, University of Melbourne, 4 Water Street, Creswick, Victoria 3363, Australia. .
| | - Terry Bertozzi
- The South Australian Museum, North Terrace Adelaide, SA 5000, Australia. 5School of Biological Sciences, The University of Adelaide, Adelaide SA 5005, Australia. .
| | - Frank Lemckert
- Australian Museum Research Institute, Australian Museum, 1 William Street Sydney NSW 2010, Australia; Eco Logical Australia, Level 7, 19 Bolton Street, Newcastle, NSW 2300, Australia. .
| | - Rohan Bilney
- Forestry Corporation of NSW, PO Box 702 Eden, NSW 2551, Australia. .
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Hamer AJ, Schmera D, Mahony MJ. Multi-species occupancy modeling provides novel insights into amphibian metacommunity structure and wetland restoration. Ecol Appl 2021; 31:e2293. [PMID: 33432692 DOI: 10.1002/eap.2293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 07/22/2020] [Accepted: 10/06/2020] [Indexed: 06/12/2023]
Abstract
A fundamental goal of community ecology is to understand species-habitat relationships and how they shape metacommunity structure. Recent advances in occupancy modeling enable habitat relationships to be assessed for both common and rare species within metacommunities using multi-species occupancy models (MSOM). These models account for imperfect species detection and offer considerable advantages over other analytical tools commonly used for community analyses under the elements of metacommunity structure (EMS) framework. Here, we demonstrate that MSOM can be used to infer habitat relationships and test metacommunity theory, using amphibians. Repeated frog surveys were undertaken at 55 wetland sites in southeastern Australia. We detected 11 frog species from three families (Limnodynastidae, Myobatrachidae, and Pelodryadidae). The rarest species was detected at only one site whereas the most common species was detected at 42 sites (naive occupancy rate 0.02-0.76). Two models were assessed representing two competing hypotheses; the best-supported model included the covariates distance to the nearest site (connectivity), wetland area, presence of the non-native eastern mosquitofish (Gambusia holbrooki), proportion cover of emergent vegetation, an interaction term between Gambusia and emergent vegetation cover, and the proportion canopy cover over a site. Hydroperiod played no detectable role in metacommunity structure. We found species-habitat relationships that fit with current metacommunity theory: occupancy increased with wetland area and connectivity. There was a strong negative relationship between occupancy and the presence of predatory Gambusia, and a positive interaction between Gambusia and emergent vegetation. The presence of canopy cover strongly increased occupancy for several tree frog species, highlighting the importance of terrestrial habitat for amphibian community structure. We demonstrated how responses by amphibians to environmental covariates at the species level can be linked to occupancy patterns at the metacommunity scale. Our results have clear management implications: wetland restoration projects for amphibians and likely other taxa should maximize wetland area and connectivity, establish partial canopy cover, and eradicate Gambusia or provide aquatic vegetation to mitigate the impact of this non-native fish. We strongly advocate the use of MSOM to elucidate the habitat drivers behind animal occupancy patterns and to derive unbiased occupancy estimates for monitoring programs.
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Affiliation(s)
- Andrew J Hamer
- Centre for Ecological Research, GINOP Sustainable Ecosystems Group, Klebelsberg K. u. 3, Tihany, H-8237, Hungary
- Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3, Tihany, H-8237, Hungary
| | - Dénes Schmera
- Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3, Tihany, H-8237, Hungary
| | - Michael J Mahony
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales, 2308, Australia
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Upton R, Clulow S, Calatayud NE, Colyvas K, Seeto RGY, Wong LAM, Mahony MJ, Clulow J. Generation of reproductively mature offspring from the endangered green and golden bell frog Litoria aurea using cryopreserved spermatozoa. Reprod Fertil Dev 2021; 33:562-572. [PMID: 33820600 DOI: 10.1071/rd20296] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 02/25/2021] [Indexed: 11/23/2022] Open
Abstract
Amphibians are becoming increasingly reliant on captive breeding programs for continued survival. Assisted reproductive technologies including gamete cryopreservation and IVF can help reduce costs of breeding programs, provide insurance against extinction and assist genetic rescue in wild populations. However, the use of these technologies to produce reproductively mature offspring has only been demonstrated in a few non-model species. We aimed to optimise sperm cryopreservation in the threatened frog Litoria aurea and generate mature offspring from frozen-thawed spermatozoa by IVF. We tested three concentrations (1.4, 2.1 and 2.8M) of the cryoprotectants dimethylsulfoxide (DMSO) and glycerol with 0.3M sucrose. Using DMSO was more likely to result in recovery of sperm motility, vitality and acrosome integrity than glycerol, regardless of concentration, with forward progressive motility being most sensitive to damage. The lowest concentrations of 1.4 and 2.1M provided the best protection regardless of cryoprotectant type. Spermatozoa cryopreserved in 2.1M DMSO outperformed spermatozoa cryopreserved in equivalent concentrations of glycerol in terms of their ability to fertilise ova, resulting in higher rates of embryos hatching and several individuals reaching sexual maturity. We have demonstrated that sperm cryopreservation and subsequent offspring generation via IVF is a feasible conservation tool for L. aurea and other threatened amphibians.
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Affiliation(s)
- Rose Upton
- The Conservation Biology Research Group, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia; and FAUNA Research Alliance, PO Box 5092, Kahibah, NSW 2290, Australia; and Corresponding author
| | - Simon Clulow
- FAUNA Research Alliance, PO Box 5092, Kahibah, NSW 2290, Australia; and Centre for Conservation Ecology and Genomics, Institute for Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia
| | - Natalie E Calatayud
- FAUNA Research Alliance, PO Box 5092, Kahibah, NSW 2290, Australia; and Taronga Institute of Science and Learning, Taronga Conservation Society Australia, Taronga Western Plains Zoo, Dubbo, NSW 2830, Australia; and San Diego Zoo Global-Beckman Center for Conservation Research, 15600 San Pasqual Valley Road, Escondido, CA 92027, USA
| | - Kim Colyvas
- School of Mathematical and Physical Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Rebecca G Y Seeto
- The Conservation Biology Research Group, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - Lesley A M Wong
- The Conservation Biology Research Group, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - Michael J Mahony
- The Conservation Biology Research Group, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia; and FAUNA Research Alliance, PO Box 5092, Kahibah, NSW 2290, Australia
| | - John Clulow
- The Conservation Biology Research Group, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia; and FAUNA Research Alliance, PO Box 5092, Kahibah, NSW 2290, Australia
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Clulow J, Pomering M, Herbert D, Upton R, Calatayud N, Clulow S, Mahony MJ, Trudeau VL. Differential success in obtaining gametes between male and female Australian temperate frogs by hormonal induction: A review. Gen Comp Endocrinol 2018; 265:141-148. [PMID: 29859744 DOI: 10.1016/j.ygcen.2018.05.032] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 05/13/2018] [Accepted: 05/30/2018] [Indexed: 01/19/2023]
Abstract
Most Australian frogs fall into two deeply split lineages, conveniently referred to as ground frogs (Myobatrachidae and Limnodynastidae) and tree frogs (Pelodryadidae). Species of both lineages are endangered because of the global chytrid pandemic, and there is increasing interest and research on the endocrine manipulation of reproduction to support the use of assisted reproductive technologies in conservation. Hormonal induction of gamete release in males and females is one such manipulation of the reproductive process. This paper reviews progress in temperate ground and tree frogs towards developing simple and efficient hormonal protocols for induction of spermiation and ovulation, and presents some new data, that together build towards an understanding of advances and obstacles towards progress in this area. We report that protocols for the non-invasive induction of sperm release, relying on single doses of gonadotropin-releasing hormone (GnRH) or human chorionic gonadotropin are very effective in both ground and tree frog species investigated to date. However, we find that, while protocols based on GnRH, and GnRH and dopamine antagonists, are moderately efficient in inducing ovulation in ground frogs, the same cannot be said for the use of such protocols in tree frogs. Although induced ovulation in the pelodryadid tree frogs has not been successfully implemented, and is difficult to explain in terms of the underlying endocrinology, we propose future avenues of investigation to address this problem, particularly the need for a source of purified or recombinant follicle-stimulating hormone and luteinising hormone for species from this group.
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Affiliation(s)
- John Clulow
- Conservation Biology Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308 Australia.
| | - Melissa Pomering
- Conservation Biology Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308 Australia
| | - Danielle Herbert
- Conservation Biology Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308 Australia
| | - Rose Upton
- Conservation Biology Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308 Australia
| | - Natalie Calatayud
- San Diego Zoo Institute for Conservation Research, Escondido, CA, USA
| | - Simon Clulow
- Conservation Biology Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308 Australia; Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109 Australia
| | - Michael J Mahony
- Conservation Biology Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308 Australia
| | - Vance L Trudeau
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
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Upton R, Clulow S, Mahony MJ, Clulow J. Generation of a sexually mature individual of the Eastern dwarf tree frog, Litoria fallax, from cryopreserved testicular macerates: proof of capacity of cryopreserved sperm derived offspring to complete development. Conserv Physiol 2018; 6:coy043. [PMID: 30151196 PMCID: PMC6101482 DOI: 10.1093/conphys/coy043] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 07/03/2018] [Accepted: 07/30/2018] [Indexed: 06/08/2023]
Abstract
Amphibians are the most threatened vertebrate class globally based on recent rates of decline and extinction. Sperm cryopreservation and other assisted reproductive technologies have the potential to help manage small and threatened populations and prevent extinctions. There are a growing number of reports of recovery of amphibian sperm after cryopreservation, but relatively few published reports of amphibian embryos generated from frozen sperm developing beyond metamorphosis to the adult stage and achieving sexual maturation. In this study on the Eastern dwarf tree frog (Litoria fallax), a temperate amphibian species from eastern Australia, a small number of viable metamorphs and one sexually mature male frog (itself producing sperm) were produced from cryopreserved sperm, demonstrating the capacity of embryos generated from cryopreserved sperm to complete the life cycle to sexual maturity. Low progression rates between developmental stages were not deemed to be due to effects of cryopreservation, since control embryos from unfrozen sperm had a similarly low progression rate through development.
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Affiliation(s)
- Rose Upton
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Simon Clulow
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Michael J Mahony
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - John Clulow
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
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Pollard CJ, Stockwell MP, Bower DS, Garnham JI, Pickett EJ, Darcovich K, O'meara J, Clulow J, Mahony MJ. Removal of an exotic fish influences amphibian breeding site selection. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21232] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Carla J. Pollard
- School of Environmental and Life SciencesUniversity of Newcastle, University DriveCallaghan2308, New South WalesAustralia
| | - Michelle P. Stockwell
- School of Environmental and Life SciencesUniversity of Newcastle, University DriveCallaghan2308, New South WalesAustralia
| | - Deborah S. Bower
- School of Environmental and Life SciencesUniversity of Newcastle, University DriveCallaghan2308, New South WalesAustralia
| | - James I. Garnham
- School of Environmental and Life SciencesUniversity of Newcastle, University DriveCallaghan2308, New South WalesAustralia
| | - Evan J. Pickett
- School of Environmental and Life SciencesUniversity of Newcastle, University DriveCallaghan2308, New South WalesAustralia
| | - Kerry Darcovich
- Sydney Olympic Park Authority8 Australia Avenue, Sydney Olympic Park, 2127New South WalesAustralia
| | - Jenny O'meara
- Sydney Olympic Park Authority8 Australia Avenue, Sydney Olympic Park, 2127New South WalesAustralia
| | - John Clulow
- School of Environmental and Life SciencesUniversity of Newcastle, University DriveCallaghan2308, New South WalesAustralia
| | - Michael J. Mahony
- School of Environmental and Life SciencesUniversity of Newcastle, University DriveCallaghan2308, New South WalesAustralia
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Klop-Toker KL, Valdez JW, Stockwell MP, Edgar ME, Fardell L, Clulow S, Clulow J, Mahony MJ. Assessing host response to disease treatment: how chytrid-susceptible frogs react to increased water salinity. Wildl Res 2017. [DOI: 10.1071/wr16145] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context
The severity and prevalence of the amphibian fungal pathogen, Batrachochytrium dendrobatidis (Bd) is correlated with several environmental variables, including salinity, temperature, and moisture content, which influence the pathogen’s growth and survival. Habitats that contain these environmental variables at levels outside of those optimal for Bd growth and survival may facilitate the survival of susceptible host species. Therefore, manipulation of environmental salinity is a potential management strategy to help conserve Bd-susceptible species. However, host behaviour also influences disease dynamics, and the success of habitat manipulation programs depends on how hosts use this altered habitat.
Aims
To assess if the Bd-susceptible green and golden bell frog, Litoria aurea, will select waterbodies with a salinity increased to S=3; if this selection is affected by infection; and if a frog’s time in a waterbody of this salinity affects infection load or blood physiology.
Methods
We conducted a filmed choice experiment and a 3-year field study where infected and uninfected frogs could choose between fresh or saline waterbodies.
Key results
In both the laboratory experiment and field study, Bd-infected L. aurea spent a significantly greater amount of time in or closer to a waterbody than uninfected frogs. Experimentally infected frogs tended to prefer the saline water over fresh, but their choice of water usage did not differ statistically from uninfected frogs. In the field, frogs began to avoid ponds when salinities rose above S=5.
Conclusions
Because both wild and captive, and infected and uninfected L. aurea readily selected waterbodies with a salinity of S=3, this salinity could potentially be used as a passive method for reducing the severity of Bd when managing this species. However, further testing is needed to understand the efficacy of this treatment, and care must be taken to prevent salinities rising above S=5, because this level seems to produce an avoidance response and therefore may not be suitable in every location.
Implications
Manipulation of aquatic habitats may be a worthwhile focus for Bd management in habitats where water level fluctuations are minimal.
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Valdez JW, Klop-Toker K, Stockwell MP, Fardell L, Clulow S, Clulow J, Mahony MJ. Differences in microhabitat selection patterns between a remnant and constructed landscape following management intervention. Wildl Res 2017. [DOI: 10.1071/wr16172] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context Achieving successful conservation outcomes in habitat creation and reintroductions requires an understanding of how species use their habitat and respond to these interventions. However, few initiatives directly compare microhabitat selection between remnant and managed habitats to measure effectiveness and evaluate outcomes. Probability of detection is also rarely included in studies on microhabitat use, which may lead to erroneous conclusions if detectability varies between variables. Methods In this study, we used the endangered green and golden bell frog (Litoria aurea) to compare differences in microhabitat-use patterns in both a remnant and a constructed habitat. A detectability study was also conducted to determine detection probabilities among microhabitats. Key results Aquatic vegetation was used more than expected in both the remnant and constructed habitats, and rock piles were utilised less than expected in the constructed habitat, despite their recommendation in most habitat templates. We found that detection probabilities altered the outcomes of abundance estimates for nearly all the measured microhabitat variables. Conclusions Future management for this species should focus on providing high proportions of aquatic vegetation. Furthermore, although rock piles have been utilised greatly in past L. aurea habitat creation, placing large rocks on a managed site is expensive and time consuming. Future management initiatives may need to focus on providing smaller proportion of rocks, which would be a more appropriate use of resources. Implications With conservation management projects increasing over the next few decades, understanding habitat use before implementing strategies should be a priority as it will provide important insights and inform decision-making for optimum habitat creation and restoration. Furthermore, accounting for detectability in microhabitat use studies is essential to avoid wrong conclusions that may negatively affect the success of ecological management strategies.
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Stockwell MP, Garnham JI, Bower DS, Clulow J, Mahony MJ. Low disease-causing threshold in a frog species susceptible to chytridiomycosis. FEMS Microbiol Lett 2016; 363:fnw111. [PMID: 27190153 DOI: 10.1093/femsle/fnw111] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2016] [Indexed: 01/05/2023] Open
Abstract
A simple diagnosis of the presence or absence of an infection is an uninformative metric when individuals differ considerably in their tolerance to different infection loads or resistance to rates of disease progression. Models that incorporate the relationship between the progression of the infection with the potential alternate outcomes provide a far more powerful predictive tool than diagnosis alone. The global decline of amphibians has been amplified by Batrachochytrium dendrobatidis, a pathogen that can cause the fatal disease chytridiomycosis. We measured the infection load and observed signs of disease in Litoria aurea Receiver operating characteristic curves were used to quantify the dissimilarity between the infection loads of L. aurea that showed signs associated with chytridiomycosis and those that did not. Litoria aurea had a 78% probability of developing chytridiomycosis past a threshold of 68 zoospore equivalents (ZE) per swab and chytridiomycosis occurred within a variable range of 0.5-490 ZE. Studies should incorporate a species-specific threshold as a predictor of chytridiomycosis, rather than a binary diagnosis. Measures of susceptibility to chytridiomycosis must account not only for the ability of B. dendrobatidis to increase its abundance on the skin of amphibians but also to determine how each species tolerates these infection loads.
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Affiliation(s)
- Michelle P Stockwell
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan NSW 2308, Australia
| | - James I Garnham
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan NSW 2308, Australia
| | - Deborah S Bower
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan NSW 2308, Australia
| | - John Clulow
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan NSW 2308, Australia
| | - Michael J Mahony
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan NSW 2308, Australia
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Stockwell MP, Bower DS, Clulow J, Mahony MJ. The role of non-declining amphibian species as alternative hosts for Batrachochytrium dendrobatidis in an amphibian community. Wildl Res 2016. [DOI: 10.1071/wr15223] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context Pathogens with reservoir hosts have been responsible for most disease-induced wildlife extinctions because the decline of susceptible hosts does not cause the decline of the pathogen. The existence of reservoirs for Batrachochytrium dendrobatidis limits population recovery and conservation actions for threatened amphibians. As such, the effect of reservoirs on disease risk within host community assemblages needs to be considered, but rarely is. Aims In this study we aimed to determine if amphibian species co-occurring with the green and golden bell frog Litoria aurea, a declining species susceptible to B. dendrobatidis, act as alternate hosts. Methods We quantified B. dendrobatidis infection levels, sub-lethal effects on body condition and terminal signs of disease in amphibian communities on Kooragang Island and Sydney Olympic Park in New South Wales, Australia, where two of the largest remaining L. aurea populations persist. Key results We found L. aurea carried infections at a similar prevalence (6–38%) to alternate species. Infection loads ranged widely (0.01–11 107.3 zoospore equivalents) and L. aurea differed from only one alternate host species (higher median load in Litoria fallax) at one site. There were no terminal or sub-lethal signs of disease in any species co-occurring with L. aurea. Conclusion Our results suggest that co-occurring species are acting as alternate hosts to L. aurea and whether their presence dilutes or amplifies B. dendrobatidis in the community is a priority for future research. Implications For L. aurea and many other susceptible species, confirming the existence of reservoir hosts and understanding their role in community disease dynamics will be important for optimising the outcomes of threat mitigation and habitat creation initiatives for their long-term conservation.
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Garnham JI, Stockwell MP, Pollard CJ, Pickett EJ, Bower DS, Clulow J, Mahony MJ. Winter microhabitat selection of a threatened pond amphibian in constructed urban wetlands. AUSTRAL ECOL 2015. [DOI: 10.1111/aec.12256] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- James I. Garnham
- School of Environmental & Life Sciences; University of Newcastle; University Drive Callaghan Newcastle New South Wales 2308 Australia
| | - Michelle P. Stockwell
- School of Environmental & Life Sciences; University of Newcastle; University Drive Callaghan Newcastle New South Wales 2308 Australia
| | - Carla J. Pollard
- School of Environmental & Life Sciences; University of Newcastle; University Drive Callaghan Newcastle New South Wales 2308 Australia
| | - Evan J. Pickett
- School of Environmental & Life Sciences; University of Newcastle; University Drive Callaghan Newcastle New South Wales 2308 Australia
| | - Deborah S. Bower
- School of Environmental & Life Sciences; University of Newcastle; University Drive Callaghan Newcastle New South Wales 2308 Australia
| | - John Clulow
- School of Environmental & Life Sciences; University of Newcastle; University Drive Callaghan Newcastle New South Wales 2308 Australia
| | - Michael J. Mahony
- School of Environmental & Life Sciences; University of Newcastle; University Drive Callaghan Newcastle New South Wales 2308 Australia
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Clulow S, Harris M, Mahony MJ. Optimization, validation and efficacy of the phytohaemagglutinin inflammation assay for use in ecoimmunological studies of amphibians. Conserv Physiol 2015; 3:cov042. [PMID: 27293727 PMCID: PMC4778488 DOI: 10.1093/conphys/cov042] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 07/29/2015] [Accepted: 08/01/2015] [Indexed: 05/30/2023]
Abstract
The global amphibian biodiversity crisis is driven by disease, habitat destruction and drastically altered ecosystems. It has given rise to an unprecedented need to understand the link between rapidly changing environments, immunocompetence and wildlife health (the nascent field of ecoimmunology). Increasing our knowledge of the ecoimmunology of amphibians necessitates the development of reliable, field-applicable methods of assessing immunocompetence in non-model species. The phytohaemagglutinin (PHA) inflammation assay uses a lectin to elicit localized inflammation that reflects an organism's capacity to mount an immune response. Although extensively used in birds to assess responses to environmental change, stress and disease, its application in amphibians has been extremely limited. We developed, validated and optimized a practical and effective phytohaemagglutinin inflammation assay in phylogenetically distant amphibians and demonstrated its suitability for use in a wide range of ecoimmunological studies. The protocol was effective for all species tested and worked equally well for both sexes and for adult and sub-adult animals. We determined that using set-force-measuring instruments resulted in a 'compression effect' that countered the inflammatory response, reinforcing the need for internal controls. We developed a novel method to determine peak response times more accurately and thereby improve assay sensitivity. Histological validation demonstrated considerable interspecies variation in the robustness of amphibian immune defences. Importantly, we applied the assay to a real-world scenario of varying environmental conditions and proved that the assay effectively detected differences in immune fitness between groups of animals exposed to ecologically meaningful levels of density stress. This provided strong evidence that one cost of metamorphic plasticity responses by tadpoles to increasing density is a reduction in post-metamorphic immune fitness and that metamorphosis does not prevent phenotypic carry-over of larval stress to the adult phenotype. This assay provides an effective tool for understanding the role of global environmental change in the amphibian extinction crisis.
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Affiliation(s)
- Simon Clulow
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Merrilee Harris
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Michael J. Mahony
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
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Bower DS, Pickett EJ, Stockwell MP, Pollard CJ, Garnham JI, Sanders MR, Clulow J, Mahony MJ. Evaluating monitoring methods to guide adaptive management of a threatened amphibian (Litoria aurea). Ecol Evol 2014; 4:1361-8. [PMID: 24834332 PMCID: PMC4020695 DOI: 10.1002/ece3.980] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Revised: 01/16/2014] [Accepted: 01/16/2014] [Indexed: 11/12/2022] Open
Abstract
Prompt detection of declines in abundance or distribution of populations is critical when managing threatened species that have high population turnover. Population monitoring programs provide the tools necessary to identify and detect decreases in abundance that will threaten the persistence of key populations and should occur in an adaptive management framework which designs monitoring to maximize detection and minimize effort. We monitored a population of Litoria aurea at Sydney Olympic Park over 5 years using mark–recapture, capture encounter, noncapture encounter, auditory, tadpole trapping, and dip-net surveys. The methods differed in the cost, time, and ability to detect changes in the population. Only capture encounter surveys were able to simultaneously detect a decline in the occupancy, relative abundance, and recruitment of frogs during the surveys. The relative abundance of L. aurea during encounter surveys correlated with the population size obtained from mark–recapture surveys, and the methods were therefore useful for detecting a change in the population. Tadpole trapping and auditory surveys did not predict overall abundance and were therefore not useful in detecting declines. Monitoring regimes should determine optimal survey times to identify periods where populations have the highest detectability. Once this has been achieved, capture encounter surveys provide a cost-effective method of effectively monitoring trends in occupancy, changes in relative abundance, and detecting recruitment in populations.
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Affiliation(s)
- Deborah S Bower
- School of Environmental and Life Sciences, The University of Newcastle University Dr. Callaghan, Newcastle, New South Wales, 2308, Australia
| | - Evan J Pickett
- School of Environmental and Life Sciences, The University of Newcastle University Dr. Callaghan, Newcastle, New South Wales, 2308, Australia
| | - Michelle P Stockwell
- School of Environmental and Life Sciences, The University of Newcastle University Dr. Callaghan, Newcastle, New South Wales, 2308, Australia
| | - Carla J Pollard
- School of Environmental and Life Sciences, The University of Newcastle University Dr. Callaghan, Newcastle, New South Wales, 2308, Australia
| | - James I Garnham
- School of Environmental and Life Sciences, The University of Newcastle University Dr. Callaghan, Newcastle, New South Wales, 2308, Australia
| | - Madeleine R Sanders
- School of Environmental and Life Sciences, The University of Newcastle University Dr. Callaghan, Newcastle, New South Wales, 2308, Australia
| | - John Clulow
- School of Environmental and Life Sciences, The University of Newcastle University Dr. Callaghan, Newcastle, New South Wales, 2308, Australia
| | - Michael J Mahony
- School of Environmental and Life Sciences, The University of Newcastle University Dr. Callaghan, Newcastle, New South Wales, 2308, Australia
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Bower DS, Pickett EJ, Garnham JI, Deboo ML, McCurry MR, Mengerink RM, Mahony MJ, Clulow J. Diet of a threatened pond frog differs over a small spatial scale. ENDANGER SPECIES RES 2014. [DOI: 10.3354/esr00559] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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McConville A, Law BS, Mahony MJ. Are regional habitat models useful at a local-scale? A case study of threatened and common insectivorous bats in South-Eastern Australia. PLoS One 2013; 8:e72420. [PMID: 23977296 PMCID: PMC3747113 DOI: 10.1371/journal.pone.0072420] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 07/09/2013] [Indexed: 11/19/2022] Open
Abstract
Habitat modelling and predictive mapping are important tools for conservation planning, particularly for lesser known species such as many insectivorous bats. However, the scale at which modelling is undertaken can affect the predictive accuracy and restrict the use of the model at different scales. We assessed the validity of existing regional-scale habitat models at a local-scale and contrasted the habitat use of two morphologically similar species with differing conservation status (Mormopterus norfolkensis and Mormopterus species 2). We used negative binomial generalised linear models created from indices of activity and environmental variables collected from systematic acoustic surveys. We found that habitat type (based on vegetation community) best explained activity of both species, which were more active in floodplain areas, with most foraging activity recorded in the freshwater wetland habitat type. The threatened M. norfolkensis avoided urban areas, which contrasts with M. species 2 which occurred frequently in urban bushland. We found that the broad habitat types predicted from local-scale models were generally consistent with those from regional-scale models. However, threshold-dependent accuracy measures indicated a poor fit and we advise caution be applied when using the regional models at a fine scale, particularly when the consequences of false negatives or positives are severe. Additionally, our study illustrates that habitat type classifications can be important predictors and we suggest they are more practical for conservation than complex combinations of raw variables, as they are easily communicated to land managers.
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Affiliation(s)
- Anna McConville
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia
- * E-mail:
| | - Bradley S. Law
- Forest Science Centre, Department of Primary Industries, Beecroft, New South Wales, Australia
| | - Michael J. Mahony
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia
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Lawson B, Clulow S, Mahony MJ, Clulow J. Towards gene banking amphibian maternal germ lines: short-term incubation, cryoprotectant tolerance and cryopreservation of embryonic cells of the frog, Limnodynastes peronii. PLoS One 2013; 8:e60760. [PMID: 23577155 PMCID: PMC3618038 DOI: 10.1371/journal.pone.0060760] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Accepted: 03/02/2013] [Indexed: 11/21/2022] Open
Abstract
Gene banking is arguably the best method available to prevent the loss of genetic diversity caused by declines in wild populations, when the causes of decline cannot be halted or reversed. For one of the most impacted vertebrate groups, the amphibians, gene banking technologies have advanced considerably, and gametes from the male line can be banked successfully for many species. However, cryopreserving the female germ line remains challenging, with attempts at cryopreserving oocytes unsuccessful due to their large size and yolk content. One possible solution is to target cryopreservation of early embryos that contain the maternal germ line, but consist of smaller cells. Here, we investigate the short term incubation, cryoprotectant tolerance, and cryopreservation of dissociated early embryonic cells from gastrulae and neurulae of the Striped Marsh Frog, Limnodynastes peronii. Embryos were dissociated and cells were incubated for up to 24 hours in various media. Viability of both gastrula and neurula cells remained high (means up to 40-60%) over 24 hours of incubation in all media, although viability was maintained at a higher level in Ca(2+)-free Simplified Amphibian Ringer; low speed centrifugation did not reduce cell viability. Tolerance of dissociated embryonic cells was tested for two cryoprotectants, glycerol and dimethyl sulphoxide; dissociated cells of both gastrulae and neurulae were highly tolerant to both-indeed, cell viability over 24 hours was higher in media containing low-to-medium concentrations than in equivalent cryoprotectant-free media. Viability over 24 hours was lower in concentrations of cryoprotectant higher than 10%. Live cells were recovered following cryopreservation of both gastrula and neurula cells, but only at low rates. Optimal cryodiluents were identified for gastrula and neurula cells. This is the first report of a slow cooling protocol for cryopreservation of amphibian embryonic cells, and sets future research directions for cryopreserving amphibian maternal germ lines.
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Affiliation(s)
- Bianca Lawson
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia
| | - Simon Clulow
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia
| | - Michael J. Mahony
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia
| | - John Clulow
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia
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Abstract
Socio-ecological models combine environmental and social factors to explain the formation of animal groups. In anurans, tadpole aggregations have been reported in numerous species, but the factors driving this behaviour remain unclear. We conducted controlled choice experiments in the lab to determine whether green and golden bell frog (Litoria aurea) tadpoles are directly attracted to conspecifics (social factors) in the absence of environmental cues. Using repeated measures, we found that individual tadpoles strongly preferred associating with conspecifics compared to being alone. Furthermore, this preference was body size dependent, and associating tadpoles were significantly smaller than non-associating tadpoles. We suggest that small tadpoles are more vulnerable to predation and therefore more likely to form aggregations as an anti-predator behaviour. We demonstrate that tadpoles present an ideal model system for investigating how social and ecological factors influence group formation in vertebrates.
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Affiliation(s)
- Stephan T Leu
- School of Environmental and Life Sciences, University of Newcastle, Newcastle, New South Wales, Australia.
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McConville A, Law BS, Mahony MJ. Mangroves as maternity roosts for a colony of the rare east-coast free-tailed bat (Mormopterus norfolkensis) in south-eastern Australia. Wildl Res 2013. [DOI: 10.1071/wr12222] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context
Maternity roosts of insectivorous bats (where females raise young) are critical to the conservation of threatened species as roost quality can influence reproductive success. Additionally, threatened species may have specialised requirements or unusual behaviour, which may be overlooked without targeted investigation.
Aims
To explore which factors influence the roost selection of Mormopterus norfolkensis, by comparing day roosts, identified via radio-tracking, with environmental variables collected at tree, patch and landscape scales.
Methods
We collected a range of variables describing maternity roosts and surrounding patches, including internal measurements of hollows and microclimate. Additionally, we derived landscape-scale variables using a geographic information system. We then explored which variables best explained roost occurrence using logistic regression.
Key results
Nineteen lactating females and two male M. norfolkensis were tracked to 40 roost trees, mostly grey mangrove, Avicennia marina subsp. australasica. Lactating females were found to be faithful to two patches of mangrove forest close to where they were captured, regularly switched roosts and roosted in hollows singularly or in small groups. The attributes of mangrove patches, especially a high proportion of hollows, better predicted roosting by lactating females than roost-tree or landscape characteristics. Additionally, although the microclimate of roost hollows was not significantly different from ambient mangrove conditions, the mangrove forest was slightly more stable and had higher humidity than did other nearby habitats.
Conclusions
Contrary to predictions, maternity roosting group sizes were relatively small, indicating that bats were not deriving thermoregulatory benefits from communal living. However, we suggest that lactating females may benefit from the operation of a fission–fusion society among the colony as a whole. Additionally, the mature mangrove forest could offer unique roosting opportunities for bats because they support high densities of hollow-bearing trees, a stable microclimate and potentially low abundances of predators and competitors.
Implications
This is one of few international bat–mangrove studies and it illustrates that threatened species can behave unexpectedly and may be overlooked in conservation strategies that are based largely on anecdotal observations. We encourage further research into the value of mangrove forests to terrestrial fauna globally.
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Clulow J, Clulow S, Guo J, French AJ, Mahony MJ, Archer M. Optimisation of an oviposition protocol employing human chorionic and pregnant mare serum gonadotropins in the barred frog Mixophyes fasciolatus (Myobatrachidae). Reprod Biol Endocrinol 2012; 10:60. [PMID: 22909256 PMCID: PMC3488330 DOI: 10.1186/1477-7827-10-60] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 08/03/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Protocols for the hormonal induction of ovulation and oviposition are essential tools for managing threatened amphibians with assisted reproduction, but responses vary greatly between species and even broad taxon groups. Consequently, it is necessary to assess effectiveness of such protocols in representative species when new taxa become targets for induction. The threatened genus Mixophyes (family Myobatrachidae) has amongst the highest proportion of endangered species of all the Australian amphibians. This study developed and optimised the induction of oviposition in a non-threatened member of this taxon, the great barred frog (Mixophyes fasciolatus). METHODS Gravid female M. fasciolatus were induced to oviposit on one or more occasions by administration of human chorionic gonadotropin (hCG) with or without priming with pregnant mare serum gonadotropin (PMSG). Treatments involved variations in hormone doses and combinations (administered via injection into the dorsal lymph sacs), and timing of administration. Pituitary homogenates from an unrelated bufonid species (Rhinella marina) were also examined with hCG. RESULTS When injected alone, hCG (900 to 1400 IU) induced oviposition. However, priming with two time dependent doses of PMSG (50 IU, 25 IU) increased responses, with lower doses of hCG (200 IU). Priming increased response rates in females from around 30% (hCG alone) to more than 50% (p = 0.035), and up to 67%. Increasing the interval between the first PMSG dose and first hCG dose from 3 to 6 days also produced significant improvement (p<0.001). Heterologous pituitary extracts administered with hCG were no more effective than hCG alone (p = 0.628). CONCLUSIONS This study found that M. fasciolatus is amongst the few amphibian species (including Xenopus (Silurana) and some bufonids) that respond well to the induction of ovulation utilising mammalian gonadotropins (hCG). The optimal protocol for M. fasciolatus involved two priming doses of PMSG (50 IU and 25 IU) administered at 6 and 4 days respectively, prior to two doses of hCG (100 IU), 24 hours apart. This study is also the first to demonstrate in an amphibian species that responds to mammalian gonadotropins that an increase in the ovulation rate occurs after priming with a gonadotropin (PMSG) with FSH activity.
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Affiliation(s)
- John Clulow
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan, NSW, 2308, Australia
| | - Simon Clulow
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan, NSW, 2308, Australia
| | - Jitong Guo
- Inner Mongolia Saikexing Reproductive Biotechnology Co., Ltd. 6 F, Mengniu Dairy R&D Center, Shengle Economic Zone of Helingeer County, Hohhot, 011517, Inner Mongolia, People's Republic of China
| | - Andrew J French
- Centre for Animal Biotechnology, Faculty of Veterinary Science, The University of Melbourne, Parkville, 3010, VIC, Australia
| | - Michael J Mahony
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan, NSW, 2308, Australia
| | - Michael Archer
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, 2052, Australia
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25
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DeBoo ML, Bertozzi T, Donnellan S, Mahony MJ. Development of eight microsatellite loci from the Green and Golden Bell Frog (Litoria aurea) through GS-FLX pyrosequencing and cross-amplification with other species of the Litoria aurea species group. CONSERV GENET RESOUR 2012. [DOI: 10.1007/s12686-012-9693-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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26
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Pickett EJ, Stockwell MP, Pollard CJ, Garnham JI, Clulow J, Mahony MJ. Estimates of sex ratio require the incorporation of unequal catchability between sexes. Wildl Res 2012. [DOI: 10.1071/wr11193] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context
Estimates of the sex ratio of a population are a common summary statistic used for ecological studies and conservation planning. However, methods to determine the sex ratio often ignore capture probability, which can lead to a perceived bias in the sex ratio when the sexes are detected at different rates.
Aims
To illustrate the bias from conventional count-based analysis methods for determining sex ratio by comparison with analytical methods that include capture probability.
Methods
Closed-population mark–recapture analysis was used to determine the population size of each sex within a population of green and golden bell frogs (Litoria aurea). This was then compared with the traditional count-based methods of estimating sex ratio to determine the effect of incorporating capture probability on the sex ratio estimate.
Key results
More males than females were detected during surveys, producing a male-biased sex ratio when there was no incorporation of capture probability. Mark–recapture results indicated a similar population size between the two sexes, suggesting that the sex ratio is closer to even.
Conclusions
Methods to estimate sex ratio that incorporate capture probability can significantly reduce the bias obtained from count data.
Implications
We suggest that population studies must incorporate capture probability to determine the sex ratio of a population.
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27
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Healy F, Mulloy E, Peirce TH, Mahony MJ. Co-morbidity in a cystic fibrosis population attending a regional clinic. Ir Med J 2010; 103:313-314. [PMID: 21560505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Pulmonary disease remains the major cause of morbidity in patients with cystic fibrosis (CF). However, of 115 patients attending a regional CF clinic we noted 16 cases (14%) with co-morbid conditions. Of this group, 4 of 115 patients (3.5%) had renal problems including both structural and functional defects and 4 (3.5%) had neurological disorders, 3 of which were types of epilepsy. Notably, 3 of 115 patients (2.6%) had different forms of neoplasia, all of which required significant surgical and/or chemotherapeutic intervention. There is now increasing evidence of the association between digestive tract malignancy and CF, which further complicates management of these already complex cases.
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Affiliation(s)
- F Healy
- Mid Western Regional Hospital, Dooradoyle, Limerick.
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28
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Stockwell MP, Clulow J, Mahony MJ. Efficacy of SYBR 14/propidium iodide viability stain for the amphibian chytrid fungus Batrachochytrium dendrobatidis. Dis Aquat Organ 2010; 88:177-181. [PMID: 20225679 DOI: 10.3354/dao02165] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The amphibian chytrid fungus Batrachochytrium dendrobatidis is a recently described pathogen that has been implicated as a causal agent in the global decline in amphibians. Research into its biology and epidemiology has frequently involved in vitro experimentation. However, this research is currently limited by the inability to differentiate between viable and inviable zoospores. Stains are frequently used to determine cell viability, and this study tested a 2-colour fluorescence assay for the detection and quantification of viable B. dendrobatidis zoospores. The results show that the nucleic acid stains SYBR 14 and propidium iodide are effective in distinguishing live from dead zoospores, and a protocol has been optimized for their use. This viability assay provides an efficient and reliable tool that will have applications in B. dendrobatidis challenge and amphibian exposure experiments.
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Affiliation(s)
- M P Stockwell
- School of Environmental and Life Sciences, University of Newcastle, Callaghan Drive, Callaghan, New South Wales 2308, Australia.
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29
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Penman TD, Lemckert FL, Mahony MJ. Applied conservation management of a threatened forest dependent frog, Heleioporus australiacus. ENDANGER SPECIES RES 2008. [DOI: 10.3354/esr00111] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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30
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Gorman CSO, Gill D, Darby C, Crowley V, Mahony MJ. Hereditary coproporphyria: report of an Irish kindred and identification of a novel gene mutation. Ir Med J 2008; 101:125. [PMID: 18557518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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31
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Penman TD, Lemckert FL, Mahony MJ. Spatial ecology of the giant burrowing frog (Heleioporus australiacus): implications for conservation prescriptions. AUST J ZOOL 2008. [DOI: 10.1071/zo08077] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Management of threatened anurans requires an understanding of a species’ behaviour and habitat requirements in both the breeding and non-breeding environments. The giant burrowing frog (Heleioporus australiacus) is a threatened species in south-eastern Australia. Little is known about its habitat requirements, creating difficulties in developing management strategies for the species. We radio-tracked 33 individual H. australiacus in order to determine their habitat use and behaviour. Data from 33 frogs followed for between 5 and 599 days show that individuals spend little time near (<15 m) their breeding sites (mean 4.7 days for males and 6.3 days for females annually). Most time is spent in distinct non-breeding activity areas 20–250 m from the breeding sites. Activity areas of females were further from the breeding site (mean 143 m) than those of males (mean 99 m), but were not significantly different in size (overall mean 500 m2; males 553 m2; females 307 m2). Within activity areas, each frog used 1–14 burrows repeatedly, which we term home burrows. Existing prescriptions are inappropriate for this species and we propose protection of key populations in the landscape as a more appropriate means of protecting this species.
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32
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Edwards DL, Mahony MJ, Clulow J. Effect of sperm concentration, medium osmolality and oocyte storage on artificial fertilisation success in a myobatrachid frog (Limnodynastes tasmaniensis). Reprod Fertil Dev 2007; 16:347-54. [PMID: 15304208 DOI: 10.10371/rd02079] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2002] [Accepted: 01/23/2004] [Indexed: 11/20/2022] Open
Abstract
The present study optimised artificial fertilisation and oocyte storage conditions in Limnodynastes tasmaniensis (Myobatrachidae). Data on general reproductive biology, the effect of sperm motility and concentration, medium osmolality and oocyte storage on artificial fertilisation success are presented. Egg number was most strongly correlated with bodyweight (r = 0.819). Sperm yield was correlated with testes weight (r = 0.827), which was strongly correlated with snout-vent length (r = 0.772). Optimal artificial fertilisation occurred in 0-7 mOsm kg(-1) amphibian Ringer, similar to ranid, bufonid and hylid species. High fertilisation rates were achieved using spermatozoa with little forwards progressive motility at comparatively low concentrations (3 x10(4) sperm cells mL(-1)) and with no relationship between percentage sperm motility and fertilisation success (correlation of fertilisation rate with sperm motility after activation: r = -0.145). Oocytes stored in 5 mOsm kg(-1) solutions showed no significant decline in fertilisability after 2 h, showing that swelling of the jelly surrounding the eggs does not prevent sperm from fusing with the oocyte in this species. Fertilisability of oocytes was extended to > 4 h in medium to high osmolality solutions (124-271 mOsm kg(-1)). These data allow for the future use of L. tasmaniensis in developing assisted reproductive technology protocols for foam-nesting myobatrachid species, many of which are now threatened with extinction in the wild.
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Affiliation(s)
- D L Edwards
- School of Animal Biology, University of Western Australia, Crawley, WA, Australia.
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33
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Healy F, Mahony MJ. Changing trends in childhood asthma admissions. Ir Med J 2007; 100:411. [PMID: 17491546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
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34
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Fitzsimmons C, McLaughlin EA, Mahony MJ, Clulow J. Optimisation of handling, activation and assessment procedures for Bufo marinus spermatozoa. Reprod Fertil Dev 2007; 19:594-601. [PMID: 17524305 DOI: 10.1071/rd06124] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2006] [Accepted: 03/25/2007] [Indexed: 01/07/2023] Open
Abstract
In the present study, we investigated handling, activation and assessment procedures for cane toad (Bufo marinus) spermatozoa. Optimisation of these techniques will facilitate the maintenance of sperm viability during cryopreservation and during in vitro fertilisation (IVF) techniques in reproduction technologies for endangered species. Spermatozoa were taken from testicular macerates and assessed using plasma membrane integrity assays (live/dead stains) and quantitative scores of motility parameters. In the assessment of sperm viability using live/dead stains, there were small but significant differences in the percentage of sperm from cryopreserved samples staining positive with propidium iodide, Hoechst H33258 and Trypan blue; these differences were not large and all stains performed acceptably. Spermatozoa were activated by dilution of testicular macerates in water at one of two dilution ratios (1 : 6 or 1 : 20) with or without 0.1–5.0 mm theophylline. Sperm plasma membrane integrity (unstained spermatozoa) was unaffected by either dilution ratio (osmolarity) or theophylline concentration. However, sperm motility was significantly affected by osmolarity and theophylline concentration. The stimulation of sperm motility increased with higher theophylline concentrations and these strongly interacted with lower osmolarities through a higher dilution ratio of sperm macerates with water. Spermatozoa were exposed to increasing centrifugation forces to determine tolerance to physical stresses encountered during washing procedures. Forces between 50 and 800g were associated with a significant reduction in motility (mean 56 ± 3% decreasing to 27 ± 3%), but did not affect staining. In conclusion, centrifugation should be minimised in anuran sperm washing procedures; osmotic shock associated with higher dilution ratios reduces the capacity of anuran sperm to achieve high percentages of motile sperm, leading to a likely trade-off between dilution required for activation and sperm motility to optimise IVF fertilisation rates; and optimal conditions for sperm motility after activation occur at lower dilutions of suspensions with 5.0 mm theophylline. The present study has improved protocols for the handling of anuran sperm during pre- and post-cryopreservation procedures.
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Affiliation(s)
- C Fitzsimmons
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
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35
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36
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Abstract
Declining species of vertebrates, including amphibians, have a life history that is characterised by low fecundity, long time to maturity, limited capacity to disperse and habitat specialisation. However, by studying aspects of the life history of an endangered amphibian in south-eastern Australia we show that a paradox may exist for some declining amphibians. We used standard mark–recapture methods over two breeding seasons (2000–01) to study a population of the green and golden bell frog (Litoria aurea) on Kooragang Island, New South Wales, with the aim of determining its age structure, and the growth and survival rates of individuals. Two age classes for males and three for females were derived using von Bertalanffy growth models. Around a quarter of the male and female marked population was a first-year cohort. The male and female age structures appeared to be stable over the two breeding seasons. However, there were fewer female L. aurea in the <12-month age class and more in the >24-month age class in 2001, which may indicate that recruitment declined in the study area. A short time to maturity (~3 months) was recorded for males. The maximum-likelihood estimate of survival for males in the 2000 breeding season was relatively high (0.76), although the capture probability was low (0.19). The biology of L. aurea conforms to an ‘r’-strategist, which is characteristic of a colonising or ‘weed-like’ species and not of one that has become extinct over much of its former range.
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37
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Penman TD, Lemckert FL, Mahony MJ. Meteorological effects on the activity of the giant burrowing frog (Heleioporus australiacus) in south-eastern Australia. Wildl Res 2006. [DOI: 10.1071/wr04081] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Activity of amphibians is strongly related to meteorological conditions. The threatened giant burrowing frog is rarely encountered, even when it is known to be present in an area. To improve its detectability and so improve our ability to manage the species we wanted to determine the conditions under which this species is active. Thirty-three frogs were tracked over a 2-year period, their location determined daily and activity measured as the proportion of frogs moved from the previous day. Animals were found to be active throughout the year and activity was associated with rainfall, humidity, temperature and wind strength. The results suggest that surveys for this species should be carried out after rainfall of at least 5mm, when temperatures are above 8°C, relative humidity above 60% and in still or light wind conditions.
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38
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O'Gorman CS, Kiely P, Kenny B, Mahony MJ. Acute gastric dilatation in a child with marked kyphoscoliosis and cerebral palsy--a case report. Ir Med J 2005; 98:242. [PMID: 16255118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
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39
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Mahony MJ. Pregnant doctors need better working conditions. Ir Med J 2004; 97:253. [PMID: 15532977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
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40
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Lane SJ, Mahony MJ. Larval anurans with synchronous and asynchronous development periods: contrasting responses to water reduction and predator presence. J Anim Ecol 2002. [DOI: 10.1046/j.1365-2656.2002.00644.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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41
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Roberts JD, Horwitz P, Wardell-Johnson G, Maxson LR, Mahony MJ. Taxonomy, Relationships and Conservation of a New Genus and Species of Myobatrachid Frog from the High Rainfall Region of Southwestern Australia. COPEIA 1997. [DOI: 10.2307/1447757] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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42
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Abstract
Karyotypes of 12 species from five genera of Australian, New Guinean and Solomon Islands ranid frogs are reported and for convenience are compared and contrasted with the 2n = 26, fundamental number (FN) = 52 karyotype of Rana, the typical karyotype of the subfamily Raninae. This karyotype was found in the four species of Rana examined. One species, Ceratobatrachus guentheri, had an increased diploid number of 30, a lower FN of 38, and altered relative lengths and centromere positions of pairs 1-5, and several of the smaller pairs. These changes could have resulted from centric fissions and pericentric rearrangements which produced an increase in the number of telocentric chromosomes. Eight species, Batrachylodes vertebralis, Discodeles bufoniformis, D. guppyi, Platymantis boulengeri, P. myersi, P. neckeri, P. solomonis and P. weberi, had reduced diploid numbers and FN. The means by which reduction in diploid number and FN has occurred in these species is unknown, but may involve centric fissions to produce telocentrics, followed by translocation onto other chromosomes, or a process involving pericentric rearrangements to produce telocentric chromosomes followed by fusion of these products. With the exception of Rana, the level of chromosomal rearrangements in the south-west Pacific ranid frogs that occur on archipelagos is high compared with that observed in the continental lineages of this subfamily.
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43
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Mahony MJ, Donnellan SC, Roberts JD. An Electrophoretic Investigation of Relationships of Diploid and Tetraploid Species of Australian Desert Frogs Neobatrachus (Anura: Myobatrachidae). AUST J ZOOL 1996. [DOI: 10.1071/zo9960639] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Allozyme electrophoresis of 27 loci was used to characterise genetic variation among 29 populations of six diploid species of the myobatrachid frog genus Neobatrachus. All six species are well differentiated genetically with the percentage of fixed differences between species ranging from 11 to 59%. The genetic data are in agreement with the currently accepted species boundaries. The four tetraploid species were examined for 25 of the 27 loci assayed in the diploid species. In contrast to the diploid species, the tetraploid species shared electromorphs with each other at all the loci examined. The tetraploid species were examined for the presence of electromorphs specific to individual diploid species. The majority of these electromorphs were observed in the tetraploid species. For cases in which the range of a tetraploid species contacts that of a diploid species and the diploid population can be characterised by unique electromorphs, then evidence of current gene flow was found in the direction of the tetraploid populations. The data are compatible with single or multiple discrete or hybrid origins of the tetraploids overlain by gene flow among the tetraploids and between the tetraploids and some and perhaps all of the diploids by means of geographically limited but ongoing episodes of introgressive hybridisation.
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44
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Mahony MJ, Corcoran M. High-strength pancreatic enzymes. Lancet 1994; 343:599-600. [PMID: 7906349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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45
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Abstract
Gastritis associated with Helicobacter pylori was present in gastric biopsies from 24/95 (25%) children and adolescents undergoing endoscopy for recurrent abdominal pain and upper gastrointestinal symptoms. H pylori associated gastritis occurred mainly in older children (8-16 years) and was significantly associated with low socioeconomic class and a family history of peptic ulcer disease. Antral nodularity was a common endoscopic finding in H pylori positive children. Eighteen children, all over 5 years of age, were treated with tripotassium dicitratobismuthate (De-Nol) for two months and ampicillin for two weeks. In 12 children follow up gastric biopsies were obtained six weeks after completion of treatment. In 9/12 (75%) children H pylori was eradicated, and gastritis improved.
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Affiliation(s)
- M J Mahony
- Department of Paediatrics, St James's University Hospital, Leeds
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46
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Crabtree JE, Mahony MJ, Taylor JD, Heatley RV, Littlewood JM, Tompkins DS. Immune responses to Helicobacter pylori in children with recurrent abdominal pain. J Clin Pathol 1991; 44:768-71. [PMID: 1918408 PMCID: PMC496728 DOI: 10.1136/jcp.44.9.768] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The systemic immune response to Helicobacter pylori was examined in 69 children with recurrent abdominal pain and upper gastrointestinal symptoms. Twenty one (30%) children were histologically positive for H pylori. Eighteen of the 21 positive subjects and two H pylori negative subjects (one with normal mucosa, one with lymphocytic gastritis) were positive for H pylori IgG antibodies by enzyme linked immunosorbent assay (ELISA) (86% sensitivity, 98% specificity). In children with H pylori associated gastritis, there was a significant positive correlation (p less than 0.05) between IgG antibody titres and patient age. Intra-assay comparison of sera from histologically negative adults with those of histologically negative children showed that the cut off for positivity in the ELISA for adults was greater than that for children. Immunoblotting showed IgG positivity in 20 of the 21 patients with H pylori infection (95% sensitivity). Both ELISA and immunoblotting for IgA and IgM H pylori antibodies had poor discriminatory value for determining infection. Serological detection of H pylori IgG antibodies seems to be valuable in the assessment of children presenting with recurrent abdominal pain and other gastrointestinal symptoms, but assays must first be validated in paediatric populations.
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Affiliation(s)
- J E Crabtree
- Department of Medicine, St James's Hospital, Leeds
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47
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Affiliation(s)
- E J Simmonds
- Regional Cystic Fibrosis Unit, St James's Hospital, Leeds
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48
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Abstract
Mechanisms of gastro-oesophageal reflux were studied by oesophageal manometry and pH monitoring in 33 children: nine controls, 15 with gastro-oesophageal reflux alone, and nine with reflux oesophagitis. A total of 122 episodes of reflux were analysed in detail: 82 (67%) were synchronous with swallowing and 40 (33%) asynchronous. Infants with trivial symptoms had gastro-oesophageal reflux synchronous with swallowing, whereas those with serious symptoms had slower acid clearance and asynchronous reflux. There were significant differences in lower oesophageal sphincter pressure and amplitude of oesophageal contractions between controls and patients with both gastro-oesophageal reflux and reflux oesophagitis. In reflux oesophagitis there was a decrease in lower oesophageal sphincter pressure and the contractions had a bizarre waveform suggesting a neuropathic process.
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Affiliation(s)
- M J Mahony
- Department of Child Health, Hospital for Sick Children, London
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49
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Abstract
Campylobacter pylori colonisation of the stomach is strongly associated with type B non-autoimmune gastritis in adults. In a retrospective study of 38 gastric biopsy specimens taken during upper gastrointestinal endoscopy in children attending this hospital we found C pylori in nine (24%). Ten biopsy specimens showed histological evidence of gastritis and C pylori was found in eight.
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Affiliation(s)
- M J Mahony
- Department of Paediatrics, St James's University Hospital, Leeds
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50
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Abstract
Budd-Chiari syndrome was diagnosed in a 13 year old boy who presented with ascites. Angiographic studies showed occlusion at the ostia of the hepatic veins. This was treated surgically by the Senning operation of transcaval dorsocranial resection of the liver and hepatocaval anastomosis. The patient's ascites cleared and he remains well 10 months after surgery.
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Affiliation(s)
- M J Mahony
- Department of Paediatrics, St James's University Hospital, Leeds
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