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Schäfer M, Sydow D, Schauer M, Doumbia J, Schmitt T, Rödel MO. Species- and sex-specific chemical composition from an internal gland-like tissue of an African frog family. Proc Biol Sci 2024; 291:20231693. [PMID: 38196358 PMCID: PMC10777154 DOI: 10.1098/rspb.2023.1693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 11/27/2023] [Indexed: 01/11/2024] Open
Abstract
Intraspecific chemical communication in frogs is understudied and the few published cases are limited to externally visible and male-specific breeding glands. Frogs of the family Odontobatrachidae, a West African endemic complex of five morphologically cryptic species, have large, fatty gland-like strands along their lower mandible. We investigated the general anatomy of this gland-like strand and analysed its chemical composition. We found the strand to be present in males and females of all species. The strand varies in markedness, with well-developed strands usually found in reproductively active individuals. The strands are situated under particularly thin skin sections, the vocal sac in male frogs and a respective area in females. Gas-chromatography/mass spectrometry and multivariate analysis revealed that the strands contain sex- and species-specific chemical profiles, which are consistent across geographically distant populations. The profiles varied between reproductive and non-reproductive individuals. These results indicate that the mandibular strands in the Odontobatrachidae comprise a so far overlooked structure (potentially a gland) that most likely plays a role in the mating and/or breeding behaviour of the five Odontobatrachus species. Our results highlight the relevance of multimodal signalling in anurans, and indicate that chemical communication in frogs may not be restricted to sexually dimorphic, apparent skin glands.
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Affiliation(s)
- Marvin Schäfer
- Museum für Naturkunde – Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, Germany
| | - David Sydow
- Zoology III Department of Animal Ecology and Tropical Biology, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Maria Schauer
- Museum für Naturkunde – Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, Germany
| | - Joseph Doumbia
- ONG EnviSud Guinée, Quartier Kipé T2 commune de Ratoma, 530 BP 558 Conakry, Guinea
| | - Thomas Schmitt
- Zoology III Department of Animal Ecology and Tropical Biology, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Mark-Oliver Rödel
- Museum für Naturkunde – Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, Germany
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Gonzalez M, Palacios-Rodriguez P, Hernandez-Restrepo J, González-Santoro M, Amézquita A, Brunetti AE, Carazzone C. First characterization of toxic alkaloids and volatile organic compounds (VOCs) in the cryptic dendrobatid Silverstoneia punctiventris. Front Zool 2021; 18:39. [PMID: 34446035 PMCID: PMC8390233 DOI: 10.1186/s12983-021-00420-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/14/2021] [Indexed: 11/24/2022] Open
Abstract
Background Poison frogs are known for the outstanding diversity of alkaloid-based chemical defences with promising therapeutic applications. However, current knowledge about chemical defences in Dendrobatoidea superfamily has two sources of bias. First, cryptic, brown-colored species have been neglected in comparison to those conspicuously colored, and second, there has been little interest in characterizing metabolites other than alkaloids mediating defensive functions. In an effort to contribute to fill the gap of knowledge about cryptic species and broadening the spectrum of compounds analyzed we have applied head-space solid phase microextraction coupled to gas chromatography and mass spectrometry (HS-SPME/GC-MS) for extracting amphibian alkaloids and volatile organic compounds (VOCs) from Silverstoneia punctiventris. Results Using the skin from 8 specimens in 4 biological replicates we have found 33 different compounds. Twenty of them were classified as VOCs into 15 chemical classes including alkanes, alcohols, carbonyl compounds, methylpyridines, benzothiazoles, N-alkylpyrrolidines, pyrazines, and sesquiterpenoids, some of which were previously reported as repellents, defence compounds or defence pheromones in other organisms, and as sex pheromones in a treefrog. Interestingly, six of the remaining compounds were identified as alkaloids previously reported in other toxic/unpalatable dendrobatid frogs. Conclusions This is the first report of alkaloids and VOCs found in the Silverstoneia genus, which has been assumed for decades as non-chemically defended. This study establishes HS-SPME/GC-MS as a new application for a simultaneous approach to amphibian alkaloids and VOCs in poison frogs while opens up new research questions to assess the co-occurrence of both type of compounds and to investigate the evolutionary significance of a defence gradient that includes olfactory avoidance, unpalatability, and toxicity in dendrobatids. In addition, our results show that amphibian alkaloids could have a dual function (olfactory at distance, taste by contact) never explored before neither in Silverstonaeia nor in any other dendrobatid species. Supplementary Information The online version contains supplementary material available at 10.1186/s12983-021-00420-1.
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Affiliation(s)
- Mabel Gonzalez
- Department of Chemistry, Universidad de los Andes, Bogotá, AA, 4976, Colombia
| | | | | | | | - Adolfo Amézquita
- Department of Biological Sciences, Universidad de los Andes, Bogotá, AA, 4976, Colombia
| | - Andrés E Brunetti
- Laboratorio de Genética Evolutiva, Instituto de Biología Subtropical (CONICET - UNaM), Facultad de Ciencias Exactas, Universidad Nacional de Misiones, N3300, Posadas, Argentina.,Departamento de Ciências Biomoleculares, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14040-903, Ribeirão Preto, SP, Brazil
| | - Chiara Carazzone
- Department of Chemistry, Universidad de los Andes, Bogotá, AA, 4976, Colombia.
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Portillo‐Estrada M, Van Moorleghem C, Janssenswillen S, Cooper RJ, Birkemeyer C, Roelants K, Van Damme R. Proton‐transfer‐reaction time‐of‐flight mass spectrometry (PTR‐TOF‐MS) as a tool for studying animal volatile organic compound (VOC) emissions. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Miguel Portillo‐Estrada
- Research Group Pleco (Plants and Ecosystems) Department of Biology University of Antwerp Wilrijk Belgium
| | - Charlotte Van Moorleghem
- Laboratory for Functional Morphology Department of Biology University of Antwerp Wilrijk Belgium
| | - Sunita Janssenswillen
- Amphibian Evolution Lab Biology Department Vrije Universiteit Brussel Brussels Belgium
| | - Richard Joseph Cooper
- Amphibian Evolution Lab Biology Department Vrije Universiteit Brussel Brussels Belgium
| | | | - Kim Roelants
- Amphibian Evolution Lab Biology Department Vrije Universiteit Brussel Brussels Belgium
| | - Raoul Van Damme
- Laboratory for Functional Morphology Department of Biology University of Antwerp Wilrijk Belgium
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Cutajar TP, Rowley JJ. Surveying frogs from the bellies of their parasites: Invertebrate-derived DNA as a novel survey method for frogs. Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2020.e00978] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Grafe TU, Ahmad Sah HH, Ahmad N, Borkent A, Meuche I, Konopik O. Studying the sensory ecology of frog‐biting midges (Corethrellidae: Diptera) and their frog hosts using ecological interaction networks. J Zool (1987) 2018. [DOI: 10.1111/jzo.12612] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- T. U. Grafe
- Department of Animal Ecology and Tropical Biology University of Würzburg Würzburg Germany
- Faculty of Science and Institute for Biodiversity and Environmental Research Universiti Brunei Darussalam Gadong Brunei Darussalam
| | - H. H. Ahmad Sah
- Faculty of Science and Institute for Biodiversity and Environmental Research Universiti Brunei Darussalam Gadong Brunei Darussalam
| | - N. Ahmad
- Faculty of Science and Institute for Biodiversity and Environmental Research Universiti Brunei Darussalam Gadong Brunei Darussalam
| | - A. Borkent
- Research Associate of the Royal British Columbia Museum Salmon Arm British Columbia Canada
| | - I. Meuche
- Faculty of Science and Institute for Biodiversity and Environmental Research Universiti Brunei Darussalam Gadong Brunei Darussalam
| | - O. Konopik
- Department of Animal Ecology and Tropical Biology University of Würzburg Würzburg Germany
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Meuche I, Keller A, Ahmad Sah HH, Ahmad N, Grafe TU. Silent listeners: can preferences of eavesdropping midges predict their hosts’ parasitism risk? Behav Ecol 2016. [DOI: 10.1093/beheco/arw002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Omondi D, Masiga DK, Ajamma YU, Fielding BC, Njoroge L, Villinger J. Unraveling Host-Vector-Arbovirus Interactions by Two-Gene High Resolution Melting Mosquito Bloodmeal Analysis in a Kenyan Wildlife-Livestock Interface. PLoS One 2015; 10:e0134375. [PMID: 26230507 PMCID: PMC4521840 DOI: 10.1371/journal.pone.0134375] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 07/08/2015] [Indexed: 11/23/2022] Open
Abstract
The blood-feeding patterns of mosquitoes are directly linked to the spread of pathogens that they transmit. Efficient identification of arthropod vector bloodmeal hosts can identify the diversity of vertebrate species potentially involved in disease transmission cycles. While molecular bloodmeal analyses rely on sequencing of cytochrome b (cyt b) or cytochrome oxidase 1 gene PCR products, recently developed bloodmeal host identification based on high resolution melting (HRM) analyses of cyt b PCR products is more cost-effective. To resolve the diverse vertebrate hosts that mosquitoes may potentially feed on in sub-Saharan Africa, we utilized HRM profiles of both cyt b and 16S ribosomal RNA genes. Among 445 blood-fed Aedeomyia, Aedes, Anopheles, Culex, Mansonia, and Mimomyia mosquitoes from Kenya’s Lake Victoria and Lake Baringo regions where many mosquito-transmitted pathogens are endemic, we identified 33 bloodmeal hosts including humans, eight domestic animal species, six peridomestic animal species and 18 wildlife species. This resolution of vertebrate host species was only possible by comparing profiles of both cyt b and 16S markers, as melting profiles of some pairs of species were similar for either marker but not both. We identified mixed bloodmeals in a Culex pipiens from Mbita that had fed on a goat and a human and in two Mansonia africana mosquitoes from Baringo that each had fed on a rodent (Arvicanthis niloticus) in addition to a human or baboon. We further detected Sindbis and Bunyamwera viruses in blood-fed mosquito homogenates by Vero cell culture and RT-PCR in Culex, Aedeomyia, Anopheles and Mansonia mosquitoes from Baringo that had fed on humans and livestock. The observed mosquito feeding on both arbovirus amplifying hosts (including sheep and goats) and possible arbovirus reservoirs (birds, porcupine, baboons, rodents) informs arbovirus disease epidemiology and vector control strategies.
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Affiliation(s)
- David Omondi
- Martin Lüscher Emerging Infectious Disease (ML-EID) Laboratory, International Centre for Insect Physiology and Ecology, P. O Box 30772-00100, Nairobi, Kenya
- Molecular Biology and Virology Laboratory, Department of Medical Biosciences, University of Western Cape, Private Bag X17, Bellville, 7535, South Africa
- Biochemistry and Molecular Biology Department, Egerton University, P.O Box 536, Egerton, 20115, Kenya
| | - Daniel K. Masiga
- Martin Lüscher Emerging Infectious Disease (ML-EID) Laboratory, International Centre for Insect Physiology and Ecology, P. O Box 30772-00100, Nairobi, Kenya
| | - Yvonne Ukamaka Ajamma
- Martin Lüscher Emerging Infectious Disease (ML-EID) Laboratory, International Centre for Insect Physiology and Ecology, P. O Box 30772-00100, Nairobi, Kenya
| | - Burtram C. Fielding
- Molecular Biology and Virology Laboratory, Department of Medical Biosciences, University of Western Cape, Private Bag X17, Bellville, 7535, South Africa
| | - Laban Njoroge
- Invertebrates Zoology Section, Zoology Department, National Museums of Kenya, P.O. Box 40658-00100, Nairobi, Kenya
| | - Jandouwe Villinger
- Martin Lüscher Emerging Infectious Disease (ML-EID) Laboratory, International Centre for Insect Physiology and Ecology, P. O Box 30772-00100, Nairobi, Kenya
- * E-mail:
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Frog Volatile Compounds: Application of in vivo SPME for the Characterization of the Odorous Secretions from Two Species of Hypsiboas Treefrogs. J Chem Ecol 2015; 41:360-72. [DOI: 10.1007/s10886-015-0564-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 03/03/2015] [Accepted: 03/04/2015] [Indexed: 11/25/2022]
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Trindade FT, Soares AA, de Moura AA, Rego TB, Soares AM, Stábeli RG, Calderon LA, E Silva ADA. Insecticidal activity of Leptodactylus knudseni and Phyllomedusa vaillantii crude skin secretions against the mosquitoes Anopheles darlingi and Aedes aegypti. J Venom Anim Toxins Incl Trop Dis 2014; 20:28. [PMID: 25165469 PMCID: PMC4145836 DOI: 10.1186/1678-9199-20-28] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 06/24/2014] [Indexed: 11/10/2022] Open
Abstract
Background Mosquitoes are important vectors of several diseases, including malaria and dengue, and control measures are mostly performed using chemical insecticides. Unfortunately, mosquito resistance to commonly applied insecticides is widespread. Therefore, a prospection for new molecules with insecticidal activity based on Amazon biodiversity using the anurans Leptodactylus knudseni and Phyllomedusa vaillantii was performed against the mosquito species Anopheles darlingi and Aedes aegypti. Methods The granular secretion from anuran skin was obtained by manual stimulation, and lethal concentrations (LCs) for larvicidal and adulticidal tests were calculated using concentrations from 1-100 ppm. The skin secretions from the anuran species tested caused significant mortality within the first 24 hours on adults and larvae, but differed within the mosquito species. Results The skin secretions from the anuran species tested caused significant mortality within the first 24 hours on adults and larvae, but differed within the mosquito species. The calculated LC50 of L. knudseni skin secretions against An. darlingi was 0.15 and 0.2 ppm for adults and larvae, respectively, but much higher for Ae. aegypti, i.e., 19 and 38 ppm, respectively. Interestingly, the calculated LCs50 of P. vaillantii against both mosquito species in adults were similar, 1.8 and 2.1 ppm, respectively, but the LC50 for An. darlingi larvae was much lower (0.4 ppm) than for Ae aegypti (2.1 ppm). Conclusions The present experiments indicate that skin secretions from L. knudseni and P. vaillantii contain bioactive molecules with potent insecticide activity. The isolation and characterization of skin secretions components will provide new insights for potential insecticidal molecules.
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Affiliation(s)
- Frances Tt Trindade
- Laboratory of Insect Bioecology, Department of Biology, Federal University of Rondônia (UNIR), Porto Velho, Rondônia State, Brazil ; Oswaldo Cruz Foundation - Rondônia (Fiocruz - Rondônia), Porto Velho, Rondônia State, Brazil
| | - Angela A Soares
- Center for the Study of Biomolecules Applicable to Health, Oswaldo Cruz Foundation - Rondônia, and Department of Medicine, Federal University of Rondônia (UNIR), Porto Velho, Rondônia State, Brazil
| | - Andréa A de Moura
- Center for the Study of Biomolecules Applicable to Health, Oswaldo Cruz Foundation - Rondônia, and Department of Medicine, Federal University of Rondônia (UNIR), Porto Velho, Rondônia State, Brazil
| | - Tiago B Rego
- Center for the Study of Biomolecules Applicable to Health, Oswaldo Cruz Foundation - Rondônia, and Department of Medicine, Federal University of Rondônia (UNIR), Porto Velho, Rondônia State, Brazil
| | - Andreimar M Soares
- Center for the Study of Biomolecules Applicable to Health, Oswaldo Cruz Foundation - Rondônia, and Department of Medicine, Federal University of Rondônia (UNIR), Porto Velho, Rondônia State, Brazil
| | - Rodrigo G Stábeli
- Oswaldo Cruz Foundation - Rondônia (Fiocruz - Rondônia), Porto Velho, Rondônia State, Brazil ; Center for the Study of Biomolecules Applicable to Health, Oswaldo Cruz Foundation - Rondônia, and Department of Medicine, Federal University of Rondônia (UNIR), Porto Velho, Rondônia State, Brazil
| | - Leonardo A Calderon
- Oswaldo Cruz Foundation - Rondônia (Fiocruz - Rondônia), Porto Velho, Rondônia State, Brazil ; Center for the Study of Biomolecules Applicable to Health, Oswaldo Cruz Foundation - Rondônia, and Department of Medicine, Federal University of Rondônia (UNIR), Porto Velho, Rondônia State, Brazil
| | - Alexandre de Almeida E Silva
- Laboratory of Insect Bioecology, Department of Biology, Federal University of Rondônia (UNIR), Porto Velho, Rondônia State, Brazil ; Oswaldo Cruz Foundation - Rondônia (Fiocruz - Rondônia), Porto Velho, Rondônia State, Brazil
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10
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Ferguson LV, Kirk Hillier N, Smith TG. Influence of Hepatozoon parasites on host-seeking and host-choice behaviour of the mosquitoes Culex territans and Culex pipiens. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2012; 2:69-76. [PMID: 24533317 PMCID: PMC3862534 DOI: 10.1016/j.ijppaw.2012.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Revised: 11/29/2012] [Accepted: 11/30/2012] [Indexed: 11/06/2022]
Abstract
Hepatozoon species are heteroxenous parasites that commonly infect the blood of vertebrates and various organs of arthropods. Despite their ubiquity, little is known about how these parasites affect host phenotype, including whether or not these parasites induce changes in hosts to increase transmission success. The objectives of this research were to investigate influences of the frog blood parasite Hepatozoon clamatae and the snake blood parasite Hepatozoon sipedon on host-seeking and host-choice behaviour of the mosquitoes Culex territans and Culex pipiens, respectively. During development of H. sipedon in C. pipiens, significantly fewer infected mosquitoes fed on uninfected snakes compared to uninfected mosquitoes. When H. sipedon was mature in C. pipiens, the number of infected and uninfected C. pipiens that fed on snakes was not significantly different. Higher numbers of mosquitoes fed on naturally infected snakes and frogs compared to laboratory-reared, uninfected control animals. However, experiments using only laboratory-raised frogs revealed that infection did not significantly affect host choice by C. territans. Behaviour of C. pipiens in the presence of H. sipedon may increase transmission success of the parasite and provide the first evidence of phenotypic changes in the invertebrate host of Hepatozoon parasites.
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Affiliation(s)
- Laura V Ferguson
- Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada B4P 2R6
| | - N Kirk Hillier
- Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada B4P 2R6
| | - Todd G Smith
- Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada B4P 2R6
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Repellent activity of Ageratum houstonianum Mill. (Asteraceae) leaf extracts against Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae). ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2012. [DOI: 10.1016/s2222-1808(12)60104-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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12
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Ferguson LV, Smith TG. Reciprocal Trophic Interactions and Transmission of Blood Parasites between Mosquitoes and Frogs. INSECTS 2012; 3:410-23. [PMID: 26466534 PMCID: PMC4553601 DOI: 10.3390/insects3020410] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 03/20/2012] [Accepted: 03/21/2012] [Indexed: 12/02/2022]
Abstract
The relationship between mosquitoes and their amphibian hosts is a unique, reciprocal trophic interaction. Instead of a one-way, predator-prey relationship, there is a cyclical dance of avoidance and attraction. This has prompted spatial and temporal synchrony between organisms, reflected in emergence time of mosquitoes in the spring and choice of habitat for oviposition. Frog-feeding mosquitoes also possess different sensory apparatuses than do their mammal-feeding counterparts. The reciprocal nature of this relationship is exploited by various blood parasites that use mechanical, salivary or trophic transmission to pass from mosquitoes to frogs. It is important to investigate the involvement of mosquitoes, frogs and parasites in this interaction in order to understand the consequences of anthropogenic actions, such as implementing biocontrol efforts against mosquitoes, and to determine potential causes of the global decline of amphibian species.
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Affiliation(s)
- Laura V Ferguson
- Department of Biology, Acadia University, Wolfville, NS B4P 2R6, Canada.
| | - Todd G Smith
- Department of Biology, Acadia University, Wolfville, NS B4P 2R6, Canada.
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Grutter AS, Rumney JG, Sinclair-Taylor T, Waldie P, Franklin CE. Fish mucous cocoons: the 'mosquito nets' of the sea. Biol Lett 2011; 7:292-4. [PMID: 21084337 PMCID: PMC3061186 DOI: 10.1098/rsbl.2010.0916] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 10/28/2010] [Indexed: 11/12/2022] Open
Abstract
Mucus performs numerous protective functions in vertebrates, and in fishes may defend them against harmful organisms, although often the evidence is contradictory. The function of the mucous cocoons that many parrotfishes and wrasses sleep in, while long used as a classical example of antipredator behaviour, remains unresolved. Ectoparasitic gnathiid isopods (Gnathiidae), which feed on the blood of fish, are removed by cleaner fish during the day; however, it is unclear how parrotfish and wrasse avoid gnathiid attacks at night. To test the novel hypothesis that mucous cocoons protect against gnathiids, we exposed the coral reef parrotfish Chlorurus sordidus (Scaridae) with and without cocoons to gnathiids overnight and measured the energetic content of cocoons. Fish without mucous cocoons were attacked more by gnathiids than fish with cocoons. The energetic content of mucous cocoons was estimated as 2.5 per cent of the fish's daily energy budget fish. Therefore, mucous cocoons protected against attacks by gnathiids, acting like mosquito nets in humans, a function of cocoons and an efficient physiological adaptation for preventing parasite infestation that is not used by any other animal.
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Affiliation(s)
- Alexandra S Grutter
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia.
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Burkett-Cadena ND, Graham SP, Hassan HK, Guyer C, Eubanks MD, Katholi CR, Unnasch TR. Blood feeding patterns of potential arbovirus vectors of the genus culex targeting ectothermic hosts. Am J Trop Med Hyg 2008; 79:809-815. [PMID: 18981528 PMCID: PMC4138019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
Reptiles and amphibians constitute a significant portion of vertebrate biomass in terrestrial ecosystems and may be important arbovirus reservoirs. To investigate mosquito preference for ectothermic hosts, feeding indices were calculated from data collected in Tuskegee National Forest, Alabama, USA. Four mosquito species fed upon ectothermic hosts, with Culex peccator and Cx. territans feeding primarily upon ectotherms. These two species appeared to target distinct species with little overlap in host choice. Culex peccator was a generalist in its feeding patterns within ectotherms, and Cx. territans appeared to be a more specialized feeder. Six of eleven ectotherm species fed upon by Cx. territans were fed upon more often than predicted based upon abundance. Spring peepers were highly preferred over other host species by Cx. territans. Blood meals taken from each host species varied temporally, with some hosts being targeted fairly evenly throughout the season and others being fed upon in seasonal peaks.
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Weldon PJ, Kramer M, Gordon S, Spande TF, Daly JW. A common pumiliotoxin from poison frogs exhibits enantioselective toxicity against mosquitoes. Proc Natl Acad Sci U S A 2006; 103:17818-21. [PMID: 17095598 PMCID: PMC1693830 DOI: 10.1073/pnas.0608646103] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neotropical poison frogs (Dendrobatidae) contain a variety of lipophilic alkaloids in their diffusely distributed cutaneous glands, including a major class of compounds known as pumiliotoxins. Pumiliotoxins are highly toxic and are believed to protect frogs against predators. Their potential activity against ectoparasites, however, has not been investigated. We tested female yellow fever mosquitoes (Aedes aegypti) for responses to 8-hydroxy-8-methyl-6-(2'-methylhexylidene)-1-azabicyclo[4.3.0]nonane, designated pumiliotoxin 251D [PTX (+)-251D], a skin alkaloid present in all genera of dendrobatids and in other anurans, and to its unnatural enantiomer, PTX (-)-251D. Both enantiomers of PTX 251D presented on silicone feeding membranes reduced landing and feeding by A. aegypti, but PTX (+)-251D did so at lower concentrations. PTX (+)-251D also induced toxicosis, shown when mosquitoes failed to fly off membranes. Similarly, mosquitoes confined with copper wires coated with PTX (+)-251D exhibited greater latencies to fly off the substrate and a higher incidence of leg autotomy than did those confined with the (-)-enantiomer. Our results on the contact toxicities of PTX 251D enantiomers parallel those reported for mice injected with them. The presentation of serial dilutions of PTX (+)-251D to A. aegypti revealed a minimum toxic concentration of 0.1 microg/cm2. This value is substantially lower than that estimated for the cutaneous abundance of this compound in some frogs, an observation consistent the function of PTX 251D in anuran chemical defense against ectoparasitic arthropods.
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Affiliation(s)
- Paul J. Weldon
- *Conservation and Research Center, Smithsonian Institution, 1500 Remount Road, Front Royal, VA 22630
- To whom correspondence may be addressed. E-mail:
or
| | - Matthew Kramer
- U.S. Department of Agriculture, Agricultural Research Service, Biometrical Consulting Service, Beltsville Agricultural Research Center, Beltsville, MD 20705
| | - Scott Gordon
- Department of Entomology, Division of Communicable Diseases and Immunology, Walter Reed Army Institute of Research, Washington, DC 20307; and
| | - Thomas F. Spande
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Building 8, Bethesda, MD 20892
| | - John W. Daly
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Building 8, Bethesda, MD 20892
- To whom correspondence may be addressed. E-mail:
or
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