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Regalado Fernández OR, Parsi-Pour P, Nyakatura JA, Wyneken J, Werneburg I. Correlations between local geoclimatic variables and hatchling body size in the sea turtles Caretta caretta and Chelonia mydas. BMC Ecol Evol 2024; 24:108. [PMID: 39143507 PMCID: PMC11325825 DOI: 10.1186/s12862-024-02290-7] [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: 03/11/2024] [Accepted: 07/12/2024] [Indexed: 08/16/2024] Open
Abstract
It has been widely demonstrated that air and sand temperatures influence the anatomy of sea turtle hatchlings. We examined the impact of precipitation during the nesting season on the hatchling body size of loggerhead and green turtles from 37 beaches worldwide. Longitudinal data collected between 2012 and 2018 from Florida (US) and from a sample on Bõa Vista Island (Cabo Verde) carried out in 2019 showed that loggerhead body size at hatching was negatively correlated with precipitation, while precipitation was not correlated with hatchling body size in green turtles. A meta-analysis revealed that precipitation is positively correlated with hatchling mass in loggerhead turtles, while it is positively correlated with straight carapace length and width in green turtle hatchlings. The strongest influence of precipitation was found in the middle of the incubation period of loggerhead turtles in Cabo Verde, and we posit that this is due to an increase in the uptake of water for embryonic growth. These findings highlight the great importance of understanding the correlated effects of regional environmental variables, such as precipitation, on the development of sea turtle hatchlings and will have an impact on the evaluation of ongoing conservation and climate change discussions.
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Affiliation(s)
- Omar Rafael Regalado Fernández
- Senckenberg Centre for Human Evolution and Palaeoenvironment an der Universität Tübingen, Sigwartstraße 10, Tübingen, 72076, Germany.
- Fachbereich Geowissenschaften an der Universität Tübingen, Hölderlinstraße 12, Tübingen, 72074, Germany.
| | - Parima Parsi-Pour
- AG Vergleichende Zoologie, Institut Für Biologie, Humboldt Universität zu Berlin, Philippstraße 12 (Haus 2), Berlin, 10115, Germany
| | - John A Nyakatura
- AG Vergleichende Zoologie, Institut Für Biologie, Humboldt Universität zu Berlin, Philippstraße 12 (Haus 2), Berlin, 10115, Germany
| | | | - Ingmar Werneburg
- Senckenberg Centre for Human Evolution and Palaeoenvironment an der Universität Tübingen, Sigwartstraße 10, Tübingen, 72076, Germany.
- Fachbereich Geowissenschaften an der Universität Tübingen, Hölderlinstraße 12, Tübingen, 72074, Germany.
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2
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Williamson SA, Hoover AL, Evans RG, Shillinger GL, Bailey H, Bruno RS, Bandimere A, Reina RD. Effects of postovipositional hypoxia and hyperoxia on leatherback turtle reproductive success and hatchling performance. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2023; 339:939-950. [PMID: 37545193 DOI: 10.1002/jez.2743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/08/2023]
Abstract
Leatherback egg clutches typically experience lower hatching success (~50%) than those of other sea turtle species (>70%). The majority of embryonic death (>50%) occurs at early stages of development, possibly because embryos fail to break preovipositional embryonic arrest after oviposition. The embryonic arrest is maintained by hypoxia in the oviduct and following oviposition increased availability of oxygen is the trigger that breaks arrest in all turtle species studied to date. We conducted an ex situ incubator experiment and an in situ hatchery experiment to examine the influence of oxygen availability on hatching success and hatchling traits in leatherbacks. After oviposition, eggs (n = 1005) were incubated in either normoxia (21% O2 ), hyperoxia (32%-42% O2 ) for 5 days, or hypoxia (1% O2 ) for 3 or 5 days. As with other turtles, hypoxic incubation maintained embryos in arrest, equivalent to the time spent in hypoxia. However, extending arrest for 5 days resulted in greater early-stage death and a significant decrease in hatching success (4% 5-day hypoxia vs. 72% normoxia). Eggs placed in incubators had greater hatching success than those placed into hatchery nests (67% vs. 47%, respectively). We found no impact of hyperoxia on the stage of embryonic death, hatching success, hatchling phenotype, exercise performance, or early dispersal. Our findings indicate that delayed nesting and the subsequent extension of embryonic arrest may negatively impact embryonic development and therefore the reproductive success of leatherbacks. They also indicate that incubation under hyperoxic conditions is unlikely to be a useful method to improve hatching success in this species.
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Affiliation(s)
- Sean A Williamson
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
| | - Aimee L Hoover
- Upwell, Monterey, California, USA
- Chesapeake Biological Laboratory, University of Maryland Centre for Environmental Science, Solomons, Maryland, USA
| | - Roger G Evans
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria, Australia
- Preclinical Critical Care Unit, Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia
| | | | - Helen Bailey
- Chesapeake Biological Laboratory, University of Maryland Centre for Environmental Science, Solomons, Maryland, USA
| | - Renato Saragoça Bruno
- Turtle Love, Barra de Parismina, Limon, Costa Rica
- Pacuare Reserve, Ecology Project International, Limon, Costa Rica
| | | | - Richard D Reina
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
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3
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Morphologic and physiologic characteristics of green sea turtle (Chelonia mydas) hatchlings in southeastern Florida, USA. J Comp Physiol B 2022; 192:751-764. [DOI: 10.1007/s00360-022-01450-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 07/07/2022] [Accepted: 07/19/2022] [Indexed: 11/27/2022]
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4
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Strategic nest site selection in one of the world's largest loggerhead turtle nesting colonies, on Maio Island, Cabo Verde. ORYX 2022. [DOI: 10.1017/s0030605321001496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Abstract
For species without parental care, such as sea turtles, nest site selection is particularly important for embryo development, hatchling survival and, ultimately, reproductive success. We conducted an 8-year (2012–2019) capture–mark–recapture study of the re-nesting behaviour of loggerhead turtles Caretta caretta to identify both inter- and intra-beach patterns of nest site selection. Our study site, Maio Island in the archipelago of Cabo Verde, hosts one of the largest loggerhead turtle nesting colonies globally. Of 1,060 females analysed, 77% laid repeated clutches within 15 km of their previous nesting sites both between and within nesting seasons. This site fidelity was particularly high (64–71%) for turtles nesting on the east coast of Maio Island. In two areas of the island (north-west and south-east) individual nesting zone consistency was extremely low (10–25%). In all cases extra-zone re-nesting events mainly occurred on the east coast. We also found that females avoided re-nesting near the shoreline, which is particularly relevant in the context of rising sea levels. Overall, loggerhead turtles nesting in Maio Island are philopatric but are using a bet-edging strategy to distribute nests amongst several beaches, choosing the safest area within each beach to maximize their reproductive success. This study highlights the priority sites for protection on Maio Island and could help to optimize capture–mark–recapture programmes. The data reveal the potential for adaptive responses to projected sea level rises.
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5
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Yao YT, Du Y, Pan JX, Lin CX, Ji X, You WH. Incubating green turtle (Chelonia mydas) eggs at constant temperatures: Hatching success, hatchling morphology and post-hatch growth. J Therm Biol 2022; 104:103182. [DOI: 10.1016/j.jtherbio.2021.103182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/18/2021] [Accepted: 12/31/2021] [Indexed: 10/19/2022]
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6
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Robledo-Avila LA, Phillips-Farfán BV, Harfush Meléndez M, Lopez Toledo L, Tafolla Venegas D, Herrera Vargas MA, Ruíz Cortés DV, Meléndez-Herrera E. Short communication: Ex-situ conservation in hatcheries is associated with spleen development in Lepidochelys olivacea turtle hatchlings. Comp Biochem Physiol A Mol Integr Physiol 2021; 265:111130. [PMID: 34954346 DOI: 10.1016/j.cbpa.2021.111130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 12/20/2021] [Accepted: 12/20/2021] [Indexed: 11/25/2022]
Abstract
Ex-situ conservation in hatcheries is a successful strategy for the recovery of sea turtle populations. However, it alters the ontogenesis of the brain and gonads, as well as body size and locomotor performance at nest emergence. Relocation to hatcheries may alter immune system development, since this depends highly on the nest environment. We hypothesized that ex-situ brooding would negatively associate with immune traits of Lepidochelys olivacea. Splenic cytoarchitecture and leukocyte quantification were used as proxies for the immune configuration. Body size, gonadal sex and sand temperature during incubation were determined. Additionally, the success of nest hatching and emergence was quantified. Linear mixed models of splenic cytoarchitecture, leucocyte proportions and body size, using sex and nest type as explanatory variables, evaluated the effects of ex-situ brooding. Generalized linear mixed models using quasibinomial distributions (log link) analyzed effects on hatching and emergence success. Hatchlings from ex-situ nests were heavier, larger and showed a greater spleen-somatic index. They showed more and better defined splenic periarteriolar lymphoid sheaths, as well as a higher proportion of heterophils but less monocytes. Moreover, ex-situ brooding increased hatching and emergence success. Sand temperatures in hatcheries favored male sex determination, while the opposite occurred for in-situ incubation. Interestingly, the immune configuration and body size were independent of sex but associated with ex-situ conservation. Greater body size promotes early hatchling survival, while better spleen development is related to a greater antibody production and a better immune response to pathogens. Altogether, the results suggest that ex-situ incubation is associated with a better immune configuration and higher survival success.
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Affiliation(s)
- Liliana Areli Robledo-Avila
- Instituto de Investigaciones sobre Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Av. San Juanito Itzícuaro s/n, Colonia Nueva Esperanza, C.P. 58337 Morelia, Michoacán, México
| | - Bryan Víctor Phillips-Farfán
- Laboratorio de Nutrición Experimental, Instituto Nacional de Pediatría, Insurgentes Sur 3700, Letra C, Alcaldía Coyoacán C.P. 04530, Cd. de México, México
| | | | - Leonel Lopez Toledo
- Instituto de Investigaciones sobre Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Av. San Juanito Itzícuaro s/n, Colonia Nueva Esperanza, C.P. 58337 Morelia, Michoacán, México
| | - David Tafolla Venegas
- Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo, Avenida Francisco J. Múgica s/n, Ciudad Universitaria, 58030 Morelia, Michoacán, México
| | - Ma Antonia Herrera Vargas
- Instituto de Investigaciones sobre Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Av. San Juanito Itzícuaro s/n, Colonia Nueva Esperanza, C.P. 58337 Morelia, Michoacán, México
| | - Diana Vanessa Ruíz Cortés
- Instituto de Investigaciones sobre Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Av. San Juanito Itzícuaro s/n, Colonia Nueva Esperanza, C.P. 58337 Morelia, Michoacán, México
| | - Esperanza Meléndez-Herrera
- Instituto de Investigaciones sobre Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Av. San Juanito Itzícuaro s/n, Colonia Nueva Esperanza, C.P. 58337 Morelia, Michoacán, México.
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7
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Mendoza P, Cerdan I, Garcia B, Furuta C, Di Santo L, Sanfilippo LF, Bícego KC, Carciofi AC. Influence of incubation temperature on embryo development, hatchling morphology and early growth rate in red-footed tortoise (Chelonoidis carbonaria). Comp Biochem Physiol A Mol Integr Physiol 2021; 259:110999. [PMID: 34098130 DOI: 10.1016/j.cbpa.2021.110999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/02/2021] [Accepted: 05/31/2021] [Indexed: 11/19/2022]
Abstract
Reptile embryos respond to temperature changes with metabolic and physiological adjustments that influence hatchling success, phenotype, behaviour, and growth rate. Climate change and global warming can affect the reptile population by altering the frequencies of hatchling survival and phenotypes. Therefore, previous studies proposed artificial incubation as a potential strategy for mitigating these effects. Red-footed tortoise (Chelonoidis carbonaria) eggs were collected and incubated at constant temperatures of 27.5 °C and 29.5 °C to investigate the physiological effects of temperature on embryo development, hatchling morphology, and early post-hatch growth rate. The direct effect of temperature on the incubation period, egg mass loss, hatching success, hatchling size, and mass was evaluated at hatching and three months of age. Hatchlings from 29.5 °C presented a shorter incubation period (141 days) than those from 27.5 °C (201 days; p < 0.05). Egg mass loss, hatchling mass, and size at hatching were not different between the incubation temperatures (p > 0.05). However, the hatching success (survival rate) was lower (64.5% versus 100%) in eggs incubated at 29.5 °C, but the hatchling mass and straight plastron width were higher at three months of age than those from eggs incubated at 27.5 °C (p < 0.05). These results indicate that incubation temperature influences hatching success and hatchling size and mass in the first months by influencing the early growth rate.
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Affiliation(s)
- Pierina Mendoza
- Department of Animal Science, School of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900 Jaboticabal, São Paulo, Brazil; W.A.R.M.I. Wildlife Animal Research and Management Integration, Lima, Peru.
| | - Isaura Cerdan
- Department of Biology Sciences, School of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900 Jaboticabal, São Paulo, Brazil
| | - Beatriz Garcia
- Department of Biology Sciences, School of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900 Jaboticabal, São Paulo, Brazil
| | - Camila Furuta
- Department of Animal Science, School of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900 Jaboticabal, São Paulo, Brazil
| | - Ludmilla Di Santo
- Department of Clinic and Veterinary Surgery, School of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900 Jaboticabal, São Paulo, Brazil
| | - Luiz F Sanfilippo
- Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 2415 - Butantã, São Paulo, SP, 05508-900, Brazil
| | - Kênia C Bícego
- Department of Animal Morphology and Physiology, School of Agricultural and Veterinary Sciences, São Paulo State University (UNESP), 14884-900, Jaboticabal, São Paulo, Brazil
| | - Aulus C Carciofi
- Department of Clinic and Veterinary Surgery, School of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900 Jaboticabal, São Paulo, Brazil
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8
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Pusapati C, Manoharakrishnan M, Phillott AD, Shanker K. Effect of Hatchery Nest Environment on Olive Ridley (Lepidochelys olivacea) Hatchling Performance. CHELONIAN CONSERVATION AND BIOLOGY 2021. [DOI: 10.2744/ccb-1450.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Chandana Pusapati
- TERI School of Advanced Studies, Plot 10, Institutional Area, Vasant Kunj, New Delhi 110070, India []
| | | | - Andrea D. Phillott
- Dakshin Foundation, 1818, 9th Cross, 5th Main, Sahakar Nagar B block, Bangalore 560092, Karnataka, India []
| | - Kartik Shanker
- Dakshin Foundation, 1818, 9th Cross, 5th Main, Sahakar Nagar B block, Bangalore 560092, Karnataka, India []
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9
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García-Grajales J, Meraz-Hernando J, Arcos García J, Ramírez-Fuentes E. Influence of nest temperature on morphology of Leatherback Turtle (Dermochelys coriacea) hatchlings incubated in hatcheries in Oaxaca, Mexico. CAN J ZOOL 2021. [DOI: 10.1139/cjz-2020-0083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The influence of nest incubation temperatures on carapace shape and morphological traits of Leatherback Turtle (Dermochelys coriacea (Vandelli, 1761)) hatchlings incubated in two hatcheries in Oaxaca, Mexico, was evaluated. This study was carried out from October 2016 through May 2017. On each beach, there are community groups consisting of volunteers not affiliated with universities who protect and relocate the nests to increase hatching success. In each translocated nest, a data logger was placed in the centre of the egg mass. Hatchlings were collected as they emerged from each nest. The carapaces of the hatchlings were photographed and subjected to geometric morphometric analysis; also, hatchlings were weighed and their bodies measured. The mean temperature of 12 nests in each hatchery was recorded, with no significant differences between hatcheries. The principal component analysis revealed an overlapping of the carapace shape under different temperature durations. Temperature had a significant influence on hatchling morphology. Higher mean incubation temperatures produced hatchlings with low mass, smaller appendages, narrower carapace widths, and shorter flipper lengths. Lower mean incubation temperatures produced hatchlings with greater mass, wider appendage widths, wider carapace widths, and longer flipper lengths. Results indicate that the Leatherback hatchlings incubated in hatcheries demonstrate morphology that varies in relation to nest incubation temperature in a similar way to hatchlings produced in natural environments.
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Affiliation(s)
- J. García-Grajales
- Instituto de Recursos, Univesidad del Mar, Km. 2.5, Carretera Federal Puerto Escondido – Sola de Vega, Puerto Escondido 71980, Oaxaca, México
| | - J.F. Meraz-Hernando
- Instituto de Recursos, Univesidad del Mar, Km. 2.5, Carretera Federal Puerto Escondido – Sola de Vega, Puerto Escondido 71980, Oaxaca, México
| | - J.L. Arcos García
- Instituto de Industrias, Univesidad del Mar, Km. 2.5, Carretera Federal Puerto Escondido – Sola de Vega, Puerto Escondido 71980, Oaxaca, México
| | - E. Ramírez-Fuentes
- Instituto de Recursos, Univesidad del Mar, Km. 2.5, Carretera Federal Puerto Escondido – Sola de Vega, Puerto Escondido 71980, Oaxaca, México
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10
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Patrício AR, Hawkes LA, Monsinjon JR, Godley BJ, Fuentes MMPB. Climate change and marine turtles: recent advances and future directions. ENDANGER SPECIES RES 2021. [DOI: 10.3354/esr01110] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Climate change is a threat to marine turtles that is expected to affect all of their life stages. To guide future research, we conducted a review of the most recent literature on this topic, highlighting knowledge gains and research gaps since a similar previous review in 2009. Most research has been focussed on the terrestrial life history phase, where expected impacts will range from habitat loss and decreased reproductive success to feminization of populations, but changes in reproductive periodicity, shifts in latitudinal ranges, and changes in foraging success are all expected in the marine life history phase. Models have been proposed to improve estimates of primary sex ratios, while technological advances promise a better understanding of how climate can influence different life stages and habitats. We suggest a number of research priorities for an improved understanding of how climate change may impact marine turtles, including: improved estimates of primary sex ratios, assessments of the implications of female-biased sex ratios and reduced male production, assessments of the variability in upper thermal limits of clutches, models of beach sediment movement under sea level rise, and assessments of impacts on foraging grounds. Lastly, we suggest that it is not yet possible to recommend manipulating aspects of turtle nesting ecology, as the evidence base with which to understand the results of such interventions is not robust enough, but that strategies for mitigation of stressors should be helpful, providing they consider the synergistic effects of climate change and other anthropogenic-induced threats to marine turtles, and focus on increasing resilience.
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Affiliation(s)
- AR Patrício
- MARE - Marine and Environmental Sciences Centre, ISPA - Instituto Universitário, 1149-041 Lisbon, Portugal
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn TR10 9FE, UK
| | - LA Hawkes
- Hatherley Laboratories, College of Life and Environmental Sciences, University of Exeter, Streatham Campus, Exeter EX4 4PS, UK
| | - JR Monsinjon
- Department of Zoology and Entomology, Rhodes University, Grahamstown 6139, South Africa
| | - BJ Godley
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn TR10 9FE, UK
| | - MMPB Fuentes
- Marine Turtle Research, Ecology and Conservation Group, Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA
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11
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Mazlan NA, Booth DT, Rusli MU. Testing the validity of using raceway and swimway performance in sea turtle hatchlings as an index of real-life crawling and swimming performance. WILDLIFE RESEARCH 2021. [DOI: 10.1071/wr21029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Kobayashi S, Endo D, Kondo S, Kitayama C, Ogawa R, Arai K, Watanabe G, Kawaguchi M. Investigating the effects of nest shading on the green turtle (Chelonia mydas) hatchling phenotype in the Ogasawara islands using a field-based split clutch experiment. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2020; 333:629-636. [PMID: 32894008 DOI: 10.1002/jez.2411] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/22/2020] [Accepted: 08/24/2020] [Indexed: 12/27/2022]
Abstract
The Ogasawara Islands are an important rookery for the green turtle (Chelonia mydas) in the North Pacific. Green turtles possess temperature-dependent sex determination, and warmer incubation temperatures produce more females than males. Therefore, conservation practices such as nest shading may be required for this population to mitigate the effect of global warming on their sex ratio. To consider the application of such conservation practices in the Ogasawara population, it is fundamental to understand how artificially modified nest environments will affect green turtle hatchling phenotypes that influence their fitness. Here, we investigated the effects of nest shading on green turtle hatchling phenotypes in the Ogasawara population by using a split clutch experiment equally separating the clutch, relocating each half-clutch into an outdoor hatchery area either with or without shading, and observing the subsequent hatchling phenotype. Our results showed that the shading treatment produced hatchlings with a better self-righting response and a larger carapace size. Additionally, the shading treatment mostly reduced the production of hatchlings with a nonmodal scute pattern and produced hatchlings with a smaller unabsorbed yolk sac, which may be associated with their residual yolk mass. These results suggest that conservation practices such as shading could alter not only the sex ratio but also the hatchling phenotype that influences their fitness. Hence, our results suggest that applications of such conservation strategies must be carefully considered.
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Affiliation(s)
- Shohei Kobayashi
- Organization for the Strategic Coordination of Research and Intellectual Property, Meiji University, Kanagawa, Japan
| | - Daisuke Endo
- Course of Applied Marine Biosciences, Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Satomi Kondo
- Everlasting Nature of Asia, Ogasawara Marine Center, Tokyo, Japan
| | - Chiyo Kitayama
- Everlasting Nature of Asia, Ogasawara Marine Center, Tokyo, Japan
| | - Ryuta Ogawa
- Everlasting Nature of Asia, Ogasawara Marine Center, Tokyo, Japan
| | - Katsuhiko Arai
- Department of Biological Production Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Gen Watanabe
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Maiko Kawaguchi
- Laboratory of Animal Behavior and Environmental Science, Department of Agriculture, School of Agriculture, Meiji University, Kanagawa, Japan
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Fleming KA, Perrault JR, Stacy NI, Coppenrath CM, Gainsbury AM. Heat, health and hatchlings: associations of in situ nest temperatures with morphological and physiological characteristics of loggerhead sea turtle hatchlings from Florida. CONSERVATION PHYSIOLOGY 2020; 8:coaa046. [PMID: 32523697 PMCID: PMC7269062 DOI: 10.1093/conphys/coaa046] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/05/2020] [Accepted: 05/06/2020] [Indexed: 05/20/2023]
Abstract
Incubation temperatures, in addition to an embryo's genetic makeup, are critical in many aspects of adequate sea turtle embryonic development. The effects of high and low incubation temperatures on hatchling quality have been previously examined; however, many of these studies were conducted on relocated or laboratory-reared nests, which do not accurately reflect natural nest temperature fluctuations. To observe the impacts of varying in situ incubation temperatures on loggerhead sea turtle (Caretta caretta) hatchling morphology, various health variables and locomotor performance, temperature data loggers were deployed in 15 loggerhead nests on Juno Beach, Florida, between May and July 2018. Over the course of the study period, 10 morphological traits were measured, blood analytes and heart rate were assessed for the establishment of reference intervals and the self-righting response in seawater was evaluated. Warmer months were associated with smaller body size and higher body condition index, larger umbilical scar size, slower righting time, lower heart rates and higher packed cell volume, hemoglobin, total solids, total white blood cell count, absolute heterophils and absolute basophils. These findings provide evidence that higher in situ incubation temperatures have the potential to adversely affect hatchlings from warmer nests due to increased risk of predation from smaller body sizes, decreased physical responses and overall fitness, altered hemodynamic balance (e.g. dehydration) and potential inflammation and/or stress. With rising temperatures, we predict sea turtle hatchlings may have increasing risks of developing suboptimal physiological features affecting overall fitness and ultimately survival. These results demonstrate that rising environmental temperatures can negatively impact sea turtle hatchlings, thus representing additional stress on sea turtle populations and contributing to our understanding of potential pathophysiological effects of climate change on the delicate life-stage class of the sea turtle hatchling. This information will be useful for formulating effective future sea turtle management plans.
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Affiliation(s)
- Kelsey A Fleming
- Department of Biological Sciences, University of South Florida St. Petersburg, St. Petersburg, FL 33701, USA
| | | | - Nicole I Stacy
- Aquatic, Amphibian, and Reptile Pathology Program, Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL 32608, USA
| | | | - Alison M Gainsbury
- Department of Biological Sciences, University of South Florida St. Petersburg, St. Petersburg, FL 33701, USA
- Corresponding author: Department of Biological Sciences, University of South Florida St. Petersburg, St. Petersburg, FL 33701, USA.
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14
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Staines MN, Booth DT, Limpus CJ. Microclimatic effects on the incubation success, hatchling morphology and locomotor performance of marine turtles. ACTA OECOLOGICA 2019. [DOI: 10.1016/j.actao.2019.04.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Usategui-Martín A, Liria-Loza A, Miller JD, Medina-Suárez M, Jiménez-Bordón S, Pérez-Mellado V, Montero D. Effects of incubation temperature on hatchling performance and phenotype in loggerhead sea turtle Caretta caretta. ENDANGER SPECIES RES 2019. [DOI: 10.3354/esr00935] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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16
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Incubation and water temperatures influence the performances of loggerhead sea turtle hatchlings during the dispersal phase. Sci Rep 2018; 8:11911. [PMID: 30093615 PMCID: PMC6085310 DOI: 10.1038/s41598-018-30347-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 07/24/2018] [Indexed: 11/13/2022] Open
Abstract
Artificial manipulation of incubation temperature has been proposed as a potential strategy for mitigating the effects of climate change on sea turtles for which sex determination is temperature-dependent, but thermal manipulation may also affect hatchling survival. Here, we demonstrated that incubation and water temperatures influenced several performance traits that contribute to the survival of loggerhead sea turtles (Caretta caretta) during the post-hatchling dispersal phase. Hatchlings from warm incubation temperatures (31 °C) had significantly shorter incubation periods, higher initial swimming performance, lower sustained swimming performance, and lower growth rates during the first three weeks post-hatching, as well as higher blood glucose concentrations, than those from cool incubation temperatures (27.5 °C). Hatchlings in warm water temperatures (30 °C) exhibited significantly greater swimming performance than those in cool water temperatures (27 °C). Our results indicated that altering incubation temperatures indirectly influences the survival of loggerhead hatchlings by modifying their swimming performance and growth rates, which may affect hatchling predator-avoidance capability. Moreover, thermal manipulation may alter the incubation period, exposing hatchling to water temperatures that they would not otherwise normally experience, which may affect swimming performance. Our results suggest that such conservation strategies may influence their survival, and thus should be carefully considered.
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17
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Booth DT. Incubation temperature induced phenotypic plasticity in oviparous reptiles: Where to next? JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2018; 329:343-350. [DOI: 10.1002/jez.2195] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 05/17/2018] [Accepted: 05/18/2018] [Indexed: 11/10/2022]
Affiliation(s)
- David T. Booth
- School of Biological Sciences; The University of Queensland; Queensland Australia
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18
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Patrício AR, Varela MR, Barbosa C, Broderick AC, Ferreira Airaud MB, Godley BJ, Regalla A, Tilley D, Catry P. Nest site selection repeatability of green turtles, Chelonia mydas, and consequences for offspring. Anim Behav 2018. [DOI: 10.1016/j.anbehav.2018.03.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Stewart TA, Booth DT, Rusli MU. Influence of sand grain size and nest microenvironment on incubation success, hatchling morphology and locomotion performance of green turtles (Chelonia mydas) at the Chagar Hutang Turtle Sanctuary, Redang Island, Malaysia. AUST J ZOOL 2018. [DOI: 10.1071/zo19025] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The nest microenvironment affects hatching and emergence success, sex ratios, morphology, and locomotion performance of hatchling sea turtles. Sand grain size is hypothesised to influence the nest microenvironment, but the influence of sand grain size on incubation of sea turtle eggs has rarely been experimentally tested. At the Chagar Hutang Turtle Sanctuary, Redang Island, Malaysia, green turtle (Chelonia mydas) nests were relocated to sands with different sand grain sizes on a natural beach to assess whether grain size affects nest temperature, oxygen partial pressure inside the nest, incubation success, hatchling morphology and hatchling locomotion performance. Green turtle nests in coarse sand were cooler; however, hatching success, nest emergence success, oxygen partial pressure, incubation length and hatchling size were not influenced by sand particle size. Nests in medium-grained sands were warmest, and hatchlings from these nests were better self-righters but poorer crawlers and swimmers. Hatchling self-righting ability was not correlated with crawling speed or swimming speed, but crawling speed was correlated with swimming speed, with hatchlings typically swimming 1.5–2 times faster than they crawled. Hence, we found that sand particle size had minimal influence on the nest microenvironment and hatchling outcomes.
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Affiliation(s)
- David T. BOOTH
- School of Biological Sciences; The University of Queensland; St Lucia Queensland Australia
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21
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Kobayashi S, Morimoto Y, Kondo S, Sato T, Suganuma H, Arai K, Watanabe G. Sex Differences and the Heritability of Scute Pattern Abnormalities in the Green Sea Turtle from the Ogasawara Archipelago, Japan. Zoolog Sci 2017; 34:281-286. [DOI: 10.2108/zs160159] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Shohei Kobayashi
- Department of Biological Production Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | | | - Satomi Kondo
- Everlasting Nature of Asia, Kanagawa 221-0822, Japan
| | - Takayuki Sato
- Everlasting Nature of Asia, Kanagawa 221-0822, Japan
| | | | - Katsuhiko Arai
- Department of Biological Production Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Gen Watanabe
- Laboratory of Veterinary Physiology, Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-0054, Japan
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Marco A, Abella E, Martins S, López O, Patino-Martinez J. Female nesting behaviour affects hatchling survival and sex ratio in the loggerhead sea turtle: implications for conservation programmes. ETHOL ECOL EVOL 2017. [DOI: 10.1080/03949370.2017.1330291] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Adolfo Marco
- Estación Biológica de Doñana, CSIC, C/Américo Vespucio s/n, Sevilla, Spain
| | - Elena Abella
- Estación Biológica de Doñana, CSIC, C/Américo Vespucio s/n, Sevilla, Spain
| | | | - Oscar López
- Universidad de Las Palmas de Gran Canaria, C/Juan de Quesada 30, 35001 Las Palmas, Spain
- Cabo Verde Natura 2000, Rua Primero de Maio 1, Sal Rei, Cabo Verde
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23
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Sim EL, Booth DT, Limpus CJ. Incubation temperature, morphology and performance in loggerhead (Caretta caretta) turtle hatchlings from Mon Repos, Queensland, Australia. Biol Open 2015; 4:685-92. [PMID: 26002933 PMCID: PMC4467188 DOI: 10.1242/bio.20148995] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Marine turtles are vulnerable to climate change because their life history and reproduction are tied to environmental temperatures. The egg incubation stage is arguably the most vulnerable stage, because marine turtle eggs require a narrow range of temperatures for successful incubation. Additionally, incubation temperature affects sex, emergence success, morphology and locomotor performance of hatchlings. Hatchlings often experience high rates of predation in the first few hours of their life, and increased size or locomotor ability may improve their chances of survival. Between 2010 and 2013 we monitored the temperature of loggerhead (Caretta caretta; Linnaeus 1758) turtle nests at Mon Repos Rookery, and used these data to calculate a mean three day maximum temperature (T3dm) for each nest. We calculated the hatching and emergence success for each nest, then measured the mass, size and locomotor performance of hatchlings that emerged from those nests. Nests with a T3dm greater than 34°C experienced a lower emergence success and produced smaller hatchlings than nests with a T3dm lower than 34°C. Hatchlings from nests with a T3dm below 34°C performed better in crawling and swimming trials than hatchlings from nests with a T3dm above 34°C. Thus even non-lethal increases in global temperatures have the potential to detrimentally affect fitness and survival of marine turtle hatchlings.
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Affiliation(s)
- Elizabeth L Sim
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - David T Booth
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Colin J Limpus
- Department of Environment and Heritage Protection, PO Box 2454, Brisbane, QLD 4001, Australia
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24
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Fisher LR, Godfrey MH, Owens DW. Incubation temperature effects on hatchling performance in the loggerhead sea turtle (Caretta caretta). PLoS One 2014; 9:e114880. [PMID: 25517114 PMCID: PMC4269397 DOI: 10.1371/journal.pone.0114880] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 11/10/2014] [Indexed: 11/26/2022] Open
Abstract
Incubation temperature has significant developmental effects on oviparous animals, including affecting sexual differentiation for several species. Incubation temperature also affects traits that can influence survival, a theory that is verified in this study for the Northwest Atlantic loggerhead sea turtle (Caretta caretta). We conducted controlled laboratory incubations and experiments to test for an effect of incubation temperature on performance of loggerhead hatchlings. Sixty-eight hatchlings were tested in 2011, and 31 in 2012, produced from eggs incubated at 11 different constant temperatures ranging from 27°C to 33°C. Following their emergence from the eggs, we tested righting response, crawling speed, and conducted a 24-hour long swim test. The results support previous studies on sea turtle hatchlings, with an effect of incubation temperature seen on survivorship, righting response time, crawling speed, change in crawl speed, and overall swim activity, and with hatchlings incubated at 27°C showing decreased locomotor abilities. No hatchlings survived to be tested in both years when incubated at 32°C and above. Differences in survivorship of hatchlings incubated at high temperatures are important in light of projected higher sand temperatures due to climate change, and could indicate increased mortality from incubation temperature effects.
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Affiliation(s)
- Leah R. Fisher
- University of Charleston South Carolina at the College of Charleston, Charleston, South Carolina, United States of America
- * E-mail:
| | - Matthew H. Godfrey
- North Carolina Wildlife Resources Commission, Beaufort, North Carolina, United States of America
- Duke University Marine Lab, Nicholas School of the Environment, Beaufort, North Carolina, United States of America
| | - David W. Owens
- University of Charleston South Carolina at the College of Charleston, Charleston, South Carolina, United States of America
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Rings CC, Rafferty AR, Guinea ML, Reina RD. The impact of extended preovipositional arrest on embryonic development and hatchling fitness in the flatback sea turtle. Physiol Biochem Zool 2014; 88:116-27. [PMID: 25730267 DOI: 10.1086/677951] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Turtle embryos pause development before oviposition in a process known as preovipositional arrest. Embryonic development arrests due to hypoxia (low oxygen) in the maternal oviducts and resumes only after exposure to normoxia when eggs are laid. Recently, several studies have hypothesized that the prolonged periods of preovipositional arrest may have a detrimental effect on embryo survival and development after eggs are laid. We tested this hypothesis by comparing embryo survival (determined by white spot formation and hatching success) and hatchling fitness (measured by self-righting, crawling, and swimming ability) of flatback sea turtle (Natator depressus) eggs following incubation in hypoxic (∼ 1%) and normoxic (∼ 21%) treatments for 5 d immediately following oviposition. We also measured embryo survival and hatchling fitness when eggs were incubated in hyperoxic conditions (42% oxygen), to determine whether hyperoxia could improve developmental outcome or whether some consequence of oxidative stress might manifest. Eggs incubated in hypoxia remained arrested during the 5-d treatment, and 97.5% of the eggs successfully recommenced development after exposure to normoxia when the treatment finished. At treatment commencement, 100% and 97.5% of eggs in the hyperoxic and normoxic treatments, respectively, began developing. Although hatching success was significantly lower following hypoxia (15%) compared to normoxia (80%) and hyperoxia (85%), hatchings from the hypoxic treatment were larger (carapace length and width and plastron length) than normoxic hatchlings. Similarly, hypoxic hatchings also swam significantly faster than hyperoxic hatchlings. Considering larger hatchlings may have a greater chance of survival, the production of larger hatchings may offset the high cost (lower hatching success) when preovipositional arrest is prolonged. Hyperoxia does not appear to have deleterious consequences for development.
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Affiliation(s)
- Chloe C Rings
- School of Biological Sciences, Monash University, Melbourne, Australia; 2Research Institute for the Environment and Livelihoods, Faculty of Education, Health and Science, Charles Darwin University, Darwin, Australia
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26
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Burger J, Gochfeld M. Factors Affecting Locomotion in Olive Ridley (Lepidochelys olivacea) Hatchlings Crawling to the Sea at Ostional Beach, Costa Rica. CHELONIAN CONSERVATION AND BIOLOGY 2014. [DOI: 10.2744/ccb-1088.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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27
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Howard R, Bell I, Pike DA. Thermal tolerances of sea turtle embryos: current understanding and future directions. ENDANGER SPECIES RES 2014. [DOI: 10.3354/esr00636] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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28
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Horne CR, Fuller WJ, Godley BJ, Rhodes KA, Snape R, Stokes KL, Broderick AC. The effect of thermal variance on the phenotype of marine turtle offspring. Physiol Biochem Zool 2014; 87:796-804. [PMID: 25461644 DOI: 10.1086/678238] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Temperature can have a profound effect on the phenotype of reptilian offspring, yet the bulk of current research considers the effects of constant incubation temperatures on offspring morphology, with few studies examining the natural thermal variance that occurs in the wild. Over two consecutive nesting seasons, we placed temperature data loggers in 57 naturally incubating clutches of loggerhead sea turtles Caretta caretta and found that greater diel thermal variance during incubation significantly reduced offspring mass, potentially reducing survival of hatchlings during their journey from the nest to offshore waters and beyond. With predicted scenarios of climate change, behavioral plasticity in nest site selection may be key for the survival of ectothermic species, particularly those with temperature-dependent sex determination.
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Affiliation(s)
- C R Horne
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Cornwall TR10 9FE, United Kingdom; 2Faculty of Veterinary Medicine, Near East University, Nicosia, North Cyprus, Mersin 10, Turkey; 3North Cyprus Society for Protection of Turtles, PK65, Kyrenia, North Cyprus, Mersin 10, Turkey
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