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Graziano M, Solberg MF, Glover KA, Vasudeva R, Dyrhovden L, Murray D, Immler S, Gage MJG. Pre-fertilization gamete thermal environment influences reproductive success, unmasking opposing sex-specific responses in Atlantic salmon ( Salmo salar). ROYAL SOCIETY OPEN SCIENCE 2023; 10:231427. [PMID: 38094267 PMCID: PMC10716643 DOI: 10.1098/rsos.231427] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 11/16/2023] [Indexed: 01/11/2024]
Abstract
The environment gametes perform in just before fertilization is increasingly recognized to affect offspring fitness, yet the contributions of male and female gametes and their adaptive significance remain largely unexplored. Here, we investigated gametic thermal plasticity and its effects on hatching success and embryo performance in Atlantic salmon (Salmo salar). Eggs and sperm were incubated overnight at 2°C or 8°C, temperatures within the optimal thermal range of this species. Crosses between warm- and cold-incubated gametes were compared using a full-factorial design, with half of each clutch reared in cold temperatures and the other in warm temperatures. This allowed disentangling single-sex interaction effects when pre-fertilization temperature of gametes mismatched embryonic conditions. Pre-fertilization temperature influenced hatch timing and synchrony, and matching sperm and embryo temperatures resulted in earlier hatching. Warm incubation benefited eggs but harmed sperm, reducing the hatching success and, overall, gametic thermal plasticity did not enhance offspring fitness, indicating vulnerability to thermal changes. We highlight the sensitivity of male gametes to higher temperatures, and that gamete acclimation may not effectively buffer against deleterious effects of thermal fluctuations. From an applied angle, we propose the differential storage of male and female gametes as a tool to enhance sustainability within the hatcheries.
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Affiliation(s)
- Marco Graziano
- Centre for Ecology, Evolution, and Conservation, School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
| | - Monica F. Solberg
- Population Genetics Group, Institute of Marine Research, 5817 Bergen, Norway
| | - Kevin A. Glover
- Population Genetics Group, Institute of Marine Research, 5817 Bergen, Norway
| | - Ramakrishnan Vasudeva
- Centre for Ecology, Evolution, and Conservation, School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
- Faculty of Biological Sciences, School of Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Lise Dyrhovden
- Population Genetics Group, Institute of Marine Research, 5817 Bergen, Norway
| | - David Murray
- Centre for Ecology, Evolution, and Conservation, School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Lowestoft NR33 0HT, UK
| | - Simone Immler
- Centre for Ecology, Evolution, and Conservation, School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
| | - Matthew J. G. Gage
- Centre for Ecology, Evolution, and Conservation, School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
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Schofield G, Dickson LCD, Westover L, Dujon AM, Katselidis KA. COVID-19 disruption reveals mass-tourism pressure on nearshore sea turtle distributions and access to optimal breeding habitat. Evol Appl 2021; 14:2516-2526. [PMID: 34548882 PMCID: PMC8444759 DOI: 10.1111/eva.13277] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 11/30/2022] Open
Abstract
Quantifying the extent to which animals detect and respond to human presence allows us to identify pressure (disturbance) and inform conservation management objectively; however, obtaining baselines against which to compare human impact is hindered in areas where human activities are already well established. For example, Zakynthos Island (Greece, Mediterranean) receives around 850,000 visitors each summer, while supporting an important loggerhead sea turtle rookery (~300 individuals/season). The coronavirus (COVID-19)-driven absence of tourism in May-June 2020 provided an opportunity to evaluate the distribution dynamics of this population in the absence (2020) vs. presence (2018 and 2019) of visitors using programmed unmanned aerial system (UAS) surveys. Ambient sea temperature transitioned from suboptimal for breeding in May to optimal in late June, with turtle distribution appearing to shift from shallow (to benefit from waters 3-5°C above ambient) to deeper waters in 2018 and 2019, but not 2020. The 2020 data set demonstrated that increased tourism pressure, not temperature, drives turtles offshore. Specifically, >50% of turtles remained within 100 m of shore at densities of 25-50 visitors/km, even when sea temperature rose, with 2018 and 2019 data supporting this trend. Reduced access to warmer, nearshore waters by tourism could delay the onset of nesting and increase the length of the egg maturation period between nesting events (internesting interval) at this site. A coastal refuge zone could be delimited in May-June where touristic infrastructure is minimal, but also where turtles frequently aggregate. In conclusion, sea turtles appear capable of perceiving changes in the level of human pressure at fine spatial and temporal scales and adjusting their distribution accordingly.
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Affiliation(s)
- Gail Schofield
- School of Biological and Chemical Sciences Queen Mary University of London London UK
| | - Liam C D Dickson
- School of Biological and Chemical Sciences Queen Mary University of London London UK
| | - Lucy Westover
- School of Biological Sciences University of Bristol Bristol UK
| | - Antoine M Dujon
- Centre for Integrative Ecology School of Life and Environmental Sciences Deakin University Geelong Vic. Australia
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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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Stubbs JL, Marn N, Vanderklift MA, Fossette S, Mitchell NJ. Simulated growth and reproduction of green turtles (Chelonia mydas) under climate change and marine heatwave scenarios. Ecol Modell 2020. [DOI: 10.1016/j.ecolmodel.2020.109185] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Thompson DM, Fillmore R, Fillmore BM, Graves KG, Ligon DB. Reproductive Investment Patterns in a Captive Population of Alligator Snapping Turtles (Macrochelys temminckii
). HERPETOLOGICA 2019. [DOI: 10.1655/herpetologica-d-19-00007.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Denise M. Thompson
- Department of Biology, Missouri State University, Springfield, MO 65897, USA
| | - Rebecca Fillmore
- Durant Hatchery, Oklahoma Department of Wildlife Conservation, Caddo, OK 74729, USA
| | - Brian M. Fillmore
- US Fish and Wildlife Service, Tishomingo National Fish Hatchery, Tishomingo, OK 73460, USA
| | - Kerry G. Graves
- US Fish and Wildlife Service, Tishomingo National Fish Hatchery, Tishomingo, OK 73460, USA
| | - Day B. Ligon
- Department of Biology, Missouri State University, Springfield, MO 65897, USA
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Clyde-Brockway C, Robinson NJ, Blanco GS, Morreale SJ, Spotila JR, Tomillo PS, Paladino FV. Local Variation in the Internesting Behavior of Green Turtles in the Gulf of Papagayo, Costa Rica. CHELONIAN CONSERVATION AND BIOLOGY 2019. [DOI: 10.2744/ccb-1352.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Chelsea Clyde-Brockway
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907 USA []
| | | | - Gabriela S. Blanco
- Instituto de Biología de Organismos Marinos, CCT CONICET-CENPAT, Puerto Madryn, Argentina []
| | - Stephen J. Morreale
- Department of Natural Resources, Cornell University, Ithaca, New York 14853 USA []
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Price ER, Sotherland PR, Wallace BP, Spotila JR, Dzialowski EM. Physiological determinants of the internesting interval in sea turtles: a novel 'water-limitation' hypothesis. Biol Lett 2019; 15:20190248. [PMID: 31164061 DOI: 10.1098/rsbl.2019.0248] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The internesting interval separates successive clutches of sea turtle eggs, and its duration varies both among and within species. Here, we review the potential physiological limits to this interval, and develop the hypothesis that desalination capacity limits the internesting interval owing to the requirement for water deposition in eggs. Sea turtles deposit 1-4 kg of water per clutch in egg albumen; for most species, this represents about 2% of adult body mass. We calculate how quickly turtles can recover this water by estimating maximal salt excretion rates, metabolic water production and urinary losses. From this water balance perspective, the 'water-limitation' hypothesis is plausible for green turtles but not for leatherbacks. Some plasma biochemistry studies indicate dehydration in sea turtles during the nesting season, although this is not a universal finding and these data have rarely been collected during the internesting interval itself. There is mixed support for a trade-off between clutch size and the length of the interval. We conclude that the 'water-limitation' hypothesis is plausible for most sea turtle species, but requires direct experimentation.
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Affiliation(s)
- Edwin R Price
- 1 Department of Biological Sciences, University of North Texas , Denton, TX 76203 , USA
| | - Paul R Sotherland
- 2 Department of Biology, Kalamazoo College , Kalamazoo, MI 49007 , USA
| | - Bryan P Wallace
- 3 Ecolibrium, Inc. , Boulder, CO 80303 , USA.,4 Nicholas School of the Environment, Duke University Marine Lab , Beaufort, NC 28516 , USA
| | - James R Spotila
- 5 Department of Biodiversity, Earth and Environmental Science, Drexel University , Philadelphia, PA 19104 , USA
| | - Edward M Dzialowski
- 1 Department of Biological Sciences, University of North Texas , Denton, TX 76203 , USA
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Do Local Environmental Factors and Lunar Cycle Influence Timing and Synchrony of Oviposition of a Turtle with Strict Nocturnal Nesting? DIVERSITY 2019. [DOI: 10.3390/d11050078] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Timing of nesting affects fitness of oviparous animals living in seasonal environments, and females may cue on environmental factors for their nesting behavior, but these relationships are understudied in tropical turtles. Here, the timing and synchrony of egg-laying relative to environmental factors were examined in the South American freshwater turtle Podocnemis unifilis on 11 nesting beaches during three nesting seasons. Daily measurements included number of nests laid, rainfall, river level, air temperature, and the phase of the lunar cycle (full moon, last quarter, new moon and first quarter). Results confirmed that P. unifilis nested at night and revealed that females in our population nest in groups from 2 to 17 females at a time. Nesting was not correlated with rainfall, but a significant relationship was found with river level, such that nesting started at the onset of the dry season when river levels dropped and nesting grounds emerged. Importantly, we found that (1) nesting events concentrated on days with intermediate daily maximum air temperature (although maxima changed annually), and that (2) larger groups of females nested around full moon, suggesting the reliance on visual cues to initiate nesting activities (consistent with social facilitation behavior). Altogether, the timing of nesting in P. unifilis may be shaped by a combination of environmental factors, moon phase and social facilitation, where visual cues play an important role.
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Averill-Murray RC, Christopher TE, Henen BT. Reproductive Ecology and Life History of Female Sonoran Desert Tortoises (Gopherus morafkai). HERPETOLOGICAL MONOGRAPHS 2018. [DOI: 10.1655/herpmonographs-d-18-00003.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Roy C. Averill-Murray
- Nongame Branch, Arizona Game and Fish Department, 5000 West Carefree Highway, Phoenix, AZ 85086, USA
| | - Terry E. Christopher
- Smithsonian Institution, Department of Zoological Research, National Zoological Park, 3001 Connecticut Avenue, Washington, DC 20008, USA
| | - Brian T. Henen
- Smithsonian Institution, Department of Zoological Research, National Zoological Park, 3001 Connecticut Avenue, Washington, DC 20008, USA
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Widespread reproductive variation in North American turtles: temperature, egg size and optimality. ZOOLOGY 2012; 115:160-9. [PMID: 22541670 DOI: 10.1016/j.zool.2011.10.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 08/03/2011] [Accepted: 10/19/2011] [Indexed: 11/20/2022]
Abstract
Theory predicts the existence of an optimal offspring size that balances the trade-off between offspring fitness and offspring number. However, in wild populations of many species, egg size can still vary from year to year for unknown reasons. Here, we hypothesize that among-year variation in population mean egg size of freshwater turtles is partly a consequence of their gonadal sensitivity to seasonal temperatures, a physiological mechanism which principally functions to synchronize reproduction with a favorable time of year. As part of this process, among-year variation in seasonal temperatures modifies the extent of egg follicle development, and this may translate into variation in mean egg size among years (both at the individual and population level). To test this hypothesis, we applied an information-theoretic approach to model relationships between mean egg mass and the temperatures experienced during discrete periods of follicular development in wild populations of three turtle species (Chrysemys picta, Chelydra serpentina, Glyptemys insculpta) over 12 consecutive years. Because follicular development occurs in the fall for C. serpentina and G. insculpta, whereas it occurs both in the fall and spring for C. picta, we expected only fall temperatures would explain egg size variation in C. serpentina and G. insculpta, whereas both fall and spring temperatures would correlate with egg size variation in C. picta. These predictions were upheld. We then compared among-year variation in within-female egg and clutch sizes of each species in order to evaluate whether such variation might still be consistent with some tenets of optimal egg size theory. In all three species, we found that clutch sizes vary more than egg sizes in spite of temperature-induced egg size variation, and this pattern of relatively high clutch-size variation matches theoretical predictions. Future work should explore the roles of direct and indirect (i.e., nutritional) influences of temperature on egg size in natural settings.
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Katselidis KA, Schofield G, Stamou G, Dimopoulos P, Pantis JD. Females first? Past, present and future variability in offspring sex ratio at a temperate sea turtle breeding area. Anim Conserv 2012. [DOI: 10.1111/j.1469-1795.2012.00543.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - G. Schofield
- Department of Biosciences; Swansea University; Swansea; UK
| | - G. Stamou
- School of Biology; Aristotle University of Thessaloniki; Thessaloniki; Greece
| | - P. Dimopoulos
- Department of Environmental & Natural Resources Management; University of Ioannina; Agrinio; Greece
| | - J. D. Pantis
- School of Biology; Aristotle University of Thessaloniki; Thessaloniki; Greece
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12
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Fossette S, Schofield G, Lilley MKS, Gleiss AC, Hays GC. Acceleration data reveal the energy management strategy of a marine ectotherm during reproduction. Funct Ecol 2012. [DOI: 10.1111/j.1365-2435.2011.01960.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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