Pub Date : 2023-04-25DOI: 10.1163/15685381-bja10135
Vukašin Bjelica, M. Milićević, Ana Lazić, Katarina Ðoković, A. Golubović
Defensive tail displays are common in squamates; however, the factors underlying the occurrence of such displays are rarely studied. We tested 268 adult dice snakes (Natrix tessellata) in a population with three colour morphs, exploring the effects of morph, sex, body size, tail length and temperature on the occurrence of tail waving in two stages of the antipredator response. When captured, the blotched morph tail waved the most, followed by melanistic then green morphs. Males displayed tail waving during post-capture immobility more often than females, possibly due to sexual dimorphism in tail length and/or fleeing speed. The occurrence of tail waving was low in response to a researcher as a “predator” (∼2.6% on capture; ∼6.8% during immobility), however the occurrence of this behaviour during encounters with real predators might be different. Large sample size is crucial for revealing fine scale effects on rare behaviours such as tail waving.
{"title":"Defensive tail displays in dice snakes (Natrix tessellata) are influenced by colour morph and sex","authors":"Vukašin Bjelica, M. Milićević, Ana Lazić, Katarina Ðoković, A. Golubović","doi":"10.1163/15685381-bja10135","DOIUrl":"https://doi.org/10.1163/15685381-bja10135","url":null,"abstract":"\u0000Defensive tail displays are common in squamates; however, the factors underlying the occurrence of such displays are rarely studied. We tested 268 adult dice snakes (Natrix tessellata) in a population with three colour morphs, exploring the effects of morph, sex, body size, tail length and temperature on the occurrence of tail waving in two stages of the antipredator response. When captured, the blotched morph tail waved the most, followed by melanistic then green morphs. Males displayed tail waving during post-capture immobility more often than females, possibly due to sexual dimorphism in tail length and/or fleeing speed. The occurrence of tail waving was low in response to a researcher as a “predator” (∼2.6% on capture; ∼6.8% during immobility), however the occurrence of this behaviour during encounters with real predators might be different. Large sample size is crucial for revealing fine scale effects on rare behaviours such as tail waving.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44902866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-24DOI: 10.1163/15685381-bja10137
P. McGovern, L. Luiselli
Defining priorities is important both in research and in conservation, especially when knowledge gaps are hindering successful management. In this review, we quantify the knowledge gaps for all non-marine West African chelonians based on 21 criteria. Additionally, we combine these knowledge gaps with each species’ maximum size, range size, presence in nationally protected areas, and IUCN Red List or TFTSG provisional status to introduce a ranking of species conservation priority in the region. Our analyses revealed a divergence between which species are lacking research studies and which would benefit most from conservation actions, though Cyclanorbis elegans is the species that is both the least-known and most-in-need of conservation. Broadly, Pelomedusidae are in the greatest need of research, yet they are also collectively the least threatened. Conversely, Trionychidae and Testudinidae have received greater research attention in most cases, however, these two families represent the greatest conservation priorities amongst West African chelonians. Our analyses also enabled us to evaluate which criteria representing aspects of chelonian biology have been most overlooked by the scientific community. Priorities for future research include reproductive and long-term population studies, each of which are critical for informing conservation actions and evaluating the results of those actions.
{"title":"Knowledge gaps and conservation priorities for west African chelonians","authors":"P. McGovern, L. Luiselli","doi":"10.1163/15685381-bja10137","DOIUrl":"https://doi.org/10.1163/15685381-bja10137","url":null,"abstract":"\u0000Defining priorities is important both in research and in conservation, especially when knowledge gaps are hindering successful management. In this review, we quantify the knowledge gaps for all non-marine West African chelonians based on 21 criteria. Additionally, we combine these knowledge gaps with each species’ maximum size, range size, presence in nationally protected areas, and IUCN Red List or TFTSG provisional status to introduce a ranking of species conservation priority in the region. Our analyses revealed a divergence between which species are lacking research studies and which would benefit most from conservation actions, though Cyclanorbis elegans is the species that is both the least-known and most-in-need of conservation. Broadly, Pelomedusidae are in the greatest need of research, yet they are also collectively the least threatened. Conversely, Trionychidae and Testudinidae have received greater research attention in most cases, however, these two families represent the greatest conservation priorities amongst West African chelonians. Our analyses also enabled us to evaluate which criteria representing aspects of chelonian biology have been most overlooked by the scientific community. Priorities for future research include reproductive and long-term population studies, each of which are critical for informing conservation actions and evaluating the results of those actions.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48692714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-18DOI: 10.1163/15685381-bja10134
Marina Garrido-Priego, David Aaragonés, H. C. Liedtke, A. Whitworth, I. Gomez‐Mestre
Habitat encroachment can have devastating effects upon biodiversity, especially amphibians. Phyllobates vittatus is an endemic frog from Costa Rica, where land cover has seen significant changes over recent decades. Here we use remote sensing to create a land cover map of the region and carry out ecological niche modelling to identify the main abiotic factors associated to the distribution of this species. We have informed our models based on our own field observations, those from other researchers, and citizen science participants to obtain a comprehensive database of P. vittatus occurrences. Elevation, forest percentage, distance to lakes and rivers, annual temperature range and precipitation variables were found to shape the ecological niche of P. vittatus, which is mostly located within protected areas. Prior knowledge of the habitat of the species was key to interpret the model output. We identify populations that might be isolated, and areas where presence has not yet been verified or that have not been occupied by the species, thus, identifying potential areas for reintroductions. We also calculated the area of occupancy and recommend that P. vittatus’ status be adjusted to “Endangered”. Future surveys and evaluation of population health and connectivity would help to better ensure the protection of the species in the long-term.
{"title":"Remote sensing and citizen science to characterize the ecological niche of an endemic and endangered Costa Rican poison frog","authors":"Marina Garrido-Priego, David Aaragonés, H. C. Liedtke, A. Whitworth, I. Gomez‐Mestre","doi":"10.1163/15685381-bja10134","DOIUrl":"https://doi.org/10.1163/15685381-bja10134","url":null,"abstract":"\u0000Habitat encroachment can have devastating effects upon biodiversity, especially amphibians. Phyllobates vittatus is an endemic frog from Costa Rica, where land cover has seen significant changes over recent decades. Here we use remote sensing to create a land cover map of the region and carry out ecological niche modelling to identify the main abiotic factors associated to the distribution of this species. We have informed our models based on our own field observations, those from other researchers, and citizen science participants to obtain a comprehensive database of P. vittatus occurrences. Elevation, forest percentage, distance to lakes and rivers, annual temperature range and precipitation variables were found to shape the ecological niche of P. vittatus, which is mostly located within protected areas. Prior knowledge of the habitat of the species was key to interpret the model output. We identify populations that might be isolated, and areas where presence has not yet been verified or that have not been occupied by the species, thus, identifying potential areas for reintroductions. We also calculated the area of occupancy and recommend that P. vittatus’ status be adjusted to “Endangered”. Future surveys and evaluation of population health and connectivity would help to better ensure the protection of the species in the long-term.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42110701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-03DOI: 10.1163/15685381-bja10133
A. Martínez-Silvestre, Fernando Loras-Ortí, Alejandro Garcia-Salmeron, E. Pujol-Buxó, Iago Pérez-Novo, Joan Maluquer-Margalef, Santiago Poch, Barbora Thumsová, Jaime Bosch
In 2020 and 2021 we detected in Catalonia (NE Spain) six new episodes of mortality or presence of dying specimens in introduced Mediterranean painted frogs (Discoglossus pictus). All affected individuals were positive to the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd). Histological examinations showed intense involvement of the superficial layers of the epidermis and qPCR analyses yielded infection loads greater than 100 000 genomic equivalents of zoospores. These results suggest that this introduced species could behave as a Bd ‘supershedder’, and recommend to control its expansion due to its important role in the dynamic of chytridiomycosis.
{"title":"Introduced Mediterranean painted frogs (Discoglossus pictus) are possible supershedders of the fungus Batrachochytrium dendrobatidis in Catalonia (NE Spain)","authors":"A. Martínez-Silvestre, Fernando Loras-Ortí, Alejandro Garcia-Salmeron, E. Pujol-Buxó, Iago Pérez-Novo, Joan Maluquer-Margalef, Santiago Poch, Barbora Thumsová, Jaime Bosch","doi":"10.1163/15685381-bja10133","DOIUrl":"https://doi.org/10.1163/15685381-bja10133","url":null,"abstract":"\u0000In 2020 and 2021 we detected in Catalonia (NE Spain) six new episodes of mortality or presence of dying specimens in introduced Mediterranean painted frogs (Discoglossus pictus). All affected individuals were positive to the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd). Histological examinations showed intense involvement of the superficial layers of the epidermis and qPCR analyses yielded infection loads greater than 100 000 genomic equivalents of zoospores. These results suggest that this introduced species could behave as a Bd ‘supershedder’, and recommend to control its expansion due to its important role in the dynamic of chytridiomycosis.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42315467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-31DOI: 10.1163/15685381-bja10132
Marta Canós-Burguete, Mizar Torrijo-Salesa, F. S. Tortosa, J. Guerrero-Casado
The lack of refuge has been suggested as one of the main factors affecting reptiles in intensive crops, but this theory has not been explored to any great extent. The aim of this work is to compare the reptile abundance and species richness between traditional and intensive vineyards and olive groves, and to test the acceptance of artificial shelter due to its scarcity in the new intensive woody crop. A total of 288 transects were carried out (144 in olive groves and 144 in vineyards) in six different types of plots: traditional olive groves, traditional vineyards, intensive olive groves with and without artificial refuge, and trellis vineyards with and without artificial refuge. The results showed a greater species richness and abundance of reptiles in the traditional plots than in the intensive plots (independently of the experimental refuges added). An important number of animals were observed using the artificial refuges in olive groves. Furthermore, most of the individuals were located on or escaped to old trees in traditional systems, including an important proportion of reptiles hidden in olive trunk cavities, whereas more individuals were observed on the ground in intensive systems. Our finding suggests the importance for reptile communities of the traditional agricultural systems due to the high availability of the refuge provided by old olive tree trunks and free-standing gobelet vineyards. Our results show that providing refuge may mitigate the negative effects of woody crops intensification on reptile communities.
{"title":"Lack of refuge as a bottleneck for reptiles in intensive woody crops","authors":"Marta Canós-Burguete, Mizar Torrijo-Salesa, F. S. Tortosa, J. Guerrero-Casado","doi":"10.1163/15685381-bja10132","DOIUrl":"https://doi.org/10.1163/15685381-bja10132","url":null,"abstract":"The lack of refuge has been suggested as one of the main factors affecting reptiles in intensive crops, but this theory has not been explored to any great extent. The aim of this work is to compare the reptile abundance and species richness between traditional and intensive vineyards and olive groves, and to test the acceptance of artificial shelter due to its scarcity in the new intensive woody crop. A total of 288 transects were carried out (144 in olive groves and 144 in vineyards) in six different types of plots: traditional olive groves, traditional vineyards, intensive olive groves with and without artificial refuge, and trellis vineyards with and without artificial refuge. The results showed a greater species richness and abundance of reptiles in the traditional plots than in the intensive plots (independently of the experimental refuges added). An important number of animals were observed using the artificial refuges in olive groves. Furthermore, most of the individuals were located on or escaped to old trees in traditional systems, including an important proportion of reptiles hidden in olive trunk cavities, whereas more individuals were observed on the ground in intensive systems. Our finding suggests the importance for reptile communities of the traditional agricultural systems due to the high availability of the refuge provided by old olive tree trunks and free-standing gobelet vineyards. Our results show that providing refuge may mitigate the negative effects of woody crops intensification on reptile communities.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42211104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-29DOI: 10.1163/15685381-bja10131
Thomas Dadda, Federico Storniolo, M. Mangiacotti, S. Scali, M. Zuffi, R. Sacchi
Melanin-based dorsal pattern polymorphisms are common in reptiles and generally evolve under the interaction between opposite selective pressures, notably thermal advantage in cold environments and background matching to avoid predation. When those pressures change over space and time, the relative frequencies of morphs can vary across the species range. However, no previous study has analysed the spatial patterns of variation of morphs under a phylogenetic perspective in addition to the adaptive responses to natural selection. In this study, we focused on the distributional patterns of the three dorsal morphs of Podarcis muralis at wide-range scale to assess how they associate with geography, climate, microhabitat, phylogeny and sexual dimorphism. By using open access data from iNaturalist, we assembled a dataset of 4096 georeferenced points with information on sex and morph. Data were analysed through Bayesian GLMs, and four alternative models were formulated depending on the specific factors affecting morphs’ frequency. The dorsal morphs are not randomly distributed in Europe, but follow clear geographic patterns, vary with altitude and habitats, show sex-specific trends, and correlate with the phylogenetic history of the species. When comparing models, the phylogenetic model always obtained the best performance, and no overlap with other models occurred, thus best explaining the distributional patterns of dorsal morphs. The evolutionary processes, in addition to present environmental pressures, can significantly affect local-scale microevolutionary adaptations, influencing the current distribution of dorsal phenotypes across the species range. More generally, results point out the importance of considering the evolutionary processes when analysing distributional patterns of polymorphisms.
{"title":"Evolutionary history drives the geographical distribution of dorsal patterns in the common wall lizard (Podarcis muralis)","authors":"Thomas Dadda, Federico Storniolo, M. Mangiacotti, S. Scali, M. Zuffi, R. Sacchi","doi":"10.1163/15685381-bja10131","DOIUrl":"https://doi.org/10.1163/15685381-bja10131","url":null,"abstract":"\u0000Melanin-based dorsal pattern polymorphisms are common in reptiles and generally evolve under the interaction between opposite selective pressures, notably thermal advantage in cold environments and background matching to avoid predation. When those pressures change over space and time, the relative frequencies of morphs can vary across the species range. However, no previous study has analysed the spatial patterns of variation of morphs under a phylogenetic perspective in addition to the adaptive responses to natural selection. In this study, we focused on the distributional patterns of the three dorsal morphs of Podarcis muralis at wide-range scale to assess how they associate with geography, climate, microhabitat, phylogeny and sexual dimorphism. By using open access data from iNaturalist, we assembled a dataset of 4096 georeferenced points with information on sex and morph. Data were analysed through Bayesian GLMs, and four alternative models were formulated depending on the specific factors affecting morphs’ frequency. The dorsal morphs are not randomly distributed in Europe, but follow clear geographic patterns, vary with altitude and habitats, show sex-specific trends, and correlate with the phylogenetic history of the species. When comparing models, the phylogenetic model always obtained the best performance, and no overlap with other models occurred, thus best explaining the distributional patterns of dorsal morphs. The evolutionary processes, in addition to present environmental pressures, can significantly affect local-scale microevolutionary adaptations, influencing the current distribution of dorsal phenotypes across the species range. More generally, results point out the importance of considering the evolutionary processes when analysing distributional patterns of polymorphisms.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44382516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-17DOI: 10.1163/15685381-bja10130
Johanna Ambu, C. Dufresnes
Conservation genetics must find the balance between the technical challenges of DNA sampling while promoting animal welfare. In amphibians, buccal swabs offer a least intrusive source of DNA, but most herpetologists still refrain to use them, partly due to doubts regarding their effectiveness to provide enough material now that next-generation sequencing (NGS) analyses have become routine. In this article, we hope to change their minds through an empirical demonstration that buccal swabs offer DNA amounts and success rates for a widely used NGS approach (RAD-sequencing) that are equivalent to those of more intrusive yet commonly used samples in frogs and toads. We thus call for a shift of DNA sampling practices, and stress the fact that beyond their proven reliability, buccal swabs facilitate the issue of collection permits by increasingly restrictive ethical committees, especially when it comes to endangered species. With this purpose in mind, we share our long-term experience with amphibian buccal swabs through visual and textual pointers.
{"title":"Buccal swabs for amphibian genomics","authors":"Johanna Ambu, C. Dufresnes","doi":"10.1163/15685381-bja10130","DOIUrl":"https://doi.org/10.1163/15685381-bja10130","url":null,"abstract":"\u0000Conservation genetics must find the balance between the technical challenges of DNA sampling while promoting animal welfare. In amphibians, buccal swabs offer a least intrusive source of DNA, but most herpetologists still refrain to use them, partly due to doubts regarding their effectiveness to provide enough material now that next-generation sequencing (NGS) analyses have become routine. In this article, we hope to change their minds through an empirical demonstration that buccal swabs offer DNA amounts and success rates for a widely used NGS approach (RAD-sequencing) that are equivalent to those of more intrusive yet commonly used samples in frogs and toads. We thus call for a shift of DNA sampling practices, and stress the fact that beyond their proven reliability, buccal swabs facilitate the issue of collection permits by increasingly restrictive ethical committees, especially when it comes to endangered species. With this purpose in mind, we share our long-term experience with amphibian buccal swabs through visual and textual pointers.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47154136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-10DOI: 10.1163/15685381-bja10129
Geoffrey R. Smith, Adam B. Wade
Plethodontid salamanders often possess the ability to detect and avoid hazards in the environment which may be important for survival. We examined whether the two main colour morphs of Plethodon cinereus differ in their avoidance of cues from a potential predator (Thamnophis sirtalis) and whether P. cinereus avoided cues from T. sirtalis of different sizes (i.e., small vs. large). Plethodon cinereus avoided chemical cues deposited by T. sirtalis on a substrate; but avoidance did not differ between colour morphs of P. cinereus, snake sizes, or individual donor snakes.
{"title":"Eastern red-backed salamanders (Plethodon cinereus) avoid chemical cues from snake predators regardless of colour morph or snake individual and size","authors":"Geoffrey R. Smith, Adam B. Wade","doi":"10.1163/15685381-bja10129","DOIUrl":"https://doi.org/10.1163/15685381-bja10129","url":null,"abstract":"\u0000Plethodontid salamanders often possess the ability to detect and avoid hazards in the environment which may be important for survival. We examined whether the two main colour morphs of Plethodon cinereus differ in their avoidance of cues from a potential predator (Thamnophis sirtalis) and whether P. cinereus avoided cues from T. sirtalis of different sizes (i.e., small vs. large). Plethodon cinereus avoided chemical cues deposited by T. sirtalis on a substrate; but avoidance did not differ between colour morphs of P. cinereus, snake sizes, or individual donor snakes.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45132120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-03DOI: 10.1163/15685381-bja10128
M. Zuffi, Luna Bollaro, C. Mancusi, L. Marsili, P. Nicolosi, Giovanni Raimondi, G. Terracciano, C. Caruso, Laura Tonelli, Lucia Venturi, T. Mingozzi
Analysis of embryonic asymmetry may inform on pathologies, metabolic deficiencies or on functional anomalies. In Chelonians, range and relative numbers of abnormalities that occur at the embryonic stages are poorly known. The relative importance of the abnormalities causing embryonic death in the context of the conditions of incubation is not known. As for Caretta caretta, very little information is available on the biometry and anomalies of dead embryos in the Mediterranean basin. We compared data on biometric variability of carapace length and width, flippers asymmetries, clutch size, and hatching success from nests of Loggerhead coming from: the Ionian Calabrian coast (Southern Italy), where nesting has longly documented, and the Northern Tyrrhenian coast (Tuscany, Central Italy), where nesting activity has started only recently. Dead embryos were found inside nests after hatchling emergence. The turtles that nested in the two areas laid similar clutch sizes, but the Northern Tyrrhenian coast shows less hatched eggs and a lower hatching success, higher number of dead embryos and of unhatched eggs. Embryos from the Northern Tyrrhenian coast were significantly smaller than the Ionian Calabrian ones. Estimated stages ranged from 26 to 31b in both regions, stages 29-31b were more abundant in the Ionian Calabrian. Left vs right fore-flipper length varied significantly, with left flipper being longer than right flipper, but this asymmetry did not differ between the two regions. Flipper asymmetry seems to be a shared pattern in both juvenile and adult stages, likely not being the cause of mortality of our studied embryos.
{"title":"Eggs, hatching and embryos variability in loggerhead sea turtle Caretta caretta show significant differences among nests coming from two Italian nesting grounds","authors":"M. Zuffi, Luna Bollaro, C. Mancusi, L. Marsili, P. Nicolosi, Giovanni Raimondi, G. Terracciano, C. Caruso, Laura Tonelli, Lucia Venturi, T. Mingozzi","doi":"10.1163/15685381-bja10128","DOIUrl":"https://doi.org/10.1163/15685381-bja10128","url":null,"abstract":"\u0000Analysis of embryonic asymmetry may inform on pathologies, metabolic deficiencies or on functional anomalies. In Chelonians, range and relative numbers of abnormalities that occur at the embryonic stages are poorly known. The relative importance of the abnormalities causing embryonic death in the context of the conditions of incubation is not known. As for Caretta caretta, very little information is available on the biometry and anomalies of dead embryos in the Mediterranean basin. We compared data on biometric variability of carapace length and width, flippers asymmetries, clutch size, and hatching success from nests of Loggerhead coming from: the Ionian Calabrian coast (Southern Italy), where nesting has longly documented, and the Northern Tyrrhenian coast (Tuscany, Central Italy), where nesting activity has started only recently. Dead embryos were found inside nests after hatchling emergence. The turtles that nested in the two areas laid similar clutch sizes, but the Northern Tyrrhenian coast shows less hatched eggs and a lower hatching success, higher number of dead embryos and of unhatched eggs. Embryos from the Northern Tyrrhenian coast were significantly smaller than the Ionian Calabrian ones. Estimated stages ranged from 26 to 31b in both regions, stages 29-31b were more abundant in the Ionian Calabrian. Left vs right fore-flipper length varied significantly, with left flipper being longer than right flipper, but this asymmetry did not differ between the two regions. Flipper asymmetry seems to be a shared pattern in both juvenile and adult stages, likely not being the cause of mortality of our studied embryos.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43125812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-01DOI: 10.1163/15685381-bja10127
Nawal Hichami, M. Znari
A previous study on the feeding habits of Moorish tortoises in west-central Morocco suggests that these animals are selective herbivores, but the nutritional consequences have not been examined. Because of the potassium excretion load, which requires water and/or nitrogen loss, we predicted that tortoises do not have salt glands. Moorish tortoises prefer plants rich in water and protein but low in potassium (PEP index). To this end, we studied the spring diet of adult tortoises in an arid steppe in west-central Morocco during two seasons of relatively dry years (2011-2012) using feces analyses. We also estimated the relative abundance of potential food plants by stratified sampling under the canopy of jujube bushes Ziziphus lotus. We statistically compared diet to plant abundance. Finally, we assessed plant species’ nutritional composition (water, crude protein, and potassium) available to tortoises. Results showed that species assemblages differed significantly between the two plant communities in both years. Nevertheless, tortoises consumed only about 5-6 and nearly the same species at the study site in 2011 and 2012, respectively. The plants consumed by the tortoises had the highest positive PEP index values indicating that there was more water and nitrogen in the food than is needed to excrete potassium.
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