Pub Date : 2022-12-31DOI: 10.2994/SAJH-D-21-00015.1
Cantekin Dursun, N. Özdemir, Serkan Gül, N. Üzüm, Bilal Kutrup
Abstract. Ecological factors such as environment, habitat, and accompanying gradients affect the morphological characteristics of species. Different environmental conditions may induce phenotypic dissimilarities in populations of a species or between closely related species causing character evolution, or they may cause phenotypic plasticity as a response to abiotic and biotic changes in living habitats. The family Bufonidae (Amphibia: Anura) contains stereotypical toads with basic phenotypic features like dry warty skin characterized by spinosity. Keratinized spines were handled in previous studies on the genus Bufo. The studies were focused on the morphological shape differences and mostly intra-specific variations, but ecological parameters were not sufficiently investigated. In this study, we tested the relationship between elevation and the intensity of keratinized spines for Bufo bufo and B. verrucosissimus species in Türkiye. We also assessed intra and interspecific variations for both species based on the spinosity. According to the results of a chi-squared test, a statistically significant difference was found in the intensity of keratinized spines between the sexes of B. bufo. Males mostly had smooth skin without spines, whereas most females had slightly keratinized spines. There was no difference in terms of intensity of keratinized spines between sexes in B. verrucosissimus species. For interspecific variations, we found that female specimens differed in terms of intensity of keratinized between species. Accordingly, all B. bufo females had heavily keratinized spines, whereas most of B. verrucosissimus females had smooth skin. We found statistically significant negative relationships between elevation and intensity of keratinized spines for both species. Accordingly, we assume that the observed disparity related to the intensity of spines demonstrates a species-specific character evolution between species. The differences between elevations might be associated with local climatic conditions and defense strategies against predators in the living space.
{"title":"Intra- and Interspecific and Elevational Variation in Keratinized Spines on the Head in Two Closely Related Bufo Species","authors":"Cantekin Dursun, N. Özdemir, Serkan Gül, N. Üzüm, Bilal Kutrup","doi":"10.2994/SAJH-D-21-00015.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-21-00015.1","url":null,"abstract":"Abstract. Ecological factors such as environment, habitat, and accompanying gradients affect the morphological characteristics of species. Different environmental conditions may induce phenotypic dissimilarities in populations of a species or between closely related species causing character evolution, or they may cause phenotypic plasticity as a response to abiotic and biotic changes in living habitats. The family Bufonidae (Amphibia: Anura) contains stereotypical toads with basic phenotypic features like dry warty skin characterized by spinosity. Keratinized spines were handled in previous studies on the genus Bufo. The studies were focused on the morphological shape differences and mostly intra-specific variations, but ecological parameters were not sufficiently investigated. In this study, we tested the relationship between elevation and the intensity of keratinized spines for Bufo bufo and B. verrucosissimus species in Türkiye. We also assessed intra and interspecific variations for both species based on the spinosity. According to the results of a chi-squared test, a statistically significant difference was found in the intensity of keratinized spines between the sexes of B. bufo. Males mostly had smooth skin without spines, whereas most females had slightly keratinized spines. There was no difference in terms of intensity of keratinized spines between sexes in B. verrucosissimus species. For interspecific variations, we found that female specimens differed in terms of intensity of keratinized between species. Accordingly, all B. bufo females had heavily keratinized spines, whereas most of B. verrucosissimus females had smooth skin. We found statistically significant negative relationships between elevation and intensity of keratinized spines for both species. Accordingly, we assume that the observed disparity related to the intensity of spines demonstrates a species-specific character evolution between species. The differences between elevations might be associated with local climatic conditions and defense strategies against predators in the living space.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"25 1","pages":"57 - 65"},"PeriodicalIF":0.9,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46132596","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 : 2022-12-31DOI: 10.2994/SAJH-D-20-00045.1
S. Portelli, C. Abdala, J. Schulte, J. D. Díaz Gómez, Linda Díaz Fernández, A. S. Quinteros
Abstract. The Liolaemus boulengeri group is part of the subgenus Eulaemus, genus Liolaemus. This group is widely distributed in Argentina, Bolivia, Chile, and Paraguay, as well as in the Peruvian Titicaca basin and the coasts of Brazil and Uruguay. Here, we combined the revision of a fossil record of Liolaemus, dated at 20 million years (Myr), with relaxed molecular clock analysis to provide a time-calibrated, molecular-based phylogenetic hypothesis including 90% of the group's known species. We found the Liolaemus boulengeri group (= L. boulengeri section) formed by three main groups, the L. wiegmannii, L. anomalus, and L. darwinii-melanops groups. We performed biogeographic analyses applying Bayesian Binary (BBM), Dispersion-Extinction-Cladogenesis (DEC), and Statistical-Dispersion-Vicariance (S-DIVA) and found that the ancestral area of the L. boulengeri group was likely located in central-west Argentina and reached its current distribution after a series of dispersal and vicariance events. These processes may have been favored by a period of climatic stasis which occurred at the beginning of the group's diversification, around 41 Myr. The congruence of the results of all three biogeographic analyses evidences new hypothetical historical distributions and events which led to the current species distribution of the L. boulengeri group. Resumen. El grupo de Liolaemus boulengeri es miembro del subgénero Eulaemus, dentro del género Liolaemus. Este grupo se distribuye en Argentina, Bolivia, Chile y Paraguay, así como en el sureste de Perú, en la cuenca del Titicaca y las costas de Brasil y Uruguay. En este trabajo obtuvimos una hipótesis filogenética basada en evidencia molecular, incluyendo el 90% de las especies conocidas para el grupo. También, obtuvimos un árbol temporalmente calibrado, usando un reloj molecular relajado y un registro fósil de Liolaemus, datado en 20 millones de años. Encontramos al grupo de Liolaemus boulengeri (= sección de L. boulengeri) formado por tres grupos principales, los grupos de L. wiegmannii, L. anomalus y L. darwinii-melanops. Realizamos un análisis biogeográfico aplicando: Bayesian Binary (BBM), Dispersion-Extinction-Cladogenesis (DEC) y Statistical-Dispersion-Vicariance (S-DIVA), encontrando que el área ancestral del grupo de L. boulengeri está ubicada en el Centro-Oeste de Argentina. Desde ahí, debido a una combinación de eventos de dispersión y vicarianza, las especies de este grupo alcanzaron su distribución actual. Estos procesos podrían haberse favorecido por un periodo de estasis climática que ocurrió al comienzo de la diversificación del grupo, hace alrededor de los 41 millones de años. La congruencia de los resultados de los tres métodos nos permitió hipotetizar las distribuciones históricas y los eventos que podrían haber afectado la distribución actual de las especies del grupo de L. boulengeri.
{"title":"Historical Biogeographic Reconstruction of the South American Liolaemus boulengeri Group (Iguania: Liolaemidae)","authors":"S. Portelli, C. Abdala, J. Schulte, J. D. Díaz Gómez, Linda Díaz Fernández, A. S. Quinteros","doi":"10.2994/SAJH-D-20-00045.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-20-00045.1","url":null,"abstract":"Abstract. The Liolaemus boulengeri group is part of the subgenus Eulaemus, genus Liolaemus. This group is widely distributed in Argentina, Bolivia, Chile, and Paraguay, as well as in the Peruvian Titicaca basin and the coasts of Brazil and Uruguay. Here, we combined the revision of a fossil record of Liolaemus, dated at 20 million years (Myr), with relaxed molecular clock analysis to provide a time-calibrated, molecular-based phylogenetic hypothesis including 90% of the group's known species. We found the Liolaemus boulengeri group (= L. boulengeri section) formed by three main groups, the L. wiegmannii, L. anomalus, and L. darwinii-melanops groups. We performed biogeographic analyses applying Bayesian Binary (BBM), Dispersion-Extinction-Cladogenesis (DEC), and Statistical-Dispersion-Vicariance (S-DIVA) and found that the ancestral area of the L. boulengeri group was likely located in central-west Argentina and reached its current distribution after a series of dispersal and vicariance events. These processes may have been favored by a period of climatic stasis which occurred at the beginning of the group's diversification, around 41 Myr. The congruence of the results of all three biogeographic analyses evidences new hypothetical historical distributions and events which led to the current species distribution of the L. boulengeri group. Resumen. El grupo de Liolaemus boulengeri es miembro del subgénero Eulaemus, dentro del género Liolaemus. Este grupo se distribuye en Argentina, Bolivia, Chile y Paraguay, así como en el sureste de Perú, en la cuenca del Titicaca y las costas de Brasil y Uruguay. En este trabajo obtuvimos una hipótesis filogenética basada en evidencia molecular, incluyendo el 90% de las especies conocidas para el grupo. También, obtuvimos un árbol temporalmente calibrado, usando un reloj molecular relajado y un registro fósil de Liolaemus, datado en 20 millones de años. Encontramos al grupo de Liolaemus boulengeri (= sección de L. boulengeri) formado por tres grupos principales, los grupos de L. wiegmannii, L. anomalus y L. darwinii-melanops. Realizamos un análisis biogeográfico aplicando: Bayesian Binary (BBM), Dispersion-Extinction-Cladogenesis (DEC) y Statistical-Dispersion-Vicariance (S-DIVA), encontrando que el área ancestral del grupo de L. boulengeri está ubicada en el Centro-Oeste de Argentina. Desde ahí, debido a una combinación de eventos de dispersión y vicarianza, las especies de este grupo alcanzaron su distribución actual. Estos procesos podrían haberse favorecido por un periodo de estasis climática que ocurrió al comienzo de la diversificación del grupo, hace alrededor de los 41 millones de años. La congruencia de los resultados de los tres métodos nos permitió hipotetizar las distribuciones históricas y los eventos que podrían haber afectado la distribución actual de las especies del grupo de L. boulengeri.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"25 1","pages":"41 - 56"},"PeriodicalIF":0.9,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43692338","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 : 2022-11-11DOI: 10.2994/SAJH-D-20-00054.1
M. Hamann, C. E. González, M. Duré, Yanina Soledad Palomas
Abstract. The present study predicts that helminth community diversity and parasite transmission are influenced by host behavior and its habitat. This prediction was tested by analyzing for the first time the helminth community of Lepidobatrachus llanensis, an aquatic species that inhabits exclusively ephemeral water bodies in the Dry Chaco ecoregion. In the drought periods, L. llanensis burrows underground and forms a cocoon to minimize water loss, emerging again in the rainy season (e.g., in summer months). A total of 21 frogs was examined for parasites. Parasite community structure was analyzed using helminth parasite richness, diversity, and abundance. The helminth community of this frog consisted of 17 species, composed mostly of platyhelminth species (76%), followed by nematodes (24%). Ophiotaenia sp. was most prevalent (71%, confidence interval [CI]: 51.4–90.6%), followed by Choledocystus elegans (57%, CI: 35.8–78.2%). Infected frogs harbored a maximum of seven helminth species. At the infracommunity level, the mean species richness was 4.24 ± 1.79 per infected frog. Parasites were found in all major organs, with highest prevalence in the body cavity. Helminth species showed a typical aggregated pattern of distribution with unequal abundances. Parasite transmission to the frog host occurs by oral ingestion and skin penetration. As predicted, we found that the composition of the parasite community of this aquatic frog included multiple helminths, including parasitic species characteristic of both aquatic and terrestrial life cycles, with greater occurrence of trematodes that likely benefit from seasonal host aggregation during the rainy period associated with their reproductive strategies and by environmental factors such as seasonal dwelling in dry soil. This behavior in an otherwise aquatic frog enables infections by nematodes (L3) with a terrestrial life cycle absent from other aquatic frogs from South America.
{"title":"Helminth Community in the Llanos Frog, Lepidobatrachus llanensis (Ceratophryidae), from the Dry Chaco","authors":"M. Hamann, C. E. González, M. Duré, Yanina Soledad Palomas","doi":"10.2994/SAJH-D-20-00054.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-20-00054.1","url":null,"abstract":"Abstract. The present study predicts that helminth community diversity and parasite transmission are influenced by host behavior and its habitat. This prediction was tested by analyzing for the first time the helminth community of Lepidobatrachus llanensis, an aquatic species that inhabits exclusively ephemeral water bodies in the Dry Chaco ecoregion. In the drought periods, L. llanensis burrows underground and forms a cocoon to minimize water loss, emerging again in the rainy season (e.g., in summer months). A total of 21 frogs was examined for parasites. Parasite community structure was analyzed using helminth parasite richness, diversity, and abundance. The helminth community of this frog consisted of 17 species, composed mostly of platyhelminth species (76%), followed by nematodes (24%). Ophiotaenia sp. was most prevalent (71%, confidence interval [CI]: 51.4–90.6%), followed by Choledocystus elegans (57%, CI: 35.8–78.2%). Infected frogs harbored a maximum of seven helminth species. At the infracommunity level, the mean species richness was 4.24 ± 1.79 per infected frog. Parasites were found in all major organs, with highest prevalence in the body cavity. Helminth species showed a typical aggregated pattern of distribution with unequal abundances. Parasite transmission to the frog host occurs by oral ingestion and skin penetration. As predicted, we found that the composition of the parasite community of this aquatic frog included multiple helminths, including parasitic species characteristic of both aquatic and terrestrial life cycles, with greater occurrence of trematodes that likely benefit from seasonal host aggregation during the rainy period associated with their reproductive strategies and by environmental factors such as seasonal dwelling in dry soil. This behavior in an otherwise aquatic frog enables infections by nematodes (L3) with a terrestrial life cycle absent from other aquatic frogs from South America.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"25 1","pages":"12 - 17"},"PeriodicalIF":0.9,"publicationDate":"2022-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44254296","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 : 2022-11-11DOI: 10.2994/SAJH-D-20-00051.1
Nicza Alveal, Reinaldo J. Rivera, Javier Pinochet, Helen Díaz-Páez
Abstract. Climate change is a global phenomenon that will generate profound changes in biodiversity in the near future. Studies have reported negative impacts of climate change for South American amphibians; however, for Andean species such as Rhinella spinulosa, the potential response to the effects of climate change is unknown. Using ecological niche models, we estimate the potential distribution of R. spinulosa, identifying the environmental variables that explain its distribution and projecting predictions in climate change scenarios to elucidate their impact on the distribution pattern. The results revealed that the variables of elevation (48.7%), mean temperature of the hottest quarter (44.2%), and topographic humidity index (3.2%) were the most important contributors to the model and are predictors of the distribution of R. spinulosa. The most suitable areas for its distribution are its current range, extending to the north, as well as on the western Andean slope and Argentine Patagonia. Predictions for the future (year 2080) under two scenarios (benign and severe) coincide with the distribution predicted for the current one. Climatic conditions will not be considerably different in the distribution area of R. spinulosa, which may be due to the buffer effect of the mountain range. However, freshwater ecosystems will be more at risk from climate change, which could affect the reproductive success and survival of amphibians. Therefore, we recommend evaluating water availability at a local scale to understand the potential changes in the geographic distribution of R. spinulosa. Resumen. El cambio climático es un fenómeno global que podría generar profundos cambios en la biodiversidad en el futuro cercano. Estudios reportan impactos negativos del cambio climático para anfibios sudamericanos, sin embargo, para especies andinas como Rhinella spinulosa, la potencial respuesta de los efectos del cambio climático es desconocida. Usando modelos de nicho ecológico (ENM), nosotros estimamos la distribución potencial de R. spinulosa, identificando las variables ambientales que explican su distribución y proyectando predicciones en escenarios de cambio climático para elucidar su impacto sobre los patrones de distribución. Los resultados revelaron que las variables altitud (48.7%), temperatura media del trimestre más cálido (44,2%) y el índice de humedad topográfica (3,2%) fueron los contribuyentes más importantes al modelo y son predictores de la distribución de R. spinulosa. Las áreas más adecuadas para su distribución es su rango actual, extendiendo su rango hacia el norte, así como en la vertiente occidental de los Andes y la Patagonia Argentina. Las predicciones para el futuro (año 2080) bajo ambos escenarios (benigno y severo) coinciden con la distribución predicha actual. Las condiciones climáticas no serán considerablemente diferentes en el área de distribución de R. spinulosa, lo que puede deberse al efecto amortiguador de la cordillera. Sin emb
{"title":"Potential Current and Future Distribution of the Andean Toad Rhinella spinulosa Wiegmann, 1834 (Anura: Bufonidae): Is the Species Vulnerable to Climate Change?","authors":"Nicza Alveal, Reinaldo J. Rivera, Javier Pinochet, Helen Díaz-Páez","doi":"10.2994/SAJH-D-20-00051.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-20-00051.1","url":null,"abstract":"Abstract. Climate change is a global phenomenon that will generate profound changes in biodiversity in the near future. Studies have reported negative impacts of climate change for South American amphibians; however, for Andean species such as Rhinella spinulosa, the potential response to the effects of climate change is unknown. Using ecological niche models, we estimate the potential distribution of R. spinulosa, identifying the environmental variables that explain its distribution and projecting predictions in climate change scenarios to elucidate their impact on the distribution pattern. The results revealed that the variables of elevation (48.7%), mean temperature of the hottest quarter (44.2%), and topographic humidity index (3.2%) were the most important contributors to the model and are predictors of the distribution of R. spinulosa. The most suitable areas for its distribution are its current range, extending to the north, as well as on the western Andean slope and Argentine Patagonia. Predictions for the future (year 2080) under two scenarios (benign and severe) coincide with the distribution predicted for the current one. Climatic conditions will not be considerably different in the distribution area of R. spinulosa, which may be due to the buffer effect of the mountain range. However, freshwater ecosystems will be more at risk from climate change, which could affect the reproductive success and survival of amphibians. Therefore, we recommend evaluating water availability at a local scale to understand the potential changes in the geographic distribution of R. spinulosa. Resumen. El cambio climático es un fenómeno global que podría generar profundos cambios en la biodiversidad en el futuro cercano. Estudios reportan impactos negativos del cambio climático para anfibios sudamericanos, sin embargo, para especies andinas como Rhinella spinulosa, la potencial respuesta de los efectos del cambio climático es desconocida. Usando modelos de nicho ecológico (ENM), nosotros estimamos la distribución potencial de R. spinulosa, identificando las variables ambientales que explican su distribución y proyectando predicciones en escenarios de cambio climático para elucidar su impacto sobre los patrones de distribución. Los resultados revelaron que las variables altitud (48.7%), temperatura media del trimestre más cálido (44,2%) y el índice de humedad topográfica (3,2%) fueron los contribuyentes más importantes al modelo y son predictores de la distribución de R. spinulosa. Las áreas más adecuadas para su distribución es su rango actual, extendiendo su rango hacia el norte, así como en la vertiente occidental de los Andes y la Patagonia Argentina. Las predicciones para el futuro (año 2080) bajo ambos escenarios (benigno y severo) coinciden con la distribución predicha actual. Las condiciones climáticas no serán considerablemente diferentes en el área de distribución de R. spinulosa, lo que puede deberse al efecto amortiguador de la cordillera. Sin emb","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"25 1","pages":"1 - 11"},"PeriodicalIF":0.9,"publicationDate":"2022-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45104212","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 : 2022-08-31DOI: 10.2994/SAJH-D-20-00013.1
Nathália G. S. Lima, V. S. Borges, J. E. Santos, N. Bazzoli, P. Eterovick
Abstract. We studied gametogenesis and reproduction of Bokermannohyla nanuzae at an Atlantic Forest site in southeastern Brazil from August 2011 to July 2012. We observed frogs with mature germ cells almost year-round, indicating continuous gametogenesis. However, advanced gonad maturation occurred in wet months, when we observed females spawning and spermiated males. We observed calling males with mature testes in all bimesters but spermiated males only from October to January. This pattern of continuous calling may be associated with male strategies to be selected by females within male choruses. We did not observe males with testes at rest or females with ovaries at rest, and throughout the year we observed spermatogenic cells in all developmental stages in males as well as vitellogenic oocytes in different maturation stages and several post-ovulatory follicles in females, indicating that both males and females may be ready to respond to a specific environmental cue to release their gametes or even be able to breed multiple times throughout the year. This promptness to breed may be adaptive as it allows frogs to reach mature stages faster when environmental conditions are suitable for breeding and even breed more than once per breeding season.
{"title":"Gonad Structure and Reproductive Cycle of Bokermannohyla nanuzae (Anura, Hylidae) in Southeastern Brazil","authors":"Nathália G. S. Lima, V. S. Borges, J. E. Santos, N. Bazzoli, P. Eterovick","doi":"10.2994/SAJH-D-20-00013.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-20-00013.1","url":null,"abstract":"Abstract. We studied gametogenesis and reproduction of Bokermannohyla nanuzae at an Atlantic Forest site in southeastern Brazil from August 2011 to July 2012. We observed frogs with mature germ cells almost year-round, indicating continuous gametogenesis. However, advanced gonad maturation occurred in wet months, when we observed females spawning and spermiated males. We observed calling males with mature testes in all bimesters but spermiated males only from October to January. This pattern of continuous calling may be associated with male strategies to be selected by females within male choruses. We did not observe males with testes at rest or females with ovaries at rest, and throughout the year we observed spermatogenic cells in all developmental stages in males as well as vitellogenic oocytes in different maturation stages and several post-ovulatory follicles in females, indicating that both males and females may be ready to respond to a specific environmental cue to release their gametes or even be able to breed multiple times throughout the year. This promptness to breed may be adaptive as it allows frogs to reach mature stages faster when environmental conditions are suitable for breeding and even breed more than once per breeding season.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"24 1","pages":"35 - 43"},"PeriodicalIF":0.9,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41314077","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}
{"title":"Cover and Masthead","authors":"","doi":"10.2994/sajh-24-00000.1","DOIUrl":"https://doi.org/10.2994/sajh-24-00000.1","url":null,"abstract":"","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"24 1","pages":"c1 - c2"},"PeriodicalIF":0.9,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43058358","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 : 2022-08-31DOI: 10.2994/SAJH-D-20-00062.1
F. J. Zamora‐Camacho, R. Calsbeek
Abstract. Whereas prey tend to reduce conspicuousness, predators remain active to locate their prey. In particular, mesopredators (i.e., predators situated in the middle of two trophic levels) may be subjected to opposing pressures. Locomotor performance influences predator–prey interactions, and together with behavior can be constrained by morphology. In this study, we test how locomotor performance and foraging behavior of larvae of the predaceous amphibian Ambystoma maculatum are influenced by morphology and exposure to chemical cues from predators and competitors. We test whether tail-injured and uninjured larvae differed in morphology, locomotor performance, and feeding rate. Larger individuals showed higher locomotor performance and prey consumption rate. These were not correlated, but the latter increased subsequent locomotor performance. Neither perceived predators nor competitors affected swimming speed or prey consumption rate. Body size was positively correlated with prey consumption rate only in those individuals not previously exposed to chemical cues from predators and competitors. Finally, tail-injured larvae were smaller, but did not experience reduced speed or prey consumption rates. Resumen. Mientras que las presas tratan de pasar desapercibidas para sus depredadores, muchos depredadores permanecen activos para tratar de localizarlas. En particular, los mesodepredadores (es decir, depredadores que se sitúan en la parte media de la cadena trófica) pueden estar sujetos a presiones opuestas. El desempeño locomotor influye en las interacciones depredador-presa, y así como el comportamiento, puede estar restringido por la morfología. En este estudio, testamos cómo la morfología y la exposición a señales químicas de depredadores y competidores afectan al desempeño en la locomoción y el comportamiento de larvas del anfibio depredador Ambystoma maculatum. También testamos si las larvas con cola dañada y sin dañar diferían en morfología, desempeño locomotor y tasas de captura de presas. Los individuos de mayor tamaño mostraron mayor desempeño locomotor y una tasa de captura de presas más alta. Estas no estuvieron correlacionadas, pero la última incrementó el desempeño locomotor subsecuente. La exposición indirecta al riesgo de depredación o la competencia no influenciaron la velocidad de natación ni a la tasa de captura de presas. El tamaño corporal estuvo positivamente correlacionado con las tasas de captura solo en los individuos no expuestos a señales químicas de depredadores o competidores. Finalmente, las larvas con cola dañada fueron más pequeñas, pero no experimentaron reducción alguna en su velocidad o tasas de captura.
摘要当猎物倾向于减少显眼性时，捕食者仍然保持活跃以确定猎物的位置。特别是中掠食者(即处于两个营养等级中间的掠食者)可能会受到相反的压力。运动表现影响捕食者-猎物的相互作用，并与行为一起受到形态的限制。在这项研究中，我们测试了食肉两栖动物Ambystoma maculatum幼虫的运动性能和觅食行为如何受到形态和暴露于捕食者和竞争对手的化学信号的影响。我们测试了尾损伤和未尾损伤的幼虫在形态、运动表现和摄食率方面是否存在差异。体型较大的个体表现出更高的运动能力和猎物消耗率。两者并不相关，但后者提高了随后的运动能力。感知到的捕食者和竞争对手都不会影响游泳速度或猎物消耗率。只有在那些之前没有接触过来自捕食者和竞争对手的化学线索的个体中，体型与猎物消耗率呈正相关。最后，尾巴受伤的幼虫体型较小，但速度或猎物消耗率并未降低。Resumen。Mientras que las presas tratas de pasar desapercibidas para as被剥削者，许多被剥削者永久的活动，para tratar de localizarlas。特别是，“mesodepredadores”(es decir, depredadores que se sitúan En la partte media de la cadena trófica)被称为“estar sujetos”和“presiones opuestas”。在相互作用下的运动影响desempeño，在相互作用下的运动影响así，在相互作用下的运动影响，在相互作用下的运动影响morfología。En este estudio, teststamos cómo la morfología y la exposición a señales químicas de depredadores y竞争者影响desempeño En la locomoción y el comportamiento de larvas del anti - fibio depredadador Ambystoma maculatum。tamambisamn teststamos是las larvas concola dañada y sin dañar diferían en morfología, desempeño运动通过tasas de capture de presas。Los individuos de mayor tamaño mostraron mayor desempeño locomotor y una tasa de capture de presas más alta。研究结果表明:两组间无明显相关性，分别为última incrementó和desempeño。exposición间接地影响了depredación的能力，不影响了natación的速度，也不影响了抓捕的速度。1 . (tamaño)与1 . (señales químicas)与1 .(1)与1 . (señales químicas)与1 .(1)与1 .(1)与1 .(1)与1 . (1))最后，las larvas concola dañada fueron más pequeñas, pero no experiment on reducción alguna en su velocidad to tasas de capture。
{"title":"The Intersection between Locomotor Performance, Prey Consumption Rate, and Morphology Under Perceived Competition and Predation in Ambystoma maculatum Larvae","authors":"F. J. Zamora‐Camacho, R. Calsbeek","doi":"10.2994/SAJH-D-20-00062.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-20-00062.1","url":null,"abstract":"Abstract. Whereas prey tend to reduce conspicuousness, predators remain active to locate their prey. In particular, mesopredators (i.e., predators situated in the middle of two trophic levels) may be subjected to opposing pressures. Locomotor performance influences predator–prey interactions, and together with behavior can be constrained by morphology. In this study, we test how locomotor performance and foraging behavior of larvae of the predaceous amphibian Ambystoma maculatum are influenced by morphology and exposure to chemical cues from predators and competitors. We test whether tail-injured and uninjured larvae differed in morphology, locomotor performance, and feeding rate. Larger individuals showed higher locomotor performance and prey consumption rate. These were not correlated, but the latter increased subsequent locomotor performance. Neither perceived predators nor competitors affected swimming speed or prey consumption rate. Body size was positively correlated with prey consumption rate only in those individuals not previously exposed to chemical cues from predators and competitors. Finally, tail-injured larvae were smaller, but did not experience reduced speed or prey consumption rates. Resumen. Mientras que las presas tratan de pasar desapercibidas para sus depredadores, muchos depredadores permanecen activos para tratar de localizarlas. En particular, los mesodepredadores (es decir, depredadores que se sitúan en la parte media de la cadena trófica) pueden estar sujetos a presiones opuestas. El desempeño locomotor influye en las interacciones depredador-presa, y así como el comportamiento, puede estar restringido por la morfología. En este estudio, testamos cómo la morfología y la exposición a señales químicas de depredadores y competidores afectan al desempeño en la locomoción y el comportamiento de larvas del anfibio depredador Ambystoma maculatum. También testamos si las larvas con cola dañada y sin dañar diferían en morfología, desempeño locomotor y tasas de captura de presas. Los individuos de mayor tamaño mostraron mayor desempeño locomotor y una tasa de captura de presas más alta. Estas no estuvieron correlacionadas, pero la última incrementó el desempeño locomotor subsecuente. La exposición indirecta al riesgo de depredación o la competencia no influenciaron la velocidad de natación ni a la tasa de captura de presas. El tamaño corporal estuvo positivamente correlacionado con las tasas de captura solo en los individuos no expuestos a señales químicas de depredadores o competidores. Finalmente, las larvas con cola dañada fueron más pequeñas, pero no experimentaron reducción alguna en su velocidad o tasas de captura.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"24 1","pages":"58 - 66"},"PeriodicalIF":0.9,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47978121","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 : 2022-08-31DOI: 10.2994/SAJH-D-18-00058.1
F. C. Resende, L. B. Nascimento
Abstract. Snakes exhibit considerable variation in reproductive patterns. However, the cycle of the sexual segment of the kidney and the testicular activity remain unknown for most Neotropical snake species. The dipsadine Atractus pantostictus is a fossorial snake species occurring in central and southeastern Brazil. The present study describes the reproductive cycle of males of this species, providing macroscopic and microscopic analyses of testes, ductus deferens, and sexual segment of the kidneys. We classified the cycle of males as pre-nuptial, as the production of gametes in males precedes the mating season. In summer, the specimens underwent testicular regression; thus, the individuals of A. pantostictus presented a discontinuous cyclical pattern in which the gonads or accessory organs become reproductively quiescent for some period during the year. At the population level, our results indicated a seasonal reproductive cycle. The sexual segment of the kidney was hypertrophied during the spring, corresponding to the mating season.
{"title":"Sexual Segment of the Kidney and Testicular Activity of the Neotropical Snake Atractus pantostictus (Squamata: Dipsadidae) from Minas Gerais State, Southeastern Brazil","authors":"F. C. Resende, L. B. Nascimento","doi":"10.2994/SAJH-D-18-00058.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-18-00058.1","url":null,"abstract":"Abstract. Snakes exhibit considerable variation in reproductive patterns. However, the cycle of the sexual segment of the kidney and the testicular activity remain unknown for most Neotropical snake species. The dipsadine Atractus pantostictus is a fossorial snake species occurring in central and southeastern Brazil. The present study describes the reproductive cycle of males of this species, providing macroscopic and microscopic analyses of testes, ductus deferens, and sexual segment of the kidneys. We classified the cycle of males as pre-nuptial, as the production of gametes in males precedes the mating season. In summer, the specimens underwent testicular regression; thus, the individuals of A. pantostictus presented a discontinuous cyclical pattern in which the gonads or accessory organs become reproductively quiescent for some period during the year. At the population level, our results indicated a seasonal reproductive cycle. The sexual segment of the kidney was hypertrophied during the spring, corresponding to the mating season.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"24 1","pages":"11 - 18"},"PeriodicalIF":0.9,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49213527","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 : 2022-08-31DOI: 10.2994/SAJH-D-20-00043.1
Samuel Hilevski, Trinidad Cordero, P. Siroski
Abstract. Several species of crocodilians consume, digest, and benefit from plant nutrients, and the animal food industry has made important efforts to use different plant materials in the development of new pellets for these animals. This information is very important within the ambit of captive breeding and crocodilian nutrition. The search for plants to supplement the diets of crocodilians is important because it may help to satisfy the nutritional demand of captive crocodilians and reduce the costs of their feeding and production. These initiatives have been mainly focused on animals such as fish and poultry, although some research has also been carried out with crocodilians. The demand for crocodilian skin and meat spiked during the 1990s. Since then, efforts have been amplified to investigate the use of different plants in the development of artificial diets to replace or complement the diet of different crocodile species, without interfering with product quality, health, and animal development while keeping production cost low. To achieve this, the existing information about the main and new sources of plant raw materials used to feed crocodilians must be known.
{"title":"Do Crocodilians Eat Plant Material? A Review of Plant Nutrients Consumed by Captive Crocodilians","authors":"Samuel Hilevski, Trinidad Cordero, P. Siroski","doi":"10.2994/SAJH-D-20-00043.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-20-00043.1","url":null,"abstract":"Abstract. Several species of crocodilians consume, digest, and benefit from plant nutrients, and the animal food industry has made important efforts to use different plant materials in the development of new pellets for these animals. This information is very important within the ambit of captive breeding and crocodilian nutrition. The search for plants to supplement the diets of crocodilians is important because it may help to satisfy the nutritional demand of captive crocodilians and reduce the costs of their feeding and production. These initiatives have been mainly focused on animals such as fish and poultry, although some research has also been carried out with crocodilians. The demand for crocodilian skin and meat spiked during the 1990s. Since then, efforts have been amplified to investigate the use of different plants in the development of artificial diets to replace or complement the diet of different crocodile species, without interfering with product quality, health, and animal development while keeping production cost low. To achieve this, the existing information about the main and new sources of plant raw materials used to feed crocodilians must be known.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"24 1","pages":"19 - 25"},"PeriodicalIF":0.9,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42902432","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 : 2022-08-31DOI: 10.2994/SAJH-D-20-00052.1
D. Ferraro, J. S. Barrionuevo
Abstract. Anurans that inhabit dry habitats exhibit particular life histories and possess morphological features associated with burrowing behavior (e.g., specialized metatarsal tubercles, short hind limbs relative to body size). The Neotropical genus Pleurodema includes 15 species distributed mainly in arid and semiarid environments. Backward burrowing behavior has been recorded in the genus, as well as the presence of specialized inner metatarsal tubercles. However, morphometric variation associated with burrowing has not been sufficiently studied in Pleurodema. To explore this variation, we scored 13 external body measurements and examined the morphology of the metatarsal tubercles of 615 adult specimens representing 14 species of Pleurodema. We also summarized available data about egg-clutch structure, hatching time, and duration of larval period of all species of the genus. Our results revealed that body shape variation mainly consists of differences in the relative length of the hind-limb elements. Pleurodema brachyops, P. diplolister, P. guayapae, P. nebulosum, P. tucumanum, and P. marmoratum have the shortest hind-limb elements relative to snout–vent length, and all but P. marmoratum also have keratinized inner metatarsal tubercles. The combination of these features has been considered a fossorial specialization on biomechanical grounds. Pleurodema brachyops, P. diplolister, P. guayapae, P. nebulosum, and P. tucumanum also have the shortest hatching time and larval period. A short larval period has been related to arrestment in the elongation phase of anuran limbs. Both burrowing performance and developmental effects could explain the variation in the limb morphology within Pleurodema.
{"title":"Morphometric Variation in Pleurodema (Anura: Leptodactylidae: Leiuperinae): Evidence of Fossoriality?","authors":"D. Ferraro, J. S. Barrionuevo","doi":"10.2994/SAJH-D-20-00052.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-20-00052.1","url":null,"abstract":"Abstract. Anurans that inhabit dry habitats exhibit particular life histories and possess morphological features associated with burrowing behavior (e.g., specialized metatarsal tubercles, short hind limbs relative to body size). The Neotropical genus Pleurodema includes 15 species distributed mainly in arid and semiarid environments. Backward burrowing behavior has been recorded in the genus, as well as the presence of specialized inner metatarsal tubercles. However, morphometric variation associated with burrowing has not been sufficiently studied in Pleurodema. To explore this variation, we scored 13 external body measurements and examined the morphology of the metatarsal tubercles of 615 adult specimens representing 14 species of Pleurodema. We also summarized available data about egg-clutch structure, hatching time, and duration of larval period of all species of the genus. Our results revealed that body shape variation mainly consists of differences in the relative length of the hind-limb elements. Pleurodema brachyops, P. diplolister, P. guayapae, P. nebulosum, P. tucumanum, and P. marmoratum have the shortest hind-limb elements relative to snout–vent length, and all but P. marmoratum also have keratinized inner metatarsal tubercles. The combination of these features has been considered a fossorial specialization on biomechanical grounds. Pleurodema brachyops, P. diplolister, P. guayapae, P. nebulosum, and P. tucumanum also have the shortest hatching time and larval period. A short larval period has been related to arrestment in the elongation phase of anuran limbs. Both burrowing performance and developmental effects could explain the variation in the limb morphology within Pleurodema.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"24 1","pages":"44 - 57"},"PeriodicalIF":0.9,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49581529","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}
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