Pub Date : 2022-08-31DOI: 10.2994/SAJH-D-21-00008.1
A. Altunışık, Fatma Üçeş, M. Yıldız
Abstract. In the present study, some demographic life-history parameters (e.g., age structure, age upon attaining sexual maturity, longevity, adult life expectancy, growth, and survival rate) and body size were investigated for the first time in two populations (urban and rural populations) of the rough bent-toed gecko, Cyrtopodion scabrum. A total of 69 (26 males, 30 females, and 13 juveniles) C. scabrum individuals were studied. Our findings indicated that age upon attaining sexual maturity was 2 and 3 years in both sexes. The maximum longevity was 7 years in females and 6 years in males. We did not find a remarkable difference in body size between females and males. When comparing both populations, neither male and female urban individuals nor both individuals together were significantly different from their counterparts from the rural population with respect to the average age and body size. The body size markedly increased with age in both males and females.
{"title":"Demographic Life-History Traits in Two Populations of Cyrtopodion scabrum (Squamata: Gekkonidae)","authors":"A. Altunışık, Fatma Üçeş, M. Yıldız","doi":"10.2994/SAJH-D-21-00008.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-21-00008.1","url":null,"abstract":"Abstract. In the present study, some demographic life-history parameters (e.g., age structure, age upon attaining sexual maturity, longevity, adult life expectancy, growth, and survival rate) and body size were investigated for the first time in two populations (urban and rural populations) of the rough bent-toed gecko, Cyrtopodion scabrum. A total of 69 (26 males, 30 females, and 13 juveniles) C. scabrum individuals were studied. Our findings indicated that age upon attaining sexual maturity was 2 and 3 years in both sexes. The maximum longevity was 7 years in females and 6 years in males. We did not find a remarkable difference in body size between females and males. When comparing both populations, neither male and female urban individuals nor both individuals together were significantly different from their counterparts from the rural population with respect to the average age and body size. The body size markedly increased with age in both males and females.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"24 1","pages":"75 - 82"},"PeriodicalIF":0.9,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49439840","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-18-00057.1
V. A. Barros, Karina Maria Pereira Silva, C. A. Rojas, S. M. Almeida‐Santos
Abstract. We describe the seasonal variation in the male reproductive cycle of Bothrops pubescens, a pitviper from southern Brazil. All specimens were collected in the state of Rio Grande do Sul, a region with climates varying from subtropical to subtemperate and temperate. We characterized male reproduction considering histological analyses of the testes, sexual segment of the kidneys (SSK), and ductus deferens, as well as macroscopic indicators of reproductive activity (testes volume and ductus deferens width in the distal portion) to allow comparisons. We also evaluated the seasonal variation of epithelial height and tubule diameter of the testes and SSK. These reproductive parameters showed significant seasonal variation, with a high increase in summer and a peak in autumn for spermatogenic and SSK activity. Courtship behavior occurs on March (end of summer/beginning of autumn), in synchrony with sperm production and SSK hypertrophy. Sperm storage occurred in the ductus deferens throughout the year. We detected an ampulla ductus deferentis in the distal portion of the ductus deferens in some individuals. Male B. pubescens exhibit a seasonal reproductive cycle, and the use of microscopic methods was highly informative for supporting this conclusion. Resumo. Nós descrevemos a variação sazonal no ciclo reprodutivo de Bothrops pubescens, uma espécie de serpente da subfamília Crotalinae, da região Sul do Brasil. Os machos foram amostrados no estado do Rio Grande do Sul, que é uma região com climas variando de subtropical a subtemperado e temperado. Os ciclos dos testículos, segmento sexual renal (SSR) e ducto deferente foram caracterizados utilizando análises histológicas para descrever o ciclo reprodutivo dos machos. Nós também avaliamos indicadores macroscópicos da atividade reprodutiva (volume do testículo e largura do ducto deferente na região distal) para fins de comparação. Considerando os dados histológicos, foram avaliadas as variações sazonais da altura do epitélio e diâmetro dos túbulos tanto dos testículos quanto do SSR. Estes parâmetros reprodutivos apresentaram variação sazonal significativa, com grande aumento no verão e pico no outono, tanto para a atividade espermatogênica quanto para o SSR. Corte em vida livre ocorre em março (fim do verão/início do outono), em sincronia com a produção de esperma e a hipertrofia do SSR. Estocagem de esperma ocorreu no ducto deferente ao longo do ano. A ampulla ductus deferentis foi observada na porção distal do ducto deferente de alguns indivíduos. O ciclo reprodutivo dos machos de B. pubescens é sazonal e o uso de métodos microscópicos foi essencial para chegar a esta conclusão.
{"title":"Male Reproductive Cycle of Bothrops pubescens (Serpentes, Viperidae) from Southern Brazil","authors":"V. A. Barros, Karina Maria Pereira Silva, C. A. Rojas, S. M. Almeida‐Santos","doi":"10.2994/SAJH-D-18-00057.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-18-00057.1","url":null,"abstract":"Abstract. We describe the seasonal variation in the male reproductive cycle of Bothrops pubescens, a pitviper from southern Brazil. All specimens were collected in the state of Rio Grande do Sul, a region with climates varying from subtropical to subtemperate and temperate. We characterized male reproduction considering histological analyses of the testes, sexual segment of the kidneys (SSK), and ductus deferens, as well as macroscopic indicators of reproductive activity (testes volume and ductus deferens width in the distal portion) to allow comparisons. We also evaluated the seasonal variation of epithelial height and tubule diameter of the testes and SSK. These reproductive parameters showed significant seasonal variation, with a high increase in summer and a peak in autumn for spermatogenic and SSK activity. Courtship behavior occurs on March (end of summer/beginning of autumn), in synchrony with sperm production and SSK hypertrophy. Sperm storage occurred in the ductus deferens throughout the year. We detected an ampulla ductus deferentis in the distal portion of the ductus deferens in some individuals. Male B. pubescens exhibit a seasonal reproductive cycle, and the use of microscopic methods was highly informative for supporting this conclusion. Resumo. Nós descrevemos a variação sazonal no ciclo reprodutivo de Bothrops pubescens, uma espécie de serpente da subfamília Crotalinae, da região Sul do Brasil. Os machos foram amostrados no estado do Rio Grande do Sul, que é uma região com climas variando de subtropical a subtemperado e temperado. Os ciclos dos testículos, segmento sexual renal (SSR) e ducto deferente foram caracterizados utilizando análises histológicas para descrever o ciclo reprodutivo dos machos. Nós também avaliamos indicadores macroscópicos da atividade reprodutiva (volume do testículo e largura do ducto deferente na região distal) para fins de comparação. Considerando os dados histológicos, foram avaliadas as variações sazonais da altura do epitélio e diâmetro dos túbulos tanto dos testículos quanto do SSR. Estes parâmetros reprodutivos apresentaram variação sazonal significativa, com grande aumento no verão e pico no outono, tanto para a atividade espermatogênica quanto para o SSR. Corte em vida livre ocorre em março (fim do verão/início do outono), em sincronia com a produção de esperma e a hipertrofia do SSR. Estocagem de esperma ocorreu no ducto deferente ao longo do ano. A ampulla ductus deferentis foi observada na porção distal do ducto deferente de alguns indivíduos. O ciclo reprodutivo dos machos de B. pubescens é sazonal e o uso de métodos microscópicos foi essencial para chegar a esta conclusão.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"24 1","pages":"1 - 10"},"PeriodicalIF":0.9,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46147470","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-20-00040.1
C. Manzano, G. Benzal, Eugenia Matas, L. Zelarayán
Abstract. Many recent studies have shown that amphibian populations have been affected by a variety of causes including climate change, pollution, habitat destruction, and disease. Such drivers could also influence the physiological and behavioral reproductive events of individuals. Rhinella arenarum is an amphibian species that has been extensively used as an experimental model for biological studies. This is an ecologically important species due to its abundance and wide distribution in South America. Our research on the female gonad of R. arenarum conducted in the last three decades has allowed us to observe that the competence of the ovary of this species has been slowly modified over the years, manifested by an increase in oocyte lysis during in vitro assays. To better understand the changes, a retrospective analysis of data from the last three decades was performed in order to quantify oocyte maturation and lysis in the presence of different incubation mediums. Data from three sampling years (1993, 2005, and 2018) were selected, and percentages of oocyte maturation and lysis were compared. Results show a significant decrease in oocyte maturation and an increase in oocyte lysis in the last sampling year. We also examined the climate conditions of the habitat of R. arenarum in each sampling year and their variation as a possible driver of decreased ovarian functionality. A significant increase in minimum temperatures, solar radiation, and relative humidity is reported. Alterations in the climate conditions of the natural habitat of R. arenarum might be one of many factors responsible for the decrease in ovarian functionality. Further analysis of the impact of the ongoing climate change on several aspects of amphibian phenology is needed to strengthen understanding of population declines and promote species conservation.
{"title":"Variations in Oocyte Maturation and Lysis of the Common Toad Rhinella arenarum (Anura: Bufonidae): Is Climate Change Affecting Oocyte Functionality?","authors":"C. Manzano, G. Benzal, Eugenia Matas, L. Zelarayán","doi":"10.2994/SAJH-D-20-00040.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-20-00040.1","url":null,"abstract":"Abstract. Many recent studies have shown that amphibian populations have been affected by a variety of causes including climate change, pollution, habitat destruction, and disease. Such drivers could also influence the physiological and behavioral reproductive events of individuals. Rhinella arenarum is an amphibian species that has been extensively used as an experimental model for biological studies. This is an ecologically important species due to its abundance and wide distribution in South America. Our research on the female gonad of R. arenarum conducted in the last three decades has allowed us to observe that the competence of the ovary of this species has been slowly modified over the years, manifested by an increase in oocyte lysis during in vitro assays. To better understand the changes, a retrospective analysis of data from the last three decades was performed in order to quantify oocyte maturation and lysis in the presence of different incubation mediums. Data from three sampling years (1993, 2005, and 2018) were selected, and percentages of oocyte maturation and lysis were compared. Results show a significant decrease in oocyte maturation and an increase in oocyte lysis in the last sampling year. We also examined the climate conditions of the habitat of R. arenarum in each sampling year and their variation as a possible driver of decreased ovarian functionality. A significant increase in minimum temperatures, solar radiation, and relative humidity is reported. Alterations in the climate conditions of the natural habitat of R. arenarum might be one of many factors responsible for the decrease in ovarian functionality. Further analysis of the impact of the ongoing climate change on several aspects of amphibian phenology is needed to strengthen understanding of population declines and promote species conservation.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"24 1","pages":"26 - 34"},"PeriodicalIF":0.9,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42558594","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-20-00047.1
Ricardo Luría-Manzano, J. L. Aguilar-López, E. Pineda
Abstract. Some amphibian species are highly abundant in riparian areas, with high numbers of both froglets and adults. These two age classes commonly have different diets. Studying how dietary differences are associated with ontogeny and the spatial distribution of frogs with respect to water bodies contributes to understanding the role of amphibians in trophic webs and in the biological dynamic of riparian ecosystems. We analyzed the diet, density, and mass of Craugastor berkenbuschii, a leaf-litter frog abundant in riparian areas in tropical forest in southern Mexico. We also estimated the number and biomass of prey consumed per area in relation to distance to streams (near: 0–15 m, far: 45–60 m) and body size. We found no differences in any diet variable between the two distances to streams, but diet composition changed with ontogeny. As snout–vent length increased, the number of prey consumed decreased and stomach content mass and mean prey length increased. Frog density and mass were higher near the streams than farther from the streams. The proportion of large and medium-sized frogs did not vary by distance to the streams, but the proportion of small frogs was marginally higher near the streams. Close to the streams, small frogs consumed a higher estimated invertebrate number per area than did medium-sized frogs, and these in turn more than large frogs. However, farther from the streams, large and medium-sized frogs preyed on a higher number of invertebrates per area than small frogs. Invertebrate biomass consumed did not differ among size classes at either of the distances, but both invertebrate number and biomass consumed by the species were higher near the streams than farther from them. The finding that prey number consumed decreased as frog size increased, together with the strong affinity of the species—particularly of small frogs—to streams, had an effect on estimates of invertebrate consumption. These results implied a higher consumption of invertebrates near than farther from the streams, and a greater impact of small than large frogs on invertebrate numbers in riparian environments. Resumen. Algunas especies de anfibios muestran una gran abundancia en áreas ribereñas, con un número alto de ranas recién metamorfoseadas y adultos. Estas dos clases de edad comúnmente exhiben diferencias en aspectos de la dieta. El estudio de cómo las diferencias en la dieta están asociadas con la ontogenia y la distribución espacial de las ranas con respecto a cuerpos de agua contribuye al entendimiento del rol de los anfibios en las redes tróficas y en la dinámica biológica de ecosistemas ribereños. Nosotros analizamos aspectos de la dieta, densidad y masa de Craugastor berkenbuschii, una rana de hojarasca abundante en áreas ribereñas del bosque tropical en el sur de México. Adicionalmente, estimamos el número y biomasa de presas consumidas por área con relación a la distancia a los arroyos (cerca: 0–15 m, lejos: 45–60 m) y al tamaño del cuerpo. No
{"title":"Diet, Density, Biomass, and Prey Consumption through Ontogeny of a Dominant Frog Species at Different Distances from Streams in a Tropical Rainforest","authors":"Ricardo Luría-Manzano, J. L. Aguilar-López, E. Pineda","doi":"10.2994/SAJH-D-20-00047.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-20-00047.1","url":null,"abstract":"Abstract. Some amphibian species are highly abundant in riparian areas, with high numbers of both froglets and adults. These two age classes commonly have different diets. Studying how dietary differences are associated with ontogeny and the spatial distribution of frogs with respect to water bodies contributes to understanding the role of amphibians in trophic webs and in the biological dynamic of riparian ecosystems. We analyzed the diet, density, and mass of Craugastor berkenbuschii, a leaf-litter frog abundant in riparian areas in tropical forest in southern Mexico. We also estimated the number and biomass of prey consumed per area in relation to distance to streams (near: 0–15 m, far: 45–60 m) and body size. We found no differences in any diet variable between the two distances to streams, but diet composition changed with ontogeny. As snout–vent length increased, the number of prey consumed decreased and stomach content mass and mean prey length increased. Frog density and mass were higher near the streams than farther from the streams. The proportion of large and medium-sized frogs did not vary by distance to the streams, but the proportion of small frogs was marginally higher near the streams. Close to the streams, small frogs consumed a higher estimated invertebrate number per area than did medium-sized frogs, and these in turn more than large frogs. However, farther from the streams, large and medium-sized frogs preyed on a higher number of invertebrates per area than small frogs. Invertebrate biomass consumed did not differ among size classes at either of the distances, but both invertebrate number and biomass consumed by the species were higher near the streams than farther from them. The finding that prey number consumed decreased as frog size increased, together with the strong affinity of the species—particularly of small frogs—to streams, had an effect on estimates of invertebrate consumption. These results implied a higher consumption of invertebrates near than farther from the streams, and a greater impact of small than large frogs on invertebrate numbers in riparian environments. Resumen. Algunas especies de anfibios muestran una gran abundancia en áreas ribereñas, con un número alto de ranas recién metamorfoseadas y adultos. Estas dos clases de edad comúnmente exhiben diferencias en aspectos de la dieta. El estudio de cómo las diferencias en la dieta están asociadas con la ontogenia y la distribución espacial de las ranas con respecto a cuerpos de agua contribuye al entendimiento del rol de los anfibios en las redes tróficas y en la dinámica biológica de ecosistemas ribereños. Nosotros analizamos aspectos de la dieta, densidad y masa de Craugastor berkenbuschii, una rana de hojarasca abundante en áreas ribereñas del bosque tropical en el sur de México. Adicionalmente, estimamos el número y biomasa de presas consumidas por área con relación a la distancia a los arroyos (cerca: 0–15 m, lejos: 45–60 m) y al tamaño del cuerpo. No ","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"24 1","pages":"67 - 74"},"PeriodicalIF":0.9,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41940180","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 : 2022-04-30DOI: 10.2994/SAJH-D-18-00081.1
Patrícia S. Marinho, J. E. Ortega Chinchilla, Henrique B. Braz, S. M. Almeida‐Santos
Abstract. Changes in the body temperature (Tb) of reproductive females are well documented in squamate reptiles. However, the direction of these changes varies among species. Pregnant females may exhibit a lower or higher (and less variable) Tb than nonpregnant females. In some species, pregnancy has no detectable effect on female Tb. In this study, we compared the Tb of female rattlesnakes (Crotalus durissus) in different reproductive statuses (pregnant and nonpregnant) to investigate whether pregnancy influences Tb. We measured the Tb of female rattlesnakes kept in a semi-natural outdoor enclosure during summer and spring 2016 and summer 2017. Pregnant females selected a higher mean Tb than nonpregnant females. Moreover, we found significant differences in Tb among seasons. Body temperatures in summer 2017 were higher than in other seasons; however, reproductive status did not influence Tb variance. Therefore, our results agree with the hypothesis that females change their thermoregulatory behavior during pregnancy. Female rattlesnakes may increase their Tb during pregnancy to increase offspring fitness or to maximize their lifetime fitness.
{"title":"Effects of Pregnancy on the Body Temperature of the South American Rattlesnake, Crotalus durissus, in Southeastern Brazil","authors":"Patrícia S. Marinho, J. E. Ortega Chinchilla, Henrique B. Braz, S. M. Almeida‐Santos","doi":"10.2994/SAJH-D-18-00081.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-18-00081.1","url":null,"abstract":"Abstract. Changes in the body temperature (Tb) of reproductive females are well documented in squamate reptiles. However, the direction of these changes varies among species. Pregnant females may exhibit a lower or higher (and less variable) Tb than nonpregnant females. In some species, pregnancy has no detectable effect on female Tb. In this study, we compared the Tb of female rattlesnakes (Crotalus durissus) in different reproductive statuses (pregnant and nonpregnant) to investigate whether pregnancy influences Tb. We measured the Tb of female rattlesnakes kept in a semi-natural outdoor enclosure during summer and spring 2016 and summer 2017. Pregnant females selected a higher mean Tb than nonpregnant females. Moreover, we found significant differences in Tb among seasons. Body temperatures in summer 2017 were higher than in other seasons; however, reproductive status did not influence Tb variance. Therefore, our results agree with the hypothesis that females change their thermoregulatory behavior during pregnancy. Female rattlesnakes may increase their Tb during pregnancy to increase offspring fitness or to maximize their lifetime fitness.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"23 1","pages":"67 - 74"},"PeriodicalIF":0.9,"publicationDate":"2022-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45359982","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 : 2022-04-30DOI: 10.2994/SAJH-D-20-00006.1
Stefanny Christie Monteiro Titon, V. R. Assis, Braz Titon Junior, G. Kinker, Nicolle Queiroz Hazarbassanov, A. S. Lima, C. O. Oliveira Massoco, P. Fernandes, F. Gomes, R. Markus
Abstract. Phagocytosis is a primary and highly conserved mechanism for clearing the extracellular milieu from pathogens and debris. In amphibians, the lack of antibodies for characterizing the different phenotypes of phagocytic cells has impaired the study of the phagocytic process. We used conventional and flowsight cytometry to determine immune cells' phagocytic activity from the blood and peritoneum of toads by in vitro and in vivo assays. Macrophage-like and neutrophil-like cells were clustered and analyzed according to cell morphology and the number of internalized zymosan particles by flowsight cytometry. We identified peritoneal and blood phagocytes (macrophage-like/monocyte-like and neutrophil-like) and lymphocyte-like cells. Besides, we observed monocyte-like/macrophage-like and neutrophil-like cells engulfing up to seven zymosan particles. Assessing the phagocytic activity from blood and peritoneal phagocytes using in vitro and in vivo assays brings better insights into phagocytosis in amphibian immune cells from distinct body compartments and approaches. Moreover, it is worth highlighting the importance of morphologically identifying the cells and evaluating the number of internalized particles by flowsight cytometry, a valuable asset to further explore phagocytosis and other cellular processes in amphibians under field and laboratory conditions.
{"title":"Optimizing Studies of Phagocytic Activity by Flowsight Cytometry in Amphibians","authors":"Stefanny Christie Monteiro Titon, V. R. Assis, Braz Titon Junior, G. Kinker, Nicolle Queiroz Hazarbassanov, A. S. Lima, C. O. Oliveira Massoco, P. Fernandes, F. Gomes, R. Markus","doi":"10.2994/SAJH-D-20-00006.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-20-00006.1","url":null,"abstract":"Abstract. Phagocytosis is a primary and highly conserved mechanism for clearing the extracellular milieu from pathogens and debris. In amphibians, the lack of antibodies for characterizing the different phenotypes of phagocytic cells has impaired the study of the phagocytic process. We used conventional and flowsight cytometry to determine immune cells' phagocytic activity from the blood and peritoneum of toads by in vitro and in vivo assays. Macrophage-like and neutrophil-like cells were clustered and analyzed according to cell morphology and the number of internalized zymosan particles by flowsight cytometry. We identified peritoneal and blood phagocytes (macrophage-like/monocyte-like and neutrophil-like) and lymphocyte-like cells. Besides, we observed monocyte-like/macrophage-like and neutrophil-like cells engulfing up to seven zymosan particles. Assessing the phagocytic activity from blood and peritoneal phagocytes using in vitro and in vivo assays brings better insights into phagocytosis in amphibian immune cells from distinct body compartments and approaches. Moreover, it is worth highlighting the importance of morphologically identifying the cells and evaluating the number of internalized particles by flowsight cytometry, a valuable asset to further explore phagocytosis and other cellular processes in amphibians under field and laboratory conditions.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"23 1","pages":"58 - 66"},"PeriodicalIF":0.9,"publicationDate":"2022-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46959863","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 : 2022-04-26DOI: 10.2994/SAJH-D-20-00023.1
J. Sharath, Shantha Kumar Samson, M. Bhagya
Abstract. Efferent ductules are part of the male reproductive system. They play a role in providing a nutrient environment for the maintenance of the spermatozoa. Efferent ductules are studied exhaustively in birds and mammals, but reptiles, the first vertebrates that successfully adapted to life on land, have received little attention among the comparative biologists. Hence, the present study aimed to study the seasonal variation in an extra-testicular portion, the efferent ductules, in the male reproductive system of the lizard Eutropis carinata. The results revealed that the epithelium of these ductules is lined by cuboidal non-ciliated cells and ciliated cells. Ultrastructural features of the non-ciliated cells revealed the role of endocytosis and secretion. During the breeding season, the epithelium is positive to periodic Schiff and bromophenol blue staining, indicating the presence of carbohydrate and protein. Histological and histometric parameters exhibit significant seasonal differences. However, there is not much seasonal ultrastructural variation, except for reduced cell height and less cytoplasm as well as reduced granular material in the lumen. Based on the above results, the present study for the first time reveals that the efferent ductules form an essential link between the testis and the epididymis and serve as a conduit for sperm, absorption of rete testis fluid, and secretion. Further, although there is no seasonal variation in the type of cells throughout the length of the efferent ductules during the breeding and non-breeding seasons in E. carinata, the morphology, ultrastructural modifications, activity, and function vary during these seasons.
{"title":"The Efferent Ductules in the Lizard Eutropis carinata: a Functional Morphology and Ultrastructural Study","authors":"J. Sharath, Shantha Kumar Samson, M. Bhagya","doi":"10.2994/SAJH-D-20-00023.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-20-00023.1","url":null,"abstract":"Abstract. Efferent ductules are part of the male reproductive system. They play a role in providing a nutrient environment for the maintenance of the spermatozoa. Efferent ductules are studied exhaustively in birds and mammals, but reptiles, the first vertebrates that successfully adapted to life on land, have received little attention among the comparative biologists. Hence, the present study aimed to study the seasonal variation in an extra-testicular portion, the efferent ductules, in the male reproductive system of the lizard Eutropis carinata. The results revealed that the epithelium of these ductules is lined by cuboidal non-ciliated cells and ciliated cells. Ultrastructural features of the non-ciliated cells revealed the role of endocytosis and secretion. During the breeding season, the epithelium is positive to periodic Schiff and bromophenol blue staining, indicating the presence of carbohydrate and protein. Histological and histometric parameters exhibit significant seasonal differences. However, there is not much seasonal ultrastructural variation, except for reduced cell height and less cytoplasm as well as reduced granular material in the lumen. Based on the above results, the present study for the first time reveals that the efferent ductules form an essential link between the testis and the epididymis and serve as a conduit for sperm, absorption of rete testis fluid, and secretion. Further, although there is no seasonal variation in the type of cells throughout the length of the efferent ductules during the breeding and non-breeding seasons in E. carinata, the morphology, ultrastructural modifications, activity, and function vary during these seasons.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"23 1","pages":"49 - 57"},"PeriodicalIF":0.9,"publicationDate":"2022-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43662407","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 : 2022-04-26DOI: 10.2994/SAJH-D-19-00110.1
A. Pereira, T. C. Portelinha, Adriana Malvasio
Abstract. Although caiman populations are being conserved in some protected areas, they face threats related to human pressure, which may ultimately influence their distribution, abundance, and behavior. In this study, we investigated the population ecology (encounter rate, size structure, sex ratio, and injury frequency) and the effects of human disturbance on Melanosuchus niger and Caiman crocodilus populations in Cantão State Park, southern Brazilian Amazon, Central Brazil. We assessed human pressure on both populations, testing the human disturbance–abundance and human disturbance–size structure relationships. We sampled waterbodies within (lakes) and adjacent to (river) protected areas via nocturnal surveys and captures. Human pressure in the river was assessed and categorized via transects with low, medium, and high levels of disturbance. Our results indicate that C. crocodilus was more abundant than M. niger, with populations of both species mainly composed of juvenile males. We also observed that injuries were more prevalent in juveniles and males. Human disturbance negatively affected C. crocodilus abundance, but no effect was found for M. niger. We found no significant effect of human disturbance on size structure for either species; however, the response for each species differed. Snout–vent length (SVL) decreased with increasing human pressure level in the C. crocodilus population, whereas M. niger showed a greater SVL at higher human pressure levels. Our results suggest that human disturbance related to boat traffic, pollution, riverine population, land use, and human activities negatively influence crocodilian populations in their distribution through a distance–abundance relationship. Additionally, the proximity of settlements and accessibility to protected areas are factors related to human disturbance and should be considered in government decisions and the management of protected areas by environmental agencies. Our results improve our understanding caiman population responses to human disturbance.
{"title":"Population Ecology and Human Disturbance Effects on Two Caiman Species in the Southern Brazilian Amazon","authors":"A. Pereira, T. C. Portelinha, Adriana Malvasio","doi":"10.2994/SAJH-D-19-00110.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-19-00110.1","url":null,"abstract":"Abstract. Although caiman populations are being conserved in some protected areas, they face threats related to human pressure, which may ultimately influence their distribution, abundance, and behavior. In this study, we investigated the population ecology (encounter rate, size structure, sex ratio, and injury frequency) and the effects of human disturbance on Melanosuchus niger and Caiman crocodilus populations in Cantão State Park, southern Brazilian Amazon, Central Brazil. We assessed human pressure on both populations, testing the human disturbance–abundance and human disturbance–size structure relationships. We sampled waterbodies within (lakes) and adjacent to (river) protected areas via nocturnal surveys and captures. Human pressure in the river was assessed and categorized via transects with low, medium, and high levels of disturbance. Our results indicate that C. crocodilus was more abundant than M. niger, with populations of both species mainly composed of juvenile males. We also observed that injuries were more prevalent in juveniles and males. Human disturbance negatively affected C. crocodilus abundance, but no effect was found for M. niger. We found no significant effect of human disturbance on size structure for either species; however, the response for each species differed. Snout–vent length (SVL) decreased with increasing human pressure level in the C. crocodilus population, whereas M. niger showed a greater SVL at higher human pressure levels. Our results suggest that human disturbance related to boat traffic, pollution, riverine population, land use, and human activities negatively influence crocodilian populations in their distribution through a distance–abundance relationship. Additionally, the proximity of settlements and accessibility to protected areas are factors related to human disturbance and should be considered in government decisions and the management of protected areas by environmental agencies. Our results improve our understanding caiman population responses to human disturbance.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"23 1","pages":"32 - 41"},"PeriodicalIF":0.9,"publicationDate":"2022-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49643123","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 : 2022-04-26DOI: 10.2994/SAJH-D-20-00008.1
J. Finger, Meghan D. Kelley, Yufeng Zhang, Cheikhouna Ka, M. Hamilton, R. Elsey, A. Kavazis, M. Mendonça
Abstract. Crocodilians in aquacultural settings exhibit variations in growth and condition. The underlying cause of this has yet to be elucidated, but corticosterone (CORT, the main crocodilian stress hormone) is thought to play a role in this. In this study, we measured baseline plasma CORT, heterophil-lymphocyte (H/L) ratios, relative glucocorticoid receptor (GR) levels in the forebrain, and body condition index (BCI) of juvenile American alligators (Alligator mississippiensis). Both univariate and multivariate analyses were used to investigate underlying relationships. In univariate analysis, BCI was negatively related with GR levels, but not by plasma CORT. Multivariate analysis revealed that both relative forebrain GR levels and plasma CORT were negatively related with alligator BCI: alligators with higher body condition had lower levels of CORT and GRs. However, H/L ratios were unrelated to BCI. Our results implicate dysregulation of the hypothalamic-pituitary-adrenal axis as an important factor influencing crocodilian body condition.
{"title":"Relationships of Brain Glucocorticoid Receptors and Commonly Used Stress Parameters with Body Condition of Juvenile American Alligators (Alligator mississippiensis)","authors":"J. Finger, Meghan D. Kelley, Yufeng Zhang, Cheikhouna Ka, M. Hamilton, R. Elsey, A. Kavazis, M. Mendonça","doi":"10.2994/SAJH-D-20-00008.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-20-00008.1","url":null,"abstract":"Abstract. Crocodilians in aquacultural settings exhibit variations in growth and condition. The underlying cause of this has yet to be elucidated, but corticosterone (CORT, the main crocodilian stress hormone) is thought to play a role in this. In this study, we measured baseline plasma CORT, heterophil-lymphocyte (H/L) ratios, relative glucocorticoid receptor (GR) levels in the forebrain, and body condition index (BCI) of juvenile American alligators (Alligator mississippiensis). Both univariate and multivariate analyses were used to investigate underlying relationships. In univariate analysis, BCI was negatively related with GR levels, but not by plasma CORT. Multivariate analysis revealed that both relative forebrain GR levels and plasma CORT were negatively related with alligator BCI: alligators with higher body condition had lower levels of CORT and GRs. However, H/L ratios were unrelated to BCI. Our results implicate dysregulation of the hypothalamic-pituitary-adrenal axis as an important factor influencing crocodilian body condition.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"23 1","pages":"42 - 48"},"PeriodicalIF":0.9,"publicationDate":"2022-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42311849","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 : 2022-04-18DOI: 10.2994/SAJH-D-19-00113.1
N. R. de Albuquerque, Fernanda Martins dos Santos, D. M. Borges-Nojosa, R. W. Ávila
Abstract. We describe a new species of Leptophis from the Caatinga ecoregion encompassing the semi-arid region of Brazil. Phylogenetic analysis of 16S rDNA sequences indicate that the new species is nested deep within the L. ahaetulla complex. The new species differs from all other congeners in the following unique character combination: two dorsolateral Light Emerald Green (142) to Robin's Egg Blue (161) stripes separated from each other by Pale Buff (1) to Smoke Gray (266) vertebral stripe (continuous to tail) present; loreal scale absent; maxillary teeth 21–24; ventrals 158–177; subcaudals 137–162; black spots on head absent; supracephalic plates of head not edged with black pigment; adult color pattern lacking dark oblique bands; keels absent on first dorsal scale rows; hemipenis unilobed, capitate, with undivided sulcus spermaticus. The new species is distinguished from L. ahaetulla ahaetulla by the Light Emerald Green (142) to Robin's Egg Blue (161) (in life) dorsolateral stripes separated from each other by a Pale Buff (1) to Smoke Gray (266) vertebral stripe (at least anteriorly), and by having white to Pale Sulphur Yellow (92) scales on the first (on anterior region of body) to fourth (midbody region) scale rows [vs. Light Grass Green (109) to Light Emerald Green (142) with Yellow Ocher (14), Cinnamon-Drab (50) or Sulphur Yellow (80) vertebral stripe; second to third—occasionally the fourth—scale rows Sulphur Yellow (80), at least anteriorly], wider snout (vs. narrow), postocular stripe wider (vs. narrow), basal region of hemipenis with 10–14 spines and first row of hemipenial body with 8–9 spines (vs. 18–22 in the basal region and 5–8 in the first row). The new species differs from L. a. liocercus, which is also distributed in the Northeast Region Brazil with a small overlap in distribution, by the dorsolateral stripes (vs. dorsum unstriped), and 18–22 spines in the fourth row of the hemipenial body (vs. 11–18). Recognition of the new species is also consistent with uncorrected pairwise distances between 16S rDNA sequences.
{"title":"A New Species of Parrot-Snake of the Genus Leptophis Bell, 1825 (Serpentes, Colubridae) from the Semi-Arid Region of Brazil","authors":"N. R. de Albuquerque, Fernanda Martins dos Santos, D. M. Borges-Nojosa, R. W. Ávila","doi":"10.2994/SAJH-D-19-00113.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-19-00113.1","url":null,"abstract":"Abstract. We describe a new species of Leptophis from the Caatinga ecoregion encompassing the semi-arid region of Brazil. Phylogenetic analysis of 16S rDNA sequences indicate that the new species is nested deep within the L. ahaetulla complex. The new species differs from all other congeners in the following unique character combination: two dorsolateral Light Emerald Green (142) to Robin's Egg Blue (161) stripes separated from each other by Pale Buff (1) to Smoke Gray (266) vertebral stripe (continuous to tail) present; loreal scale absent; maxillary teeth 21–24; ventrals 158–177; subcaudals 137–162; black spots on head absent; supracephalic plates of head not edged with black pigment; adult color pattern lacking dark oblique bands; keels absent on first dorsal scale rows; hemipenis unilobed, capitate, with undivided sulcus spermaticus. The new species is distinguished from L. ahaetulla ahaetulla by the Light Emerald Green (142) to Robin's Egg Blue (161) (in life) dorsolateral stripes separated from each other by a Pale Buff (1) to Smoke Gray (266) vertebral stripe (at least anteriorly), and by having white to Pale Sulphur Yellow (92) scales on the first (on anterior region of body) to fourth (midbody region) scale rows [vs. Light Grass Green (109) to Light Emerald Green (142) with Yellow Ocher (14), Cinnamon-Drab (50) or Sulphur Yellow (80) vertebral stripe; second to third—occasionally the fourth—scale rows Sulphur Yellow (80), at least anteriorly], wider snout (vs. narrow), postocular stripe wider (vs. narrow), basal region of hemipenis with 10–14 spines and first row of hemipenial body with 8–9 spines (vs. 18–22 in the basal region and 5–8 in the first row). The new species differs from L. a. liocercus, which is also distributed in the Northeast Region Brazil with a small overlap in distribution, by the dorsolateral stripes (vs. dorsum unstriped), and 18–22 spines in the fourth row of the hemipenial body (vs. 11–18). Recognition of the new species is also consistent with uncorrected pairwise distances between 16S rDNA sequences.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"23 1","pages":"7 - 24"},"PeriodicalIF":0.9,"publicationDate":"2022-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41835022","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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