Junichiro Naito, Chiaki Kambayashi, Renshiro Namba, Natsuhiko Yoshikawa, N. Shimizu
Abstract: Hynobiid salamanders of the genus Onychodactylus are known to possess palmar and tarsal black tubercles or asperities during the breeding season, which were once considered male-specific characters used for spawning activity. However, such tubercles and asperities have also been observed in females and are not always developed in breeding individuals; thus, their functions remain unclear. In this study, we investigated the developmental process of the tubercles and asperities in two Onychodactylus species in the Chugoku Mountains. We found that these traits appear rapidly immediately before the start of spawning. Tubercles and asperities were also observed in females, in which they showed a similar temporal developmental pattern to that observed in males; thus, they may be adaptive traits for migration to underground spawning sites or for breeding activity at these sites. In the Chugoku Mountains, O. kinneburi and O. japonicus are known to share breeding sites for spawning, but their reproductive isolation mechanism remains unknown. In the course of our survey, we found a temporal gap in breeding season between the two species, which may be involved in premating reproductive isolation.
{"title":"Seasonal Changes in Breeding Characters of Two Syntopic Onychodactylus Salamanders with Special Reference to Differentiation in Their Breeding Seasons","authors":"Junichiro Naito, Chiaki Kambayashi, Renshiro Namba, Natsuhiko Yoshikawa, N. Shimizu","doi":"10.5358/hsj.41.196","DOIUrl":"https://doi.org/10.5358/hsj.41.196","url":null,"abstract":"Abstract: Hynobiid salamanders of the genus Onychodactylus are known to possess palmar and tarsal black tubercles or asperities during the breeding season, which were once considered male-specific characters used for spawning activity. However, such tubercles and asperities have also been observed in females and are not always developed in breeding individuals; thus, their functions remain unclear. In this study, we investigated the developmental process of the tubercles and asperities in two Onychodactylus species in the Chugoku Mountains. We found that these traits appear rapidly immediately before the start of spawning. Tubercles and asperities were also observed in females, in which they showed a similar temporal developmental pattern to that observed in males; thus, they may be adaptive traits for migration to underground spawning sites or for breeding activity at these sites. In the Chugoku Mountains, O. kinneburi and O. japonicus are known to share breeding sites for spawning, but their reproductive isolation mechanism remains unknown. In the course of our survey, we found a temporal gap in breeding season between the two species, which may be involved in premating reproductive isolation.","PeriodicalId":56053,"journal":{"name":"Current Herpetology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48650946","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}
Abstract: In the Ogasawara Islands adhesive traps are the primary means of controlling non-native Anolis carolinensis. If the types of tree trunks most frequently used by this lizard are identified, trapping efficiency can be improved by concentrating traps at such points. To analyze selectivity by trunk diameter, the diameters of 270 tree trunks used by the lizards and 1,024 tree trunks in the study area were measured. The analysis indicated the lizards avoided trunks of 1 cm or less in diameter. On the other hand, trunks with diameters over 2 cm appeared to be used randomly, regardless of diameter size. The diameter class distribution of trees varies by region and by forest. The range of tree trunk diameters commonly used by lizards is thus expected to vary by location. It would be advantageous to develop a capture technique that is effective for trunks and branches of various diameters.
{"title":"Selectivity of Perch Diameter by Green Anole (Anolis carolinensis) for Trapping in Ogasawara","authors":"N. Mitani","doi":"10.5358/hsj.41.172","DOIUrl":"https://doi.org/10.5358/hsj.41.172","url":null,"abstract":"Abstract: In the Ogasawara Islands adhesive traps are the primary means of controlling non-native Anolis carolinensis. If the types of tree trunks most frequently used by this lizard are identified, trapping efficiency can be improved by concentrating traps at such points. To analyze selectivity by trunk diameter, the diameters of 270 tree trunks used by the lizards and 1,024 tree trunks in the study area were measured. The analysis indicated the lizards avoided trunks of 1 cm or less in diameter. On the other hand, trunks with diameters over 2 cm appeared to be used randomly, regardless of diameter size. The diameter class distribution of trees varies by region and by forest. The range of tree trunk diameters commonly used by lizards is thus expected to vary by location. It would be advantageous to develop a capture technique that is effective for trunks and branches of various diameters.","PeriodicalId":56053,"journal":{"name":"Current Herpetology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47999188","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}
Abstract: The number of species of salamanders of the genus Onychodactylus in Japan has increased from one to six nominal species over the past decade, by taxonomic studies based not only on morphological but also molecular phylogenetic data. However, the presence of an additional cryptic species has been suggested by a series of previous studies. Here, we describe a new species, Onychodactylus pyrrhonotus sp. nov., from the Kinki, Chubu and Hokuriku Districts of central Honshu, Japan, based on morphological and genetic evidence. It belongs to the O. japonicus species complex and is the sister species of O. kinneburi from Shikoku Island and westernmost part of Honshu with 5.5% sequence divergence in the mitochondrial cytochrome b gene. The range of the new species completely overlaps with that of O. japonicus sensu stricto, and they are syntopic in at least six known localities. As shown in a previous study, reproductive isolation between these sympatric species is substantial. The new species is morphologically most easily distinguished from congeners by coloration, a sharply defined scarlet to pinkish dorsal stripe or mottling on a black background and dusty white dots on the venter.
摘要/ Abstract摘要:在过去的十年中，通过形态学和分子系统发育数据的分类研究，日本的蝾螈属(Onychodactylus)的名义种数从1种增加到6种。然而，一系列先前的研究表明存在另外一种隐种。本文基于形态学和遗传证据，描述了一种新的物种——Onychodactylus pyrrhonotus sp. nov.，来自日本本州中部近基、中部和北ku地区。它属于O. japonicus种复合体，是来自四国岛和本州最西部的O. kinneburi的姐妹种，线粒体细胞色素b基因序列差异为5.5%。该新种的分布范围与日本血吸虫(O. japonicus sensu stricto)的分布范围完全重叠，并且在至少6个已知的地方具有同位性。正如先前的研究表明，这些同域物种之间的生殖隔离是实质性的。这个新物种在形态上最容易从颜色上与同类区分开来，黑色背景上有清晰的猩红色到粉红色的背条纹或斑驳，腹部有灰白色的点。
{"title":"A New Salamander of the Genus Onychodactylus from Central Honshu, Japan (Amphibia, Caudata, Hynobiidae)","authors":"Natsuhiko Yoshikawa, M. Matsui","doi":"10.5358/hsj.41.82","DOIUrl":"https://doi.org/10.5358/hsj.41.82","url":null,"abstract":"Abstract: The number of species of salamanders of the genus Onychodactylus in Japan has increased from one to six nominal species over the past decade, by taxonomic studies based not only on morphological but also molecular phylogenetic data. However, the presence of an additional cryptic species has been suggested by a series of previous studies. Here, we describe a new species, Onychodactylus pyrrhonotus sp. nov., from the Kinki, Chubu and Hokuriku Districts of central Honshu, Japan, based on morphological and genetic evidence. It belongs to the O. japonicus species complex and is the sister species of O. kinneburi from Shikoku Island and westernmost part of Honshu with 5.5% sequence divergence in the mitochondrial cytochrome b gene. The range of the new species completely overlaps with that of O. japonicus sensu stricto, and they are syntopic in at least six known localities. As shown in a previous study, reproductive isolation between these sympatric species is substantial. The new species is morphologically most easily distinguished from congeners by coloration, a sharply defined scarlet to pinkish dorsal stripe or mottling on a black background and dusty white dots on the venter.","PeriodicalId":56053,"journal":{"name":"Current Herpetology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44472411","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}
Masaru Senzaki, S. Sano, Atsushi Takemoto, I. Miura, M. Ogata
Abstract: We uncovered the phylogenetic origins of the Japanese red-bellied newt (Cynops pyrrhogaster) population newly found in Yokohama city and 11 neighboring populations in Kanagawa Prefecture based on mitochondrial NADH6-tRNAGlu-cytochrome b DNA sequences. The Yokohama city population was found to be an alien population introduced from Western Japan. On the other hand, the other populations we investigated belong to either of two genetic lineages of the newt (CENTRAL and NORTHERN), and they are distributed parapatrically around the foot of the Tanzawa Mountains.
摘要基于线粒体NADH6-tRNAGlu-cytochrome b DNA序列，揭示了横滨市和神奈川县11个邻近种群新发现的日本红腹蝾螈(Cynops pyrrhogaster)种群的系统发育起源。横滨市人口被发现是从日本西部引进的外来人口。另一方面，我们调查的其他种群属于两种遗传谱系(中部和北部)中的任何一种，它们分布在坦桑尼亚山脚下。
{"title":"Phylogenetic Origins of a Newly Found Japanese Red-Bellied Newt Population in Yokohama City and Other Populations in Kanagawa Prefecture","authors":"Masaru Senzaki, S. Sano, Atsushi Takemoto, I. Miura, M. Ogata","doi":"10.5358/hsj.41.132","DOIUrl":"https://doi.org/10.5358/hsj.41.132","url":null,"abstract":"Abstract: We uncovered the phylogenetic origins of the Japanese red-bellied newt (Cynops pyrrhogaster) population newly found in Yokohama city and 11 neighboring populations in Kanagawa Prefecture based on mitochondrial NADH6-tRNAGlu-cytochrome b DNA sequences. The Yokohama city population was found to be an alien population introduced from Western Japan. On the other hand, the other populations we investigated belong to either of two genetic lineages of the newt (CENTRAL and NORTHERN), and they are distributed parapatrically around the foot of the Tanzawa Mountains.","PeriodicalId":56053,"journal":{"name":"Current Herpetology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70621503","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}
Felix Landry Yuan, Tracey-Leigh Prigge, Yik‐Hei Sung, C. Dingle, T. Bonebrake
Abstract: Kraits (genus Bungarus) are a group of highly venomous elapid snakes found across tropical Asia. Although they are notorious for causing many, often deadly, envenomations throughout the continent, their taxonomy and species nomenclature is subject to regular revisions. The boundaries demarcating B. candidus, B. multicinctus, and B. wanghaotingi, in Southern China and Northern Myanmar are particularly obscure. Despite the extensively overlapping distributions for the three species, only B. multicinctus has been documented in Hong Kong. Following genetic analyses, we suggest that both B. multincinctus and B. wanghaotingi occur in Hong Kong. However, our morphological examinations are overall inconclusive in distinguishing the two species. With potential interspecific antivenin differences, the new identification of B. wanghaotingi in Hong Kong is of important medical interest. We recommend further ecological, taxonomic, and behavioural studies be conducted to properly distinguish B. multincinctus and B. wanghaotingi in the region.
{"title":"Two Genetically Distinct yet Morphologically Indistinct Bungarus Species (Squamata, Elapidae) in Hong Kong","authors":"Felix Landry Yuan, Tracey-Leigh Prigge, Yik‐Hei Sung, C. Dingle, T. Bonebrake","doi":"10.5358/hsj.41.114","DOIUrl":"https://doi.org/10.5358/hsj.41.114","url":null,"abstract":"Abstract: Kraits (genus Bungarus) are a group of highly venomous elapid snakes found across tropical Asia. Although they are notorious for causing many, often deadly, envenomations throughout the continent, their taxonomy and species nomenclature is subject to regular revisions. The boundaries demarcating B. candidus, B. multicinctus, and B. wanghaotingi, in Southern China and Northern Myanmar are particularly obscure. Despite the extensively overlapping distributions for the three species, only B. multicinctus has been documented in Hong Kong. Following genetic analyses, we suggest that both B. multincinctus and B. wanghaotingi occur in Hong Kong. However, our morphological examinations are overall inconclusive in distinguishing the two species. With potential interspecific antivenin differences, the new identification of B. wanghaotingi in Hong Kong is of important medical interest. We recommend further ecological, taxonomic, and behavioural studies be conducted to properly distinguish B. multincinctus and B. wanghaotingi in the region.","PeriodicalId":56053,"journal":{"name":"Current Herpetology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44279552","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}
Keita Niwa, Natsuhiko Yoshikawa, K. Nishikawa, M. Matsui
Abstract: We developed eight novel microsatellite markers for the salamander Hynobius tsuensis, which is endemic to Tsushima Island, Japan. In H. tsuensis, the number of alleles, observed heterozygosity, and expected heterozygosity in each locus ranged from 1 to 10, 0.00 to 0.76, and 0.00 to 0.76, respectively. In cross-species amplification, five and four of the eight loci were successfully amplified for all individuals of Hynobius sp. from Tsushima and H. nebulosus, respectively. Three species of Hynobius were clearly split from each other in the STRUCTURE analysis, indicating genetic differentiation in nuclear DNA among three species. This is the first report on genetic variation between two close relatives, Hynobius sp. from Tsushima and H. nebulosus based on nuclear loci. These novel markers will be useful for elucidating intraspecific variations and inferring conservation units within H. tsuensis, and studying intra- and inter-specific variations in other Hynobius.
{"title":"Development of Eight Microsatellite Markers for the Tsushima Salamander, Hynobius tsuensis, and its Close Relatives (Amphibia: Caudata) with Preliminary Analysis of Genetic Differentiation","authors":"Keita Niwa, Natsuhiko Yoshikawa, K. Nishikawa, M. Matsui","doi":"10.5358/hsj.41.125","DOIUrl":"https://doi.org/10.5358/hsj.41.125","url":null,"abstract":"Abstract: We developed eight novel microsatellite markers for the salamander Hynobius tsuensis, which is endemic to Tsushima Island, Japan. In H. tsuensis, the number of alleles, observed heterozygosity, and expected heterozygosity in each locus ranged from 1 to 10, 0.00 to 0.76, and 0.00 to 0.76, respectively. In cross-species amplification, five and four of the eight loci were successfully amplified for all individuals of Hynobius sp. from Tsushima and H. nebulosus, respectively. Three species of Hynobius were clearly split from each other in the STRUCTURE analysis, indicating genetic differentiation in nuclear DNA among three species. This is the first report on genetic variation between two close relatives, Hynobius sp. from Tsushima and H. nebulosus based on nuclear loci. These novel markers will be useful for elucidating intraspecific variations and inferring conservation units within H. tsuensis, and studying intra- and inter-specific variations in other Hynobius.","PeriodicalId":56053,"journal":{"name":"Current Herpetology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45278806","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}
Abstract: The development of lotic-breeding Bufo torrenticola is described from zygote to completion of metamorphosis in captivity at 13±1°C. We delimit 56 developmental stages based on external features. We describe developmental stages so as to be comparable to common stages that are widely used for anurans. We also compare the larval development between B. torrenticola in lotic water and lentic water, and with lentic-breeding B. japonicus formosus in lentic water. Our results suggest tadpole mouth size in B. torrenticola is determined by genetic factors, but the tail muscle volume is determined by both genetic and environmental factors.
{"title":"Developmental Stages of Lotic-breeding Toad, Bufo torrenticola, with a Comparison to Lentic-breeding B. japonicus formosus (Amphibia: Anura: Bufonidae)","authors":"Kazuhiro Tanaka, K. Nishikawa","doi":"10.5358/hsj.41.8","DOIUrl":"https://doi.org/10.5358/hsj.41.8","url":null,"abstract":"Abstract: The development of lotic-breeding Bufo torrenticola is described from zygote to completion of metamorphosis in captivity at 13±1°C. We delimit 56 developmental stages based on external features. We describe developmental stages so as to be comparable to common stages that are widely used for anurans. We also compare the larval development between B. torrenticola in lotic water and lentic water, and with lentic-breeding B. japonicus formosus in lentic water. Our results suggest tadpole mouth size in B. torrenticola is determined by genetic factors, but the tail muscle volume is determined by both genetic and environmental factors.","PeriodicalId":56053,"journal":{"name":"Current Herpetology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45203345","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}
Abstract: Life history parameters are essential when we consider appropriate strategy for conservation of wildlife based on population dynamics modelling. In this study, life history stage and sex-specific survival rates of a Japanese pond turtle (Mauremys japonica) population in foothill region were estimated. Life history was divided into three stages based on the age, separately for males and females, estimated by counting the number of annual rings on scutes: juvenile (1–2 years old), young adult (3–4), and adult (>5) in males, and juvenile (1–4), subadult (5–7), and adult (>8) in females. The median annual survival of subadult and adult females was 0.84 (95% credible interval: 0.54–0.99) and 0.94 (0.77–1.00), respectively, and higher than the survival of juvenile females. In contrast, adult survival of males was estimated as 0.79 (0.44–0.99), and it was higher than the survival of young adult and juvenile males. This study showed that the patterns of survivorship of M. japonica coincide with those of other chelonians.
{"title":"Life History Stage and Sex-specific Survival Rates for the Japanese Pond Turtle, Mauremys japonica, in the Foothill Region of Chiba Prefecture, Japan","authors":"Shawichi Kagayama","doi":"10.5358/hsj.41.138","DOIUrl":"https://doi.org/10.5358/hsj.41.138","url":null,"abstract":"Abstract: Life history parameters are essential when we consider appropriate strategy for conservation of wildlife based on population dynamics modelling. In this study, life history stage and sex-specific survival rates of a Japanese pond turtle (Mauremys japonica) population in foothill region were estimated. Life history was divided into three stages based on the age, separately for males and females, estimated by counting the number of annual rings on scutes: juvenile (1–2 years old), young adult (3–4), and adult (>5) in males, and juvenile (1–4), subadult (5–7), and adult (>8) in females. The median annual survival of subadult and adult females was 0.84 (95% credible interval: 0.54–0.99) and 0.94 (0.77–1.00), respectively, and higher than the survival of juvenile females. In contrast, adult survival of males was estimated as 0.79 (0.44–0.99), and it was higher than the survival of young adult and juvenile males. This study showed that the patterns of survivorship of M. japonica coincide with those of other chelonians.","PeriodicalId":56053,"journal":{"name":"Current Herpetology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49470194","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}
Abstract: Sexual dimorphism and geographic variation are common in snakes. The white-lipped pitviper (Trimeresurus albolabris) is a common and widely distributed venomous snake species throughout the Southeast Asia. We report on the sexual dimorphism and geographic variation of T. albolabris in China. Ninety-nine specimens (57 females and 42 males) were examined by using analysis of variance, analysis of covariance, principal component analysis, and other statistical methods for 68 morphological characters. The result showed that T. albolabris displays significant sexual dimorphism in several external characters. Females have a longer snout-vent length, wider anal scales, and larger head size than males, whilst males exhibit a longer tail length and larger number of subcaudal scales. No significant geographic variation was detected, suggesting the absence of obvious morphological differentiation among local populations in China.
{"title":"Sexual Dimorphism and Geographic Variation of the White-lipped Pit Viper (Trimeresurus albolabris) in China","authors":"Fei Zhu, Ling-Chu Chen, P. Guo, Yu Xu, Qin Liu","doi":"10.5358/hsj.41.24","DOIUrl":"https://doi.org/10.5358/hsj.41.24","url":null,"abstract":"Abstract: Sexual dimorphism and geographic variation are common in snakes. The white-lipped pitviper (Trimeresurus albolabris) is a common and widely distributed venomous snake species throughout the Southeast Asia. We report on the sexual dimorphism and geographic variation of T. albolabris in China. Ninety-nine specimens (57 females and 42 males) were examined by using analysis of variance, analysis of covariance, principal component analysis, and other statistical methods for 68 morphological characters. The result showed that T. albolabris displays significant sexual dimorphism in several external characters. Females have a longer snout-vent length, wider anal scales, and larger head size than males, whilst males exhibit a longer tail length and larger number of subcaudal scales. No significant geographic variation was detected, suggesting the absence of obvious morphological differentiation among local populations in China.","PeriodicalId":56053,"journal":{"name":"Current Herpetology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47365737","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}
Abstract: Captive breeding programs are utilized worldwide for the recovery and conservation of endangered species, including the critically-endangered hawksbill turtle (Eretmochelys imbricata). However, aggression is an issue that is commonly reported among captive hawksbill turtles housed together. In the present study, we installed rocks in a captive environment to assess whether they can suppress aggressive behavior in captive hawksbill turtles. The behavior of immature female hawksbill turtles (n=6) was recorded over a 10 d period (between 0900 and 1700 h daily) in an experimental tank under the following conditions: (1) housed alone or paired with another individual in the (2) presence and (3) absence of rocks. Resting behavior was recorded as the total amount of time spent resting per day, while hiding and biting behaviors (i.e., aggressive behavior) were recorded as the total number of events observed per day. Serum corticosterone concentrations were measured at 0900 and 1700 h daily throughout the experimental period. The median number of hiding and biting events was significantly lower for paired individuals housed in the presence of rocks than that for those housed in the absence of rocks. Although no significant differences in serum corticosterone concentrations were observed among the experimental groups, paired individuals spent significantly more time resting in the presence of rocks. Our results suggest that underwater rock installations effectively reduce aggression in captive hawksbill turtles.
{"title":"Rock Installation Reduces Aggressive Behavior in Captive Hawksbill Turtles","authors":"Isao Kawazu, Miwa Suzuki, Konomi Maeda","doi":"10.5358/hsj.41.1","DOIUrl":"https://doi.org/10.5358/hsj.41.1","url":null,"abstract":"Abstract: Captive breeding programs are utilized worldwide for the recovery and conservation of endangered species, including the critically-endangered hawksbill turtle (Eretmochelys imbricata). However, aggression is an issue that is commonly reported among captive hawksbill turtles housed together. In the present study, we installed rocks in a captive environment to assess whether they can suppress aggressive behavior in captive hawksbill turtles. The behavior of immature female hawksbill turtles (n=6) was recorded over a 10 d period (between 0900 and 1700 h daily) in an experimental tank under the following conditions: (1) housed alone or paired with another individual in the (2) presence and (3) absence of rocks. Resting behavior was recorded as the total amount of time spent resting per day, while hiding and biting behaviors (i.e., aggressive behavior) were recorded as the total number of events observed per day. Serum corticosterone concentrations were measured at 0900 and 1700 h daily throughout the experimental period. The median number of hiding and biting events was significantly lower for paired individuals housed in the presence of rocks than that for those housed in the absence of rocks. Although no significant differences in serum corticosterone concentrations were observed among the experimental groups, paired individuals spent significantly more time resting in the presence of rocks. Our results suggest that underwater rock installations effectively reduce aggression in captive hawksbill turtles.","PeriodicalId":56053,"journal":{"name":"Current Herpetology","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41454724","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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