Skeletochronology is a method commonly used for estimating the age of amphibians and reptiles in the wild. However, the number of lines of arrested growth （LAGs） does not necessarily reflect age in some species. We ...Skeletochronology is a method commonly used for estimating the age of amphibians and reptiles in the wild. However, the number of lines of arrested growth （LAGs） does not necessarily reflect age in some species. We validated the applicability of this method to an endangered eublepharid gecko, Goniurosaurus kuroiwae, then inferred its longevity and age structures in wild populations. We classified young geckos into three groups using previously published data for early growth： Group 1 contained hatchlings before the first winter, Group 2 contained hatchlings after the first win- ter, and Group 3 included yearlings after the second winter. LAG numbers in these groups were then compared. All individuals in Group 1 possessed a single LAG, which was considered as a hatching line. Most individuals in Groups 2 and 3 possessed one and two additional LAGs, respectively （LAG1 and LAG2）, corroborating the notion that LAGs are formed annually. A few geckos exhibited fewer LAGs than expected. Analysis of variations in LAG and marrow cavity diameter demonstrated that in animals with fewer LAGs, endosteal resorption or fusion of hatching line and LAG1 had occurred. LAG2 was never lost by endosteal resorption and was identifiable by its diameter. Thus, the age of adult geckos could be determined by counting LAGs outward from LAG2. Application of this method to wild populations re- vealed that the longevity of this species is not less than 83 months, but that almost all individuals in fragmented habitats die before 50 months, suggesting lower population sustainability in such habitats.展开更多
Gekko liboensis Zhou and Li, 1982 is a poorly known gecko originating from Libo, Guizhou, southern China. Since the original description based on a single female from Libo, only three specimens（two females and one ju...Gekko liboensis Zhou and Li, 1982 is a poorly known gecko originating from Libo, Guizhou, southern China. Since the original description based on a single female from Libo, only three specimens（two females and one juvenile） have been reported from the type locality. Because of its close morphological resemblance to G. hokouensis Pope, 1927, G. liboensis is required to be reevaluated for its taxonomic status by studies based on additional specimens. Here we report for the first time the morphological features of 31 newly obtained specimens of G. liboensis from type locality and others, including males, and compare them with those of related species, chiefly on the basis of information from the literature. In addition, specimen-based comparisons were also made with G. hokouensis and an undescribed cryptic species known from the Ryukyus Islands, Japan. Results showed that the species is distinguished from its congeners in having a larger body size（60–91 mm）, 0–2 small internasals, 10–13 supralabials, 10–13 infralabials, smooth enlarged tubercles present on the dorsum forming 4–10 irregular rows at the midbody but absent on the four limbs and tail, both fingers and toes without developed interdigital webs, a single cloacal spur on each side, and 10–12 precloacal pores in males. It most resembles G. hokouensis and its cryptic species but is clearly differentiated by having a larger body size, a predominantly absent internasal, fewer number of dorsal tubercle rows, larger number of precloacal pores, and conspicuous white marks on the dorsum and head. Judging from these results, we confirmed the taxonomic validity of G. liboensis. In addition, the geographic distribution of this gecko on the basis of obtained data was briefly discussed.展开更多
基金supported by the Zoshinkai Fund for Protection of Endangered Animals and the Grant from the Japan Society for the Promotion of Science (JSPS KAKENHI Grant number 22510244)
文摘Skeletochronology is a method commonly used for estimating the age of amphibians and reptiles in the wild. However, the number of lines of arrested growth （LAGs） does not necessarily reflect age in some species. We validated the applicability of this method to an endangered eublepharid gecko, Goniurosaurus kuroiwae, then inferred its longevity and age structures in wild populations. We classified young geckos into three groups using previously published data for early growth： Group 1 contained hatchlings before the first winter, Group 2 contained hatchlings after the first win- ter, and Group 3 included yearlings after the second winter. LAG numbers in these groups were then compared. All individuals in Group 1 possessed a single LAG, which was considered as a hatching line. Most individuals in Groups 2 and 3 possessed one and two additional LAGs, respectively （LAG1 and LAG2）, corroborating the notion that LAGs are formed annually. A few geckos exhibited fewer LAGs than expected. Analysis of variations in LAG and marrow cavity diameter demonstrated that in animals with fewer LAGs, endosteal resorption or fusion of hatching line and LAG1 had occurred. LAG2 was never lost by endosteal resorption and was identifiable by its diameter. Thus, the age of adult geckos could be determined by counting LAGs outward from LAG2. Application of this method to wild populations re- vealed that the longevity of this species is not less than 83 months, but that almost all individuals in fragmented habitats die before 50 months, suggesting lower population sustainability in such habitats.
基金financially supported by a Fellowship for Young International Scientists of the Chinese Academy of Sciences (No. Y4J3011100) to TJ
文摘Gekko liboensis Zhou and Li, 1982 is a poorly known gecko originating from Libo, Guizhou, southern China. Since the original description based on a single female from Libo, only three specimens（two females and one juvenile） have been reported from the type locality. Because of its close morphological resemblance to G. hokouensis Pope, 1927, G. liboensis is required to be reevaluated for its taxonomic status by studies based on additional specimens. Here we report for the first time the morphological features of 31 newly obtained specimens of G. liboensis from type locality and others, including males, and compare them with those of related species, chiefly on the basis of information from the literature. In addition, specimen-based comparisons were also made with G. hokouensis and an undescribed cryptic species known from the Ryukyus Islands, Japan. Results showed that the species is distinguished from its congeners in having a larger body size（60–91 mm）, 0–2 small internasals, 10–13 supralabials, 10–13 infralabials, smooth enlarged tubercles present on the dorsum forming 4–10 irregular rows at the midbody but absent on the four limbs and tail, both fingers and toes without developed interdigital webs, a single cloacal spur on each side, and 10–12 precloacal pores in males. It most resembles G. hokouensis and its cryptic species but is clearly differentiated by having a larger body size, a predominantly absent internasal, fewer number of dorsal tubercle rows, larger number of precloacal pores, and conspicuous white marks on the dorsum and head. Judging from these results, we confirmed the taxonomic validity of G. liboensis. In addition, the geographic distribution of this gecko on the basis of obtained data was briefly discussed.
