Comprehensive surveys on the distribution of the endangered Chinting alpine toad(Scutiger chintingensis) were recently conducted, revealing important findings regarding its population characteristics. This study integ...Comprehensive surveys on the distribution of the endangered Chinting alpine toad(Scutiger chintingensis) were recently conducted, revealing important findings regarding its population characteristics. This study integrated morphological and molecular analyses to clarify the taxonomic status of these populations. Based on detailed morphological comparisons and phylogenetic analyses, the population from Wolong, Wenchuan County,Sichuan, China, is identified as a new species, which is formally described herein. The new species can be distinguished from all known congeners by a unique combination of following characteristics:(1) small body size, SVL 42.2–46.9 mm in adult males, SVL54.3–56.3 in adult females;(2) vomerine ridges and vomerine teeth absent, maxillary teeth present;(3)internasal distance and interorbital distance relatively large;(4) subarticular tubercle absent on fingers and toes;(5) dorsal and lateral skin rough with densely-distributed horny spines in males, smooth and lacking black horny spines in females;(6) vocal sac absent in males;(7) pair of pectoral glands and pair of axillary glands present on chest in males, axillary gland about two-thirds pectoral gland in size;(8) in breeding males, pectoral glands and axillary glands covered by dense spines, belly rough with horny spines, nuptial spines present on dorsal and lateral surface of first and second fingers and inner side of third finger,dense spines on inner forelimb aligned, extending from wrist to near axilla. This study highlights the critical importance of accurate taxonomic identification, particularly for endangered species, as misidentifications can misguide subsequent biological research and conservation efforts.展开更多
A new species of Scutiger Theobald, 1868 is described from Medog, southeastern Tibet, China, based on morphological and molecular data. The new species was previously identified as Scutiger nyingchiensis, but it can b...A new species of Scutiger Theobald, 1868 is described from Medog, southeastern Tibet, China, based on morphological and molecular data. The new species was previously identified as Scutiger nyingchiensis, but it can be differentiated from the latter and all other congeners by the following combination of characters： （1） medium adult body size, SVL 50.5-55.6 mm in males and 53.8-57.2 mm in females; （2） maxillary teeth absent; （3） web rudimen- tary between toes; （4） prominent, conical-shaped tubercles on dorsal and lateral surfaces of body and limbs; （5） tubercles covered by black spines in both sexes in breeding condition; （6） a pair of pectoral glands and a pair of axillary glands present and covered by black spines in males in breeding condition, width of axillary gland less than 50% of pectoral gland; （7） nuptial spines present on dorsal surface of first and second fingers, and inner side of third finger in males in breeding condition; （8） spines absent on the abdominal region; （9） vocal sac absent. In addition, the distribution and conservation status of the new species are also discussed展开更多
This study investigated the systematics of the megophryid genus Scutiger from eastern and western Nepal using molecular and morphological data. Our results support two divergent lineages, one of which has nuptial spin...This study investigated the systematics of the megophryid genus Scutiger from eastern and western Nepal using molecular and morphological data. Our results support two divergent lineages, one of which has nuptial spines on the dorsal surface of the first three fingers while the other has spines only on the dorsal surface of the first two fingers. The Ghunsa lineage from eastern Nepal shows significant morphological and molecular differences to other species of genus Scutiger and is here described as a new species. Based on the molecular analysis, the Muktinath lineage from western Nepal is confirmed to be Scutiger boulengeri and represents a species complex widespread throughout the Himalayan region. The newly described taxon is endemic to the eastern Himalayas and currently known only from the Ghunsa valley, Taplejung district, Nepal.展开更多
Theory predicts that well-developed limb musculature can result from sexual selection favoring strong males.We tested for this prediction in the Boulenger's lazy toad(Scutiger boulengeri),a species that exhibits i...Theory predicts that well-developed limb musculature can result from sexual selection favoring strong males.We tested for this prediction in the Boulenger's lazy toad(Scutiger boulengeri),a species that exhibits inguinal amplexus.As expected,we found that males had more massive forelimbs and hindlimbs than those of females.In addition,amplectant males had relatively more massive hindlimbs than non-amplectant males.This pattern can be explained by sexual selection,as the greater forelimb muscles allow males to hold females more tightly and massive hindlimbs likely confer a locomotor advantage in defending mates.This study contributes to an increasing body of literature clarifying the role of sexual selection in producing sexual dimorphism in anuran limbs.展开更多
Fifteen microsatellite DNA markers were developed from a transcriptome assembly of the alpine stream frog （Scutiger boulengeri）.To characterize these loci, we genotyped 23 individuals collected from two sites. Eleve...Fifteen microsatellite DNA markers were developed from a transcriptome assembly of the alpine stream frog （Scutiger boulengeri）.To characterize these loci, we genotyped 23 individuals collected from two sites. Eleven loci were variable, with the number of alleles ranging from one to six within each population. The expected and observed heterozygosities ranged from 0 to 0.78 and from 0 to 0.64, respectively. None of the loci was in linkage disequilibrium and one locus for one population was deviated from will offer useful tools in detecting population structure Tibetan Plateau, where the species resides. the Hardy-Weinberg equilibrium. We hope that these markers of S. boulengeri and in monitoring the fragile ecosystem of the展开更多
The mating calls of six forms belonging to four genera Megophrys,Oreloalax,Scutiger and Leptolalax were recorded in Wawu Mountain National Forest Park,Sichuan Province of China,using cassette tape recorder (Aiwa) and ...The mating calls of six forms belonging to four genera Megophrys,Oreloalax,Scutiger and Leptolalax were recorded in Wawu Mountain National Forest Park,Sichuan Province of China,using cassette tape recorder (Aiwa) and Sony tape with an external microphone.All recordings were analyzed with an IBM PC based 'SIGNAL' software analysis system (Engineering Design,USA).The range of analyzed frequency was set as 0-10 kHz.Acoustic analysis shows that the dominant frequency of L.oshanensis,M.minor,M.sp.,S.(S.)chintingensis,O.omeimontis,and O.schmidti is 4521.9,3456.4,2293.8,1076.5,1071.0 and 1849.4 Hz on average respectively;the note duration is 46.2,90.8,99.6,72.2,78.8 and 110.3 millisecond on average respectively;the note interval is 140.4,253.0,681.4,1517.7,461.3 and 619.5 millisecond on average respectively.One-Way ANOVA analysis indicates that there are significant differences among the analyzed six forms on the dominant frequency,the note duration,and the note interval (P<0.01).Multiple comparisons using Least-Significant Difference (LSD) show that the difference of the dominant frequency between S.(S.) chintingensis and O.omeimontis is not significant (P=0.917>0.05);on the note duration,only L.oshanensis is significantly different from M.minor,M.sp.,O.omeimontis and O.schmidti (P<0.01);on the note interval,L.oshanensis is not significantly different from M.minor,the same with M.sp.versus O.schmidti and O.omeimontis versus O.schmidti (P>0.05).Correlation analysis indicates that there are no significant correlation among the three acoustic characters of dominant frequency,note duration and note interval,and two environmental factors of the elevation and air temperature (P>0.05) except that the note interval is significantly linear correlated with the elevation (r=0.943,P=0.005<0.01).In the light of above,it is suggested that acoustic characteristics of calls are useful in distinguishing forms;the change of the note interval with the elevation may be a kind of strategy of reproduction.展开更多
Considering the increased anthropogenic impacts,species with a limited range and low detectability often lack fundamental information and conservation actions,placing them at a high risk of endangerment.The Chinting a...Considering the increased anthropogenic impacts,species with a limited range and low detectability often lack fundamental information and conservation actions,placing them at a high risk of endangerment.The Chinting alpine toad Scutiger chintingensis is a rare mountain amphibian endemic to the eastern margin of the Qinghai-Xizang Plateau in China.Within its whole distribution range,only three known populations(Wolong,Emei,and Wawu)exist and no recent population status report has been documented for this species over the past two decades.From 2020 to 2023,we investigated the species distribution,and assessed the risk factors for the main populations.We recorded this species in all distribution areas,and updated a new distribution site with a lower elevation limit.The relative population density was 0.024±0.012 ind./m^(2)on Mount Emei,whereas only 0.008±0.017 ind./m^(2)on Mount Wawu.No significant difference was observed in the number of individuals between the two populations;however,the relative population density was significantly different.Sewage and waste discharge resulting from the construction of scenic areas,as well as disturbances from tourism,were the primary anthropogenic factors that influenced the survival of this species.Our results provide the updated information on the distribution and population status of the Chinting alpine toad,and suggest that unrecorded populations,as well as a wider elevation range,may exist for this species.Our findings emphasise the importance of timely updates of species distribution and population information and offer a basis for the future conservation of endangered amphibians.展开更多
For oviparous species with little or no parental care, oviposition site choice may be a powerful agent of natural selection, playing an important role in the evolution of species fitness and life history. Identifying ...For oviparous species with little or no parental care, oviposition site choice may be a powerful agent of natural selection, playing an important role in the evolution of species fitness and life history. Identifying and clarifying the microhabitat characteristics of oviposition sites are key to understanding life history strategies and local adaptations for amphibians with complex biphasic life cycles. However, oviposition strategies for amphibians in alpine streams remain poorly understood. Here, we focused on oviposition site selection for the Chinting alpine toad(Scutiger chintingensis) on Mount Wawu on the eastern margin of the Qinghai-Xizang Plateau. We identified the microhabitat differences between oviposition sites and non-oviposition sites for this species, predicted oviposition site selection patterns,and evaluated the relative importance of each microhabitat variable as well as the effects of the variables on the model prediction probabilities. This study revealed that the microhabitat characteristics of oviposition sites in this species included high water velocity, shallow water, and high-water surface coverage. Water velocity and rock volume were the most important variables explaining the categories of oviposition sites. Additionally, we observed nearly half the proportion of overlapping oviposition in this species, and the benefits of this behavior in terms of microhabitat characteristics need to be explored in the future. Our study revealed an oviposition site selection strategy for amphibians within alpine streams, and contributed to understanding the life history and environmental adaptation strategies of an endemic alpine stream species, and thereby providing guidance for effective conservation strategies for alpine stream amphibians under global change.展开更多
基金supported by the National Key Program of Research and Development, Ministry of Science and Technology of China (2023YFF1304800)National Natural Science Foundation of China (32400361, 32200363, 32370498)+2 种基金Sichuan Science and Technology Program (2024NSFSC1180, 2023NSFSC1155)the Second Tibetan Plateau Scientific Expedition and Research Program (STEP) (2019QZKK0501)Taxonomist Position, Chinese Academy of Sciences (CAS-TAX-24-052, CAS-TAX-24-051),Biological Resources Programme, Chinese Academy of Sciences (KFJ-BRP-017-086, KFJ-BRP-017-65)。
文摘Comprehensive surveys on the distribution of the endangered Chinting alpine toad(Scutiger chintingensis) were recently conducted, revealing important findings regarding its population characteristics. This study integrated morphological and molecular analyses to clarify the taxonomic status of these populations. Based on detailed morphological comparisons and phylogenetic analyses, the population from Wolong, Wenchuan County,Sichuan, China, is identified as a new species, which is formally described herein. The new species can be distinguished from all known congeners by a unique combination of following characteristics:(1) small body size, SVL 42.2–46.9 mm in adult males, SVL54.3–56.3 in adult females;(2) vomerine ridges and vomerine teeth absent, maxillary teeth present;(3)internasal distance and interorbital distance relatively large;(4) subarticular tubercle absent on fingers and toes;(5) dorsal and lateral skin rough with densely-distributed horny spines in males, smooth and lacking black horny spines in females;(6) vocal sac absent in males;(7) pair of pectoral glands and pair of axillary glands present on chest in males, axillary gland about two-thirds pectoral gland in size;(8) in breeding males, pectoral glands and axillary glands covered by dense spines, belly rough with horny spines, nuptial spines present on dorsal and lateral surface of first and second fingers and inner side of third finger,dense spines on inner forelimb aligned, extending from wrist to near axilla. This study highlights the critical importance of accurate taxonomic identification, particularly for endangered species, as misidentifications can misguide subsequent biological research and conservation efforts.
基金Foundation items： This study was supported by the ＂Light of West China＂ Program of the Chinese Academy of sciences （CAS）, the Ministry of Science and Technology of China （2014FY210200, 2011FY120200）, and the Animal Branch of the Germplasm Bank of Wild Species of Chinese Academy of Sciences （the Large Research Infrastructure Funding）
文摘A new species of Scutiger Theobald, 1868 is described from Medog, southeastern Tibet, China, based on morphological and molecular data. The new species was previously identified as Scutiger nyingchiensis, but it can be differentiated from the latter and all other congeners by the following combination of characters： （1） medium adult body size, SVL 50.5-55.6 mm in males and 53.8-57.2 mm in females; （2） maxillary teeth absent; （3） web rudimen- tary between toes; （4） prominent, conical-shaped tubercles on dorsal and lateral surfaces of body and limbs; （5） tubercles covered by black spines in both sexes in breeding condition; （6） a pair of pectoral glands and a pair of axillary glands present and covered by black spines in males in breeding condition, width of axillary gland less than 50% of pectoral gland; （7） nuptial spines present on dorsal surface of first and second fingers, and inner side of third finger in males in breeding condition; （8） spines absent on the abdominal region; （9） vocal sac absent. In addition, the distribution and conservation status of the new species are also discussed
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA23080101)National Natural Sciences Foundation of China (NSFC-31471964)+1 种基金grants to Jianping Jiang and the second comprehensive science investigation of Qinghai-Tibet Plateau (QTP) (II08-T05-2017-04/06)supported by the CAS-TWAS President Fellowship and Chinese Academy of Sciences President’s International Fellowship Initiative (2018PB0016)
文摘This study investigated the systematics of the megophryid genus Scutiger from eastern and western Nepal using molecular and morphological data. Our results support two divergent lineages, one of which has nuptial spines on the dorsal surface of the first three fingers while the other has spines only on the dorsal surface of the first two fingers. The Ghunsa lineage from eastern Nepal shows significant morphological and molecular differences to other species of genus Scutiger and is here described as a new species. Based on the molecular analysis, the Muktinath lineage from western Nepal is confirmed to be Scutiger boulengeri and represents a species complex widespread throughout the Himalayan region. The newly described taxon is endemic to the eastern Himalayas and currently known only from the Ghunsa valley, Taplejung district, Nepal.
基金supported by the Joint Funds for Fostering Talents of NSFC and the People's Government of Henan Province (No.U1304309)National Sciences Foundation of China (No.31501870 and No.31872216)。
文摘Theory predicts that well-developed limb musculature can result from sexual selection favoring strong males.We tested for this prediction in the Boulenger's lazy toad(Scutiger boulengeri),a species that exhibits inguinal amplexus.As expected,we found that males had more massive forelimbs and hindlimbs than those of females.In addition,amplectant males had relatively more massive hindlimbs than non-amplectant males.This pattern can be explained by sexual selection,as the greater forelimb muscles allow males to hold females more tightly and massive hindlimbs likely confer a locomotor advantage in defending mates.This study contributes to an increasing body of literature clarifying the role of sexual selection in producing sexual dimorphism in anuran limbs.
基金supported by a scholarship from the China Scholarship Council to Z.DU
文摘Fifteen microsatellite DNA markers were developed from a transcriptome assembly of the alpine stream frog （Scutiger boulengeri）.To characterize these loci, we genotyped 23 individuals collected from two sites. Eleven loci were variable, with the number of alleles ranging from one to six within each population. The expected and observed heterozygosities ranged from 0 to 0.78 and from 0 to 0.64, respectively. None of the loci was in linkage disequilibrium and one locus for one population was deviated from will offer useful tools in detecting population structure Tibetan Plateau, where the species resides. the Hardy-Weinberg equilibrium. We hope that these markers of S. boulengeri and in monitoring the fragile ecosystem of the
文摘The mating calls of six forms belonging to four genera Megophrys,Oreloalax,Scutiger and Leptolalax were recorded in Wawu Mountain National Forest Park,Sichuan Province of China,using cassette tape recorder (Aiwa) and Sony tape with an external microphone.All recordings were analyzed with an IBM PC based 'SIGNAL' software analysis system (Engineering Design,USA).The range of analyzed frequency was set as 0-10 kHz.Acoustic analysis shows that the dominant frequency of L.oshanensis,M.minor,M.sp.,S.(S.)chintingensis,O.omeimontis,and O.schmidti is 4521.9,3456.4,2293.8,1076.5,1071.0 and 1849.4 Hz on average respectively;the note duration is 46.2,90.8,99.6,72.2,78.8 and 110.3 millisecond on average respectively;the note interval is 140.4,253.0,681.4,1517.7,461.3 and 619.5 millisecond on average respectively.One-Way ANOVA analysis indicates that there are significant differences among the analyzed six forms on the dominant frequency,the note duration,and the note interval (P<0.01).Multiple comparisons using Least-Significant Difference (LSD) show that the difference of the dominant frequency between S.(S.) chintingensis and O.omeimontis is not significant (P=0.917>0.05);on the note duration,only L.oshanensis is significantly different from M.minor,M.sp.,O.omeimontis and O.schmidti (P<0.01);on the note interval,L.oshanensis is not significantly different from M.minor,the same with M.sp.versus O.schmidti and O.omeimontis versus O.schmidti (P>0.05).Correlation analysis indicates that there are no significant correlation among the three acoustic characters of dominant frequency,note duration and note interval,and two environmental factors of the elevation and air temperature (P>0.05) except that the note interval is significantly linear correlated with the elevation (r=0.943,P=0.005<0.01).In the light of above,it is suggested that acoustic characteristics of calls are useful in distinguishing forms;the change of the note interval with the elevation may be a kind of strategy of reproduction.
基金supported by the National Natural Science Foundation of China(32271737,32071544)the Interdisciplinary Innovation Team of the Chinese Academy of Sciences(CAS)“Light of West China”Program(xbzg-zdsys-202207)+1 种基金the Shenzhen Zhilan Foundation(2021070451A)Nature Science Foundation of Sichuan Province(2022NSFSC0125).
文摘Considering the increased anthropogenic impacts,species with a limited range and low detectability often lack fundamental information and conservation actions,placing them at a high risk of endangerment.The Chinting alpine toad Scutiger chintingensis is a rare mountain amphibian endemic to the eastern margin of the Qinghai-Xizang Plateau in China.Within its whole distribution range,only three known populations(Wolong,Emei,and Wawu)exist and no recent population status report has been documented for this species over the past two decades.From 2020 to 2023,we investigated the species distribution,and assessed the risk factors for the main populations.We recorded this species in all distribution areas,and updated a new distribution site with a lower elevation limit.The relative population density was 0.024±0.012 ind./m^(2)on Mount Emei,whereas only 0.008±0.017 ind./m^(2)on Mount Wawu.No significant difference was observed in the number of individuals between the two populations;however,the relative population density was significantly different.Sewage and waste discharge resulting from the construction of scenic areas,as well as disturbances from tourism,were the primary anthropogenic factors that influenced the survival of this species.Our results provide the updated information on the distribution and population status of the Chinting alpine toad,and suggest that unrecorded populations,as well as a wider elevation range,may exist for this species.Our findings emphasise the importance of timely updates of species distribution and population information and offer a basis for the future conservation of endangered amphibians.
基金supported by the National Natural Science Foundation of China (32271737, 32071544)the Interdisciplinary Innovation Team of the Chinese Academy of Sciences (CAS) “Light of West China” Program (xbzg-zdsys-202207)+1 种基金the Shenzhen Zhilan Foundation (2023010291A)Nature Science Foundation of Sichuan Province (24NSFSC2934)。
文摘For oviparous species with little or no parental care, oviposition site choice may be a powerful agent of natural selection, playing an important role in the evolution of species fitness and life history. Identifying and clarifying the microhabitat characteristics of oviposition sites are key to understanding life history strategies and local adaptations for amphibians with complex biphasic life cycles. However, oviposition strategies for amphibians in alpine streams remain poorly understood. Here, we focused on oviposition site selection for the Chinting alpine toad(Scutiger chintingensis) on Mount Wawu on the eastern margin of the Qinghai-Xizang Plateau. We identified the microhabitat differences between oviposition sites and non-oviposition sites for this species, predicted oviposition site selection patterns,and evaluated the relative importance of each microhabitat variable as well as the effects of the variables on the model prediction probabilities. This study revealed that the microhabitat characteristics of oviposition sites in this species included high water velocity, shallow water, and high-water surface coverage. Water velocity and rock volume were the most important variables explaining the categories of oviposition sites. Additionally, we observed nearly half the proportion of overlapping oviposition in this species, and the benefits of this behavior in terms of microhabitat characteristics need to be explored in the future. Our study revealed an oviposition site selection strategy for amphibians within alpine streams, and contributed to understanding the life history and environmental adaptation strategies of an endemic alpine stream species, and thereby providing guidance for effective conservation strategies for alpine stream amphibians under global change.
