We reexamined sexual dimorphism and female reproduction in the Many-Lined Sun Skink Eutropis multifasciata from Hainan,China. Our data confirm that adults are sexually dimorphic in body size and shape,with males being...We reexamined sexual dimorphism and female reproduction in the Many-Lined Sun Skink Eutropis multifasciata from Hainan,China. Our data confirm that adults are sexually dimorphic in body size and shape,with males being the larger sex and larger in head size but shorter in abdomen length than females of the same snoutvent length(SVL). The rate at which head width increased with SVL was greater in males as opposed to the previous conclusion that the rate does not differ between the sexes. Maternal size was the main determinant of reproductive investment,with larger females generally producing more,as well as larger,offspring. Females produced up to nine offspring per litter as opposed to the previously reported 2–7. Most females gave birth between March and August,a time period approximately four months longer than that(May–June) reported previously. Females with a higher fecundity tended to produce smaller offspring as opposed to the previous conclusion that females do not tradeoff offspring size against number. Litter size,neonate mass and litter mass remained remarkably constant among years,and litter mass was more tightly related to female body size than litter size or neonate mass. Smaller females could produce relatively heavier litters without a concomitant reduction in postpartum body condition.展开更多
We studied sexual dimorphism in body size and shape and female reproductive characteristics in the Hainan Water Skink(Tropidophorus hainanus)from Hainan,South China.In our sample the largest female and male were 61.1 ...We studied sexual dimorphism in body size and shape and female reproductive characteristics in the Hainan Water Skink(Tropidophorus hainanus)from Hainan,South China.In our sample the largest female and male were 61.1 and 55.2 mm snout-vent length(SVL),respectively.The mean SVL was larger in adult females(52.0 mm)than in adult males(48.3 mm).Juveniles were sexually dimorphic in head length but not in other examined morphological variables.Adult males were longer in head length and shorter in abdomen length and fore-limb length than adult females of the same SVL.Ontogenetic shifts in sexual dimorphism in body shape were evident,as revealed by the fact that morphological differences between the sexes were more pronounced in adults than in juveniles.Females produced a single litter of 3–6 offspring per season from early August to early September.Litter size,litter mass and offspring(neonate)mass were positively related to female SVL.Neonate mass was independent of relative fecundity.From the above findings we draw three main conclusions.First,females are the larger sex in T.hainanus,and sexual dimorphism in body shape is more pronounced in adults than in juveniles.Second,larger female T.hainanus produce more and larger offspring and thus heavier litters than smaller ones.Third,the offspring size-number trade-off does is not evident in T.hainanus.展开更多
We collected 75 adult Tonkin forest skinks(Sphenomorphus tonkinensis) from Hainan, South China and incubated eggs at four constant temperatures ranging from 22 ℃ to 28 ℃ to study sexual dimorphism, female reproducti...We collected 75 adult Tonkin forest skinks(Sphenomorphus tonkinensis) from Hainan, South China and incubated eggs at four constant temperatures ranging from 22 ℃ to 28 ℃ to study sexual dimorphism, female reproductive characteristics and embryonic thermosensitivity. The largest male was 53.4 mm snout-vent length(SVL), and the largest female was 54.3 mm SVL. The mean SVL was slightly greater in adult females(49.9 mm) than in adult males(48.8 mm), but the difference was not significant.Head length, head width, fore-limb length and hindlimb length were longer in adult males and abdomen length was longer in adult females after accounting for SVL. Accordingly, we conclude that S. tonkinensis is basically a sexually size-monomorphic species with sexual dimorphism in head size, abdomen(trunk)length and limb size. Females laid up to two clutches of 1–4 eggs each per egg-laying season from February to May. Egg mass, clutch size and clutch mass were independent of female SVL. Embryonic stages at laying varied from Dufaure and Hubert’s stage 30 to 31. With female SVL held constant, the negative correlation between egg mass and clutch size was not significant, suggesting that the offspring(egg) sizenumber trade-off between is not evident or eggs are well optimized for size in S. tonkinensis. None of the eggs at 28 ℃ hatched;hatching success was lower at 22 ℃ than at 24 ℃ or 26 ℃. The mean incubation length was 52.9 d at 22 ℃, 40.4 d at 24 ℃ and 33.6 d at 26 ℃. Hatchlings from eggs incubated at 22 ℃,24 ℃ and 26 ℃ did not differ morphologically at hatching, suggesting that temperatures within this range do not differentially affect hatchling morphology in S. tonkinensis.展开更多
Body size and female reproduction in the water adult females larger than 500 mm SVL and 32 adult males Ledong, Hainan under permit to our laboratory in Hainan monitor lizard (Varanus salvator) were studied. Forty-tw...Body size and female reproduction in the water adult females larger than 500 mm SVL and 32 adult males Ledong, Hainan under permit to our laboratory in Hainan monitor lizard (Varanus salvator) were studied. Forty-two larger than 400 mm SVL were donated by local people in in 2013 and 2014. The largest male and female measured 745 and 755 mm SVL, respectively. The mean SVL was greater in adult females than in adult males. Males had larger heads (head width) than females of the same SVL. The smallest reproductive female in our sample was 565 mm SVL. Females produced a single clutch of 17.1 (10-23) pliable-shelled eggs per breeding season stretching from mid-June and mid-September. Clutch size and clutch mass were all positively related to female SVL. However, there was no significant linear relationship between egg mass and female SVL. Larger females generally produced more eggs, and thus heavier clutches than did smaller ones. There was no significant linear relationship between relative clutch mass and female SVL. Phylogenetic generalized least squares (PGLS) analysis, accounting for phylogenetic relationships, showed that clutch size was positively correlated with mean maternal SVL in varanid lizards. PGLS analysis showed that phylogenetic relationships did not affect clutch (or/and egg) mass and the SVL although there were significant linear relationship between clutch (or/and egg) mass and mean maternal SVL. Therefore, we could draw some general conclusions about the body size and reproductive tactics in varanid lizards that larger females generally produced more eggs, larger eggs and thus heavier clutches than did smaller ones.展开更多
[Objectives] This study was conducted to further investigate the taxonomic status of Hainan population of Trimeresurus stejnegeri from the morphological point of view.[Methods]The difference coefficients between diffe...[Objectives] This study was conducted to further investigate the taxonomic status of Hainan population of Trimeresurus stejnegeri from the morphological point of view.[Methods]The difference coefficients between different populations were compared using the 75% law,and the relationship between scales and latitudes was analyzed.[Results] The scales(abdominal and subcaudal) of 325 Trimeresurus individuals were counted according to China Animal Fauna,including156 T.stejnegeri individuals.Some difference coefficients between the Hainan population and others were greater than 1.28,and there was no correlation between the number of scales and latitude.It conforms to subclassification criteria.[Conclusions]The view about the subspecies status of T.stejnegeri chenbihuii should be supported.展开更多
According to the contradictions about classification on Trimeresurus between "China's Fauna" and international database, the rationality about Trimeresurus divided to multiple genera based on molecular systematies ...According to the contradictions about classification on Trimeresurus between "China's Fauna" and international database, the rationality about Trimeresurus divided to multiple genera based on molecular systematies was discussed. The genetic distance was calculated by sequencing 12S gene of the original Trimeresurus snakes, including 80 individuals of 33 species ; and the molecular phylogenetie tree was established by taking Hypnale hypnale as the outgroup. The results showed that the topological structures of ME tree and ML tree were basically consistent, and all of the species in the molecular trees were divided into 8 branches; and the difference of T. albolabris between Hainan and other locations is not obvious. The viewpoint that original Trimeresurus genera subdivided into 8 genera was more rational, and new authoritative reference books are expected to be published in China.展开更多
We recorded locomotor performance of Reeves' butterfly lizards(Leiolepis reevesii) on a racetrack and to describe hindlimb kinematic patterns and to evaluate the effect of speed on hindlimb kinematics. The studied ...We recorded locomotor performance of Reeves' butterfly lizards(Leiolepis reevesii) on a racetrack and to describe hindlimb kinematic patterns and to evaluate the effect of speed on hindlimb kinematics. The studied lizards predominantly used quadrupedal locomotion at relatively low speeds, but ran bipedally with a digitigrade posture at high speeds. Speed was positively correlated with both stride length and stride frequency, and was negatively correlated with duty factor. Lizards modulated speed probably by a combination of changing frequency and amplitude of limb movements. Within the range of standardized speeds from 50 to 150 cm/s, speed effects on 28 out of a total of 56 kinematic variables were significant. The hip height at footfall increased as speed increased, whereas the amplitude of vertical oscillations of the hip did not vary with speed. The total longitudinal and dorsoventral movements relative to the hip varied with speed for all parts of the limb that were distal to the knee, whereas the lateral movements did not. The knee and ankle angle at footfall varied with speed, but did not at the end of stance. The degree of pelvis rotation during the entire stride cycle did not vary with speed. Our results suggest that pelvic rotation and femoral protraction/retraction have a minor role in modulating speed in L. reevesii.展开更多
We used mitochondrial cytochrome b and ND4 genes and 9 microsatellite loci to determine genetic diversity,population structure,evolutionary history,and migration patterns within the Reeves’butterfly lizard Leiolepis ...We used mitochondrial cytochrome b and ND4 genes and 9 microsatellite loci to determine genetic diversity,population structure,evolutionary history,and migration patterns within the Reeves’butterfly lizard Leiolepis reevesii(Agamidae).Considering molecular-based phylogeographical lineages,we then performed niche equivalency and similarity tests between divergent lineages.Phylogenetic analyses based on mitochondrial DNA(mtDNA)data revealed 2 lineages(A and B)diverging≈0.84 million years ago and,respectively,restricted to the northern and southern portions of the Wuzhishan and Yinggeling mountain ranges.Lineage B contains individuals from southern Hainan;Lineage A includes individuals from all other localities and can be further divided into 3 clusters according to microsatellite data.The null hypothesis that the 2 lineages shared identical niches was rejected in all niche equivalency tests,indicating niche shifts during genetic divergence.Similarity tests provided evidence of niche conservatism,suggesting that the 2 lineages share more characteristics of their niche spaces than randomly expected.The niche similarity and equivalency tests indicated a complex niche pattern in which both lineages share a main portion of their ecological spaces.The climatic niche of Lineage B represented a marginal and specialized fraction of the entire ecological space of the climatic niche of Lineage A,with warmer conditions.Isolation caused by orogenesis and subsequent niche divergence,together with local adaptation,may have led to genetic differentiation and further lineage sorting in L.reevesii.展开更多
基金supported by the grants from the National Natural Science Foundation of China (30670281 and 31060064)the Priority Academic Program Development of Jiangsu Higher Education Institutions (CXLX11_0885)the Hainan Key Program of Science and Technology (ZDXM20110008)
文摘We reexamined sexual dimorphism and female reproduction in the Many-Lined Sun Skink Eutropis multifasciata from Hainan,China. Our data confirm that adults are sexually dimorphic in body size and shape,with males being the larger sex and larger in head size but shorter in abdomen length than females of the same snoutvent length(SVL). The rate at which head width increased with SVL was greater in males as opposed to the previous conclusion that the rate does not differ between the sexes. Maternal size was the main determinant of reproductive investment,with larger females generally producing more,as well as larger,offspring. Females produced up to nine offspring per litter as opposed to the previously reported 2–7. Most females gave birth between March and August,a time period approximately four months longer than that(May–June) reported previously. Females with a higher fecundity tended to produce smaller offspring as opposed to the previous conclusion that females do not tradeoff offspring size against number. Litter size,neonate mass and litter mass remained remarkably constant among years,and litter mass was more tightly related to female body size than litter size or neonate mass. Smaller females could produce relatively heavier litters without a concomitant reduction in postpartum body condition.
基金supported by grants from the Special Foundation for Basic Work of the Science and Technology Ministry of China (2022FY100500-2)National Natural Science Foundation of China (31470471)+2 种基金Hainan Key Program of Science and Technology (ZDXM20110008)Hainan Specially Supporting Discipline of ZoologyWenzhou Ecological Park Research Project。
文摘We studied sexual dimorphism in body size and shape and female reproductive characteristics in the Hainan Water Skink(Tropidophorus hainanus)from Hainan,South China.In our sample the largest female and male were 61.1 and 55.2 mm snout-vent length(SVL),respectively.The mean SVL was larger in adult females(52.0 mm)than in adult males(48.3 mm).Juveniles were sexually dimorphic in head length but not in other examined morphological variables.Adult males were longer in head length and shorter in abdomen length and fore-limb length than adult females of the same SVL.Ontogenetic shifts in sexual dimorphism in body shape were evident,as revealed by the fact that morphological differences between the sexes were more pronounced in adults than in juveniles.Females produced a single litter of 3–6 offspring per season from early August to early September.Litter size,litter mass and offspring(neonate)mass were positively related to female SVL.Neonate mass was independent of relative fecundity.From the above findings we draw three main conclusions.First,females are the larger sex in T.hainanus,and sexual dimorphism in body shape is more pronounced in adults than in juveniles.Second,larger female T.hainanus produce more and larger offspring and thus heavier litters than smaller ones.Third,the offspring size-number trade-off does is not evident in T.hainanus.
基金This work was supported by grants from the Special Foundation for Basic Work of the Science and Technology Ministry of China(2022FY100500-2)Hainan Key Program of Science and Technology(ZDXM20110008)Hainan Specially Supporting Discipline of Zoology。
文摘We collected 75 adult Tonkin forest skinks(Sphenomorphus tonkinensis) from Hainan, South China and incubated eggs at four constant temperatures ranging from 22 ℃ to 28 ℃ to study sexual dimorphism, female reproductive characteristics and embryonic thermosensitivity. The largest male was 53.4 mm snout-vent length(SVL), and the largest female was 54.3 mm SVL. The mean SVL was slightly greater in adult females(49.9 mm) than in adult males(48.8 mm), but the difference was not significant.Head length, head width, fore-limb length and hindlimb length were longer in adult males and abdomen length was longer in adult females after accounting for SVL. Accordingly, we conclude that S. tonkinensis is basically a sexually size-monomorphic species with sexual dimorphism in head size, abdomen(trunk)length and limb size. Females laid up to two clutches of 1–4 eggs each per egg-laying season from February to May. Egg mass, clutch size and clutch mass were independent of female SVL. Embryonic stages at laying varied from Dufaure and Hubert’s stage 30 to 31. With female SVL held constant, the negative correlation between egg mass and clutch size was not significant, suggesting that the offspring(egg) sizenumber trade-off between is not evident or eggs are well optimized for size in S. tonkinensis. None of the eggs at 28 ℃ hatched;hatching success was lower at 22 ℃ than at 24 ℃ or 26 ℃. The mean incubation length was 52.9 d at 22 ℃, 40.4 d at 24 ℃ and 33.6 d at 26 ℃. Hatchlings from eggs incubated at 22 ℃,24 ℃ and 26 ℃ did not differ morphologically at hatching, suggesting that temperatures within this range do not differentially affect hatchling morphology in S. tonkinensis.
基金Financial supports were provided by grants from Natural Science Foundation of China (31270571)Hainan Key Program of Science and Technology (ZDXM20110008)131 Talent Project of Hangzhou City
文摘Body size and female reproduction in the water adult females larger than 500 mm SVL and 32 adult males Ledong, Hainan under permit to our laboratory in Hainan monitor lizard (Varanus salvator) were studied. Forty-two larger than 400 mm SVL were donated by local people in in 2013 and 2014. The largest male and female measured 745 and 755 mm SVL, respectively. The mean SVL was greater in adult females than in adult males. Males had larger heads (head width) than females of the same SVL. The smallest reproductive female in our sample was 565 mm SVL. Females produced a single clutch of 17.1 (10-23) pliable-shelled eggs per breeding season stretching from mid-June and mid-September. Clutch size and clutch mass were all positively related to female SVL. However, there was no significant linear relationship between egg mass and female SVL. Larger females generally produced more eggs, and thus heavier clutches than did smaller ones. There was no significant linear relationship between relative clutch mass and female SVL. Phylogenetic generalized least squares (PGLS) analysis, accounting for phylogenetic relationships, showed that clutch size was positively correlated with mean maternal SVL in varanid lizards. PGLS analysis showed that phylogenetic relationships did not affect clutch (or/and egg) mass and the SVL although there were significant linear relationship between clutch (or/and egg) mass and mean maternal SVL. Therefore, we could draw some general conclusions about the body size and reproductive tactics in varanid lizards that larger females generally produced more eggs, larger eggs and thus heavier clutches than did smaller ones.
基金Supported by Scientific Research Project of Colleges and Universities in Hainan Province(Hnky2017-47)Sanya Special Scientific Research Pilot Project(2016KS05)+2 种基金Provincial Key(Supporting)Discipline for Ordinary Colleges and Universities in Hainan Province:Zoology2018 Special Fund for the Development of Institutions of Higher Learning(phaseⅠ)Provincial Characteristic Discipline:Marine Science。
文摘[Objectives] This study was conducted to further investigate the taxonomic status of Hainan population of Trimeresurus stejnegeri from the morphological point of view.[Methods]The difference coefficients between different populations were compared using the 75% law,and the relationship between scales and latitudes was analyzed.[Results] The scales(abdominal and subcaudal) of 325 Trimeresurus individuals were counted according to China Animal Fauna,including156 T.stejnegeri individuals.Some difference coefficients between the Hainan population and others were greater than 1.28,and there was no correlation between the number of scales and latitude.It conforms to subclassification criteria.[Conclusions]The view about the subspecies status of T.stejnegeri chenbihuii should be supported.
基金Supported by Fund for Provincial Key DIscipline in Colleges and Universities of Hainan Province:Zoology(2017-02-01,HNZ201702)General Project of National Natural Science Foundation of Hainan Province(20163073),Study on the taxonomic status of Trimeresurus produced in Hainan+4 种基金Special Fund for Scientific Research Trail-produce Project of Sanya City(2016KS05)Scientific Research Project of Colleges and Universities of Hainan Province(Hnky2017-47),Study on the taxonomic status of the subspecies Trimeresurus stejnegeri chenbihuii in Hainan based on morphologyMajor Science and Technology Planning Project of Hainan Province(ZDKJ2016009-2-1)Agricultural Science and Technology Innovation Project of Sanya City(2016NK13)Key Discipline Construction Fund of School of Ocean Science and Technology(Special Fund for Development of Institutions of Higher Learning in 2017(the fourth batch)):Marine Science
文摘According to the contradictions about classification on Trimeresurus between "China's Fauna" and international database, the rationality about Trimeresurus divided to multiple genera based on molecular systematies was discussed. The genetic distance was calculated by sequencing 12S gene of the original Trimeresurus snakes, including 80 individuals of 33 species ; and the molecular phylogenetie tree was established by taking Hypnale hypnale as the outgroup. The results showed that the topological structures of ME tree and ML tree were basically consistent, and all of the species in the molecular trees were divided into 8 branches; and the difference of T. albolabris between Hainan and other locations is not obvious. The viewpoint that original Trimeresurus genera subdivided into 8 genera was more rational, and new authoritative reference books are expected to be published in China.
基金supported by grants from the National Natural Science Foundation of China (project no. 30860046)Nanjing Normal University
文摘We recorded locomotor performance of Reeves' butterfly lizards(Leiolepis reevesii) on a racetrack and to describe hindlimb kinematic patterns and to evaluate the effect of speed on hindlimb kinematics. The studied lizards predominantly used quadrupedal locomotion at relatively low speeds, but ran bipedally with a digitigrade posture at high speeds. Speed was positively correlated with both stride length and stride frequency, and was negatively correlated with duty factor. Lizards modulated speed probably by a combination of changing frequency and amplitude of limb movements. Within the range of standardized speeds from 50 to 150 cm/s, speed effects on 28 out of a total of 56 kinematic variables were significant. The hip height at footfall increased as speed increased, whereas the amplitude of vertical oscillations of the hip did not vary with speed. The total longitudinal and dorsoventral movements relative to the hip varied with speed for all parts of the limb that were distal to the knee, whereas the lateral movements did not. The knee and ankle angle at footfall varied with speed, but did not at the end of stance. The degree of pelvis rotation during the entire stride cycle did not vary with speed. Our results suggest that pelvic rotation and femoral protraction/retraction have a minor role in modulating speed in L. reevesii.
基金This work was supported by the National Natural Science Foundation of China(31971414 and 31470471)the Finance Science and Technology Project of Hainan Province(ZDYF2018219)。
文摘We used mitochondrial cytochrome b and ND4 genes and 9 microsatellite loci to determine genetic diversity,population structure,evolutionary history,and migration patterns within the Reeves’butterfly lizard Leiolepis reevesii(Agamidae).Considering molecular-based phylogeographical lineages,we then performed niche equivalency and similarity tests between divergent lineages.Phylogenetic analyses based on mitochondrial DNA(mtDNA)data revealed 2 lineages(A and B)diverging≈0.84 million years ago and,respectively,restricted to the northern and southern portions of the Wuzhishan and Yinggeling mountain ranges.Lineage B contains individuals from southern Hainan;Lineage A includes individuals from all other localities and can be further divided into 3 clusters according to microsatellite data.The null hypothesis that the 2 lineages shared identical niches was rejected in all niche equivalency tests,indicating niche shifts during genetic divergence.Similarity tests provided evidence of niche conservatism,suggesting that the 2 lineages share more characteristics of their niche spaces than randomly expected.The niche similarity and equivalency tests indicated a complex niche pattern in which both lineages share a main portion of their ecological spaces.The climatic niche of Lineage B represented a marginal and specialized fraction of the entire ecological space of the climatic niche of Lineage A,with warmer conditions.Isolation caused by orogenesis and subsequent niche divergence,together with local adaptation,may have led to genetic differentiation and further lineage sorting in L.reevesii.