Endoctinological action is generally thought to be a way for animals to respond to stress at low temperatures. To learn the role of hormones in ectotherms inhabiting alpine environments, we studied the effects of acut...Endoctinological action is generally thought to be a way for animals to respond to stress at low temperatures. To learn the role of hormones in ectotherms inhabiting alpine environments, we studied the effects of acute low temperature exposure on tile endocrinological reactions of Qinghai toad-headed lizards in the Qinghai-Tibetan Plateau. We monitored plasma corticos- terone and insulin concentration of the lizards under five low temperature treatments. We found no significant difference in plasma corticosterone or insulin in lizards among our five different treatments. For males and females the correlation between plasma corticosterone and insulin concentrations was not significant. In contrast to other studies on reptiles at low altitude, we suggest that due to the alpine environment （low temperature and low oxygen concentration） they inhabit, Qinghai toad-headed lizards respond to experimental cold stress slightly to mobilize energy and live their vivid life. In addition, corticosterone and insulin of Qinghai toad-headed lizards are secreted independently along with low temperature treatments展开更多
The gut microbiota has gained attention because of its importance in facilitating host survival and evolution.However,it is unclear whether gut microbial communities are determined by the host(heritable factor) or env...The gut microbiota has gained attention because of its importance in facilitating host survival and evolution.However,it is unclear whether gut microbial communities are determined by the host(heritable factor) or environment(environmental factor).In this study,we investigated the gut microbial communities and potential functional signatures of two sympatric species distributed along an elevation gradient,the toadheaded lizards Phrynocephalus axillaris and P.forsythii.Our results indicated that at high elevations,the gut microbial communities of P.axillaris and P.forsythii did not significantly differ,and the phylogenetic relationships of gut microbial communities contradicted their hosts.At low altitudes,the two lizards could be distinguished based on their significantly different gut microbial communities.Compared to low-altitude populations,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis showed that at higher altitudes,energy metabolism,such as carbohydrate,lipid,and amino acids metabolism were higher in both lizards.While a larger number of pathogenic bacteria were found in the lowaltitude population of P.forsythii.This suggests that the convergence of gut microbiota of two lizards at highaltitude stem from environmental factors,as they were exposed to the same environmental stress,whereas the divergence at low-altitude stemmed from heritable factors,as they were exposed to different environmental stresses.These results provide a new perspective regarding whether heritable or environmental factors dominate the gut microbiota during exposure to environmental stress.展开更多
Phrynocephalus guinanensis has sexual dimorphism in abdominal coloration, but its ontogenetic development of sexual size dimorphism （SSD） is unknown. Using mark-recapture data during four days each year from August ...Phrynocephalus guinanensis has sexual dimorphism in abdominal coloration, but its ontogenetic development of sexual size dimorphism （SSD） is unknown. Using mark-recapture data during four days each year from August from 2014 to 2016, we investigated the development of sex ratios, SSD, sex-specific survivorship and growth rates in a population of P guinanensis. Our results indicated that the sex ratio of males to females was 1：2.8. Males had a lower survival rate （6%） than females （14%） across the age range from hatchling to adult, which supported the discovered female-biased sex ratio potentially associated with the low survival rate of males between hatchlings and juveniles. Male-biased SSD in tail length and head width existed in adults rather than in hatchling or juvenile lizards. The growth rates in body dimensions were undistinguishable between the sexes during the age from hatchling to juvenile, but the growth rate in head length from juvenile to adult was significantly larger in males than females. Average growth rate of all morphological measurements from hatchling to juvenile were larger compared with corresponding measurements from juvenile to adult, but only being significant in tail length, head width, abdomen length in females and snout-vent length in males. We provided a case study to strengthen our understanding of the important life history traits on how a viviparous lizard population can survive and develop their morphology in cold climates.展开更多
The pattern that many ectotherms have smaller body sizes in coM environments follows the converse to Bergmann＇s rule and is most frequently found in lizards. Allen＇s rule predicts animals from warm climates usually ...The pattern that many ectotherms have smaller body sizes in coM environments follows the converse to Bergmann＇s rule and is most frequently found in lizards. Allen＇s rule predicts animals from warm climates usually have longer tails and limbs, while these traits tend to be shorter in individuals from cold climates. We examined body size variation in an endemic Chinese lizard Phrynocephalus theobaldi along a broad elevational gradient （3,600-5,000 m on the Qinghai-Tibetan Plateau）. Female body size showed a U-shaped cline, decreasing with increased elevation within the range 3,600-4,200 m, but increasing at eleva- tions 〉 4200 m. Male body size continued to increase with increasing elevations. Both sexes showed an increased pattern of ex- tremity length with elevation that does not conform to Allen＇s rule. Limb length and tail length increased along the elevational gradients. In terms of color pattern, an abdominal black speckled area appears at elevations 〉4,200 m. This trait increases in size with increased elevation. Unlike most studies, our results indicated that annual sunshine hours corresponding to the activity pe- riod of the lizards could play an important role on the positive body size cline in environments at very high elevations 〉 4200 m展开更多
We examined the dietary diversity and food intake of Phrynocephalus frontalis, compared the difference of insect diversity in the natural habitats with different lizard densities, and discussed the potential role of t...We examined the dietary diversity and food intake of Phrynocephalus frontalis, compared the difference of insect diversity in the natural habitats with different lizard densities, and discussed the potential role of this lizard in the desert ecosystem. The results show that： （1） arthropodans of the orders Coleoptera, Hymenoptera and Hemiptera were major dietary components of P. frontalis; （2） coleoptera larvae always formed the predominant component of lizard diets; （3） dietary diversities of P. frontalis were not significantly different between summer and autumn or between the two sexes; （4） the similarity in trophic niches between seasons was 0.756, whereas the similarity in trophic niches between sexes was 0.994; （5） stomach content weight of lizards varied significantly among different seasons, but there was no significant difference in stomach content weight between sexes; （6） insect diversity differed significantly among the groups of the habitat with different degrees of lizard density, and the habitat with moderate lizards density had the highest insect diversity. We infer that P. frontalis prey mainly on insects and change their diet and food intake with season; males and females consumed similar preys in types and weights. As an important predator, P. frontalis could affect the insect community in the arid ecosystem of Hunshandak Desert on the Mongolian Plateau.展开更多
文摘Endoctinological action is generally thought to be a way for animals to respond to stress at low temperatures. To learn the role of hormones in ectotherms inhabiting alpine environments, we studied the effects of acute low temperature exposure on tile endocrinological reactions of Qinghai toad-headed lizards in the Qinghai-Tibetan Plateau. We monitored plasma corticos- terone and insulin concentration of the lizards under five low temperature treatments. We found no significant difference in plasma corticosterone or insulin in lizards among our five different treatments. For males and females the correlation between plasma corticosterone and insulin concentrations was not significant. In contrast to other studies on reptiles at low altitude, we suggest that due to the alpine environment （low temperature and low oxygen concentration） they inhabit, Qinghai toad-headed lizards respond to experimental cold stress slightly to mobilize energy and live their vivid life. In addition, corticosterone and insulin of Qinghai toad-headed lizards are secreted independently along with low temperature treatments
基金supported by the National Natural Science Foundation of China (No.31471988 and N0.31200287)。
文摘The gut microbiota has gained attention because of its importance in facilitating host survival and evolution.However,it is unclear whether gut microbial communities are determined by the host(heritable factor) or environment(environmental factor).In this study,we investigated the gut microbial communities and potential functional signatures of two sympatric species distributed along an elevation gradient,the toadheaded lizards Phrynocephalus axillaris and P.forsythii.Our results indicated that at high elevations,the gut microbial communities of P.axillaris and P.forsythii did not significantly differ,and the phylogenetic relationships of gut microbial communities contradicted their hosts.At low altitudes,the two lizards could be distinguished based on their significantly different gut microbial communities.Compared to low-altitude populations,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis showed that at higher altitudes,energy metabolism,such as carbohydrate,lipid,and amino acids metabolism were higher in both lizards.While a larger number of pathogenic bacteria were found in the lowaltitude population of P.forsythii.This suggests that the convergence of gut microbiota of two lizards at highaltitude stem from environmental factors,as they were exposed to the same environmental stress,whereas the divergence at low-altitude stemmed from heritable factors,as they were exposed to different environmental stresses.These results provide a new perspective regarding whether heritable or environmental factors dominate the gut microbiota during exposure to environmental stress.
基金supported by the National Natural Science Foundation of China (31372183, 31772447, 31471988)
文摘Phrynocephalus guinanensis has sexual dimorphism in abdominal coloration, but its ontogenetic development of sexual size dimorphism （SSD） is unknown. Using mark-recapture data during four days each year from August from 2014 to 2016, we investigated the development of sex ratios, SSD, sex-specific survivorship and growth rates in a population of P guinanensis. Our results indicated that the sex ratio of males to females was 1：2.8. Males had a lower survival rate （6%） than females （14%） across the age range from hatchling to adult, which supported the discovered female-biased sex ratio potentially associated with the low survival rate of males between hatchlings and juveniles. Male-biased SSD in tail length and head width existed in adults rather than in hatchling or juvenile lizards. The growth rates in body dimensions were undistinguishable between the sexes during the age from hatchling to juvenile, but the growth rate in head length from juvenile to adult was significantly larger in males than females. Average growth rate of all morphological measurements from hatchling to juvenile were larger compared with corresponding measurements from juvenile to adult, but only being significant in tail length, head width, abdomen length in females and snout-vent length in males. We provided a case study to strengthen our understanding of the important life history traits on how a viviparous lizard population can survive and develop their morphology in cold climates.
基金Acknowledgments This work was supported by the National Natural Science Foundation of China （31372183, 31000950）. We thank the Chinese National Climate Data Center for his- torical climatic data, and the Tibetan government for permis- sion to collect specimens. We thank R. Brown, S. Mullin for their kind detailed reviews on the manuscript before submis- sion, and appreciate R. Brown for his extensive help in im- proving the language of the manuscript before publication. We also thank S. Meiri and another anonymous referee for their kind revisions or suggestions on our submitted manuscript.
文摘The pattern that many ectotherms have smaller body sizes in coM environments follows the converse to Bergmann＇s rule and is most frequently found in lizards. Allen＇s rule predicts animals from warm climates usually have longer tails and limbs, while these traits tend to be shorter in individuals from cold climates. We examined body size variation in an endemic Chinese lizard Phrynocephalus theobaldi along a broad elevational gradient （3,600-5,000 m on the Qinghai-Tibetan Plateau）. Female body size showed a U-shaped cline, decreasing with increased elevation within the range 3,600-4,200 m, but increasing at eleva- tions 〉 4200 m. Male body size continued to increase with increasing elevations. Both sexes showed an increased pattern of ex- tremity length with elevation that does not conform to Allen＇s rule. Limb length and tail length increased along the elevational gradients. In terms of color pattern, an abdominal black speckled area appears at elevations 〉4,200 m. This trait increases in size with increased elevation. Unlike most studies, our results indicated that annual sunshine hours corresponding to the activity pe- riod of the lizards could play an important role on the positive body size cline in environments at very high elevations 〉 4200 m
基金the financial support of the Knowledge Innovation Project of the Chinese Academy of Sciences (KSCX2-EW-J-2)the Special Program for Key Basic Research of the Ministry of Science and Technology, China (2013FY110300)
文摘We examined the dietary diversity and food intake of Phrynocephalus frontalis, compared the difference of insect diversity in the natural habitats with different lizard densities, and discussed the potential role of this lizard in the desert ecosystem. The results show that： （1） arthropodans of the orders Coleoptera, Hymenoptera and Hemiptera were major dietary components of P. frontalis; （2） coleoptera larvae always formed the predominant component of lizard diets; （3） dietary diversities of P. frontalis were not significantly different between summer and autumn or between the two sexes; （4） the similarity in trophic niches between seasons was 0.756, whereas the similarity in trophic niches between sexes was 0.994; （5） stomach content weight of lizards varied significantly among different seasons, but there was no significant difference in stomach content weight between sexes; （6） insect diversity differed significantly among the groups of the habitat with different degrees of lizard density, and the habitat with moderate lizards density had the highest insect diversity. We infer that P. frontalis prey mainly on insects and change their diet and food intake with season; males and females consumed similar preys in types and weights. As an important predator, P. frontalis could affect the insect community in the arid ecosystem of Hunshandak Desert on the Mongolian Plateau.
