Niviventer confucianus is a common species of rodent in South China. We designed an experimental protocol to determine the influence of temperature on energy requirement and food assimilation of the N. confucianus . I...Niviventer confucianus is a common species of rodent in South China. We designed an experimental protocol to determine the influence of temperature on energy requirement and food assimilation of the N. confucianus . In our feeding trials, four experimental temperatures were applied: 17℃,22℃,27℃ and 32℃. The energy requirements of N. confucianus under different temperature were:107 43±6 44 KJ/animal/day (17℃),94 76±4 46 KJ/animal/day (22℃),73 96±5 65 KJ/animal/day(27℃),and 62 80±5 15 KJ/animal/day(32℃),respectively. Moreover, the energy intake, digested and assimilated energy of N. confucianus decreased with temperature increase. However, no significant differences on digestibility and assimilation rate of N. confucianus were found among four experimental temperatures. It indicated that, during a range of particular temperatures, N. confucianus might maintain relatively high digestibility by change of digest tract morphology.展开更多
The Chinese skink ( Eumeces chinensis) is sexually dimorphic in both body size and head size,and males are the larger.A comprehensive analysis of the ecological and evolutionary sources of sex differences in growth an...The Chinese skink ( Eumeces chinensis) is sexually dimorphic in both body size and head size,and males are the larger.A comprehensive analysis of the ecological and evolutionary sources of sex differences in growth and size of head requires a detailed understanding of growth trajectories during ontogeny.Here,we pay particular attention to the point during ontogeny at which males and females diverge.Hatchlings (newly emerged young) and juveniles smaller than 70 mm SVL do not exhibit sexual dimorphism in head size,whereas males and females larger than 70mm SVL begin to diverge.The sexual dimorphism in head size is much more pronounced in adults than in juveniles sharing this character.Adult females partition relatively less resources into head growth but more into carcass growth,thereby leaving a larger space for eggs so as to increase reproductive output.Adult males,on the contrary,partition relatively more resources into head growth,thereby increasing their reproductive success and enhancing their ability to defend predators.Skinks at different ontogenetic stages slightly differ in food niche width and breadth.However,no direct evidence shows a substantial contribution of the divergence in head size to the segregation of food niche between males and females.Our results indicate that sexual selection is the main evolutionary source of sexual dimorphism in body and head sizes in E.chinensis .展开更多
文摘Niviventer confucianus is a common species of rodent in South China. We designed an experimental protocol to determine the influence of temperature on energy requirement and food assimilation of the N. confucianus . In our feeding trials, four experimental temperatures were applied: 17℃,22℃,27℃ and 32℃. The energy requirements of N. confucianus under different temperature were:107 43±6 44 KJ/animal/day (17℃),94 76±4 46 KJ/animal/day (22℃),73 96±5 65 KJ/animal/day(27℃),and 62 80±5 15 KJ/animal/day(32℃),respectively. Moreover, the energy intake, digested and assimilated energy of N. confucianus decreased with temperature increase. However, no significant differences on digestibility and assimilation rate of N. confucianus were found among four experimental temperatures. It indicated that, during a range of particular temperatures, N. confucianus might maintain relatively high digestibility by change of digest tract morphology.
文摘The Chinese skink ( Eumeces chinensis) is sexually dimorphic in both body size and head size,and males are the larger.A comprehensive analysis of the ecological and evolutionary sources of sex differences in growth and size of head requires a detailed understanding of growth trajectories during ontogeny.Here,we pay particular attention to the point during ontogeny at which males and females diverge.Hatchlings (newly emerged young) and juveniles smaller than 70 mm SVL do not exhibit sexual dimorphism in head size,whereas males and females larger than 70mm SVL begin to diverge.The sexual dimorphism in head size is much more pronounced in adults than in juveniles sharing this character.Adult females partition relatively less resources into head growth but more into carcass growth,thereby leaving a larger space for eggs so as to increase reproductive output.Adult males,on the contrary,partition relatively more resources into head growth,thereby increasing their reproductive success and enhancing their ability to defend predators.Skinks at different ontogenetic stages slightly differ in food niche width and breadth.However,no direct evidence shows a substantial contribution of the divergence in head size to the segregation of food niche between males and females.Our results indicate that sexual selection is the main evolutionary source of sexual dimorphism in body and head sizes in E.chinensis .
