Testes size in most animals commonly shows directional asymmetry. In birds, the left testis mass is usually larger than the right one, but the reports on the testes asymmetry in anurans are very few. Moller （1994） h...Testes size in most animals commonly shows directional asymmetry. In birds, the left testis mass is usually larger than the right one, but the reports on the testes asymmetry in anurans are very few. Moller （1994） hypothesized that the right testis serves a compensatory role and increases in size when the left one is defective, and further suggested that testes asymmetry may be a reliable indicator of individual body condition. In this paper, we tested the compensation hypothesis in the Guenther＇s frog, Hylarana guentheri. From 60 sampled males, we found that there was a significant directional asymmetry in testes mass, with the left testis size being significantly correlated with relative testes asymmetry, providing evidence that the right testis had a compensatory function. However, testes mass and asymmetry were not correlated with body condition. Hence, we found no evidence that testes asymmetry in the Guenther＇s frog reflected male condition, and male age was also not related to testes mass or asymmetry.展开更多
Difference in environmental condition shapes variation in digestive tract length in evolutionary process.In particular,environmental difference results in variation in food resource among different habitats,and thereb...Difference in environmental condition shapes variation in digestive tract length in evolutionary process.In particular,environmental difference results in variation in food resource among different habitats,and thereby affecting energy intake and energy allocation.The digestive theory predicts that animals foraging high indigestible materials of stomach contents can promote the increased gut dimensions.Here,we studied variation in digestive tract and gut length across six Hylarana guentheri populations at different altitudes and latitudes to test the prediction of the digestive theory.We found that altitude and latitude did not affect variation in relative size of digestive tract and gut among populations.We also found that relative size of digestive tract and gut did not be correlated with diversity of prey items,but negatively correlated with proportion of digestible materials.Our findings suggest that individuals foraging less digestible materials display relatively longer digestive tract than individuals foraging more digestible materials.展开更多
[ Objective ] This paper aimed to study the sexual dimorphism of Rana guentheri. [ Method ] Sixty-seven Rana guentheri were collected in Zhaoqing ar- ea to measure their morphological indexes, count the brood amount o...[ Objective ] This paper aimed to study the sexual dimorphism of Rana guentheri. [ Method ] Sixty-seven Rana guentheri were collected in Zhaoqing ar- ea to measure their morphological indexes, count the brood amount of female Rana guentheri and study sexual dimorphism and female reproductive characteristics . [Result] The average snout-vent length of male Rana guentheri was （75.07 ± 1.21 ） mm and the average snout-vent length of female Rana guentheri was （78.67 ± 1.23 ） mm. The snout-vent length and weight of female Rana guentheri were significantly different from that of male Rana guentheri, which illustrated that snout-vent length and body weight of Rana gttentheri had significant sexual dimorphism. The sexual dimorphism index was 0.05. The Local morphological inde- xes of Rana guentheri were positively related with the snout-vent length. The average brood amount of female Rana guentheri was 4 916. The snout-vent length and body weight were positively related with the brood amount of female Rana guentheri. [ Conclusion] Rana guentheri in Zhaoqing area had obvious sexual dimor- phism.展开更多
基金support is provided by the Foundation of Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education,China WesNormal University(XNYB01-3)
文摘Testes size in most animals commonly shows directional asymmetry. In birds, the left testis mass is usually larger than the right one, but the reports on the testes asymmetry in anurans are very few. Moller （1994） hypothesized that the right testis serves a compensatory role and increases in size when the left one is defective, and further suggested that testes asymmetry may be a reliable indicator of individual body condition. In this paper, we tested the compensation hypothesis in the Guenther＇s frog, Hylarana guentheri. From 60 sampled males, we found that there was a significant directional asymmetry in testes mass, with the left testis size being significantly correlated with relative testes asymmetry, providing evidence that the right testis had a compensatory function. However, testes mass and asymmetry were not correlated with body condition. Hence, we found no evidence that testes asymmetry in the Guenther＇s frog reflected male condition, and male age was also not related to testes mass or asymmetry.
基金Financial support was provided by the National Natural Sciences Foundation of China(31772451,31970393)the Science and Technology Youth Innovation Team of Sichuan Province(19CXTD0022)+1 种基金the Key Cultivation Foundation of China West Normal University(17A006)Talent Project of China West Normal University(17YC335)。
文摘Difference in environmental condition shapes variation in digestive tract length in evolutionary process.In particular,environmental difference results in variation in food resource among different habitats,and thereby affecting energy intake and energy allocation.The digestive theory predicts that animals foraging high indigestible materials of stomach contents can promote the increased gut dimensions.Here,we studied variation in digestive tract and gut length across six Hylarana guentheri populations at different altitudes and latitudes to test the prediction of the digestive theory.We found that altitude and latitude did not affect variation in relative size of digestive tract and gut among populations.We also found that relative size of digestive tract and gut did not be correlated with diversity of prey items,but negatively correlated with proportion of digestible materials.Our findings suggest that individuals foraging less digestible materials display relatively longer digestive tract than individuals foraging more digestible materials.
基金Supported by National Natural Science Foundation of China(31271124)Natural Foundation Project of Guangdong Province(s2013010016062)Planned Project for Innovation and Entrepreneurship by Undergraduate(DC201455)
文摘[ Objective ] This paper aimed to study the sexual dimorphism of Rana guentheri. [ Method ] Sixty-seven Rana guentheri were collected in Zhaoqing ar- ea to measure their morphological indexes, count the brood amount of female Rana guentheri and study sexual dimorphism and female reproductive characteristics . [Result] The average snout-vent length of male Rana guentheri was （75.07 ± 1.21 ） mm and the average snout-vent length of female Rana guentheri was （78.67 ± 1.23 ） mm. The snout-vent length and weight of female Rana guentheri were significantly different from that of male Rana guentheri, which illustrated that snout-vent length and body weight of Rana gttentheri had significant sexual dimorphism. The sexual dimorphism index was 0.05. The Local morphological inde- xes of Rana guentheri were positively related with the snout-vent length. The average brood amount of female Rana guentheri was 4 916. The snout-vent length and body weight were positively related with the brood amount of female Rana guentheri. [ Conclusion] Rana guentheri in Zhaoqing area had obvious sexual dimor- phism.
