Two new freshwater atyid shrimps, Caridina angustipes sp nov.and C clavipes sp nov.from Hunan Province,China are described. C angustipes sp nov.is similar to C baojingensis Guo,He et Bai,1992,b...Two new freshwater atyid shrimps, Caridina angustipes sp nov.and C clavipes sp nov.from Hunan Province,China are described. C angustipes sp nov.is similar to C baojingensis Guo,He et Bai,1992,but with longer rostrum,15-27 dorsal teeth,3-6 ventral teeth,and straighter inner margin of endopods in male 1st pleopods. C clavipes sp nov.is similar to C angustipes ,but with narrower distal and fewer spines on inner margin of endopds in male 1st pleopods,and shorter and thinner appendix masculina in male 2nd pleopods with only 1 spine on inner lateral margin and 4 spines in apex.The holotypes are deposited in Shanghai Fisheries University.Some representative paratypes are deposited in Foshan Science and Technology College.展开更多
After being kept in captivity and isolated from natural predators for more than 1,200 years, P6re David＇s deer has been reintroduced in China and now occurs in a reserve where human activity is the only potential thr...After being kept in captivity and isolated from natural predators for more than 1,200 years, P6re David＇s deer has been reintroduced in China and now occurs in a reserve where human activity is the only potential threat. Antipredator vigilance i~ an important component of survival for many prey animals in their natural habitat. Do deer still adjust vigilance as a function of risk after such a long period of relaxed predation pressure？ Here, we examined vigilance levels in P6re David＇s deer groups as a function of group size, sex and level of human disturbance. The results showed that individual vigilance significantly decreased with group size in all-female groups but not in all-males or mixed-sex groups. In rutting season, males compete with one another and harass females, and we argue that vigilance is partly aimed at threatening males and that such vigilance increases with group size. This explains why overall vigilance did not vary with group size for males in general and for females in mixed-sex groups. Vigilance increased in more disturbed areas but in in male deer only. The results indicate that despite relaxed predation pressure over centuries, P6re David＇s deer can still adjust antipredator responses as a function of perceived risk. Such information may become useful in the rewilding programme now under way for this species in China [Current Zoology 59 （2）： 265-270, 2013].展开更多
文摘Two new freshwater atyid shrimps, Caridina angustipes sp nov.and C clavipes sp nov.from Hunan Province,China are described. C angustipes sp nov.is similar to C baojingensis Guo,He et Bai,1992,but with longer rostrum,15-27 dorsal teeth,3-6 ventral teeth,and straighter inner margin of endopods in male 1st pleopods. C clavipes sp nov.is similar to C angustipes ,but with narrower distal and fewer spines on inner margin of endopds in male 1st pleopods,and shorter and thinner appendix masculina in male 2nd pleopods with only 1 spine on inner lateral margin and 4 spines in apex.The holotypes are deposited in Shanghai Fisheries University.Some representative paratypes are deposited in Foshan Science and Technology College.
基金Acknowledgements Financial support for this work was provided by the National Natural Science Foundation of China （No. 31000174 ＆ No. Jl103512）. We thank Prof. Ding Yuhua and other staff members at Dafeng Milu National Natural Reserve for supporting our field research in the reserve. We also thank Xianlong Li, Rongrong Wang, Jia He, Dameng Li, Ruonan Jia, Yilei Hua, and Long Wang for help with the field work, and Chen Ge and Cheng Huang for useful discussions.
文摘After being kept in captivity and isolated from natural predators for more than 1,200 years, P6re David＇s deer has been reintroduced in China and now occurs in a reserve where human activity is the only potential threat. Antipredator vigilance i~ an important component of survival for many prey animals in their natural habitat. Do deer still adjust vigilance as a function of risk after such a long period of relaxed predation pressure？ Here, we examined vigilance levels in P6re David＇s deer groups as a function of group size, sex and level of human disturbance. The results showed that individual vigilance significantly decreased with group size in all-female groups but not in all-males or mixed-sex groups. In rutting season, males compete with one another and harass females, and we argue that vigilance is partly aimed at threatening males and that such vigilance increases with group size. This explains why overall vigilance did not vary with group size for males in general and for females in mixed-sex groups. Vigilance increased in more disturbed areas but in in male deer only. The results indicate that despite relaxed predation pressure over centuries, P6re David＇s deer can still adjust antipredator responses as a function of perceived risk. Such information may become useful in the rewilding programme now under way for this species in China [Current Zoology 59 （2）： 265-270, 2013].
