Abstract:

Supercooling and thermal tolerance of two overwinter zooplankton species, Drepanopus bispinosus and a calanoida copepod, Cydlppida sp. in an Antarcitc littoral lake-Burton lake, were tested in both seasons. The results show that female adults of D. bispinosus and Cydippida sp. have quite stronger temperature tolerance. The upper thermal 12hrLD50 of female copepod and ctenophore is about 12℃ , and their supercooling 12hrLD50 is -8℃ and -10℃ respectively. The range of their temperature tolerance is wider than that of some other previously reported Antarctic marine invertebrates. The ability of animals in temperature tolerance evidently presented seasonal variation, and it suggests that the animals have good physiological regulation for adapting to enviromental temperature change. This may be resulted in naturel acclimatization in the lake.