1.College of Life Science,Nanjing Normal University,Nanjing 210046,China;2.Key Laboratory of Aquaculture and Ecology of Coastal Pool of Jiangsu Province,College of Chemistry and Biology Engineering,Yancheng Institute of Technology,Yancheng 224003,China
Abstract: Many zooplankton species including rotifer previously considered as cosmopolitan are complexes of sibling species.In the present study,durations of juvenile period,durations of embryonic development,lifetime fecundity,life cycle parameters and fertilization rate were studied in Nanjing(NJ)strain collected from Nanjing,China and Florida(FL)strain ofBrachionus calyciflorus.There were no significant differences in the juvenile period, hatching time of the first neonate and lifetime fecundity in FL and NJ strains(P＞0.05).The NJ strain had significantly shorter durations of embryonic development than FL strain(P＜0.05),being induced by 6.9%.The net reproduction rate(R0),life expectancy(e0),the intrinsic rate of population increase(rm)and the generation period(T)were found to be higher in NJ strain than in FL strain(P＜0.05).Cross-mating tests demonstrated that the fertilization rate was less between NJ strain and FL strain than that in the strains,demonstrating that completely reproductive isolation was not found in the two strains,and that the NJ and FL strains were not sibling species inB. calyciflorusspecies complex.
2012, Vol. 27 
