Comparative analyses of reproductive characteristics of functional sex reversal male gynogenetic red crucian carp and ordinary male red crucian carp

摘要

Functional sex reversal male gynogenetic red crucian carp (RGRCC) were obtained by oral administration of 17-alpha-methyltestosterone (MT) at a dosage of 100 mu g/g diet for 60 days to gynogenetic red crucian carp. In the present study, we aim to investigate whether MT induction sex-reversal impairs morphology and reproductive function of RGRCC. During the reproductive season, 20 mature males of both ordinary red crucian carp (RCC) and RGRCC were randomly chosen to measure the phenotypic traits and reproductive traits. None of the morphological traits and nor sperm traits measured differed significantly between RGRCC and ordinary male RCC (P > .05). The mean body weight, gonadosomatic index (GSI), sperm concentration, sperm volume and fertilization rate of RGRCC and ordinary male RCC, were 265.92 and 270.71 g, 3.74 and 3.82%, 3.04 and 3.22 x 10(10) cells ml(-1), 8.73 and 8.87 kg ml(-1), 84.66% and 86.84%, respectively. In addition, six sperm motility parameters including values of curvilinear velocity, average path velocity, straight line velocity, linearity, percentage of motile sperm and amplitude of lateral displacement of the sperm head were assessed by computer assisted sperm analysis and there were not significant differences (P > .05) between these two fishes. We concluded that the reproductive capacities of RGRCC were not affected by MT treatments. RGRCC could be used to obtain all-female RCC which will increase their production potential for application in aquaculture.