Artificial Change Of Physiological Sex About Bumper Crucian Carp (Carassius Auratus Of Pengze♀×Cyprinus Acutidorsalis Wang♂),the Growth Of Its Gonad, And The Studies Of Physiological And Biochemical Quality

The thesis studied effects of concentration and time of male hormone (17-a-methyltestosterone) on physiological sex of Bumper crucian carp {Carassius auratus of Fengze x Cyprinus acutidorsalis Wang). The change of physiological sex of Bumper crucian carp and the development of gonad under the male hormone function had been studied, so as to see if it had any influence on the growth rate and death rate of Bumper crucian carp. The results showed that 30gMT/mL alcohol feedstuff was the most economical feeding concentration and a month was the shortest time, which could change the gonad of Bumper crucian carp from female to male by the rate of over 95%, if the fish had been fed as it opened its mouth to eat feedstuff on 17-a-methyltestosterone. Different concentration of male hormone had some effects on the death rate of Bumper crucian carp fry. High dosage group made the death rate higher than that of low dosage group. It had no obvious effect on the growth rate. The sex differentiation time of Bumper crucian carp was about 20 days through anatomizing fish and observing organic slice. An amphigenetic mosaic had been found. The results of organic slice showed that oocyte were degenerated.The thesis also studied on the digestive enzyme activity in digestive organs between Bumper crucian carp and its parents. The results showed that three digestive enzyme activities in digestive organs of Bumper crucian carp were either intervenient its parents' or higher than its parents'. Three digestive enzyme activities in digestive organs of Bumper crucian carp were also higher than its mother's, but the difference between mother and filial generation was lower than that between father and filial generation. The results accorded with the characteristic that the phenotypes of Bumper crucian carp were unanimous with its mother's, and it also indicated that heterogeneous sperm had certain effect on digestive enzyme activity. This experiment offered the evidence for the growth effect of Bumper crucian carp. The research of muscle nutritive value showed that the muscle nutritive component was mostly intervenient its parents, which was inaccordance with the experimental results of digestive enzyme activitie. It showed that digestion had some relativity with nutritive value. The experiment proved that Bumper crucian carp was a ideal merchandise variety, which is of high protein, high nutritive value and low fat. Meanwhile it has abundant kinds of amino acid with high content of human essential amino acids and delicious amino acids, certain officinal value and so on.