Differences Of Nutrition And Enzymatic Activity Between Male And Female Clams(Ruditapes Philippinarum ) And Preliminary Study Of Sex Reversal

Ruditapes philippinarum(short for clam) is one of the traditional important aquaculture species and have the characteristics of high yield, distribution range wide, fast growing. It has been reported that there is a sex reverse phenomenon of clam under the natural condition, and it also has been found there is hermaphroditism exist. This study compared the nutrients differences of male and female clam and also the changes of immune activity index under high temperature and high salt stress. The study also focuses on the changes of the gonad and endogenous hormone levels of the clam under the stimulation of in vitro steroid hormone exposure.The results are as follows:1. The study found that there were differences in the nutritional composition of the male and female clam. The amount of essential amino acids, total amino acids, and the flavor amino acids were slightly higher in females than in males; isoleucine and valine ofessential amino acids were significant higher infemale than that of in male; the arginine Arg of the non essential amino acid in male was obviously higher than that in the female; the delicious amino acids in Glu and Asp2 wasevidently higher in female than that in male; the content of sweet characteristic amino acid Gly in Male clam was significantly higher than that in female.2. The immune activity indexes between male and female clam were also different under high temperature and high salt stress. Both mutations in the external environment stress rate of enzyme activity in the lower body or in sustained high salt and high temperature stress the persistence of enzyme activity,the antioxidant enzyme class such as SOD and CAT in female clam were significantly higher than that of male.For digestive enzymes pepsin and amylase, the former showed no significant difference between male and female clam, the male clam anti high temperature stress may be better than that of female.For hydrolases AKP, male clam may be better than the femaleunder high salt stress. For the LYZ activity, the male clam was superior to the female in the ability of heat stress.3.Observe the male and female gonadal tissue sections after stimulation of exogenous steroids.The results showed that the different levels of hormone in different concentrations of male and female clams had different effects. In the testosterone treatment group, the ovary didnot degrade significantly in the low concentration and high concentration groups, whereas the ovarian degeneration was obviously; in the lower concentration of testosterone, the sperm follicle was good, no obvious degeneration and the high concentration testosterone treatment degraded severely.In the estrone treatment group, each group of female clams showed no significant difference and most of them were in the discharge to the recession and there were also no observably difference in male groups. Male individuals were good in the low concentration group while in the high concentration group they degraded significantly under the treatment of estradiol.As for females, gonadal degradation was not severe in all groups.4.We found hermaphroditic individuals in 500ng/L group of testosterone, 500ng/L group and 1?g/L of estrone group. The effect of different concentrations of different hormones on endogenous hormone levels of clam was also significantly different.