Study On Embryonic Nutrition Metabolism Of Cherax Quadricarinatus

Redclaw crayfish (Cherax quadricarinatus )was also called Australian freshwater lobster, subordinated to Crustacea, Decapoda, Pleocyemata, Astacidea, Parastacoidea, Parastacidae, Cherax. It originally distributed to east north coast of Australia, was one of the rarely economic lobster in the world. Redclaw crayfish not only had merits of big individual, miscellaneous diets, better adaptability, fast growing, but also had delicious taste, high eatable rate, enduring line-haul, approving freshwater raising, coming into the market with fresh and so on. Under common situation, redclaw crayfish had about 40 % meatable rate. According to concerned files: redclaw crayfish contented 16 % protein, 2.46 % lipid , 18.69 mg/g free amino acid in its meat, and had abundant Na+, k+, Mg+, Ca+,Cr+ and so on. Especially, its muscle contented low cholesterin, was exploited as health protection food by many countries in Occident. America and South America had most hearty demands, other areas, such as Japan, France and East South Asia also had potential consuming requirements, so redclaw crayfish was becoming to one of the considerably potential breed. Many countries fetched in and tried to cultivate at the end of 80's last century. It was fetched in our country in 1992, tried to cultivate in Guangdong, Hubei, Fujian, Jiangshu, Shangdong, Peking et al, and got primary success.Redclaw crayfish hetched in China several years ago and had some successful breed reports, but still didn't come into large scale cultivation right now. The key problem of redclaw crayfish's large scale cultivation was how to solve the problem of the larvae providing. Due to the low spawn numbers, low hatch rate and survival rate of redclaw crayfish, there still couldn't provide large-scale larvae in the market right now, brought about high price of larvae. Such as in 2001, the larvae length about 1 cm were sold 800-1000 yuan per thousand individuals, but the larvae of Maeobrachium tosenbergii was only 50 yuan per thousand individuals, about 1/20 price of redclaw crayfish. Because of the high price, there still hadn't have steady mature lobster providing in the market right now. It greatly contrasted with the potential needs in the market. And now more and more people prepared to breed the redclaw crayfish, larvae providing couldn't far off meet the demands of them . Quite lot of larvae must import from oversea, led to increase the cost of breeding andventure rate.Among the three produce taches of parent cultivation, embryonic development, larve cultivation, there had many valid technical measures in enhancing parent's nutrition, improving spawn numbers, optimizing larve cultivation by physical and chemical factors. But still hadn't perfect methods to solve the problems of decreasing embryonic mortality rate and increasing hatch rate. It was low survival rate and unsteady in artificial larvae cultivation. It was commonly to pay more attention to parent lobster's nutrition in order to increasing spawn numbers, but ignored the relationship between nutritional accumulation and equilibrium in eggs and embryonic development. Good or bad embryonic development directly effected the survival rate and haleness degree of offspring, therefore, it was necessary to study the embryonic nutritional metabolish and development.This study based on already studies, synthesized the ideas of development biology and propagation nutrition. Took advantage of biochemisty, molecular biology and other modern biological methods and technologies, synthesized immunology, histology, electricity microscope and so on. Systematically studied the rules or mechanisms of how to use up nutrition in embryonic development stages of redclaw crayfish and their relationships. Exploited molecular study field in Crustacean procreation biology. And discuss the mechanism mong main nutritional element, gene expression and development control. In order to understand the rules of Crustacean embryonic development. These not only possessed the important realism instruction meaning to cultivate redclaw cra...