GENETICS BREEDING SRUDIES OF SEA CUCUMBERS AND SEA URCHINS IN CHINA

1*Yaqing Chang

1Key Lab of Mariculture, Ministry of Agriculture,
Dalian Fisheries University, P. R. China 116023
*yqchang@dlfu.edu.cn Various species of sea urchins and sea cucumbers are consumed in China. As wild stocks decreased since 1980s, research efforts on genetics and breeding developed the technology of echinoderms aquaculture. Consequent echinoderm culture developed significantly, making it a large industry in China.

1. Sea cucumber
Supported by the Chinese national 863 major program, we carried out a research study on interspecies cross-breeding between Chinese and Russian population of sea cucumbers (Apostichopus japonius). Chinese sea cucumbers have higher nutrition quality and better environmental adaptability. Russian sea cucumbers, on the other hand, have thicker body wall with six lines of more and longer papillaes. We achieved improvements of traits in hybrid via hybridization among the two populations. Family breeding is another simple and effective breeding method we are studying on. Full-sib families of sea cucumbers were established in our lab. To breed special strains against high temperature and low salinity, we established special strains against high temperature and low salinity.

2. Sea urchin
We investigated growth, development and viability at the larval, juvenile and adult stages of three sea urchin species and their hybrids and achieved improvements of traits related to growth in hybrid F1 via hybridization among the parents. Two batches of full-sib families (52 full-sib families and 161 full-sib families) of sea urchins (Strongylocentrotus intermedius) were established using unbalanced nested design (1 :3) in October 2006 and November 2007, respectively. After the establishment of F1 families, 72 full-sib F2 families of sea urchins were established for different growth performance using unbalanced nested design in June 2008. The growth performance among families was obviously different. Moreover, Sea urchin phenotypes prediction models were established using ISSR marker technology.

Unusual mortality of edible echinoderms has been reported in China since 2000, which largely reduced the production of economically important echinoderms. Since then, various studies were carried out to deal with the industrial problems of both sea cucumbers and sea urchins in China. Although diseases have been adequately addressed through studies focused on genetics and breeding to improve the quantity and quality of cultured echinoderms, additional efforts should look at making the industry more environmentally friendly.