The Research On Ecological System And Mechanism Of Abalone And Whelk Polyculture

Abalone aquaculture was a pillar industry of rural economy in the coastal area of Fujian.Especially, raft culture in the sea area is above70%of abalone production in this province.however, there were a lot of fouling organisms on abalone shell and inside breeding cages inrecent years，such as oysters, barnacles, Ciona intestinalis etc., which caused them to have slowgrowth and a low survival rate. Therefore, in this paper, by constructing ecological system ofabalone and whelk and using the ecological principle of mutualistic symbiosis, it solvedtechnical problems of controlling fouling organisms in the farming system, which brough hugeeconomic benefits and effectively promoted the development of abalone aquaculture.This study aimed to use ecology concept and introduce whelk into abalone breeding tosolve the problem of fouling organisms in the sea area abalone culture. Mixed farming system ofabalone and whelk was constructed and studied. At the same time, the mechanism that howwhelk control fouling organisms were researched. This study test was divided into three parts.The details of results were as follows:From May to October in2012, the first part compared the effects of mixing three differentwhelks (Cantharus cecillei, Thais clavigera Kuster, Purpura gradate Jonas) and abalonerespectively. And it reached a decision that C. cecillei was best. The best ratio of polyculture was6whelks each cage that growth rate and survival rate of abalone were the highest. This provideda theoretical basis and production guidance for sea breeding, and achieved the goal of improvingthe yields and shortening the breeding cycle of abalone.The second part studying C. cecillei reported the type and quantity of fouling organismsunder different ratios of abalone and wheal polyculture, and explored the effect that foulingorganisms were controlled. The results had shown that fouling organisms gradually reduced withthe increase of number of wheal in breeding cages. When there were6whelks each cage, thetype and quantity of fouling organisms had dropped to low. if added one again, the trend of thefouling organisms did not significantly reduce. Considering increasing the number of whelk hadcertain effect on abalone’s growth, as well as the first part’s conclusion, it was thought that thebest ratio of breeding density was6whelks every cage.In order to explore mechanism of C. cecillei controlling fouling organisms, the third parthas carried on the preliminary research for its feeding habits. Through the tests of hanging cageand observing whether C. cecillei feeded these fouling organisms, it is found that C. cecillei had a wide range of feeding, belonged to the carnivorous whelk, and feed on Phylum Coelenterata,Bryozoa, Polychaetes, Molluscs, Crustacea, Ascidian and Echinoderm. In addition, by looking attest, we learned that the order of C. cecillei feeding some fouling organisms from high to low inturn is Mytilus edulis, Balanus, Styela clava, Ostreidae. And its feeding mechanism wasdiscussed.In conclusion, this study chose three different kinds of whelk and observed their influenceon abalone’s growth, results showed that C. cecillei was the best of them. And it reported on C.cecillei controlling fouling organisms in the abalone culture and its feeding habit, discussed C.cecillei control effect of fouling organisms. So it is preliminary concluded that C. cecillei couldeffectively control fouling organisms on breeding cages and abalone shell, which promote toincrease abalone aquaculture production in see area.