Choice And Cultivation Of The First Feeds Of Seahorse Larval

At present,feedstuff plays an important role in the farming seahorse.The purpose ofthis paper is to select a copepod species which would be easier to feed the larval seahorse.And it might be not only suitable for seahorse culture as larval food, but an effective methodof exploit copepods.Choosing a adequate first feeds of larval rearing of seahorse, it was zooplankton-Tisbefurcata from the sea near Yantai. Studying the effect of different temperature and salinity onTisbe furcata growth and population growth rate by using single factor experiment method.Studying its composition and structure by using histological method. Studying the survival ofseahorse larval reared on Artemia nauplii and Tisbe furcata. Results of these experimentsshow that:Selection: Tisbe furcata have the characteristic of the little size bodys,fooding on thefilter-feeding or omnivore, weak swimming ability and not concentration on the surface of thewater. During a period of time the Tisbe furcata became dominant specie among the allcopepod species. It have a high tolerance in sharp change temperature and salinity. The aboveall which made it the only species to be further studied.The growth of population and body length: Comparison of the effects of different culturetemperature on Tisbe furcata, the maximum population density and body length appears in the22℃. Comparison of the effects of different culture salinities, the maximum populationdensity and body length appeared in the38‰. The above all which made the22℃and38‰the most suitable conditions of culture Tisbe furcata.Feeding: Compared with Artemia nauplii, seahorse larvae like to eat Tisbe furcata. ButTisbe furcata were harmful to seahorse larvae in High-density.The mortality of seahorselarvae feed by Tisbe furcata density more than0.5/ml were significantly higher than it feed byArtemia nauplii. seahorse larvae could live with eating dead Tisbe furcata. A lot of vulnerawere found by using histological method.Histology: The results show that the digestive system of Tisbe furcata consists ofesophagus, the caecus, the midgut, and the hindgut. From the inner to the outer is theepithelial layer and the muscle layer. The secretory cells secrete digestive enzymess in thecaecus and the midgut, the absorption and digestion are the main function of the caecus andthe midgut. The nervous systems consists of brain, circumpharyngeal connective and ventral nerve cord. Soma are distributed in nerve fibers. The female reproductive physiology systemis M-shaped and consisted of the single ovary and the a pair of oviduct. The process ofoogenesis is divided into four stages: oogonium stage, primary oocyte stage, secondary oocytestage and mature ovum stage. The male reproductive system included the single testis, ductusdeferens and spermatophore sac. The process of spermatogenesis was divided into fife stages:spermatogonia stage, primary spermatocyte stage, seconday spermatocyte stage, spermatidstage and spermatozoon stage.