The Control Of Sea Squirt (Ciona Intestinalis) In The Sea Cucumber Nursery

As Apostichopus japonicus cultivation bagan more and more popular and culturing scale increased gradually day and day, Ciona intestinalis harm tothe Apostichopus japonicus proplem is more graveness,causing serious economic losses and becoming one of the limiting factors in the sustainabledevelopment of this industry.From 2006 to 2008,the author carried out a comprehensive investigation on,in which have been discovered in the yellow sea and Bo sea of China.In the two areas it is dominant species.Young individual visible to the naked eye can be found in early June in Shandong area.reached a peak in August and decreased in December.There has been certain differences in other regions with different temperature and environment.The results of Consumes the oxygen rate and Arranges the ammonia rate experiments indicated that COR 180 Cand AAR 230C are maximum.In outside Apostichopus japonicus pool 13～150C and breed young Apostichopus japonicus pool 200C it's growth speedy and feeding vigorous stage hurt graveness, especially young Apostichopus japonicus.Acute toxicity of ten chemicals to sea squirt (Ciona intestinalis) was determined.Of ten dugs,there were seven ones that had no lethal effect to C.intestinalis.These seven drugs were zinc sulfate(≤3mg/L),sodium bicarbonate(≤2.5%),tea saponin(≤6.7ml/L),cypermethrin(≤0.2ml/L), trichlorfon refined flour(≤4mg/L),trichlorfon and phoxim mixture(≤3mg/L) and potassium permanganate(≤5mg/L).In contrast,copper sulfate(≥1mg/L), MQL(≥5mg/L)and herbal mixture CQS(≥15mg/L) could kill sea squirt in 24h, and the lethal dose concentration (LC50)of these three chemicals was0.58mg/L,3.33mg/L and 10.80mg/L,respectively. At the concentration of 1 mg/L,coppersulfate could cause juveniles Apostichopus japonicus to disgorge their internal organs in 3h.Thus,copper sulfate is not suitable to use in culturepractice.In addition,MQL and CQS had no toxin effects to juveniles Apostichopus japonicus in 96h at the concentration of 10 mg/L and 20 mg/L, respectively.Therefore,MQL and CQS were considered as the effective drugs To kill C.intestinalis in the sea cucumber nursery system,while the dosagebeing 5mg/L and 15mg/L for soaking 24h were suggested in their application.This report was helpful for kill C.intestinalis.Ciona intestinalis tectology research can become conscious of incurrent siphon,outcurrent siphon,ganglion,endostyle,mantle,heart,spermary,ovary,oviduct,stomach,intestine,anus.Tunicin in it's exterior,pharynx and atrium is not patency.Ciona intestinalis tectology research supply reference for the future.