Study On Selectivity Of Selenium Sources Of The Selenium-enriched Stichopus Japonicus

Stichopus japonicus whose specifications were10g,20g and50g were selected separately tocarry out96h acute toxicity tests with selenomethionine, sodium selenate and sodium selenite.The result of study showed that the96h-LC50of selenomethionine to Stichopus japonicas of10g,20g and50g were0.639mg/L,0.741mg/L,0.795mg/L. The96h-LC50of sodiumselenite toStichopus japonicas of10g,20g and50g were0.279mg/L,0.299mg/L,0.324mg/L. The96h-LC50of sodium selenate to Stichopus japonicas of10g,20g and50g were0.305mg/L,0.346mg/L,0.368mg/L. Acute toxicity of three drugs for Stichopus japonicas are, Sodiumselenite＞Sodium selenate＞Selenomethionine.At water temperature10.2℃~12.4℃, salinity24~28, PH7.8~8.0, the juveniles(initial body weight2.28g±0.26g,at a rate of30per cage)and the Stichopus japonicus (initialbody weight54.97g±9.49g,at a rate of15per cage) were restocking in cages and fed the dietscontaining sodium selenate, sodium selenite, selenomethionine at a rate of0.6×10-6selenium(without addition of selenium as control).The result showed that the Stichopus japonicus fed thediets supplemented with selenium had significantly higher SGRLand SGRMthan the Stichopusjaponicus fed the diets without the supplementation of selenium (P＜0.05),the maximal bodyweight and length gain being observed in the Stichopus japonicus fed the diets containingselenomethionine. Stichopus japonicus fed the diets supplemented with selenium hadsignificantly higher oxygen consumption rate than control (P <0.05), ammonia excretion ratedecreased in the Stichopus japonicus fed the diets supplemented with selenium, but there wereno significant difference between the juveniles fed the diets supplemented with selenium and thecontrol group in ammonia excretion rate (P>0.05). Oxygen-nitrogen ratio of the Stichopusjaponicus that fed the diets supplemented with selenium had significantly higher than the control,the diets supplemented with selenium can improve the nutritional needs and utilization ofStichopus japonicus.Stichopus japonicus fed in the corresponding period with the above for two month. Andthen we fed Stichopus japonicus with the basal diet. The Stichopus japonicus were fed60days,and the juveniles were fed45days. After determination of selenium content in the body wallevery five days, we obtain selenium content of the body wall metabolism and pharmacokineticparameters model through drug concentration-time data which came from three kinds ofselenium compounds fortified Stichopus japonicus and juveniles. The elimination characteristics of selenium compound in Stichopus japonicus could be described by the equations as follows:YSelenomethionine=2.1991, YSodium selenate=0.8838, YSodium selenite=1.0377The elimination characteristics of selenium compound in the juvenilescould be described by the equations as follows:ySelenomethionine=1.4955,ySodium selenate=0.8565, ySodium selenite=1.085. And T1/2were13.86d,8.66d,9.63d,7.97d,6.66d,5.33d.