The Impact Of Pond Environment To The Food Composition Of The Apostichopus Japonicus And Temperature Variation To The Apostichopus Japonicus’s Growth And Fatty Acid Composition

In this study, the biology composition of the food environment and their impactto seasonal variation of food sources in sea cucumber in the pond was analyzed, theeffects of water temperature on the growth and fatty acid composition of young seacucumber was also analyzed in order to study the young sea cucumber’s adaptation towater temperature. the primary results were listed as below：1The biology composition of sea mud and its impact to seasonalvariations of food sources in sea cucumber Apostichopus japonicusindicated by fatty acid biomarkers analysisIn this study,16:1(n-7)/16:0and EPA were selected as diatom fatty acidbiomarkers according to the fatty acid composition. DHA and20:4(n-6) were usedas fatty acid biomarkers of flagellate or protozoan alga and brown alga. Odd&branched FAs and18:1(n-7) were the fatty acid biomarkers of heterotrophic bacteria.The biology composition of sea mud and its impact to seasonal variations of foodsources in sea cucumber Apostichopus japonicus was determined by fatty acidbiomarkers analysis. The results showed that the main biology composition of seamud was diatoms, flagellate or protozoan, bacteria and brown alga, which showedsignificant seasonal variation (p<0.05). Apostichopus japonicus’s diet consisted ofdiatoms, flagellate or protozoan, bacteria and brown alga, which showed significantseasonal variation (p<0.05). The correlation matrix of fatty acid in sea mud and A.Japonicus showed that diatoms, protozoan and bacteria of A. japonicus’s diet was mainly from the sea mud.2The biology composition of the suspended particular matter in thepond, the reef in the pond and their impact to seasonal variations offood sources in sea cucumber Apostichopus japonicus indicated byfatty acid biomarkers analysisIn this study,16:1(n-7)/16:0and EPA were selected as diatom fatty acidbiomarkers according to the fatty acid composition. DHA and20:4(n-6) were usedas fatty acid biomarkers of flagellate or protozoan alga and brown alga. Odd&branched FAs and18:1(n-7) were the fatty acid biomarkers of heterotrophic bacteria.The biology composition of the suspended particular matter in the pond and the reefin the pond and their impact to seasonal variations of food sources in sea cucumberApostichopus japonicus was determined by fatty acid biomarkers analysis. Theresults showed that the main biology composition of the suspended particular matterin the pond was diatoms, flagellate or protozoan,and bacteria, which showedsignificant seasonal variation (p<0.05). The main biology composition of the reef inthe pond was diatoms, flagellate or protozoan, bacteria and brown alg, which showedsignificant seasonal variation (p<0.05). The results showed that the reef in the pondand the suspended particular matter in the pond were ones of the food sources of theApostichopus japonicus’s diet.3Effects of water temperature on the growth and fatty acidcomposition of young sea cucumber Apostichopus japonicusIn order to study the effects of water temperature on the growth and the fatty acidcomposition of young sea cucumber Apostichopus japonicus, the experiment studiedthe growth and fatty acid composition of the young sea cucumber Apostichopusjaponicus at the initial weight4.02g±0.11g under the four temperature of14℃,18℃,22℃and26℃. The results showed that the specific growth rate of young sea cucumber were significantly different when they were under different temperatureconditions (p <0.05), the young sea cucumber grown best at18℃(the SGR was1.21±0.23), the young sea cucumber grown worst at26℃(the SGR was0.65±0.19).The results showed that the SFA ratio of neutral lipids in sea cucumber wassignificantly higher than the SFA ratio in the phospholipid fatty acids or fatty acidspercentage (p <0.05). The results suggested that the lower the temperature was, thehigher ratio of PUFA(especially n-3series PUFA)of the phospholipid fatty acids orfatty acids in sea cucumber was, which showed the adaptation of the young seacucumber to the water temperature environment. Therefore,14℃-18℃is conductiveto improve the growth and the quality of sea cucumber.