Effects of lipid sources on the growth performance, gonad development, fatty acid profile and transcription of related genes in juvenile sea urchin (Strongylocentrotus intermedius)

This experiment was conducted to compare the effects of three lipid sources on the growth and gonad development in juvenile sea urchin (Strongylocentrotus intermedius). Kelp (Laminaria japonica) and three formulated feeds with the supplementation of fish oil (FO), linseed oil (LO) or soybean oil (SO) as the sole lipid source. Results showed that sea urchins fed kelp had significantly higher weight gain rate (WGR) but lower gonadosomatic index (GSI), than those fed formulated feeds (p < .05). WGR and GSI of sea urchins fed SO were significantly lower than that fed LO and FO (p < .05). The content of EPA in the gonad of sea urchins fed LO was significantly higher than that fed SO (p < .05). The content of ARA in SO was higher than that in FO and LO (p > .05). The expression of elongase 4, Delta 6 desaturase and Delta 5 desaturase was significantly lower in the intestine of sea urchins fed FO than that fed LO and SO (p < .05). These results indicated that LO and FO, but not SO were the ideal lipid sources for the juvenileS. intermedius. The elevated transcription of fatty acid synthesis-related genes could be responsible for the increased EPA and ARA deposition in LO and SO, respectively.