eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2016-06-10 11 Spl.Edn.1 331 338 10.13005/bbra/1427 11874 article N. Sri Kumaran 1,2 S. Bragadeeswaran 2 Department of Marine Biotechnology, AMET University, Kanathur, Chennai - 603112, India Faculty of Marine Science, Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai – 608 502, India. In the present investigation the colonial ascidians E. viride and D. psammathodes were collected from the rocks of near Hare Island, Tuticorin coast. The collected ascidian samples were tested for biochemical assays (carbohydrate, protein, lipid, amino acids and fatty acids). All these assays were followed by standard methods. In bio chemical analysis protein content in E. viride and D. psammathodes tissues showed 3.78 and 3.62 μgmL-1, total carbohydrate content 2.15 and 2.2 μgmL-1, crude fiber content 9.2 and 7.9 μgmL-1and total free amino acid content 3.2 and 3.9 μgmL-1. From the amino acid analysis leucine, lysine, isoleucine, threonine, methionine, histidine and arginine shows high amount in E. viride and D. psammathodes tissues. The total lipid content in ascidians E. viride and D. psammathodes tissues showed 0.23 and 0.32 μgmL- 1 respectively. In fatty acids estimation, E. viride and D. psammathodes shows 31.71 % and 32.96 % total saturated fatty acids (Σ of SFAs), 24.55 % and 25.52 % total mono unsaturated fatty acids (Σ of MUFAs) and 29.07 % and 33.59 % total poly unsaturated fatty acids (Σ of PUFAs). The results from this study may help in developing appropriate diets for human nutrition. https://www.biotech-asia.org/vol11_nospl_edn1/nutritional-composition-of-the-colonial-ascidian-eudistoma-viride-and-didemnum-psammathodes/ ascidian; nutrient composition; food; feed