The evaluation effect of extract of Sargassum angustifolium on growth and survival rates of Litopenaeus vannamei (Boone, 1931)

Marine algae (sea weed) were important role in the aquatic feed. The aim of this study evaluation were different levels effects extract Sargassum angustifolium in compared with commercial concentrate feed on the growth and survival of juveniles 5-4 grams of Litopenaeus vannamei collected from the coastal city of Mahshahr. This study was consisting of three experimental treatments (fed with 1.5, 2.5 and 3 % of S. angustifolium diet) and control treatment (fed commercial concentrate diet) each had three replications that were daily fed for 60 day. the highest average weight and length of shrimp treatments alluded the treatments fed diet containing 2.5 % seaweed extract of S. angustifolium with 10/01±0/19 g and 10/95±0/54 cm respectively compared with shrimp fed diet containing 3 and 5.1 % seaweed extract. In this study observed specific growth rate (SGR) of shrimp fed with diets containing 2.5 % seaweed extract were 1.57 % compare with control groups were increased significantly (P<0.05). The results obtained in the experiment were indicated food conversation rate of experimental of post larval significantly less than control treatment (P<0.05). On the other hand it was observed that survival rate of shrimp treatments 76.85, 76.58 and 77.65 %, respectively, significantly higher than the control shrimp were with the 70.40 % (P <0.05).Thus, despite the absence of a significant difference in the nutritional value of different diets containing seaweed extract, the results showed that no significant difference in the growth and survival of shrimp fed with 3% seaweed extract fed to shrimp seaweed was observed with diets containing 2.5 %.However, the growth index and survival of shrimp was significantly lower than the control shrimp. It can be said that the use of seaweed extract as a supplement in the diet by 2.5 % during the period of investigation is able to improve the growth and survival of L. vannamei.