Using Oman Sea Sargassum illicifolium meal for feeding white leg shrimp Litopenaeus vannamei

The brown seaweed Sargassum illicifolium is abundant along the Iranian coastline of the Oman Sea in which is rich in nutrients. The aim of the present study was to test the hypothesis which it can be used as a source of protein in shrimp diets. The experiment was conducted in a laboratory, ۲۰۱۳, where ۳g shrimp juvenile acclimation in a ۵۰۰۰L tank. They were then kept in plastic tank containing ۳۰۰L sea water and ۳۰ shrimp juveniles in which were fed daily (۳% of biomass) in four equal portions with one of four different diets in four repetitions for a period of ۴۵ days. All diets contained ۳۳% crude protein (isoprotein) and ۳۵۵ kcal ۱۰۰ g−۱ (isocaloric), with different percentages of Sargassum powder: Diet “A” ۱۵% Diet “B” ۱۰%, Diet “C” ۵%, and Diet “D” (Control) without seaweed. Final biomass values ranged from ۱۲۰.۸۹ to ۱۲۸.۶۶ g. L−۱ weight gains in biomass ranged from ۱۰۶.۴۹ to ۱۲۴.۳۶ g L−۱, and SGR ranged from ۴.۶۸ to ۵.۶۸% exhibited no significant differences between treatments(p>.۰۵). Survival rate ۹۵.۲ to ۹۷.۰% was almost equal under the four experimental conditions (p>.۰۵). Diets “A” and “B”, with a greater content of algae, exhibited better feed conversion (۱.۱۵:۱ and ۱.۱۷:۱) than diets “C” and “D” (۱.۳۰:۱ and ۱.۳۳:۱) (p<.۰۵). The physicochemical variables of the water showed no significant variation and remained within the standards necessary for the wellbeing of the animals. If sufficient biomass of beached algae can be practically and economically collected, it can be used as a component in the making of shrimp feed.

Keywords:

Sargassum , Diet , Shrimp , Growth rate , Survival rate , Oman Sea