Effects of Artemia Urmiana Nauplii Bioencapsulated with Ergosan on Growth Factors, Surviva1 Rate and Stress Resistance of Persian Sturgeon(Acipense persicus Bordin, 1897) Larvae

The peresent study was conducted to evaluate the effect of Ergosan on the growth factors, survival rate (%) and resistance to thermal stress of Acipenser persicus Larvae via bioencapsulation of Artemia urmiana. This experiment was conducted in a completely random design in three groups and group (A) with triplicate. The test groups were as follows: Artemia urmiana bioencapsulated with Ergosan 0. 1, 0. 2, 0. 3, (B, C, D groups respectively) g. /lit. in suspension of broth and non-enriched Artemia nauplii (group A). Artemia nauplii enriched with Ergosan was bioencapsulated for 12 hours and Persian sturgeon larvae were fed on it. The larves were fed on six times a day, every four hours with bioencapsulated nauplii. At day 20th, immersion in thermal water (30C˚, 34C˚) was performed to evaluate larvae resistance to thermal stress. The results indicated that the Ergosan according to the concentrations used in suspensions enrichment, significantly different in treatment groups, on the growth factors, final weight, Specific growth rate, Dailey growth rate (%) and survival rate (p<0. 05). No significant difference in the condition factor was observed (p>0. 05). Mortality rate was significantly different in thermal stress after 2 hours and mortality was lower in bioencapsulated groups than non- bioencapsulated (p<0. 05). The experiment indicated that the ability of Ergosan to influence the increase of the growth performance،survival rate (%) and resistance to thermal stress is relatively high in Acipenser persicus larvae.