Study on the effects of sorting in some growth indices of fry (Acipenser gueldenstaedtii)

The aim of this survey was conduct to evaluated sorting efficiency on some growth indices of two weight group (245±20.33gr) and (490±23.58gr) (n=189) fry (Acipenser gueldenstaedtii). After environmental adaptation fish divided in three group (Small, Large and Mixed (none-grade)) by three replication, feed as appetite thrice a day in 8 weeks by ExS4mm commercial diet and measured some growth indices each two weeks. The results shown (p>0.05) in initial biomass (BWI), Condition factor (CF) and Survival rate (SR %) between treatments. While in (p<0.05) between treatments in Gain weight (GW), Gain weight percent (GW %), Growth Rate (GR), Special growth rate (SGR), food concentration ratio (FCR) and final biomass (BWF) and other indexes. Also, the mixed treatment had the best amount of FCR than others. Hence to the main goal of aquaculture sorting was improved the FCR and BWF index. Despite of increasing the BWF in Small treatment cause to lack of stress and manipulating cost (Acipenser gueldenstaedtii) sorting in these weights(fry size) were necessary.