بررسي مقايسه اي اثرات تغذيه اي سيست د كپسوله ناپلي آرتميا و غذاي كنسانتره در لارو قزل آلاي رنگين كمان

A comparative study on the effects of feeding Artemia decapsulated cysts and nauplii and concentrated feed on growth and survival rates of Rainbow trout (Oncorhynchus mykiss) larvae

The use of live food in larviculture is of great concern in modern aquaculture. Live food not only provides the essential nutritional elements for fish larvae, but also increases their digestive enzymes activity. In addition, the role of live food in increasing the growth and survival rates of the larvae by enhancement of digestion efficiency of concentrated feeds has been proven. In this study the effects of five different feeding rations, concentrated feed (treatment 1), decapsulated Artemia urmiana cysts (treatment 2), Artemia nauplii (treatment 3), mixture of concentrated feed and decapsulated Artemia cysts (treatment 4) and mixture of concentrated feed and Artemia nauplii (treatment 5), on the growth, survival rates, feed conversion ratio (FCR) and fatty acids and protein profiles of Rainbow trout larvae were investigated. Each treatment was done in triplicates. Results showed significant differences in the growth rate of the larvae of different treatments (P < 0.05). The larvae fed with Artemia nauplii had the highest growth rate and FCR = 0.82. This was significantly different from the other feeing treatments. While, the larvae which fed with concentrated feed had the lowest growth rate and highest FCR (FCR = 1.04) compared to the other treatments. The maximum survival rate (90.6% and 92.6%) was observed in the larvae of treatments 3 and 5, and these were significantly different from those of the remaining treatments. Keywords: Larvae, Rainbow trout, Artemia urmiana, survival rate, feed conversion ratio (FCR)