Comparision of morpholin imprinting in different fry stages of kutum (Rutilus firissi kutum)

Morpholine as retrieving agent has been used by many researchers for homing of fish.Brooders were selected from Khoshkrud River and breeding was done in Shahid Ansari hatchery, Rasht in 2005. To determine the critical period for imprinting of morpholine 10450 kutum fish were exposed to 10^5-5 mg/lit of morpholine in different stages (yolk sac fry, active fry, 2-3g fingerlings, 4-5 g fingerlings) and released into Khoshkrud River. The return rate of released fish were studied and recorded in 2008 .Results showed significant difference between kutum return rate in active fry stage(1 %) compare to other stages i.e., yolk sac fry (0.23%), 2-3 g. fingerling(0.23%), 4-5 g. fingerling (0.26%) and control(0.13) during the tree years of study period(P<0.001). There was significant difference in sex ratio [M(1.42): F(1)] in recaptured fish in Khoshkrud river( x^2=6.4 α=0.05 df=1).Higher recapturing rate of 6.7 % recorded in the present study compared to recapture rate of 5% reported during last 5 years, revealed that morpholine can be used for return rate enhancing of kutum fish

Evaluation of restocking program in north Alborz

Gillan , Mazandaran and Gorgan provinces have temperate climate, thus they have more potential for aquatic animal culture. There are thousands hectare of lands for Aquaculture and fisheries in adjacent to Caspian Sea in this provinces. These areas (North alborz) have provided a favorable back ground for aquatic animal breeding and stock enhancement of species in the sea. As a result, this investigation executed during two stages (phases). At first stage, the goal of this project included the feasibility study and demonstrating the existing situation of fish stock enhancement activities in North Alborz area and second phase is to survey on distribution, and production activities of stock enhancing hatcheries as well as their constructions, and production time table. Survey was started from 2006 to 2008 by using qestionaries in 7 hatcheries from tree provinces. Results reviled that there are more than 10 species was subjected to restocking .Total releasing was about 300 millions of fry and finger lings in to the Caspian sea