As investigation of quantity and quality factors and healty condition situation for sturgeon fry in Shahid Margany and Sade Voshmgir Hatcheries

Abstract

Survy on some quality and quantity factors on Strugeon fry has been conducted at two ratcheries in cluding Shaiid Marjany and Voshmgear Sad from may to late July for the years 2000 to 2001. Of 64 , 15 and 2 ponds have been randomly collected in 2000 for Voshmgear sad and Shaiid Marjany respectively.In 2001, 17 and 5 out of 65 ponds were collected for the former and latter ones respectively. The items for the quality investigation included : 1- inspection of fry disease 2- inspection of physical and chemical factors for ponds 3- inspection of phytoplankton. Quality investigation was related to count the fry during releasing, growth coefficient and condition factor. No disease was observed for fry in Shaiid Marjany hatcheries Based on 210 and 372 fish examined in 2000 and 2001respectively. In 2000, of 953 fry specimen examined in Voshmgear Sad ,36.1% was infected to Tricodina parasite and 16.4% out of the total 1196 specimen examined in 2001, followed by Jearodactylous parasite.In relation to physical and chemical factors, the average temperature of water was higher than the opitimal one for both hatcheries. Transparency was low wherease NO3 , NO2 and aurtophofat was in optimum condition..It was indicated that phytoplanktons belonging to Clorophyta phylum constituted the highest value in terms of biomass , followed by Clorophyta and cyanophyta Ones. The highest abundance was related to pediastrum , cholorella and scenedesmus genouses. It was the same for Shaiid Margany hatchenes. Quality investigations showed that Voshmgear and Shaiid Marjany hatcheries accounted for 836% and 16.4% of the total provience production in 2000. It indicated 59% and 40.36% for the hatcheries respectively in 2001. In 2000, high and low proudction of voshmgear Sad was as 84.4% and 3.8 which was related to Acipenser persicvs borodine , Acipenser guldenstadti brondt respecively. In 2001 , These amounts were as 98% and 0.5% for these species respectively.The highest value of releasing for fish below 3g belonged to to Acipenser persicvs borodine species which was as 76% and 63% in 2000 and 2001 respectively. In 2000 , the hishest and lowest level of proudction at Sahiid Marjany hatcheries was related to Acipenser guldenstadti brondt and Acipenser persicvs borodine species with values of 35.6% and 29.28% respectively. Acipenser persicvs borodine species accounted for 83.5% of the toal fish below 3g, indicating the lowest value in 380 and Acipenser persicus borodine , Huso huso constituted the highest (71%) and lowest (8%) production .The highest level of releasing for fiy (below 39 g) was related to Acipenser persicus borodine species (23.8%).