The study of rearing density effect on growth and survival of fingerlings Kutum, Rutilus kutum, with Caspian Sea water

Rutilus kutum is one of the most important economic fish species of Iranian costal of Caspian Sea. This species conducted more than 60% of fish caught in Caspian Sea annually, and more than 10 thousands fisherman engaged to its fishery. In present study, kutum fingerlings reared in two different densities include of 25 and 40 fish/m^2 with mean weight of 17.5±5.87 g. The period of test being planned 10 weeks and the test organism housed in circular concrete pools of 3 m^3 capacity with flowing water and aeration in pools are supplied. The fishes feed by extrude food with 45% crude protein and 14% crude fat. After termination of the experiment, the result showed that weight gain performance, specific growth rate, condition factor, food efficiency rate and protein efficiency rate decreased, while food conversion ratio increased with rising of density, as their different was significance in two experimental treatments (p<0.05). The kutum reared in low density showed significantly higher survival rate (SVR) (with 88.8%) than high density (with 76.9%) (p<0.05). Based on the different observed effects of the density on growth and survival, it is recommended the use of a 25 kutum/m^2 density for rearing by Caspian Sea water

The study of establishment of rainbow trout culture and hatchery farms on Zayanderood’s River region in Caharmahal and Bakhtiyari Province

The aim of this study was to find the best location for establishment of rainbow trout culture and hatcheries farms on Zayanderood’s river region in Charmahal and Bakhtiyari province. This survey carried out over ten station along Zayanderood’s river. The result of physical and chemical analysis showd that the annual average of air temperature varied from 9.5oC - 10oC where the pH annual average value were between 7.5 and 8.8. the dissolve oxygen concentration in stations except in rainbow trout farm effluent were above 10 mg/l. the other chemical , pollutant as well as pesticides levels were under the limiting concentration for rainbow trout culture and Hatcheries activity. The plankton survey showed that the Bacillurophyta were the dominant group of phytoplankton where protozoa constituted the most abundant group of zooplankton the Benthic organisms sensitive to pollutant in particular Epirus were dominant group in all stations. In regard to fishes presence in river, five species of Ciprinidae, one species from Balitoridae and one species from salmonidae families were identified. The capacity for development of rainbow trout culture for tow phase period in Zayanderood’s river region with respect to self purification potential (self purification potential were determined from the oxidation of the effluent of the only active trout farm of the river region), minimum of 10 L/s water requirement for production of trout in concrete canal and pond system and 1 L/S water need for production in semi circular closed system were estimated to be 5202 metric tons