فهرست مطالب . jasem ghofleh marammazi

White spot disease is one of the most serious viral diseases which affect farmed shrimp in the world. In Iran the disease maked serious damages to shrimp farmers. During a culture period, shrimp farms of Abadan were visited and those shrimps with clinical symptoms of WSSD were sampled. The samples which had the highest frequency of white spot disease were used as a template in subsequent experiments. This isolate was named: IRI-KHZ/904. By designing of primers, VP28 gene amplification and sequence was recorded in gene bank with accession number: AB855742. The nucleotide sequences obtained in this study had 100% homology with most isolates from different countries which recorded in the gene bank. Also in comparison with 4 other isolates that had been recorded in gene bank, Iranian isolate showed 99% homology.

A feeding trial was carried out where, three protein concentrations [45%, 55% and 65%) crude protein (CP)] and three dietary energy concentrations [20, 22and 24 kj g-1 crude energy (CE)] were fed to 540 yellowfin seabreams (Acanthopagrus latus) fingerlings to establish the protein and energy requirement for this species. 9 treatments with triplicate groups of 20 fish each (initial weight 12g) were stocked in 300-L fiberglass tanks and fed twice a day to apparent satiation. After 8 weeks, the survival rate was not dependent on the dietary treatments, but average fish weight gain (AWG), specific growth rate (SGR) and feed efficiency ratio (FER) were significantly affected by dietary protein (P<0.05). Protein retention (PR) were increased by dietary energy level (P<0.05). Feed efficiency ratio, PER and Hepatosomatic Index (HIS) was not affected by dietary protein and energy concentrations (P>0.05). At same protein level, PER, PR increased with the increase in energy levels from 20 to24 Kj g-1. Carcass moisture and ash contents were significantly affected by dietary protein and energy levels (P<0.05) but carcass protein was not significantly affected by dietary protein and dietary energy levels (P>0.05). With increase dietary energy, carcass fat content was increased from 20 to 24 Kj g-1. The results indicate that the optimum dietary protein and energy levels for growth of juvenile yellowfin seabream are 56. 20 – 57. 47g in Kg-1diet and 21.9-24.56Kj in gr diet and 23.15-25.95mgr kg-1, respectively.

A total of 311 specimens were collected from November 2006 to October 2007. We estimated Population parameters from length frequency data. These cases consist of the von Bertalanffy growth parameters and mortality, as well as exploitation rate. The result indicated that pickhandle barracuda had L∞ =109.21 cm total length, K=0.37 and theoretical age at zero length, = -0.5 The total mortality rate (Z) was estimated to be 1.91, the fishing mortality rate (F) and the natural mortality(M) were 1.30 and 0.61, respectively. The exploitation rate (E) was 0.68. The exploitation rate indicated that the stockis in high pressure of catch and overexploited.

Study was conducted to investigate the effects of various energy levels on growth performance, food conversion ratio (FCR) and whole body composition in Gattan, Barbus xanthopterus fingerlings (12.12±0.28 g) for 8 week. Feeding trial was conducted using 3 semipurfied diets containing 3 levels of digestible energy (DE 2.5, 3 and 3.5 kcal/g) and same protein level 35%, in a flow-through system (1L/min) at 26.2 ± 0.460C. Triplicate groups of 15 fish (12.12±0.22 g) each, were stocked in 300-L circular polyethylene tanks and fish were fed to satiety thrice daily throughout the feeding trial. The best of total weight gain (146.67 g), FCR (2.21), protein efficiency ratio (1.31), apparent net protein utilization (ANPU%) (34.69) and condition factor (CF) (1.26) were observed in diet containing 3 kcal/g DE. The viscerosomatic index (VSI) and hepatosomatic index (HSI) did not show any significant difference between treatments (P>0.05). The final whole body moisture content decreased significantly with increasing energy levels in diets (P<0.05). Although whole body lipid and protein contents did not show significant variation among treatments (P>0.05), but the highest lipid and protein deposition were observed in diets containing 3.5 and 3kcal/g DE, respectively. Comparison between varying levels of dietary energy on the growth, feed utilization and whole body composition of Gattan indicated that 3 kcal g-1 DE could be the preferential dietary energy levels in fingerlings of this species.