Big bester production probability study

Aquaculture of sturgeon species and their hybrids is being considered as an important substitution for sturgeon catch due to highly decrease of natural populations, artificial propagation and fingerling release in the sea. In this study, big bester, a new hybrid sturgeon (female beluga × male bester) was produced for the first time in IRAN. Sperm of 7350 ± 1682 kg male bester was used to fertilize the eggs of one 54 kg female Huso huso. The fries of big bester and control treatment of beluga were fed by artificial concentrated food (48-50% protein and 15-17% fat) after egg yolk absorbance, a period of feeding on Artemia and Daphnia. Results showed that rearing and feeding of bester broods was efficient to reach the fish to maturation stage and there is an opportunity to collect qualified ova and sperm from F1 generation. Meanwhile sex determination and maturity assessment of gonads were successfully done via laparoscopy method. The comparison of produced big bester fingerlings with control beluga fingerling showed that the weight of big bester fingerlings has not significant difference with beluga's (p0.05), but there are faster growth rate in big bester fingerlings from 3 months of age up to 5 months (p>0.05) in comparison with belugas fingerlings. Meanwhile no statistically significant difference was found between length of big bester and beluga fingerlings among any age. The results of current study showed the potential of rearing male bester to produce matured broods and collection of their sperm for big bester production

An investigation of annual discards of the trawlers and gillnet in Khuzestan coastal water, northwest Persian Gulf

The main objective of this study was to describe and estimate the seasonal pattern of discarded fish in the waters of the Persian Gulf coast in Khuzestan. Data were collected from the fishing dhow with Khuzestan Fisheries partnership in fishing areas of Lifeh, Boseif, Khure-mussa and Bahrakan from October 2011 to September 2012. Discarded fish samples were included 109 species from 67 families, nearly 40 percent commercial and 60 percent of non-commercial species. Rayfish and catfish have been observed in most fishing nets. Average sizes of most species particularly bony fish were under 15 cm. The amount of discarded fish per unit of fishing effort was not significantly different between seasons. The highest portion of the catch belongs to rayfishes. Total discarded fishes of gillnets were estimated 3162 tones. Total weight of commercial fishes with small size in discarded fish was estimated 225 tones. The rate and ratio of discarded fish in total catch of gillnet was estimated 0.23 and 0.31 respectively. Chondrichthyes with 12 species and 60% of gillnet catch has the highest percentage of discarded fish of gillnet. High number of commercial species with small size could be due to nursery role of Khuzestan coastal waters. Trawl net has more impact on type and amount of discarded fish than moving gill net. According to different aquatic groups, the highest percentage of protein (77.84±2.088) in Perciformes belongs to Eupleurogrammus muticus and the lowest percentage (40.40±0.322) belongs to Liza klunzingeri, the most percentage of lipid was in Liza klunzingeri (33.78±0.277) and the lowest percentage was in Grammoplites suppositus (3.34±0.025), the highest and lowest percentage of ash (minerals) were in Cynoglossus arel and Acanthocephola abbreviate (28.14±.377) and oligo duvauceli (0.7±0.02) respectively. Therefore discarded fish have great potential in fulfilling nutritional requirements as fresh food (minimally processed) and with nutritional additives in forms of fish powder and fish oil and it can play an effective role in aquaculture development in the region