فصلنامه آبزیان و شیلات
پیاپی 15 (پاییز 1392)

This study was carried out on fatty acid composition in wild and culturedof two fish species, Epinephelus coioides and Sparidentex hasta . Fresh fish samples collected from Hormozgan, Iran. After oil extraction, fatty acids composition was analysed by gas chromatography. Results showed DHA (C22:6n3), EPA (C20:5n3), Palmitic acid (C16:0), Stearic acid (C18:0), Myristic acid (C14:0), Oleic acid (C18:1n9c) and Palmitoleic acid (C16:1) were important fatty acids in the fish samples. There was low concentrate of linolenic acid (ALA, C18:3n3) in all analyzed samples. Cultured fishes were found to contain significantly higher values of SFA, while its wild relative contained higher levels of MUFA followed by PUFA. In the wild fish species among PUFA, DHA was the most abundant followed by EPA. Altogether, EPA was the abundant followed by DHA in the cultured fish species. Also the ω3/ω6 ratio was significantly higher in wild fishes and it was highest (13.04 mg/ml) in wild Epinephelus coioides .

Protein hydrolysates were produced from Caspian Sea sprat ( Clupeonella Cultiventris ) at time 90 min, pH 7, using commercial enzyme Promod and bromelain and an enzyme to substrate ratio of 1% raw material protein at 55°C. The results indicated that, protein hydrolysate from Promod, had significantly higher protein recovery (86.15%) and degree of hydrolysis (21.89%) than bromelain (68.15%, 13.35% respectively) (P<0.05), peptide chain length of protein hydrolysate from promod (4.58) significantly lower (7.53) from bromelain. Peptones from the enzymatic hydrolysis were used instead of standard peptones used in commercial media, Triptic Soy Agar (TSA). They were tested as growth media for the bacterial strains of Bacillus subtilis , B a c ill u s li c h e n i f o r m i s and Vi b r i o a n g u ill a r u m as an alternative to commonly used complex sources (peptones). All bacteria were cultured on traditional standard media as controls, and their growth was compared to ones grown on experimental media containing peptone instead of the standard peptone. The results showed that all the bromellain and promod peptones were more effective at promoting bacterial growth than the standards used in traditional media, while the peptone from promod, was more effective than bromelain, the result suggested that fish protein hydrolysate can be used as an alternative substrate for microorganism culture purposes.

Partner or live probiotic bacteria as dietary supplements are living through the improvement of intestinal microbial host, provide beneficial effects in animal hosts. Also the amino acid composition of canola meal is as a protein with a similar amino acid protein of fish flour. The aim of this study was to investigate the effect of canola meal and Lactobacillus rhamnosus in a same time on growth and viability of children of rainbow trout, was performed. This experiment, in four groups of 265 rainbow trout larvae with an initial weight of 5 ± mg100 each Group was performed. Group (1) include groups receiving 0.10 g / kg Probiotic Lactobacillus rhamnosus and 25% canola meal, (2) the groups receiving g / kg 0.50 Probiotic Lactobacillus rhamnosus and 50% canola meal, Group 3 the groups receiving 1.5 g / kg Probiotic Lactobacillus rhamnosus and 100% canola meal they were received within 65 days; Group (4)that were controls, they were received only dry food without probiotic Lactobacillus rhamnosus and canola meal for 65 days'. The obtained results was evaluated with SPSS17 software (P ≤ 0.05) . In different amounts of Lactobacillus rhamnosus probiotics canola meal, fish larvae fed with diet containing 0.50 g per kg dry foods and probiotics L a c t o b a c ill u s r h a m n o s u s and 50% canola meal,had more growth than the control and experimental groups(P≤0.05) Also viability of fish larvae fed with probiotics Lactobacillus rhamnosus and canola meal was higher than the control group (P ≤ 0.05).

The Caspian Sea is the largest lake in the world, depending on which is very important. Bony fishes of the Caspian Sea, which are among the most important and most valuable fish stocks. Unfortunately, it has been declining in recent years for several reasons. In this study, bone fishing conditions in fishing cooperatives on the southern shores of the Caspian Sea (Provinces: Golestan, Mazandaran and Guilan ) 2009 to 2011 years experience in fishing seasons were analyzed. Results showed that from 2009 to 2011 bony fish catches have declined. The highest decrease in the amount of fishing to catch of kutum with 22.5 % and the highest rate of decline in percen of fishing carp fishing with 67 % of the species are. And the only species that has increased the catch of mullet is about 33.9 % of the catch has increased. The catch per unit of fishing effort (CPUE) in 2011 is compared to 2009 represents approximately 9.7 % for bony fish increased from about 197 kg to about 216 kg is reached. The catch per unit of fishing effort were marked with the mullet fish increased only about 63.9 has had the kutum and carp and other fish species in the 5.2 and 60 and 6.9 percentage has decreased. Generally, Caspian Sea Bony fish have large fluctuation over the past decades and the current figures, the total can be inferred that the uncontrolled exploitation of these stocks have been fished so the pressure on some species (such as carp in Golestan province), resulting in a severe reduction in the population of the Iranian coast of the Caspian Sea is that fisheries management and recommended a comprehensive program to prevent the extinction of this species.

Barbell sturgeon is belonged to sturgeon species which is suitable for cultivation. For this preparing feed ration is necessary. There had been less attention about nutritional requirement of sturgeon species. This study was conducted to determine different levels of vitamin C and folic acid on growth performance of juvenile A c i p e n s e r n u d i v e n t r i s . Six practical diets were formulated as follow; control: without supplementation, T1; 200 mg ascorbic acid (AA), T2: 3.5 mg Folic Acid (FA), T3: 200 mg AA + 1.5 mg FA, T4: 200 mg AA + 3.5 mg FA and T5: 200 mg AA + 5.5 FA equivalent kg-1 diet.. The experiment lasted for 8 weeks. After acclimatization of fish to hand feeding, 10 fish with average body weight of 31.8± 1.8 distributed to 500L fiberglass tanks. At the end of experiment, FCR ،SGR ،BWI ،GR ،CF was showed significant differences between treatments. As high levels of WG, SGR ،BWI and GR were observed in treatment 3 and lower levels of WG ،SGR ،BWI ،GR and CF were obtained in control treatment. Results of this study suggested that optimum level of vitamin C and folic acid were 200 and5.5 mg/kg of the diet, respectively

Identification and distribution of edible and decoration shells were carried out in Bushehr shoreline areas (50˚ 38´ - 29˚ 27´ to 52˚ 41´ – 27˚ 17´) from September 2008 to July 2009. The objectives of this study were identification, distribution and stock abundance of edible and decoration shells and in Bushehr shorelines. Samples were obtained bimonthly or seasonally from Ganaveh to Nayband at low tide. Some transects were selected and in each transects two sampling quadrat (0.25 m2) was placed at random. In one location Derage was used. Specimens were identified and numbered and the percentage of samples was used to show the distribution of the species in different areas. Faunal affinity between stations was calculated by Sorensen formula. In the studied area a total of 45 species or species groups were identified. The main area distribution for live edible bivalve, Solen brevis was located sat Bopatil, Gassir, Kaloo, Piazi and Bordekhoon. Other bivalve, Paphia cor that was sampled alive was distributed in the Gassir and also empty bivalve shell (90%) was seen in the Bordekhoon shoreline. Also the most important areas for the decoration shells were located in the Golestan and Nayband that 74% of these species were included of olive shells. In Golestan 50% of the shells was Callista spp. The empty bivalve shells, Trachycardium lacunosum were distributed in Lavar shoreline. The other species or species groups were distributed in the shoreline of the study areas in different months with the low abundance.

This study was investigated to determine the annual diet of threadfin bream from Deylam coast of Boushehr Province. Sampling was done seasonally from autumn 1389 to end of summer in 1390. Total length and weight of samples were 18.5 to 28.5 cm and 88.81 to 231.18 g, respectively. Gastrointestinal emptiness index, mean relative length of the intestine and mean feeding rate were 19.4, 1.07±0.18 and 99.50±16.97 respectively. Results showed that food preference of threadfin bream is related to season which feeding more on fish in autumn and winter but in spring, more feeding on gastropods. In autumn and winter, fish and in spring, gastropods were main food items of threadfin bream. Also, with increase in length of fish, their diet leads to ingest more crustaceans as in length of 25-29 cm, 22-25 cm and 18-22 cm crustaceans, fishes, and gastropods and fishes were the most ingested prey, respectively. This study show that threadfin bream is carnivorous species and fishes are the main diet of this species in Deylam coast.