JOURNAL OF AQUATIC ANIMALS & FISHERIES
Year:2011 | Volume:2 | Issue:7|Papers Count:8

This trial was carried out in order to evaluation of some biological indicesHuso huso fingerlings at Shahid Marjani (S.M) and Voshmgir Reservoir (V.R), and the fingerlings producers in these centers that release to rivers were investigated. The mean weight for releasing to S.M and V.R centers were 15.1±1.1 gr and 16.17±1.3 gr, respectively. The area for cultivating Huso huso fingerlings, the number of cultured fingerlings, the number of released fingerlings and survival rate in S.M center were 16 ha, 1300000, 743705 and 54.3%, respectively. Also, the area for cultivating Huso huso fingerlings in V.R center was 4 ha, the number of cultured fingerlings was 260000, the number of released fingerlings was 64810 and survival rate was calculated 53.6%. The length of fingerlings was in range of 10.5-23 cm and 8-33 gr in S.M center, and these factors were 14-20 cm and 10-25 gr in S.V center, respectively. Condition factor and growth rate in S.M. center were 0.45±0.02 and 5.4±0.8 respectively, and these parameters were 0.4±0.02 and 5.1±0.4 in V.R. center. The results of this study showed that condition factor and growth rate of fingerlings revealed no significant variation in S.M and V.R. centers (P>0.05). Regarding to proper growth of fingerlings, it can be concluded that rearing condition is average for this life stage in S.M and V.R.

Present study is part of the identification and determination of Clupeidae (Genus Alosa), in the southern area of the Caspian sea, off coastal waters in the Gillan Province during 1997_98. Total of 132 specimens were sampled. Morphometric_merestic parameters such as Gill rakers and ratio of eye to head length, etc. were used for the species identification purpose. Three species of Clupeidae, namely as: Alosa brashnikovi (Borodin, 1904), A. kessleri (Grimm, 1887) and A. caspia (Eichwald, 1938). Results showed that A. brashnikovi had 22_49 with average of 36.6±5.41, A. caspia had 74_128 with average of 106.3±14.96, and A. kessleri had 49_73 with average of 58.5±10.5 percent Gill rakers. Results also indicated that the ratio of eye to head length for A. brashnikovi was between 15.91_21.88 with average of 18.53±1.03 percent for A. caspia was between 19.38_24.30 with average of 22.48±1.34 percent, and finally for A. kessleri was between 17.75_22.4 with average of 20.88±1.54 percent.

In this study, concentration of Cd, Zn and Pb metals has been surveyed with sampling of surface sediment, Saccostrea cucullata and Solen brevis from six stations at Bandare Lengeh and Bushehr in fall 2010 and spring 2011 respectively. The results obtained show that the pattern of metals accumulation in surface sediment in Bandare Lengeh was Pb>Zn>Cd, while the average concentration of heavy metals in surface sediment in Bushehr was Zn>Pb>Cd. The findings also indicated that there is a significant and positive correlation between Zn and Pb concentrations in soft tissue and shell in the both of two species and their concentrations in sediment respectively. It is noticeable that there was no observed a similar pattern for Cd metals in both of two species, so that in Saccostrea cucullata there was showed a positive and significant correlation between soft tissue of oyster and sediment, while in Solen brevis there was recorded a positive and significant correlation between Cd concentrations in the shell of Solen brevis and sediment.

In the recent century due to over fishing destroyed habitat sturgeon declined their stocks.Acipenser persicus mostly indigenous Iranian coast is in comparison with other species and the effect is more important in our fishing. Hence in this study growth, survival of fish larvae Iranian enrichment in freshwater Rotifer three different dietary treatments and three replications of each treatment in Jun 2008 in Live food research station in Anzali was evaluated. Treatment 1: a multiplication of similar centers breeding and culture, initially Decapsulate Artemia cysts and Daphny. Treatment 2: A mixture of Artemia, Rotifer and daphny. Treatment 3: Rotifer enriched with vitamin C (Ascorbic acid 6 palmitate). In each treatment 45 larvae numbers in the 100-liter tub that measures up to 30 liters of water were repeated at 3 week for 8 days as 30 percent based 22.5±0.5 in cintegrade, pH of water 8.5±0.1and Oxygen 9.58±0.2 mg per litr was brought on. In examining specific growth rate (SGR), weight gaine (WG) food concentration rate (FCR) condition factor (cf) as the most significant treatment 3 Respectively, with 10.47±0.04, 124.24±0.62, 1.51±0.008, 0.079±0.07 showed. Also showed that the survival ratio between the first and second treatment, three treatment significant is difference. The results showed Brachionus calyciflorus suitable for live food enrichment with vitamins C and pools can be created for this purpose out in duplicate, sometimes along with other freshwater Rotifer enrichment and use in culture.

The diet of the Scaly Whipray, Himantura Walga, in Persian Gulf coasts, Hormozgan Province was investigated through stomach content analysis. Two major and two minor prey groups were identified. The diet of H. Walga was dominated by crustaceans. The Index of food preference indicated that shrimps and crabs were the most important prey groups consumed, representing 79.35% and 51.09% of the diet respectively. Sea urchin (17.39%) and small zoobenthos (7.84%) were minor dietary components. Analysis of stomach contents for H. Walga revealed that diet did not vary with season. This stingray is a carnivorous fish based on intestine relative length index and stomach contents. Analysis of seasonal variation in the stomach fullness indicated that feeding intensity fluctuated throughout the year, with the highest value in spring. Vacuity index indicated this species was of voracious appetite fishes. Meanwhile, the feeding intensity increased with increasing in size.

The aim of this study was to evaluate histhopathological effects of diazinon on liver and gill tissues in rainbow trout fry and was performed in the Fisheries and Marine Science Center doctor keyvan (Islamic Azad of University, Chamkhaleh port). The presence of diazinon, an organophosphorous pesticide, in rivers near the paddy fields has been reported by some authors. During 20 days 120 pieces of rainbow trout fries were exposed to three different concentration of Diazinon including 25, 50 and 75 percent of LC50 (LC50=1.65 mg/lit) in 3 experimental groups and one blank group (by three times replicates) by O.E.C.D method. The histhopathological effects of diazinon on liver and gill tissues were examined by light microscopy. bile stagnation, cell necrosis, fatty degeneration, atrophy of cells were observed in the liver tissues of fish exposed to diazinon. Also the changes in the gill tissue were, congestion, Gills hyperplasia, adhesions of Lamlahay secondary, Clubbing lamella in fish treated pesticide Diazinon. Histopathology of these changes significantly increased with increasing concentrations of toxin.

Phytoplankton concentration and diversity investigated in the coastal waters of Bandar Abbas in four stations inclouding Bandar e Bahonar- Khoor e shilat- Khoor e mokhaberat and sooroo in winter 2009 and spring 2010. Sampling done monthly of water surface layer. In this study 48 genera of phytoplanktons related to Diatoms, Dinofllagellates, Blue-green (Cyanophyceae), and Haptophyceae identified that diatoms with 31 genera (%64.59), followed by dinofllagellates with 13 genera (%27.08), blue-green alga with 3 genera (%6.25), and Haptophyceae with 1 genera (%2.08) were dominate phytoplankton community respectively. Amphora, Coscinodiscus and Pleurosigma were major dominate diatom genera. Gymnodinium, Prorocentrum and Peridinium were the major Dinoflagellates genera. Oscillatoria and Coccolithopher were the dominant genera of cyanophyceae and haptophyceae respectively. Dinoflagellates concentration mean was 10886 (Cell/litr) followed by diatoms with 5340 (Cell/lit), cyanophyceae 3070 (Cell/lit) and haptophyceae 391 (Cell/lit) reported. Margalleff biodiversity index rate for phytoplankton communites between 0.332 to 2.035 in Bandar Abbas coastal waters that the maximum rate of this index calculated for Bahonar station and minimum rate of this index reported for Khoor e Mokhaberat station. Non-parametric Kruskal-Walllis and Kolmogorov-Smirnov analyses showed that phytoplankton frequency in different month were statistically different (p<0.05). No significant statistical difference was found between different station (p>0.05).

The color rearing tanks is an important factor that can attract fish meal may have to use it to fish growth and survival is greater. This experiment was conducted for 8 weeks in the center propagation of fish bone in Syjuval, Bandar Turkman, Golestan province. The tests conducted on 4 treatments and 3 replications were as follows: treatment 1: red tank, treatment 2: blue tanks, treatment 3: white tanks, treatment 4: black tanks. Feeding rate was 10% of total body weight of fingerlings. Physical and chemical factors were so controlled through the experiment that the amount of dissolved oxygen was fixed on 5.5 -6 ppm, the temperature 26±2oC and pH 7.5-8. Cyprinus carpiowere fed during the experimental period with SFC foods containing: 8.7% moisture, 11.2% ash, 32% protein and 10.5% fat. According to the results of this study, it was shown that various color tanks affect body weight and length gain of fish and these differences are significant (p<0.05). Maximum weight and length of body was in treatment 3 with white. Results also showed that there is significant difference in the rate of SGR, BWI% and GR (p<0.05). However, there were no significant differences with regard to the amount of FCR, CF and survival (p>0.05). This study showed that use of white tanks make better growth in Cyprinus carpio.