JOURNAL OF MARINE BIOLOGY
Year:2011 | Volume:3 | Issue:9|Papers Count:8

Investigation of Diet biology of Nemipterus japonicas in Persin Gulf waters (Hormozghan Beaches) was performed since November 2010 until July 2011. In this Investigation biometry and feeding of 160fishes were studied. Stomach Fullness of Index (FI), Vacuity Index (VI), Food Preference Index (FP), Gastro Somatic Index (GSI), Condition Factor (CF) was calculated according to the computer software Excel and for statistical Ievels, SPSS software was used. In this study the average Length for this species was 208.54 ml and weight average was 159.20 gr. It was observed that females were greedier than males. Study of the presence of prey abundance index (J) in the stomach of Nemipterus japonicas, Abundance index for R Squilla mantis (Stomatopoda) was 60.67% that as the main food of fish is considered. Abundance index were 41.57% Crabs, 28.08% Shrimps, 26.96% Fishes, 14.60% Amphipoda, 13.48% Mollusca, 12.35% Brittle Stars and 11.23% Nematode that they are side food for this species. Other food groups like Copepod with abundance index 4.49%, fish egg 4.49%, Euphausiacea 1.12% ND Polychaete 1.12% were random food for species.

This study was carried out during the artificial propagation season in the shahid beheshti Sturgeon Rearing and Propagation Center and International STURGEON Research Institute (Rasht) during 2009. Eleven wild male Acipenser Persicus brood fish were used for this study. Each brood fish was stripped after receiving hormone injection and then sperm samples were examined separately. Fertilization rate and hatching rate of larvae were also determined. Analysis of relationship between sperm pHand density and indices of reproduction showed positive and direct relationship between hatching rate and sperm pH (p<0.05, r=0.711), as well as between sperm pH and fertilization rate (p<0.05, r=0.633). However egative relationship was opserved between sperm density and fertilization rate(p<0.05, r=0.640) and between sperm density and hatching rate (p<0.05, r=0.745).

Benthic Fauna study was conducted in four rivers (Dalichahi, Absefid, Elarm and Kamardasht) that leading to lake Reservoir behind the lar dam in 12 smpling larintervals and sampled monthly during June to October in the years 2009 and 2010. Samples were conducted using the Sorber (dimensions 40´40 cm square) in the four stations of the rivers with three replications. Samples collected and fixed by 4 percent formaldehydesolution then after isolation in the laboratory, the benthos were identified and counted. According to results 15 Order of Benthic were identified, among them anaquatic insect larvae had greatest diversity. species belonging to two orders Diptera and Ephemeroptera were the dominant organisms at all stations are. Mean total density and biomass were 13104 /m2 and 70.62 g/m2 respectively. The above Order had 85 genus and species. Order Diptera with a mean frequency of 10234 /m2 (60.22 gr/m2) in the first rank, and then orders Ephemeroptera with a mean frequency of 1680 /m2 (2.33 gr/m2) was the second highesity. The Most Macrobenthos order was Diptera with frequency in the month Jully total number of 2569. Based on Kruskal-Wallis test except the insects, in terms of abundance and biomass, has had a significant difference (P<0.05). Density at different depths within the sediments studied organic mater rates in sediments, a high correlation (R=20.92-0.98) was observed. The amount of organic matter in sediments at different depths in the summer with another season of the year showed a significant difference (P<0.05). there was no statistically significant difference in Total Macrobenthos biomass between 4 stations in the river, However, the abundance of organisms in the stations were significant different (P<0.05).

Effect parasitic infections on some hematological parameters in migratory Kutum (Rutilus frisii kutum) of the Tajan River during migration reproduction season of Kutum in 2008, 30 Kutum was studied. The fishes were collected by passive fishing and transferred live to Caspian sea Ecoligy Research Center. After biometry and age determination, the blood samples of fish were collected by routine method. Hematological parameters in blood samples were measured following laboratory standards methods. Then autopsy have was carried out on the fish. Parasites were separated and deteramined by the means of valid identification keys. In this study, average length (45.83 cm) and weight (824.67 g) were recorded. According to the results, four parasite species, Asymphylodora kubanicum, Paradiplozoom chazarikum, Dactylogyrus sp. And Diplostomum spathaceum were identified. The mean of red blood cell was 1811333.33 mm3, white blood cell 16500.00 mm3, Hematocrite 53.47%, MCV 307.87 fl, MCH 96.22 pg, Lym 73.80%, Mon 0.73% Neu 12.93% and Myel 12.53%. the current study showed that, there was no significant relationship between blood parameters and Parasite (P>0.05).

The two studied family of Clupeiforms (Engraulidae and Pristigastidea) have worldwide distribution. The most of species in these families have regarded as economically important fishes in fisheries. In this paper, taxonomy, Classification and revising in classification of species of Engraulididae and Pristigasteridae have been considered. for purpose, the collected samples from south coasts of Iran, including Chabahar, Boushehr, Bandar abbas and Bandar lenge, the Taxidermic sample in Museum, research centers, universities and all of the published valid Ichthyology`s reference, were investigated. Then the species identification was conformed to valid available identification keys which are presented by FAO. After this stage, distribution of this species in Iranian water of Persian Gulf and Oman Sea compared with their distribution in other water of the world. The Result identified and confirmed 14 species of family Engraulididae and 4 species of Pristigasteridae in Iranian water of Persian Gulf and Oman Sea the distribution of these fishes in Iranian water of Oman sea is more than their distribution in Iranian water of Persian Gulf.

Effect of ditary prebiotic inulin on growth performance, survival and body composition in Kutum (Rutilus frisii kutum) fry stage were investigated for 8 week in 2010. Fish with initially average weight 1.1±0.82 g were randomly distributed into fiberglass tank (75 fish per tank). A commercial diet supplemented with inulin: 0 (control), 0.5%, 1.0% and 1.5% diet in a totally randomized design trial in triplicate groups. The result showed that inulin at level of 0.5% of diet had significience difference on growth performance including weight gain, food conversion ratio rate, final weight and intestinal lactic acid bacteria in comparison with other group (p<0.05). There was no significance difference in survival and body composition among the groups (p>0.05). The results of linear regression showed that there were a negative relationship between some growth indices and survival and supplementation level of inulin. Based on the present results inulin at dose rate of 0.5% could have a positeve affect growth and survival of kutum in culture.

In order to study the effect of replacementof fish meal of diet by soybean meal in the levels of 0,25,50 and 75 percent of diet, on fatty acid profile and quality changes of fillet in Rainbow trout (Oncorhynchus mykiss), four isocaleric and isonitrigenous diet was formulated and feed during 8 week. All treatment were carried out in 2m3 fiberglass tank with 30 fish per tank. Fish were fed 3 times daily at libitum. At the end, of the experiment, fatty acid composition of fillets was evaluated and TBA at 4oc was measured over 9 days period. Results indicated that  SN-6 PUFA in the trout fed the highest soybean meal level were significantly higher than other treatment, also SN-3 PUFA in the trout fed no soybean meal, was significantly higher than other treatments .fillet TBA in the trout t fed no soybean meal, was significantly higher than other treatment at 4oC over 9 days period. statistical analysis showed that effect of diet, storage time and diet´storage time on the TBA was significant in the 95 confidence level. In summery replacement of fish meal by soybean meal showed significant changes in the fatty acid profile and lipid oxidation capacity of fillets.

The key to successful aquaculture industry is in the formulation of suitable food formulas containing all necessary elements for growth and improvement of quality in aquatic animals. Rainbow trout is the main Iranian cultivated cold water fish and introducing rations for improving its health and growth, are very important. In this research, 204 rainbow trouts with average initial weight of 50 g received different amounts of manganese sulfate in 4 treatments with 3 repetitions, for 90 days. The amount of manganese sulfate for the treatments 1, 2 and 3, were measured as 48, 78 and 98 mg/kg of food respectively. Treatment 3 had highest increase in growth with 135 g in weight, 7.5 cm in length, with SGR index of 1.66, PER index of 1.62 and FCR index of 1.60. the control group had the lowest increase in growth with 126g in weight, 5.69 cm in length, and SGR index of 1.41, PER index of 1.56 and highest FCR index of 1.71. the results indicated no significant changes between treatments and controls (P>0.05). There was no significant difference (P>0.05) in survival among treatments. Therefore, despite the increase in growth of rainbow trout with diet containing manganese, but the differences were not significant statistically.