JOURNAL OF MARINE BIOLOGY
Year:2014 | Volume:6 | Issue:22|Papers Count:8

Barracuda is one of the commercial fishes, which catch every year in the southern fishing grounds of Iran. This study aimed to achieve biomass of Sphyraena jello in Bushehr Province coastal waters, South of Iran. For this purpose R/V vessel in depth layers of C1, C2, C3 and D1, D2, D3 and E2, E3 was used to investigate. Sampling was conducted for 10 days in January 2011. From total 43 hauling in different depth and layers, 1050 kg Sphyraena jello were caught. The biomass were calculated 8163.2 Kg. Maximum and minimum of biomass were estimated in depth layer 10-20 (26.83±10.62 Kg/hours) form C1 region and 20-30 (33.7±15.27 Kg/hours) from E2, respectively. Total Catch per unit effort (CPUE) was calculated 11859.2 Kg/Nautical miles for Barracuda in Bushehr waters. In terms of different regions and depth, maximum CPUA were calculated 7709.3 Kg/Nautical miles in north region of Bushehr province waters and 52233.09 Kg/Nautical miles in 10-20 depth Layer, respectively. In addition, maximum biomass investigated 6007.8 Kg in north region of Bushehr province waters and 3765.4 Kg 30-50 depth layer.

The present study aimed to investigate the effects of different levels of temperature and salinity on the body shape of Sophiae toothed carp (Aphanius sophiae) using geometric morphometrics technique. A total of 120 specimens were reared at four combined treatments with two levels of temperatures (16 and 25oC) and two levels of salinity (0 and 14 ppt) for one month. The left side of the specimens were photographed and 17 landmark-points were defined and digitized on 2D images using the tpsDig2 software to extract body shape data in geometric morphometrics technique. The obtained data superimposed using Generalized Procrustes Analysis toremove effects of size, position and orientation. The obtained data were analyzed using PCA, CVA and CA. The results revealed a significant difference between the body shape of treatments exposed to different combination of temperature and salinity (P<0.05). The results showed that changes in the body shape of 16oC and 0 ppttreatment includes the anteroventral shift of the snout, the elongation of the opercle, increasing the depth of the head and eye diameter. At 16oC and f 14ppttreatment, decreasing in the height of opercle was observed. At 25oC and 0 ppt treatment, the height of the opercle was increased, and at 25oC and 14 ppttreatment, the observed changes were related to the tip of snout. The results of the present study indicated the effect of temperature and salinity on the body shape of the Sophiae toothed carp.

The efforts of other alternative products to replace fish meal protein in fish diets are being done in order to producing cheaper diet. This study was carried out with the aim of alternating Canola meal instead of fish meal in fish diet over a 60-day period during the autumn and the winter 2011 in the Sefidrood Aquaculture Research Station (Inland Water Aquaculture Research Institute).The fingerlings of Rutilus frisii kutum with weight 1.2 grams were transferred to 100-liter fiberglass tanks and stocked with 15 fingerlings in each tank. The fish were divided into five treatments including 10%, 20%, 30%, and 40% of Canola meal and also control group. Each treatment was repeated 4 times. According to Duncan test, there was no significant statistical difference between 20% treatment with 30% and 40% treatments, and also control group and 10% treatment (P<0.05), considering to food conversion rate (FCR), special growth rate (SGR), and weight gain (WG). The results showed that the maximum and minimum amount of weight gain were occurred in 10% treatment (mean= 97.74±3.81) and 40% (mean= 65.22±9.17), respectively. The minimum of the special growth rate (0.83±0.09) was observed in 40% and the maximum of that (1.44±0.03) was measured in 10% treatment. The minimum average of FCR (3.01±0.08) was referred to 10% treatment and the maximum of that (4.1±0.44) was referred to the 40% treatment. According to the obtained results, it is recommended that 10% treatment of Canola meal can be used in the diet of Rutilus frisii kutum fingerlings. The lowest carcass protein, 20% with the 58.85 and 60.11 was the highest in the control. The lowest and the highest carcass fat percentage was observed in control (24) and treated 40% (25.8), respectively. Minimum and maximum amount of ash and rubble in order to control treatment and treatment was 30% and minimum and maximum amount of moisture in the treatment of carcass were 10% (72.11) and 30% (73.75), respectively). Respecting to results, it can alternate canola meal instead of fish meal at amount of 10 percentage in diet of Rutilus frisii kutum.

The purpose of this study is to evaluate the antibacterial activity of potential probiotic bacteria of Bacillus and Lactobacillus isolated from the digestive tract of Epinephelus coioides against two of marine pathogenic bacteria (Vibrio harveyi [ATCC:700104], Elizabethkingia meningoseptica [ATCC:33953T]). Therefore, 15 young and healthy E. coioides, were hunted from in Deylam seaport inspring2013, were selected, and aseptically, some pieces from different parts of their digestive system were cut and sampled. After culturing in specific media of Bacilluscereus agar and MRS agar, performing biochemical tests related to diagnosis of Bacillus and Lactobacillus genus and isolation, purification and coding of different bacterial strains, the in vitro antagonism test was performed by disc diffusion method in order to find effective probiotics. The findings indicated that eight bacterial strains candidate for probiotic properties had inhibitory effect on marine pathogens and regarding the inhibitory diameter of growth zone, bacterial strains candidate for probiotic properties could prevent the growth of pathogenic bacteria roughly as 1 to 2.6 cm.

Nannochlorosis microalgae is belonged to phylum Chlorophyta and sub-phylum Eustigmatophyceae. In this study growth of Nannochloropsis oculata has been evaluated in four different media (Conway, Guillard, N8, TMRL) and different salinity (20, 25, 30 ppt) with triplicate for treatments in laboratory (temperature was 25oC, pH=11, light intensity=2500LUX, light duration=18hours and 6 hours darkness and also aeration using aquarium pump for 24 hours) During 14 days culturing. The growth of Nannochloropsis oculata has been determined with two counting methods, neobar lam and cellular concentration and the amount of a chlorophyll a by using spectrometry method. According to the results, significant differences between treatments with medium salinity differences exist (p <0.05) and medium Conway salinity 25 ppt in terms of increased density and salinity 20 ppt the amount of a chlorophyll a in the first grade, medium Guillard with salinity 20ppt in terms of increased density and a chlorophyll a second level, medium TMRL salinity 25 ppt in terms of increased density and a chlorophyll a third and medium N 8 with salinity 25 ppt in terms of increased density and salinity 20 ppt the amount of a chlorophyll a in fourth place fall.

The aim of the present study is to evaluate the inhibitory effect of bacterial strain Staphylococcus equorum on growth performance of pathogenic bacteria, Aeromonas dhakensis. As A. dhakensis is a pathogenic strain for many kind of the fish species in the domain of aquaculture industry and being introduced as a threat, it will be beneficial to inhibit this bacterium by use of a biological procedure instead of using chemical antibiotics, such as applying probiotics. Staphylococcus equorum seems to be a good candidate among the staphylococci group. In this regard after preparing pure cultures of both strains, the inhibitory effect was being determined through inducing both strains in BHI media and monitor the growth curve and also inducing the strains in TSA media and counting the colonyforming units. The results showed that Staphylococcus equorum has an inhibitory effect on Aeromonas dhakensis, but the reduction of colony forming units were not significant (P>0.05), and can be introduced as a remarkable probiotic strain, but it should be mentioned that it is necessary to distinct the inhibitory process.

In order to evaluating of herbicide Butachlor sublethal effects on Acipenser persicus fingerlings acute toxicity examination was carried out statistically using OECD standard method in the International Sturgeon Research Institute (Rasht-Iran). A total of 120 fish (with mean weight 10±2 gr) were exposed to different concentrations including 0 (control), 0.107, 0.215 and 0.322 mg/L of butachlor. Mean lethal concentration of butachlor (LC50 96h) determined 0.43 mg/L during 96 hours. Blood samples were collected from caudal vein after 24 and 96 hours for biochemical studies. The study for determining sublethal effects of butachlor on liver tissue of Persian sturgeon carried out in laboratory conditions. Results showed that cortisol and glucose levels increased significantly (P<0.05) in different concentrations compared to control. The histological study of liver tissues of the experimental fish with the control groups showed clear changes including congestion, hemorrhage, cytoplasm vacuolation and pycnosis of nucleus, the cumulative haemosiderin in the melanomacrophage cells and also necrosis and acidophilic changes of the cells. Results indicated that butachlor at low level induced abnormal effects on biophysiological structure of Acipenser persicus fingerlings.

Heavy metal pollution of aquatic ecosystem and consequently accumulation of these metals in aquatic organism tissues is one of the recent concerns in seafood industries. Current study has been focused on concentration of some essential and non–essential (toxic) heavy metals in different tissues of the Caspian Kutum, Rutilus kutum and Caspian Roach, Rutilus rutilus as species for human consumption, that are very dangerous for environment. A total of 100 fish samples of two species, Rutilus kutum and Rutilus rutilus were caught from Babolsar and Tonekabon stations (in the southeast of Caspian Sea) during fishing seasons in 2011 and 2012. The muscle, liver and gonad samples from two species were carefully dissected for the determination of heavy metals, Copper, Lead and Cadmium levels. Heavy metals studied at this research are hazardous substances in the environment. Levels of heavy metals were determined using Atomic Absorption Spectrophotometer and statistical analysis was carried out by SPSS19 software. The result showed that the Lead concentration was the maximum levels followed by Cu>Cd, while metal abundance in different organs of these fish was in the order liver>gonad>muscle. Cadmium was the least accumulated metal. The highest levels of Pb and Cu were recorded in liver tissues. Linear regression analysis showed that there was a significant increase in the level of Pb in muscles, livers and gonads of both in Kutum and Roach. Also there was a significant positive relationship between fish size and the Cu in livers of the fishes. The data showed that the edible part of fish do not carry heavy metals loads and their concentrations were below the legal value for fish and fish products established by World Health Organization (WHO), NHMRC and UK (MAFF)showed that the fish from investigated region are safety for consumers.