24 research outputs found

    Age, growth and maturity of Hilsa shad (Tenualosa ilisha) in northwestern part of the Persian Gulf

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    In this study age, growth and maturity of Hilsa shad in Khuzestan province were analyzed. 394 number of fishes from marine habitat (Lifeh-Boseif), estuaries (Bahmanshir and Arvand) and rivers (Bahmanshir and Karoon) from February 2014 to September 2014 were collected using commercial fishing with gill net. Total length and wet weight of each fish were measured with precision of 1 cm and 1 gram. Sagittal otoliths were extracted for age determination of the fish. Since the otoliths were fragile, they were sectioned by polishing with sandpapers 800, 1500 and 2000. Then abdominal cavity of each sample were opened for determining sex and maturity stage. Growth parameters were calculated using von Bertalanffy growth function (L_∞=58.365, K=0.26, t0=-0.16). Phi-prime constant was obtained 2.95. Length and age at first maturity were obtained 27.32cm and 2.4 g respectively using logistic model to fit a and b parameters with observed data in spawning season

    Accumulation of heavy metals in sediment and oyster (Saccostrea cucullata) in the intertidal zone of Chabahar coast

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    In order to understand the extent of heavy metals contamination in sediments and rock oyster Saccostrea cucullata, of Chabahar intertidal zone, samples of sediment and oyster were collected from 5 different stations namely Guatr, Beris, Ramin, Shahid Beheshti and Tiss during low tide. Sediment and tissue samples were acid digested and heavy metals content of the samples were analyzed. Results showed that Cu, Pb and Ni concentration in the sediment samples was 15.87-16.96, 10.98-15.79 and 12.39-17.10 ”g/g, respectively. Heavy metals concentration in soft tissues of oyster was 84.96-289.93, 3.83-5.26 and 6.05-7.19 ”g/g for Cu, Pb and Ni, respectively. Similarly, Cu, Pb and Ni concentration in shell ranged between 13.83-6.67, 11.32-14.93 and 5.97-7.97 ”g/g, respectively. No significant difference was found between Cu and Ni concentrations in sediment samples. It is suggested that metals accumulation in different oyster tissues was related to their essentiality for oyster. Heavy metals concentration in oyster and sediment was found to fall within the range of some available standards, indicating that metals contamination does not seems to be problematic in the area

    Spatial and temporal variability of brittle star (Macrophiothrix cheneyi: Ophiuroidea) in the shores of Chabahar Bay, Oman Sea

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    Echinoderm species are important members of benthic communities existing in subtropical to Polar Regions. They have an important role in nutrient cycles and other communications between organisms. This study investigated the distribution and abundance of brittle star Macrophiothrix cheneyi in the intertidal zone of Chabahar bay, the Oman Sea. Sampling was randomly done bimonthly using a square meter quadrate during one year, from November 2008 to September 2009, at 5 selected stations. According to the results of a Kruskal-Wallis analysis, the density of this species at different sampling times and stations revealed a significant difference (P<0/05). The highest frequency of this species was measured at the station of Chabahar University of Maritime and Marine Science in September 2008 (±1/54 3/58 ind.m^-2) and its lowest frequency was measured at Kolbe Qavasi station during the whole year except January. The difference in abundance (between the different months and stations) seems to be influenced by ecological (bed, food and shelter) and biological factors (fertility, hunting and competition). The investigation of distribution revealed that brittle stars in the intertidal zone under study followed random and patchy dispersion. The results of the stability indicator revealed that though the brittle star was rarely found during some periods, it was a common species in September 2008

    Heavy metals (Hg, Cd, Pb and Cu) bioaccumulation in the oyster Crassostrea gigas of Imam Khomeini Port

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    Heavy metals are major group of dangerous contaminants in marine environment. Due to their persistence, they may enter aquatic food chains and transfer from one trophic level to another. They also may be harmful for human being which is placed at the top of the food chain. Imam Khomeini’s Port is located in the north west end of Persian Gulf and ships traffic and several industries especially petrochemical industries around of the port, discharge various organic and non-organic contaminants such as heavy metals into this ecosystem. In this study in order to investigate the levels of heavy metals (Hg, Cd, Pb and Cu) in soft tissue of oyster Crassostrea gigas from Imam Khomeini port, oysters of the same size were sampled on March 2010 from 5 different locations including harbors of Petroshimi, Doc Sorsoreh, 15, 28 and 33 in the Imam Khomeini port. The samples were freeze dried and acid digested in order to determine their heavy metal content with atomic absorption spectrophotometry. Results indicated that the content of Hg, Cd, Pb and Cu in the oysters’ soft tissue were 3.12±2.97, 7.56±3.62, 7.1±3.30 and 440.57±66.17 ”g/g of dry weight, respectively. The highest level of Hg, Pb and Cu were recorded in harbor of Petroshimi while the highest level of Cd was measured in harbor no 15.The concentration of Hg, Cd, Cu and Pb in bivalve soft tissue was more than standard limits. This can be dangerous for public health therefore regular monitoring of heavy metals in the area is recommended

    Effects of bis-phenol A (BPA) on cellular and molecular levels of yellowfin seabream (Acanthopagrus latus)

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    Today, Bisphenol A is an industrial important chemical that is abundantly used as a primary raw material for the production of plastics and resin. BPA reaches the aquatic environment mainly through urban and industrial sewage effluents; thereby posing a potential threat to the organisms living in these ecosystems. In this study, effects of BPA onerythrocytic nuclear abnormalities (ENA) stimulus (MN Test) and liver DNA integrity (DNA Unwinding Assay), in male yellowfin seabream (Acanthopagrus latus) were investigated. For this reason, fish received intraperitoneal injections during a period of 2 weeks with 10, 50, 100 and 150 ”g g^-1 week^-1 of BPA dissolved in coconut oil. Solventcontrols received the coconut oil whereas controls were not injected. The fish were sampled on day 0, 7 and 14. In order to evaluate cytotoxicity of BPA presented in blood, the erythrocytic nuclear abnormalities (ENA) frequency in yellowfinseabrem was determined. Our results demonstrated a significant increase in fish micronuclei frequency after the treatment with bisphenol A in comparison to the control groups and in dose dependent manner. In addition, the rate of liver DNA integrity was tested using the DNA alkaline unwinding assay. Results showed a decrease in the rate of liver DNAintegrityin treated fishes after 7 and 14 days of BPA exposure in comparison to the control group. In conclusion, results of the current project indicated that BPA has highgenotoxic and/orcytogenotoxic potential.It could be concluded that Micronucleus test and DNA strand breaks can be used as sensitive cellular and molecular indicators of exposure to genotoxic BPA

    Determination of lethal range and median lethal concentration (LC50 96h) values of diazinon on Caspian Sea common bream (Abramis brama)

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    Pesticides are environmental contaminants which normally enter to aquatic ecosystems after being used in aquaculture. In this research, acute toxicity of diazinon was studied on Caspian Sea common bream (Abramis brama). This pesticide may enter in aquatic food chain and cause serious problems for aquatic organisms as well as human. The acute toxicity test was performed during 96h in static renewal system based on the standard method proposed by OECD. A range finding test was carried out in aquariums containing 10L of test solution to determine the lethal range of diazinon on fish. The acute toxicity test was then preformed in 5 treatments and 3 triplicates for each treatment. Obtained data were analyzed using probit analysis with %5 confidence limit. According to the results, LC_50 24h, LC_50 48h, LC_50 72h and LC_50 96h of diazinon on Caspian Sea common bream was 10.974, 10.391, 9.134 and 7.316 respectively. The maximum acceptable toxicant concentration (MATC) of diazinon on Caspian Sea common bream was 0.073 mg/l and the lowest observed effect concentration which is equal to LC_50 96h was 2.63 mg/l. According to the results and comparing with other studies, it can be discussed that Caspian Sea common bream is more resistant against diazinon rather than other fish species. In addition, lethal toxicity of diazinon takes place in a moderate range of toxicant concentrations

    Evaluation of biological removal of anthracene by a Bacillus pumilus strain isolated from oil sediments of Imam Khomeini Port

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    Due to their toxicities, oil pollutions and its derivatives such as anthracene are one of the most important issues of environmental researches all over the world. Oil hydrocarbons in contaminated soils, sediments and water can be degraded by microorganisms. Removal of hydrocarbons from aqueous solutions is also possible using cultured bacteria. In this study, the anthracene bioremediation by Bacillus pumilus isolated from oil sediments of Imam Khomeini port, was investigated. This bacterium made no clear halo on blood agar medium and couldn’t disperse the mineral oil but created a halo with a diameter of 0.5 cm on the surface of crude oil. As a result, the bacterium was detected as a non-producing biosurfactant species. The optical density of this species in the sample containing 30 mg/l of anthracene finally reached to 0.086. Measurement of anthracene degradation by HPLC showed that %40.833 of mentioned hydrocarbon was removed after 5 days. Therefore, the results indicate that the isolated bacterium can probably behave the same in the natural environment and couid have the potential in bioremediation of this pollutant from environments

    New observation of two species of sea cucumbers from Chabahar Bay (Southeast Coasts of Iran)

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    Although, sea cucumbers are well known animals in Eastern Asia, in Iran they are not popular marine animals. Divers recorded these animals in their dives but this is the first scientific approach in identification of holoturians in Southeast coast of Iran. All sea cucumbers were collected with SCUBA diving and species identification was done through morphological keys and review of their dermal ossicles. There are two species of sea cucumber belong to genus Holothuria were collected on subtidal zone of Chabahar Bay in the late of 2007. This is the first report of H. hilla, H. parva from Chabahar Bay (North of Oman Sea). This study is revealed the special characteristics of the presented species in order to just identification of them. In the studied areas, H. parva has known as a rare species
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