In the present study, the effects of xenoestrogen 4-nonylphenol (4-NP) and 17β-estradiol (E2) on the synthesis of vitellogenin (VTG) in immature male yellowfin seabream (Acanthoparus latus) were assessed to determine the potential use of this species as a biological model for studying endocrine disrupters in the Musa estuary in southern seawaters of Iran. A total number of 104 fish were injected by 10, 50, 100, 150 and 200 µg g(-) (1) week(-) (1) of 4-NP and 2 µg g(-) (1) week(-) (1) of E2, and their blood plasma was obtained for biochemical analysis on days 0, 7 and 14. The hepatosomatic index (HSI) of each fish was also recorded at each sampling time. The results showed that 4-NP significantly induced VTG synthesis in A. latus, which was detected by gel electrophoresis as two major protein bands (∼210 and 191 KDa). The induction of VTG was also determined indirectly by measuring the alkali-labile phosphate, total plasma calcium and protein. All of these VTG indicators significantly increased in the plasma of 4-NP- and E2-treated fish. Meanwhile, a significant dose-dependent increase was observed in HSI, indicating the activation of hepatic VTG production in 4-NP- and E2-injected fish. Furthermore, the plasma alanine aminotransferase and aspartate aminotransferase concentrations significantly increased in 4-NP-treated fish, presumably reflecting a situation of hepatic tissue damage due to 4-NP toxicity. Based on the results, it is suggested that A. latus could be used successfully as a model species for future studies of endocrine disrupting contaminants in the Musa estuary.
The aims of the present study were to investigate the metal contents of sediments of several creeks that discharged into coastal waters using the Risk index. This study was carried out in eight creeks in Mahshahr coastal waters in the Northwest of Persian Gulf from October 2005 to November 2006. Superficial sediments were collected seasonally by Peterson grab, and the concentrations of heavy metals were measured by using a voltammetric polarographic method. The range and the mean concentrations obtained in ppm were 15.03-35.16 (27.01) for Cu, 65.57-171.41 (102.67) for Ni, 4.63-20.06 (13.22) for Co, 0.093-0.78 (0.22) for Hg, 65.07-379 (113.70) for Zn, 0.27-1.00 (0.56) for Cd and 7.09-29.72 (14.66) for Pb. To evaluate the levels of sediment contamination, the background values of the different heavy metals were calculated, and the contamination factor for each metal and the degree of contamination for each creek were determined as well. The results show that some elements such as Hg, Zn, and Ni are at risk level, and all of the studied creeks are classified as undergoing a moderate degree of pollution except for Ghannam that showed a considerable degree of contamination. According to the Risk index values, based on sedimentological toxic factors (S(t)) of each metal and the BIO Production Index (BPI) in the studied area, the creeks were classified as considerable and with a very high level of ecological risk.
Abstract:The abundances and species compositions of chaetognaths were investigated on the northwestern coasts of the Persian Gulf in Khuzestan province (2004Khuzestan province ( -2005. Highest mean chaetognath abundance was observed during the summer (324.7Ϯ97.6 indiv. m Ϫ3 ), while lowest values occurred during the winter (79.3Ϯ18.6 indiv. m Ϫ3 ). Six species were identified, Sagitta bedfordi, S. enflata, S. ferox, S. hexaptera, S. neglecta and Krohnitta pacifica. Sagitta ferox was most abundant. It represented 49.7% of total chaetognath numbers. Abundance variation throughout the year cycle seemed to be related to environmental factors. The correlation coefficients between abundance of chaetognaths and the water temperature were significantly positive but there was no significant relation for abundance and salinity. However, salinity values in the Persian Gulf are very high compared with other regions and perhaps pelagic chaetognaths species that inhabit this region are adapted to very high salinities of up to 45.
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