جستجوی مقالات مرتبط با کلیدواژه « zooxanthellae » در نشریات گروه « زیست شناسی »

The present study was conducted to study the morphology of the symbiotic Zooxanthellae with an anemone of Stichodactyla haddoni. Sampling of the sea anemone was carried out in the east coast the Island of Hormuz during a full tide in summer of 2015. The samples were placed in a nitrogen tank and transferred to a laboratory in the shortest possible time. Extracting and counting the Zooxanthellae cells which coexist in symbiosis with the sea anemone were made with an electrical homogenizer. The stages of preparation and fixation of samples were conducted by glutaraldehyde 3%, alcohol and acetone and then the Zooxanthellae cells were examined with the optical microscopes of HP31 and Zeiss and an the electron microscope. The results of the study showed that, firstly, Zooxanthellae can be multiplied only by mitosis in coexistence conditions. Secondly, it is known that the cells of one species should be approximately one size, but the size of some cells, which were extracted, were considerably different from other. Therefore, it is possible to assume that the studied anemone of Stichodactyla haddoni included more than one species of the symbiotic Zooxanthellae in the investigated time.

Density, mitotic index and cell size of Symbiotic dinoflagellates of reef building coral "Porites compressa" of Larak Island, Khark Island and Nay band Bay was studied. Corals of Larak Island that are near to strait of Hormoz have exposed to high nutrients from Oman Sea. Corals of Nayband Bay are always exposed to high environmental stress because of developement in oil and gas activities for about 15 years. Corals of Khark Island located in western north Persian Gulf are exposed to organic matter, oil activities and fresh waters. According to ANOVA analysis, the density and cell size of zooxanthellae in corals of Larak Island is higher than from other locations, and also showed significantly different to Khark Island. In addition, there have not seen significant difference among all of factors between Larak Island and Nay band Bay and between Khark Island and Nay band Bay.

Coral reefs function in a symbiotic relationship with dinoflagellates (zooxanthellae). Continuous release of anthropogenic pollutants، mainly into the aquatic environments، and the resulting global climate change threatens coral health by endangering this symbiotic relationship. The object of this study is to measure the zooxanthellae density in Poritescompressa to estimate health of coral reefs in the Northern part of Nay Band Bay in the vicinity of the South Pars Petrochemical facilities and southern part of Nay Band Bay farther away from these industrials. Corals in the north of Nay Band Bay showed more signs of degradation. The highest mean zooxanthellae density was 3607849±229894 N/cm2 in south of Nay Band Bay in February. Mean zooxanthellae density was significantly (p<0. 05) higher in the south of Nay Bad Bay in February than other months، indicating healthier corals at this region.