Species Composition and Seasonal Variations of the Gastropoda in Upper Sakarya River System (Turkey) in Relation to Water Quality     

Yeim abuk  Naime Arslan  Veysel Y&#x;lmaz 《洁净——土壤、空气、水》2004,32(6):393-400

Species composition, abundance, and seasonal distribution of the Gastropoda fauna and the physical and chemical variables of Upper Sakarya River System have been investigated between October 1998 and August 1999. Gastropod fauna in the Upper Sakarya River System was represented by 9 species of Prosobranchia and 7 species of Pulmonata. Diversity, dominance, and abundance of the Gastropoda species were recorded seasonally. The abundance of some of the 16 species was correlated positively with temperature, dissolved oxygen and negatively or positively with pH and nitrate. It was observed that Gyraulus albus (Müller, 1774), Physa acuta Draparnaud, 1805, Valvata pulchella Studer, 1820, and Oxyloma elegans (Risso, 1826) can tolerate a high level of NO‐N while V. piscinalis (Müller, 1774) spread out in unpolluted water. Although the species and their numbers change at the stations, the maximum numbers were found during autumn, while minimums were identified during the winter sampling. Gyraulus albus was the most widespread species in our research area. Only 5 species (Gyraulus albus, Physa acuta, Valvata cristata (Muller, 1774), Valvata pulchella, Melanopsis praemorsa costata (Olivier, 1804)) were determined each season. However, no Gastropoda were found at the station 3 that has high BOD, NO‐N, NO‐N, and NH₃ levels.  相似文献   

Occurrence of Clostridia in the Sediment of an Extremely Polluted Danube Reach     

Z. Lagn 《洁净——土壤、空气、水》1999,27(1):19-26

The species composition of clostridial communities of the sediment in a polluted area of the Danube (South of Budapest, Háros‐Bay, Hungary) was investigated. The spore counts exceeded 700...800 CFU per gram (wet weight). 23 clostridial strains were identified by using API 20A anaerobe identification kits, another 20 physiological, biochemical, and ecological tests were also carried out. Results of numerical analysis showed that the clostridial community in the sediment of the Danube is composed of at least 4 different species. Members of C. perfringens, indicating to fecal contamination, C. subterminale and related bacteria were dominant in the examined area. All strains showed wide pH (5...9) and temperature (3...45°C) tolerance. They were able to grow on media containing significant amounts of lead (Pb²⁺), mercury (Hg²⁺), copper (Cu²⁺), and zinc (Zn²⁺). Strains of C. perfringens showed a wide range of degradative capacities (acid production from many different carbohydrates, gelatinase, lecithinase, lipase production, etc.).  相似文献