First record of Limnodrilus claparedeianus Ratzel, ۱۸۶۸ (Annelida: Oligochaeta: Tubificidae) in Anzali Wetland, Guilan province, Iran

Oligochaeta worms are important organisms in aquatic ecosystem. Their omnipresence makes them as an indicator of environmental changes and health of aquatic ecosystem. The members of the family Tubificidae and in particular, genus Limnodrilus are considered as the most tolerant oligochaets to aquatic pollution. Therefore identification and biological characteristics of this taxon are of great help to evaluate the ecosystem of water bodies. Limnodrilus claparedeianus were collected from Anzali Wetland with a grab of ۰.۰۴ m۲ capacity at ۱۳ stations from August ۲۰۱۲ through June ۲۰۱۳. Penis sheath was one of the main characteristics to identify them. Results showed their maximum and the minimum density in spring (۶۰۱.۲۷±  ۴۶۶.۸۳۴۶ Ind.m-۲) and in autumn (۱۵۶.۱۲ ±۱۳۶.۳Ind.m-۲) respectively which was significantly different (P<۰.۰۵). Comparative spatial distribution of L. claparedeianus among ۱۳ stations revealed significant differences in the west stations (P<۰.۰۵). According to the results, correlation analysis did not exhibit any relation between abundance of L. claparedeianus and total organic matter, abundance of the species and percentage of silt in substrate sediment.

کلیدواژه ها:

Anzali Wetland ، Limnodrilus claparedeianus ، new record