Studying oligochaeta density and distribution in the southern coasts of the Caspian Sea

Abstract

The oligochaeta density and distribution in the southern coasts of the Caspian was surveyed. Sampling was carried out in the depths of 10-20-50-100 meters from to Bandar-e-Turkaman. The results indicated that oligochaeta density enhanced with the increase in depth (in the surveyed areas). The main reasons for the enhancement are the smaller sediments particles and higher density of organiv matter in deeper sea beds. The studies were carried out in three different phases and time span. Hence lots of differences in Oligocheata densities were observed in each square meter. Also their frequency varied in different seasons. The maximum was observed in autumn and the minimum in summer. Temperature is indicate as an important parameter in this survey and the average temperature in each depth is calculated.