Spatial distribution of nematode community in relation to environmental conditions in the southern Caspian Sea

The spatial distribution and biodiversity of free-living nematodes and their relationship with environmental factors were investigated in four stations in the southern Caspian Sea in November ۲۰۱۳. Nematode densities varied between ۱۴-۱۶۰ ind.۱۰ cm۲ at coarse silt and medium sand stations, respectively. Twelve species belonging to eight genera were identified and genus Daptonema with five species was the numerically dominant group. The highest species number and Shannon diversity were obtained in all sandy sediments while coarse silt station showed the lowest values. Results of Permanova analysis revealed two main different nematode communities in the sampling stations. Results of DISTLM analyses showed that median grain size was the principal factor affected the horizontal distribution of the nematode density, species number, Shannon diversity and community composition. Non-selective deposit feeders (۱B) were the most dominant in sandy stations while predators/omnivores (۲B) was the most important feeding group at coarse silt station

Keywords:

nematodes , median grain size , density , diversity , community , Caspian Sea.