Community Structure of Benthic invertebrate in Greater Zab River/Iraq

A study_ of macroinvertebrate community has been carried out atthree sites selected on greater zab river included Qandel, Efraz andKhabat region. A total of 32 species of benthic invertebrates wererecorded including Nematoda, Oligochaeta, Ostracoda, Decapoda, Insectaand Mollusca. During studied period the insecta were regarded the mostdominated group, as they observed during all studied periods followed byOligochaeta which observed in all studied sites. Shanon-Weiner indexwas used to reflect the effect of environmental fll..lctuation on benthicinvertebrate communities, and the results showed that the speciesdiversity of studied sites was ranged between 0.41 to 2049 bits/ind. inQandel and Efraz regions respectively.