Survey on Distribution and seasonal fluctuations of macrobenthic invertebrates of Dadin Spring in Kezerun

In order to study and identify macrobenthic invertebrates’ fauna of Dadin Spring in Kezerun, Fars south-west, Iran was conducted from April, 2014 to March, 2015. Benthic samples were collected from five different stations of spring including: center, north, south, west and east. Sediment was performed by using Van Veen Grab. After washing the sediment to avoid spoilage, organisms were fixed with 1% formalin and then macrobenthic invertebrates were identified based on key identification. The results showed that three phyla of macrobenthic invertebrates were diagnosed in the Dadin spring which these three phyla including Arthropoda, represented by seven genera: Epitheca sp., Argia sp., Chironomus sp., Chysops sp., Hydropsyche sp., Potamon sp., Caridina sp.. Annelida represented by two genera, Uncinais sp. and Lumbriculus sp. and Mollusca represented by four genera of gastropods including Theodoxus sp., Monacha sp., Melanopsis sp. and Melanoides sp.. Mollusca dominated the macrobenthic invertebrates with a total abundance of 48% and Annelida were the least abundant, 15.5% by number. Although the abundant of Arthropoda was less than Mollusca (36.75%),but the diversity of Arthropoda was more than others. One-way Aonwa showed that there was significant relationship between collected samples and season (P≤0.05) while this relationship was not seen between collected samples and sampling station(P>0.05).