Introduction and Distribution of Chironomidae larvae in Sardabroud estuary of Chalus (south Caspian Sea)

Abstract

In order to study the biodiversity and distribution of the chironomid larvae and their relationship with environmental factors in Sardabroud estuary of Chalus (south Caspian Sea basin), bimonthly Samples were taken in three stations (S1 in the river environment, S2 in estuary environment, and S3 in the marine environment), using Van Veen grab (0.03 m2) and Surber (0.1 m2, 0.2 mm-mesh sizes) with three replicates from November 2014 to September 2015,. In this study, three subfamilies were identified, including Chironominae (5 genera), Orthocladinae (3 genera) and Tanypodinae (1 genus). Nine genera are reported from the river and estuary of Sardabroud for the first time. Among identified genera, the highest average density belonged to Polypedilum (282±122 ind. m-2) and the lowest belonged to Paratendipes (72.2±30 ind. m-2). Among sampling stations, river station (S1) showed higher density (200.4±84 ind. m-2) than estuary station (S2) (96.2±35.6 ind. m-2) and marine station (S3) (0±0 ind. m-2) which were significantly different (P<0.05). According to the results, the highest and lowest density of chironomid larvae were in January (378.5±166.5 ind. m-2) and in July (37.6±15.3 ind. m-2), respectively. A significant correlation (P<0.05) between the density of chironomid larvae and environmental variables was found.

Keywords

• caspian sea
• chalus
• chironomidae
• density
• distribution
• sardabroud