A new species of freshwater amphipod of the genus Gammarus from Iran.

A new species Gammarus ilamensis sp. nov., is described and named from Sarab-e-Meimeh in Ilam Province, Iran. This species description is based on the analysis of morphological characters and molecular data (28S rDNA and COI genes). Its taxonomic status within the genus is discussed in comparison to the 18 known Iranian species and some species from other areas. Results revealed that G. ilamensis sp. nov. is placed phylogenetically in the G. komareki species complex. The new species is easily distinguished by several distinctive characters including two medial palmar spines on propodi of gnathopod 1, endopodite of uropod 3 as long as 0.9 of exopodite, antennal gland-cone longer than the third peduncle article, and pereopod 7 basis without protruding lobe but with setae in the postero-distal corner. [ABSTRACT FROM AUTHOR]