Gammarus sirvannus Hekmatara, Sari & Heidari Baladehi, 2011

Gammarus sirvannus Hekmatara, Sari & Heidari Baladehi, 2011: 49 –56, Figs. 8–13.

Locus typicus. Sirvan River-Paveh branch (N 35º 0 7ʹ, E 46º 15ʹ), 25 Km west of Paveh city, Kermanshah province, Iran.

Material examined. Paratypes, September 2008, leg. M. Hekmatara (ZUTC amph. 2251).

Distribution. This species was found only in locus typicus in north-west of the Zagros, in western Iran.

Ecological notes. This cold mountainous region lies at an altitude of ca. 700 m asl.

Taxonomic remarks. Long setation of antenna 2 makes G. sirvannus resembling a few other species present in the same region. However, in G. komareki, such setae are slightly curled, it has small eyes, lacks the distinctly projecting postero-distal corner lobe in bases of pereopods 6–7, and has few short setae on pereopod 5–7. Elongated eyes and setation of antenna 2 make G. sirvannus similar to G. loeffleri and to G. shirazinus, but the latter differ with highly setose pereopod 3–7. G. parthicus may be obviously told apart from G. sirvannus by the small eyes and lack of distinct projection in postero-distal corner of pereopod 6–7 bases in the former species. In a detailed examination, presence of a single long seta on the first article of mandible palp is a deciding criterion to differentiate G. sirvannus from all the other similar species.