14. Benthophilus macrocephalus (Pallas, 1787), Caspian Tadpole Goby

Gobius macrocephalus Pallas, 1787: 352, pl. 10, figs. 4–6; type locality: Caspian Sea; types: no types known.

Etymology: Greek, makros = long + Greek, kephale = head, refers to the relatively large head.

Distribution and habitat: Coastal waters of all three areas of the Caspian Sea (Fig. 11B). One of the most abundant species in the North Caspian Sea. In the Middle Caspian Sea, it has been recorded along the western coast, and in the South Caspian Sea eastward to Gorgan Bay, Iran (Ragimov 1965; Boldyrev & Bogutskaya 2007). In the South Caspian Sea sub-basin, this species has been reported from the Anzali Wetland and Gorgan Bay in Iran and between Kultuk and Astara in Azerbaijan (Ragimov 1965). De Filippi (1865) reported this species in freshwaters of the Anzali Wetlands. The species has not been found along the eastern coast of the Middle Caspian Sea. The range is rather similar to that of B. leobergius (but the latter also has been collected at Ogurchinskiy Island). Occurs in coastal waters and estuaries usually at depths from 0.5–10 m, over muddy bottoms, and in the lower reaches of rivers. Widely distributed, but more abundant in areas having salinities less than 7–8 ‰. During warm seasons, it prefers coastal waters down to 10 m deep. In the North Caspian Sea region, it migrates to deeper areas (20–25 m) in the winter (Boldyrev & Bogutskaya 2007).

IUCN: LC (Freyhof & Kottelat 2008e).