Boleophthalmus dussumieri, Valenciennes, 1837

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 682-683

Boleophthalmus dussumieri

Common name. Gel Khorok mudskipper.

Diagnosis. Distinguished from other freshwater gobies in the Persian Gulf basin and the Arabian Peninsula by: ● one large canine tooth behind jaw symphysis and behind row of teeth in lower jaw / ○ no barbels on ventral side of head / ● eye strongly elevated from head profile / ● usually only one row of teeth in lower jaw / ○ 103–185 scales in lateral series / ○ 48–56 predorsal scales. Size up to 187 mm SL.

Distribution. Persian Gulf basin to western India. Upper Shur ( Iran) found 55 km upstream from coast and expected to occur in other brackish rivers.

Habitat. Intertidal mudflats. Also, mudflats of brackish rivers far inland.

Boleophthalmus dussumieri ; Kuwait; ~ 120 mm SL. © M. Pope.

Biology. Lives up to 6–7 years, usually spawns for a single season and then dies. Spawns first time at 2 years, in April– August. Digs U-shaped vertical burrows to a depth of about 1 m with mud dams around entries. Mud dams usually pentagonal, rarely hexagonal or square, shape varies between populations. Mud dams help to keep water in burrow at low tide. Hides in burrow at high tide, low winter, and very high summer temperatures and when threatened. Active between 13 and 40°C. Muscular pectoral fin aid movement on land. Keeps water under gill cover to maintain a moist atmosphere for gills. Usually remains within mud walls of its territory, submerged in water or wet mud. Emerges from burrows at 10°C, often coming out of burrows to test temperatures. Basks to raise body temperature to 14°C. Keeps itself wet by regular immersion in pools and burrows and cool by evaporative loss of body fluids. Even at 40°C air temperature, body temperature does not exceed 33°C. Mucous cells prevent dehydration. Gas exchange in air and water occurs through gills, inner operculum, nasal, body, and outer operculum skin. Spawns in male burrow. Male guard eggs. Larvae emerge mid-July, usually in August. Male compete for females during courtship. A male usually has five neighbors, half of which are females. Male identify and attract female by raising fins and jumping with about two-thirds of body above ground. Pectoral fin waves, lateral tail beats, and quivers are other signals. On coast, feeds mainly

on diatoms, blue-green algae, and filamentous algae, using polygonal enclosure between mud walls as a ‘farm’ for diatom growth.

Conservation status. LC.

Remarks. Records of this species from the east coast of India refer to Boleophthalmus boddarti .

Further reading. Clayton & Vaughan 1982; Clayton & Wright 1989 (behaviour, habitat); Murdy 1989 (description); Polgar et al. 2013 (revision).