Gobiesox is a genus of clingfishes found in the Americas, including offshore islands. Most species inhabit coastal marine and brackish waters, but G. lanceolatus is a deep-water species found at a depth of around 300 m (980 ft), and seven species (G. cephalus, G. fluviatilis, G. fulvus, G. juniperoserrai, G. juradoensis, G. mexicanus and G. potamius) are from fast-flowing rivers and streams. These seven are the only known freshwater clingfish.

The genus includes both widespread and common species, and more restricted species that are virtually unknown. Three freshwater species that are endemic to Mexico (G. fluviatilis, G. juniperoserrai and G. mexicanus) are considered threatened by Mexican authorities, and three species that are endemic to small offshore islands (G aethus and G. canidens of the Revillagigedo Islands, and G. woodsi of Cocos Island) are considered vulnerable by the IUCN.

Gobiesox are small fish, mostly less than 7 cm (2.8 in), but at up to 15 cm (5.9 in) in standard length the largest species are among the largest clingfish.

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