Periophthalmus — Chambers's Encyclopaedia

Periophthalmus, a remarkable genus of acanthopterous fishes, allied to the gobies. Their eyes protrude and are very mobile; their pectoral fins can be used as legs. Several species occur on the coasts of the Indian Ocean and Western Africa; of these the best known is P. koelreuteri.

A black and white illustration of the fish Periophthalmus koelreuteri. The fish is shown in a dynamic pose, with its body arched and its head turned back, highlighting its large, protruding eye. Its pectoral fins are spread out, demonstrating their use as legs. The fish is positioned on a rocky or sandy surface, with water visible in the background. — *Periophthalmus koelreuteri*.

(From Hickson's Naturalist in North Celebes, 1890.)

This fish lives about low tide-mark on the muddy flats or among rocks, and by means of its pectoral fins and tail hops along in search of crustaceans, insects, and gastropods. Respiration seems to be effected through the skin of the tail even more than by the gills. They cling by their fins to rocks and mangrove-roots, and keep their tails in the water; or they climb entirely out of the water, and jump with agility when disturbed.