Freshwater Blenny

Salaria fluviatilis

The freshwater blenny (Salaria fluviatilis) is a small, characterful fish reaching about 15 cm in length, native to rivers and lakes of the Mediterranean basin. It has a robust, elongated body with a blunt head, large eyes, and a fleshy tentacle-like structure (supraorbital tentacle) above each eye that gives it an expressive, almost comical appearance. Coloration is variable, typically olive-brown to dark grey with darker bars or mottling that provides camouflage among stones and gravel. Males develop more intense coloration and larger head crests during the breeding season. Unlike most blennies which are marine, this species has fully adapted to freshwater life. It inhabits clean, well-oxygenated rivers and lakes with rocky or pebbly substrates, where it lives on and among stones in shallow water. It feeds on algae, small invertebrates, and insect larvae, scraping food from rock surfaces. Males guard eggs deposited under stones by females. Freshwater divers in Mediterranean countries may find these charming fish perched on or peeking out from beneath stones in clear streams.