Fin's Fish Guide
The Butterfly blenny (Blennius ocellaris) is a saltwater fish of the family Blenniidae that grows up to 20 cm.
Northeast Atlantic and the Mediterranean Sea, on sandy, silty and shell bottoms, deeper than most blennies.
Description
The butterfly blenny is a striking blenny of the family Blenniidae reaching about 20 cm. Characteristic is the tall, sail-like first dorsal fin with a large black eyespot ringed in pale; a fringed skin crest stands between the eyes. The brownish body bears several dark cross-bars. Unlike most blennies, which live in the tidal zone, the butterfly blenny stays at somewhat greater depth on sand, mud and shell bottoms of the north-eastern Atlantic and the Mediterranean. As a bottom-dweller it hunts small crustaceans and invertebrates. The male guards the eggs laid in an empty shell, cavity or even a discarded object. Because of its small size it has no fishery importance.
Frequently asked questions
How do you recognise the Butterfly blenny?
The Butterfly blenny has an elongate, eel-like body, is mainly brown and shows a vertical stripes pattern. Blenny with a conspicuously high, sail-shaped first dorsal fin with a large black eyespot; between the eyes stands a fringed skin crest.
Where does the Butterfly blenny live?
The Butterfly blenny lives in the sea (marine waters) and is mostly found around sand or mud bottom. Northeast Atlantic and the Mediterranean Sea, on sandy, silty and shell bottoms, deeper than most blennies.
How big does the Butterfly blenny get?
The Butterfly blenny grows to a maximum of about 20 cm.
Is the Butterfly blenny dangerous to humans?
No, the Butterfly blenny is harmless to humans. None required: this species is harmless to humans.
Is the Butterfly blenny edible?
The Butterfly blenny is not usually eaten.
More photos
Easily confused with
These species look like the Butterfly blenny and live in the same waters.
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All data
Identification
Appearance
Habitat & distribution
Behaviour & biology
For anglers
Safety
Status & sources
Same genus Blennius
More from the family Blenniidae
Want the complete picture on the Butterfly blenny?
Point your camera at the fish and Fin names the species in seconds. Free, and the Butterfly blenny is one of 12,519 species in the app.