Tripterygion melanurum is a species of fish in the family Tripterygiidae, the threefin blennies.

[3] They are permanently red in color and females and non-territorial males have a marbled head.

Territorial males have a black head, are slightly darker and usually have vertical bars and white spots across their back, while they also have longer rays in their second dorsal fin.

[2] Adults of Tripterygion melanurum are demersal fish that live in dimly-lit areas[2] with vegetation, usually at a depth of less than 40 meters.

The eggs are hemispherical and covered with sticky threads that anchor them in the algae on the nesting sites.