Black-faced Blenny

Overview

The black-faced blenny is a small, benthic fish easily recognized by its three distinct dorsal fins, which differentiate it from similar-looking blennies and gobies. It is a common inhabitant of rocky coastal environments, where it often seeks shelter in shaded areas or crevices.

Distribution & habitat

This species is found throughout the Mediterranean Sea and the eastern Atlantic, ranging from the English Channel south to Senegal, including the Canary Islands and Madeira. It typically resides on rocky substrates, often favoring areas with reduced light such as cave entrances, overhangs, and deep crevices, though it may be found in more exposed, well-lit biotopes in parts of the Atlantic.

Appearance

Adults reach a maximum length of approximately 9 cm. The species exhibits striking sexual dimorphism during the breeding season: territorial males develop a vibrant yellow body, a jet-black head, and fins edged in blue. In contrast, females and non-territorial males maintain a cryptic, grey-brown coloration with five broad, vertical dark bars along the body and a distinct dark spot on the caudal peduncle.

Biology & behavior

These fish are generally solitary and territorial, particularly during the breeding season when males aggressively defend nesting sites. Males perform a characteristic figure-eight swimming display to court females. The eggs are hemispherical and anchored to algae by sticky threads, where they receive parental care.

Feeding

As a carnivore, the black-faced blenny feeds on a variety of small benthic invertebrates, including amphipods, copepods, and harpacticoids.