Tompot Blenny

The tompot blenny is a robust, distinctively marked blenny in the family Blenniidae, genus Parablennius, common along rocky shores of the northeastern Atlantic and Mediterranean. It is one of the largest and most frequently observed blennies in British and Irish coastal waters, often found peering out from crevices in harbor walls, piers, and rocky reefs. The species is popular among divers and underwater photographers for its bold, curious personality and expressive facial appendages. Tompot blennies are not migratory and typically remain within a small home range for much of their lives. The species is common and not considered at conservation risk.

The tompot blenny has a robust, elongated body in mottled brown to reddish-brown with irregular darker vertical banding along the flanks.

• Prominent, branched tentacles (cirri) above each eye, larger and more elaborate than in most other blennies
• Large, blunt head with thick fleshy lips
• Single long dorsal fin extending the length of the back
• Scaleless, smooth-looking skin

Its notably large, branched eye tentacles combined with its bigger overall size distinguish it from smaller blenny species found in the same rocky habitats, such as the shanny, which has much smaller, simpler cirri.

Tompot blennies inhabit rocky reefs, harbor walls, piers, and wrecks along the northeastern Atlantic coast, from Scotland and Ireland south through the English Channel to the Mediterranean and northwest Africa. They favor crevices, holes, and man-made structures at depths from the shallow subtidal down to about 20 meters, and are frequently encountered by divers at popular UK dive sites. The species prefers cooler temperate water with good structural complexity for shelter, and shows strong site fidelity, often occupying the same crevice for extended periods.

Tompot blennies are solitary and territorial, often seen peering out from a favored crevice with only the head visible, retreating fully inside when disturbed. They feed on small invertebrates such as crustaceans and worms picked from the surrounding rock and rubble. The species is notably bold and inquisitive compared to many blennies, sometimes approaching divers closely. During the breeding season, males guard a nest site within a crevice or man-made cavity, where females lay adhesive eggs that the male then fans and protects until they hatch. Their strong site fidelity and territorial behavior make individual tompot blennies easy for divers to relocate at the same site over multiple visits.