Description: Clingfish have a small sucker disc on their underside that allows them to cling to rocks, even where there is strong wave action or current. They have a flat body with a triangular head, and smooth scaleless skin. This small clingfish has a short snout and one single dorsal fin, which is obviously separate from the caudal fin. It can vary a lot in colour but is most commonly mottled red with some brown and blue spots, although this is not a good identification character. The male has two distinctive purple spots ringed with yellow behind his pectoral fins, but females can be harder to definitively identify, and are very difficult to tell apart from the small-headed clingfish Apletodon dentatus.

Habitat: Can be found in rockpools on the lower shore down to depths of 100 m. Prefers rocky habitat (although not usually bedrock) and is often found under cobbles and boulders. Can also occasionally be found on sediment or bivalve beds.

Distribution: Occasionally recorded all around Britain and Ireland but seems to be rare on east coast of Britain.

Similar Species: Could be confused with Apletodon dentatus, especially if the fish are females. The male Diplecogaster bimaculata can be reliably identified by the purple spots ringed with yellow behind his pectoral fins. Females may not be able to be distinguished in the field. Detailed examination of teeth, fin rays and head size relative to body may be required.

Key Identification Features:

• Small, smooth bodied fish with a short snout and triangular head.
• Sucker disc on underside.
• Single dorsal fin that is obviously separate to caudal fin.
• Males can be identified by purple circles ringed with yellow behind pectoral fins.

Distribution Map from NBN: Diplecogaster bimaculata at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Diplecogaster bimaculata at iNaturalist World Species Observations database.

GBIF data for Diplecogaster bimaculata

WoRMS: Diplecogaster bimaculata at World Register of Marine Species. Accepted name: Diplecogaster bimaculata (Bonnaterre, 1788). AphiaID: 126513.

Classification: Biota; Animalia; Chordata; Vertebrata; Gnathostomata; Osteichthyes; Actinopterygii; Actinopteri; Teleostei; Gobiesociformes; Gobiesocidae; Gobiesocinae; Diplecogaster