Triplefin Blennies have a dorsal fin which is separated into three parts, and the family name Tripterygiidae is derived from the Greek word 'tripteros' which means 'three wings'. These small fish can be seen resting on corals and sponges on all Koh Lanta diving trips.
Generally this is a family of small fish, with most species below 6 cm in length. Triplefin Blennies have a similar form to other blennies, long body, wide, low set mouth, large, high set eyes and large pectoral fins.
This family are territorial fish, and active during the day. Many species differ in colour between male and female, with the females being generally drab, and the males much more brightly coloured.
Triplefin Blennies usually live on hard surfaces, on rocks or hard corals and are typically found in shallow, clear waters. They are shy fish and will retreat quickly to protective rocky or coral crevices if feeling threatened. They mostly feed on small invertebrates.