Triplefins

Scientific name : Trypterygidae

Family Tripterygiidae includes probably over 200 species, many still undescribed. Most of them have cryptic behaviour, and are very difficult to observe. Few species live at the surface of corals and sponges: although very small those can be observed, and they never leave a small territory.
Those are very small fishes, with long and thin body, skin covered with tiny scales. The dorsal fin is divided into 3 smaller distinct fins (hence the family name).
Many species are cryptic, virtually invisible. Few species live among corals and sponges, where especially the male never leaves a small territory, where invites the females to lay eggs. They feed on small crustaceans.
The main feature to distinguish them from other small bottom fish families (blennies, gobies, dragonets) is the number of the dorsal fins (3, well separated). Sometimes to count the small and transparent fins can be difficult, and it is easy to mistake them for small gobies. Normally triplefins have a more pointed snout than gobies, and a slightly different posture, with raised head. They perch themselves on narrow ventral fins instead of the typical disc of the gobies.