A common sight, mainly at the offshore locations such as Sail Rock and Chumphon Pinnacles, Teira Batfish (Platax Teira) are a real favourite with divers and photographers due to their inquisitive nature and habit of forming large, spectacular schools.
Fully grown, the Teira Batfish can reach approximately 60cm although as with most other species of Batfish, adults differ greatly in their physical appearance from juveniles.
Adults and sub-adults are reasonably easy to distinguish from other Batfish species with their overall pale grey to dusky brown colouration, yellow pelvic fins and in particular, the dark spot in the area between the pelvic and pectoral fins (this is the main distinguishing characteristic of the species).
There are also three vertical bands on the body, one of which is narrow and runs down through the eye. The second band is much broader and extends from the front edge of the dorsal fin to behind the pectoral fin.
The third band is much less distinctive, often invisible, and although it also begins at the dorsal fin, it does not extend down the full height of the body.
Juveniles, which are not a common sight, tend to inhabit protected inshore areas and are easily recognized by their hugely elongated dorsal and pelvic fins (relative to their overall body size) with yellow margins.
As the fish matures, it becomes progressively paler in colour whilst the fins decrease in size as the body size increases.
As with many fish species, Teira Batfish are capable of rapidly changing their overall colour, most noticeably from their usual dusky brown/greyish colour with dark bands to almost white, at which point the dark bands may almost disappear entirely.
This colour changing behaviour is most noticeable when individuals, or small groups, break away from the main school in order to seek out the cleaning services of the Blue-Streak Cleaner Wrasse (Labroides Dimidiatus).