The blacksaddle filefish, Paraluteres prionurus, is a filefish of the family Monacanthidae. It reaches a length of a maximum 11 cm.
The blacksaddle filefish are found in pairs or in small schools and inhabit reefs across the Indian and Pacific oceans.
Coloration is sandy to grey with distinctive black "saddles" on the back and a yellow tail.
The blacksaddle filefish has evolved to mimic Blacksaddle Toby (Canthigaster valentine), a highly poisonous pufferfish commonly found where ever P. prionurus is found. The two species have been known to school together.
The Blacksaddle Filefish is white with dark brown bars. It has two pairs of spines on the caudal peduncle.
The species can be distinguished from the Blacksaddle Toby (Canthigaster valentine) by comparing their dorsal fins. The Blacksaddle Filefish has two dorsal fins, while the Blacksaddle Toby has only one. The second dorsal fin and anal fin are long-based (22-28 rays) in the Blacksaddle Filefish but short-based (9 rays) in the Blacksaddle Toby (Canthigaster valentine).
Inhabit clear lagoon and seaward reefs to at least 25 meters.
Did you know?
Mimic the poisonous puffer, Canthigaster valentini which it greatly resembles.
Adults usually in pairs, but sometimes seen in small aggregations.
Feed on eggs, gastropods and grazes the substrate.
Breeding with filefish usually takes place between one male and several females. The females lay their eggs on the substrate and they are fertilized by the male. The eggs are then guarded by the female to prevent them from being eaten by predators. The Blacksaddle filefish is more often than not seen in pairs in the wild. It seems likely that they differ from other filefish and that the pairs are mated pairs.