The Slingjaw Wrasse (Epibulus insidiator) is becoming more common again in the Tanzanian coastal areas. Until 2017 dynamiting was common in the coastal areas of Tanzania and this species certainly did not do well with it. It has taken several years for their numbers to come up to where they should be. They were always fairly common in the protected Marine Parks areas but outside of these areas one almost never saw them. They obtain their name from their jaw, which when extended forward into its tubular form can be up to a third of their normal body length. The jaw is hinged and tucks neatly into the underside of the head area. In the image below of a mature female, the specimen is busy folding its jaw back into the folded position.
SLINGJAW WRASSE APPEARANCE
The Slingjaw Wrasse is a robust wrasse growing up to 51 cm in length , juveniles and initial phase females are mainly a dark brown color often with a yellow tail. There is also a bright yellow colouration for the initial pg=has females. As they age so the scales become quite proportionally large and are often lined with black. As the fish switches over into a terminal phase male these lines on the scales become more predominant and the upper head area goes a orange color and the face goes a silver/ white color with black marks extending over the eye. There are few of these males around compared to the numbers of females and presumably they they have large territories. The dorsal and pectoral fins on the males go yellow and orange. The juveniles in other parts of the world are brown with thin white lines radiating out from the eyes but in Tanzania we have never seen this coloration , all he ones we have seen have been brown or yellow.
IN THE WILD
The Slingjaw Wrasse is quite shy in Tanzanian waters and although one can get close to them, they are quite difficult to photograph because they are generally moving very fast when there are divers around. The larger adult males are much more shy than the females and juveniles and can be annoyingly difficult to photograph. They seem to prefer reef tops with abundant corals and are more common from 10 meters down to about 18 meters. The small juveniles are quite reclusive and are always close to a hiding spot.
HABITAT
The Slingjaw Wrasse is found from East Africa including the Red Sea to Okinawa in the north, across to Hawaii and down south to Australia.
DIET
The Slingjaw Wrasse feed on small grass bed dwelling invertebrates that they pick off with their pointy mouth. That is however just an assumption.
REPRODUCTION
Little is known of their reproductive habits, but they are assumed to be protogynous hermaphrodites. There are not that many terminal phase males around and these appear to be haremic as the males patrol large areas.
AQUARIUMS
Slingjaw Wrasse are not commonly kept in aquariums and there seems to be little literature on keeping them.
SLINGJAW WRASSE CLASSIFICATION
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Labriformes
Family: Labridae
Genus: Epibulus
Species: E. insidiator