Fangtooth, Anoplogaster cornuta (Valenciennes, 1833)
Introduction
The aptly named Fangtooth has enormous pointed fangs. The two fangs at the front of the lower jaw slide into pockets in the roof of the mouth.
Identification
The Fangtooth has a short deep body with a large head and mouth. The body is covered with small prickly scales. The distinct lateral line is an open groove partially covered by scales. There are mucous cavities on the head separated by serrated ridges. As the common name suggests, this fish has very long pointed teeth. The lower jaw fangs slide into pockets in the roof of the mouth when the jaws close.
The species is dark brown to black.
Adults and juveniles look very different and eat different prey items. Juveniles have long head spines and are light grey. They don't begin to look like adults until they reach about 8 cm in length. Adults and juveniles look so different they were described as a different species in the 1800s.
A second species in the genus Anoplogaster was described using seven juveniles (20 mm to 60 mm SL) in 1986. A.brachycera differs from the Fangtooth by a combination of characters including less dorsal fin rays (16 to 17 versus 17 to 19), shorter head spines (the name brachycera is derived from Greek and means "short-horned"), and differences in the growth of the fangs and scales.
Habitat
It is known from bathypelagic and mesopelagic depths down to about 5000 m, but is most common between 500 m and 2000 m.
Distribution
The species occurs in temperate marine waters worldwide.
In Australia it is known from off central to southern New South Wales.
The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Source: Atlas of Living Australia.
Feeding and diet
Juveniles eat crustaceans. Adults eat fishes. This incredible footage from the BBC shows a feeding Fangtooth, Anoplogaster cornuta. The video talks about the very long pointed teeth but does not say that the lower jaw fangs, in fact, slide into pockets in the roof of the mouth when the jaws close (see image to the above).
References
- Paxton, J.R. in Paxton, J.R. & W.N. Eschmeyer (Eds). 1994. Encyclopedia of Fishes. Sydney: New South Wales University Press; San Diego: Academic Press [1995]. Pp. 240.
- Kotlyar, A.N. 1986. Classification and distribution of fishes of the family Anoplogasteridae. Voprosy Ikhtiol. 26(4): 531-551. [In Russian, English translation in Journal of Ichthyology. 26(4)].
- Paxton, J.R. in Carpenter, K.E. & V.H. Niem. 1999. The Living Marine Resources of the Western Central Pacific. Volume 4. Bony fishes part 2 (Mugilidae to Carangidae). FAO. Rome Pp. iii-v, 2069-2790.
- Hoese, D.F., Bray, D.J., Paxton, J.R. & G.R. Allen. 2006. Fishes. In Beesley, P.L. & A. Wells. (eds) Zoological Catalogue of Australia. Volume 35. ABRS & CSIRO Publishing: Australia. parts 1-3, pages 1-2178.