Anoplogaster cornuta, the common fangtooth, is a species of deep sea fish found in temperate and tropical oceans worldwide.

Adults are dark brown to black, the head is very large, bony and finely sculptured but does not bear any spines.

[2] The juveniles were first described as Anoplogaster cornuta by the French zoologist Achille Valenciennes in 1833, and it was fifty years later that the adults were described and given the name Caulolepis longidens.

They have several long spines on the head, large eyes and slender, pointed gill rakers, but have small teeth and lack the fangs of the adult fish.

[5] Although almost no light penetrates to the deep sea from the surface, the common fangtooth has evolved features that make it practically invisible.

Like other deep sea fish, it needs to avoid being seen by predators, some of which hunt for prey by creating their own light by means of bioluminescence.

Altogether, the absorption of light is 99.5% efficient, a fact that makes photographing this fish in its natural habitat very difficult.