Southern stoplight loosejaw
Malacosteus australis, the southern stoplight loosejaw, is a species of barbeled dragonfish. This species is mainly distinguished from Malacosteus niger by a smaller postorbital photophore in both sexes and lower numbers of lateral photophores. It also differs in having somewhat smaller jaws, a fleshy orbit, and several subtle morphological traits. The maximum known length is 253.2 mm. Its specific epithet comes from the Latin austral, meaning "southern". It is known for its red bioluminescence which helps M. australis visualize in the aphotic deep sea.
Malacosteus australis have long bodies with large eyes. The blunt and short snout has a single round nostril. This species have barbed, curved, knife-shaped teeth. They have thin, scale-less, black skin.