Aristostomias

Aristostomias is a genus of barbeled dragonfishes native to the ocean depths in the Pacific, Atlantic, and Indian oceans. They are noted for their elongated bodies, large heads, and distinct loosejaw. Aristostomias feed on midwater fishes and follow daily vertical migration patterns. They are known for their red bioluminescence and visual systems built to perceive red light.

== Description == Members of the genus Aristostomias are deep-sea dragonfishes characterized by elongated bodies, large heads, and highly specialized jaw structures typical of loosejaw dragonfishes in the family Stomiidae. These fishes possess extremely large gape angles and modified cranial joints that allow the head to rotate upward during feeding. A flexible head joint formed by a folding of the notochordal sheath around the occipital condyle enables the skull to elevate farther than in most other teleost fishes. This adaptation allows Aristostomias to open its mouth to angles approaching 120°, enabling the capture of relatively large prey in the mesopelagic zone.