Marine Animal Encyclopedia
Stoplight Loosejaw Malacosteus niger
Like many other deep-sea fish, the stoplight loosejaw is black, relatively small, and has a large mouth. However, it is unique in that it has no floor to its mouth, hence its name. Instead, a ribbon of muscle that joins the gill basket and the lower jaw contracts to shut the mouth. This arrangement may allow the fish a wider gape and a faster strike at prey. This fish is also a specialist in light production. It has two large photophores under each eye, one that produces normal blue-green bioluminescence and the other red. No natural red light reaches these depths, so most deep-sea creatures cannot see it. The red bioluminescence reflects well off a red animal, such as a shrimp, but the shrimp will be unaware that it has been spotlighted.