Angler fish

The angler fish was a bloated-looking solitary species of fish, named for its dorsal fin's resemblance to a fishing line.

Description
Angler fish varied in size; most anglers were no larger than a human's fist, though they could rarely get as large as in length. Additionally, in some species the males were only a fraction of the female's size. Anglers had large jaws with teeth that curved inward, making it difficult for them to release anything that got caught in their maw. However, their bloated bodies made them clumsy swimmers, thus anglers had to rely upon their illicium to lure prey towards them.

The illicium, a modified ray of their dorsal fin, was the most notable feature of the angler fish. Those closer to the surface had illicium that resembled either worms or one or more hooks that they could use to draw prey down to their jaw, while those in the deeper reaches of the ocean had a bioluminescent growth. Some anglers lacked an illicium entirely, instead having a bioluminescent growth that protruded from the palate of their mouth.

Diet
The angler fish was a carnivorous type of fish. In most species of angler fish it was only the females who hunted, while the males clung to them like lampreys and lived off of them like parasite.

Usages
The flesh of an angler fish was edible, though by human standards it was far from a delicacy.