The Deep Sea Dragonfish
< Dragonfish belong to a group of deep sea fishes known as Stomiidae, and vary greatly based on sex. Females grow to just over foot and are much more aggressive than the male, who is ten times smaller, toothless and without a working gut. Females of some species also boast an illuminated barbell that grows from the chin, which is used as a lure for prey. Apart from the barbell, Dragonfish also have light emitting organs called photophores along the length of their bodies and in their fins.
Incredible Bioluminescence: Firefly Squid
Firefly squid, also known as Sparkling Enope Squid, grow to about 3 inches in length. Like many other squids, their body is covered in pigmentation cells (chromatophores) that allow it precise control over its coloration. Unlike most other squids, though, it is also covered in photophores, which produce light.
The brightest of these are in the tentacle tips, but they can use those located over the rest of their body to match the light coming from above, so they will remain unseen by predators below. Firefly squid are (so far) the only squid known to have color vision. They are also supposed to be very tasty.