Why do some fish give off their own light?

Answer 1

Animals which produce light directly are known as producing Bioluminescence. Anglerfish are different. They do not produce the light with their own bodies like fire flies, rather they have a unique relationship with bacteria called symbiosis, and the bacteria actually produce the light for the anglerfish. This symbiotic relationship is called bioluminesce.

This is how it works:

Bacteria produce light -> Prey for the Anglerfish are attracted to this light -> Anglerfish feed -> Bacteria receives nourishment and shelter -> Repeat

Answer 2

Glowing fish use their light for different reasons. Deep in the ocean, some bioluminescent fish turn on the lights to attract their next meal. Other animals use light to blind predators that try to stalk and eat them. Some species create light to blend in with their surroundings. Some worms spit out glowing ooze, although no one can figure out why. It's also a mystery why tiny plankton glow when disturbed by storms, waves, and passing boats.

Answer 3

Some fish use specialized cells called photophores which emit light.

Answer 4

The same reason as any animal does anything - Becaue they can, and because it works for them.