Bioluminescence

Bioluminescence is the generation of light by living organisms, including deep-sea species of squids, octopus, worms, and mollusks, and the firefly in the air.

Deep-sea life

The light created by the deep-sea life is produced by special cells or by bacteria that live within the fish. Some fishes have lights of different colors and on various parts of the body that the light displays are unknown, they presumably function as a form of communication.

Some predatory species use bioluminescence to lure prey. Deep-sea angler fish, have log filaments with a light on the end dangling over the top of the head. These anglers feed on other fishes that mistake the light for small prey and swim into the angler's enormous mouth.

Firefly

The light produced by the firefly is said to be "cold," because the efficiency of the utilization of the energy is so great that little of it is converted into heat. The processes involved in this light production have been imitated in the laboratory by mixing together in a test tube the four substances isolated from the lantern of fireflies. These are luciferase, and enzyme that acts as a catalyst; luciferin, an organic substance which emits light when oxidized; magnesium ion; and adenosine triphosphate, a compound which occurs in all organisms and is the immediate source of muscular contraction. When these four substances are mixed in the test tube, firefly light is emitted.

The light organs of the firefly, located on the underside of the sixth and seventh abdominal segments, are apparently derived from fat-bodied cells. They are richly supplied with nerves and tracheae which supply the oxygen necessary for light production. It is generally accepted that the light attracts opposite sex. Males and females of each species have a characteristic flash enabling them to find each other.

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