Counterillumination camouflage

In many animals of the deep sea, including several squid species, bacterial bioluminescence is used for camouflage by counterillumination, in which the animal matches the overhead environmental light. In these animals, photoreceptors control the illumination to match the brightness of the background

Attraction 

FireFlies uses light to attract mates. Females emit light from their abdomens to attract males; in the other, flying males emit signals to which the sometimes sedentary females respond. 

 Click beetle emit an

orange light from their

abdomen when flying

and a green light from

the thorax when they are disturbed.

​Defence

Some animals also produces light to disturb the predators in an attempt to catching them like when squid use ink. These animals are called the cephalopod. They produce bioluminescent chemical mixtures to disturb the predators when attacking them.

Dinoflagellate  may use bioluminescence for defence against predators. They shine when they detect a predator, possibly making

the predator itself more vulnerable by attracting the attention of predators from higher trophic levels. 

Warning 

 Aposematism is a widely used function of bioluminescence, providing a warning that the creature concerned is unpalatable. It is suggested that many firefly larvae glow to repel predators; millipedes glow for the same purpose.

The marine snail Hinea brasiliana uses flashes of light probably to deter predators.

The light signals that result from bioluminescence can be used during life for things such as mating rituals, and in death. For example, when bioluminescent bacteria infect certain types of larvae, the death of the larvae can lead to bright lights, letting

predators know of the dead

meal. 

Communication

Bioluminescence can be used in many ways,

and among those ways is mimicry, or the action of imitating someone or something. There are two common ways that organisms can use mimicry: Aggressive mimicry and defensive mimicry.

Aggressive mimicry is used by predators to appear harmless, leading their prey to come within attacking distance. Underwater, the cookiecutter shark, for example, uses bioluminescence for this technique; it uses the glow to camouflage its underside, leaving a small part dark. Smaller fish swim by, assuming that this dark area is a fish like themselves, unknowingly getting to close to a shark. In the air, the female Photuris firefly mimics the light pattern of male photinus fireflies. The photinus flies to where the signals are being made, only to to be taken down and devoured by the female firefly.

Mimicry

While aggressive mimicry is used

to hunt prey, defensive mimicry

is used by the prey to keep itself from harm, deceiving an enemy into thinking they are something they’re not. The cockroach, Lucihormetica luckae, found in 2010 used bioluminescence in the form of bacteria on its back, each group taking the shape of one spot in there. These bacteria glow in fluorescent light, thus giving the cockroach a different appearance.The effect is intensified by the fact the spots are covered by a reflective surface, making them act in similar to headlights.”

Mimicry

Illumination 

While most marine bioluminescence is green to blue, some deep sea barbeled dragonfishes in the genera Aristostomias, Pachystomias and Malacosteus emit a red glow. This adaptation allows the fish to see red-pigmented prey, which are normally invisible in the deep ocean environment where red light has been filtered out by the water column.