What is bioluminescence.

Explanation

Bioluminescence, the property of a living organism to emit light is well-marked in ctenophores.
Ctenophores, commonly known as sea walnuts or comb jellies are exclusively marine, radially symmetrical, diploblastic organisms with tissue level of organisation.
The body bears eight external rows of ciliated comb plates, which help in locomotion.
Digestion is both extracellular and intracellular.
Sexes are not separate.
Reproduction takes place only by sexual means.
Fertilisation is external with indirect development.
Examples : Pleurobrachia and Ctenoplana.