Write the general characteristics of the phylum Ctenophora.

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