The property of a living organism to emit light is well marked in the members of the phylum with
The property of bioluminescence is well marked in Ctenophora. Ciliated comb plates help in locomotion in these organisms.
Bioluminiscence is not observed in sponges, flatworms or roundworms.
Canal system - Sponges
Hooks - Platyhelminthes
Pseudocoelom - Aschelminthes