write short note on phylum ctenophora
Answers
They are exclusively marine.
They are biradially symmetric.
They have comb plates.
They have tissue level of organization.
They are acoelomates.
Eg. Pluerobrachia, Ctenoplana
Phylum: Ctenophora
These are commonly called comb jellies or sea walnuts. These are exclusively marine, free swimming animals. Body is diploblastic, radially symmetrical with blind-sac body plan. Animals have tissue-level organisation. Locomotion is carried out by eight rows of cilliated comb plates. Characteristic featurebof ctenophores is bioluminescence. Like cnidarians, ctenophores also exhibit extra and intracellular digestion. Reproduction is sexual with indirect development. Cnidoblasts are absent hence these are called acnidarians. Instead, they have colloblasts (sticky cells) to capture the prey. Ctenophora is represented by very few members, hence it is considered as one of the minor phyla. e.g. Pleurobrachia, Ctenoplana.
