Narinder Singh, Academic content writer at edumarz
Characteristics:
Consisting of bi-radially symmetrical marine-water invertebrates, they are mainly transparent and beautiful organisms.
Mainly belonging to beautiful habitat, they do not reside in fresh water.
The name of the phylum came from Greek word “Ctene” meaning comb and “Phora” meaning bearer, showing the ciliary like combs on the organism’s
surface.
First identified in 1671 by Linnaeus, putting them under Zoophyte.
Phylum Ctenophora was first identified by Zoologist Eschscholtz in 1829.
Presence of a tissue level organization.
Sexes are not separate (hermaphrodite), with reproduction taking place by sexual means.
External fertilisation with indirect development.
No specific organ for respiration and excretion, with both done by the body surface.
They are further classified into two classes:
Tentaculate:
Contain two tentacles retracting into sheaths and Stomadaeum.
Sea walnuts contain and feed on Larval molluscs and copepods.
Whereas, Venus Girdle is ribbon like and flattened, and are found in
Tropical waters.
Example include: Sea Walnut and Sea gooseberry.
Nuda:
They donot contain tentacles.
Contain large mouth, feed on jellyfish and other ctenophores.
Free swimmers found in all oceans and seas around the world
Example includes: Beroe and Mnepmiopsis.
Ctenophore
Importance:
1. Making beautiful sights while diving and snorkelling.
2. They produce Luminescence, which is used as a “Biomarker” and “Biotag”.
3. Used in research by scientists to identify activation genes.
4. Can maintain the plankton population underwater.
5. Can adapt to changing environmental conditions.