Cestidae is a
family of
comb jellies. It is the only family in the monotypic order Cestida. Unlike other comb jellies, the body of cestids is greatly flattened, and drawn out into a long ribbon-like shape. The two
tentacles are greatly shortened, and two of the four
cilia
The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projecti ...
ted comb rows are reduced. The unusual body form allows the animals to swim by means of muscular undulation, as well as by using their cilia. The largest species, belonging to the genus ''Cestum'', can reach in length.
Classification
The order Cestida has one family, Cestidae, which contains two
genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
: ''
Cestum'' and ''
Velamen''. Each genus contains one
species.
* ''
Cestum veneris''
Lesueur, 1813
* ''
Velamen parallelum''
(Fol, 1869)
References
Tentaculata
{{Ctenophore-stub