Marine Species Identification Portal : Phylum Ctenophora

Ctenophora are exclusively free swimming animals that are biradially symmetrical, the body axis is oral-aboral. The body wall consists of an ectoderm and an entoderm, separated by a cellular mesenchyme giving the body a gelatinous appearance; usually transparent. The body bears eight meridional rows of ciliary plates (ctenes or combs) at some stage of the life cycle; the unique apical statocyst controls the occilation of the cilia, which facilitates the locomotion of the animal. The digestive tract comprises of a stomach and a biradial canal system with a single opening functioning as mouth. Ctenophores do not have cnidae (as in the Cnidaria) but many have a pair of long retractile tentacles, which can catch prey by means of sticky colloblasts. Most ctenophores are hermaphroditic, capable of self-fertilisation; typically with a cydippid larval stage. The development is monomorphic.

Ecology
Ctenophora are strictly marine; most species are pelagic and then holoplanktonic, but some have secondarily developed a benthic but non-sessile way of life.

The key to the ctenophore species of the North Saa plankton starts at Page 392: Ctenophora.

[After Brusca and Brusca, 1990; Hayward and Ryland, 1995]

The following species of Ctenophora are included in the present volume:

Class Tentaculata
Order Cydippida
Family Pleurobrachiidae
Pleurobrachia pileus
Order Lobata
Family Bolinopsidae
Bolinopsis infundibulum
Class Nuda
Order Beroida
Family Beroidae
Beroe gracilis
Beroe cucumis

Phylum Ctenophora