Ctenophora

Author: Kelly Clay
__**EXAMPLES**__:
 * Comb Jellies


 * Sea Gooseberries


 * Sea Walnuts


 * Venus's Girdles

__**HABITAT**__:
 * They live in the sea and found in depths up to three kilometers
 * Their habitat is fixed primarily by the ocean currents, in particular tides
 * Many species live as plankton on ocean layers near the surface. These are transparent, frail and no more than few millimeters
 * About 35 species live on the sea bed

__**TYPE OF COELOM:**__
 * Acoelomate


 * __ENDOSKELETON or EXOSKELETON__:**
 * No true skeleton
 * Elastic mesenchyme provides "skeletal" support


 * __TYPE OF NERVOUS SYSTEM__:**
 * Nerve Net
 * No Centralization
 * Neurons are bare and nonpolar

__**FEEDER**__:
 * All ctenophora are predatory
 * Prey is captured by the tentacles, using a sticky filament that is produced by colloblasts
 * Prey is ingested into pharynx, there it is exposed to enzymes and moved by ciliary action
 * Undigested food expelled through mouth and anuses

__**SYMMETRY**__:
 * Bi-radially symmetrical, with and underlying bilateral symmetry.
 * Main body axis running from mouth to statocyst, but split into higher and lower symmetry
 * Lower is shifted by 90 degrees from higher symmetry

__**REPRODUCTION**__:
 * Sexual reproduction
 * Most species are hermaphroditic, but some gonochoristic
 * for most, fertilization and development are external.

__**CIRCULATORY SYSTEM**__:
 * No organized system
 * Gas exchange through diffusion

__**ENDOTHERMIC or EXOTHERMIC**__.
 * None

__**SEGMENTATION**__:
 * None

__**WORKS CITED**__:

"101 Invertebrates - Biology - Www.101science.com." //Learn Science Electronics Biology Chemistry Physics//. Web. 30 Mar. 2011. .

"Ctenophora." //Vassar College Public Access Employee Directory//. Web. 30 Mar. 2011. .

"Ctenophore - New World Encyclopedia." //Info:Main Page - New World Encyclopedia//. 29 Aug. 2008. Web. 30 Mar. 2011. .