Post on 10-Jan-2016
description
Phylum Cnidaria
Cnidaria & Ctenophora
CnidariaRadially symmetricalTentacles contain nematocysts (stinging cells)
CnidariaMedusa: free-swimming
Polyp: sessile
Class Anthozoa6000 species, including sea anemones, corals and sea fans.May be solitary or colonialHexacorallia: 6-part symmetry, hard coralsOctocorallia: 8-part symmetry, soft corals
Class Hydrozoa2700 species, including Portuguese man-of-war, and fire coralBoth polyp and medusaPolyps may be for feeding, defense, and reproduction
Order SiphonophoraDrifting colonies that inhabit tropical and sub-tropical regionsPhysalia (Portuguese man-of-war)blue sail-like floattentacles may reach several meters below the float.
Class Scyphozoa
200 species of jellyfishCold to tropical water2-40cm (up to 2m)Most jellies can swim horizontally and verticallyAurelia (Moon jelly)Cassiopea or upside-down jellyfish (filter feed / zooxanthellae)
Class Cubozoa Box jelly or sea wasp (Chironex fleckeri)Strong toxin, causes immediate, extreme painDeath can occur 3-20 min after a sting
Phylum Ctenophora8 comb rowsHave colloblasts: sticky ends that are used to capture preyCatch food with tentacles
Comb jelliesBioluminescentAll marineMost are pea-size to golf ball-size