What is Anthozoa?
{{taxobox | regnum = [[Animalia]] | phylum = [[Cnidaria]] | classis = Anthozoa | fossil_range = <br/>late [[Ediacaran]] to present | image = Scheibenanemonen (Actinodiscus spec).jpg | image_caption = Stony corals | image_width = 250px | authority = [[Christian Gottfried Ehrenberg|Ehrenberg]], 1834 | display orders = | subclassis = [[Ceriantharia]] <br /> [[Hexacorallia]] <br /> [[Octocorallia]]}} [[File:Acropora latistella (Table coral).jpg|thumb|250px|A stony coral in its natural habitat]] [[File:Giant Green Anemone.gif|thumb|250px|right|Giant green anemone, Southern [[California]]]] '''Anthozoa''' are a [[Class (biology)|class]] in the [[phylum]] [[Cnidaria]]. It includes the [[sea anemone]]s and the [[coral]]s. It is a [[monophyletic]] [[clade]], one of two in the Cnidaria. The other is the [[Medusozoa]].<ref name=Daly>Daly M. ''et al'' 2007. The phylum Cnidaria: a review of phylogenetic patterns and diversity 300 years after Linnaeus. ''Zootaxa'', '''1668''': 127–182, Wellington. [http://www.mapress.com/zootaxa/2007f/zt01668p182.pdf Abstract - PDF]</ref> The class does not have a [[Medusa (animal)|medusa]] [[larva]]l stage in its development, unlike the rest of the phylum. Like all Cnidaria, their food-catching and defense are done by [[nematocyst]]s, which are extremely effective [[sting]]ing cells. Over 6,100 species have been described.<ref>{{cite book| author=Crowther A.L. |chapter=Class Anthozoa Ehrenberg, 1834 |editor=Z.-Q. Zhang |title=Animal biodiversity: an outline of higher-level classification and survey of taxonomic richness |journal=Zootaxa |volume=3148 |year=2011 |pages=19–23 |doi=10.11646/zootaxa.3148.1.5 |chapter-url=http://mapress.com/zootaxa/2011/f/zt03148p023.pdf}}</ref><ref>estimates of species numbers differ between authorities.</ref> There are three subclasses: *[[Ceriantharia]]: the tube-dwelling anemones or cerianthids *[[Hexacorallia]]: 4,300 species of [[colony (biology)|colonial]] [[polyp]]s, usually with 6-fold [[symmetry]]. This includes all of the [[stony coral]]s, which