|Etymology:- From the Greek Echis for Viper and Ura a tail.|
Characteristics of Echiura:-
1)Bilaterally symmetrical and vermiform.
2)Body has more than two cell layers, tissues and organs.
3)Body cavity is a true coelom.
4)Body possesses a through gut with a mouth and anus.
5)Body possesses an extensible and contractile proboscis.
6)Has a simple simple nervous system with no brain but a ventral nerve chord.
7)Has a true circulatory system, closed or open.
8)Reproduction normally sexual and gonochoristic.
9)Feed on detritus.
10)All live in marine environments.