CLASSIFICATION OF ANTEDON OR FEATHER STAR
PHYLUM :- ECHINODERMATA (Coelomate, pentaradiate and spiny skinned animals with vascular system.)
SUB-PHYLUM :- PELMATOZOA (Sedentary throughout life.)
CLASS :- CRINOIDEA (Attachment by aboral stalk, Pedicellariae spines and madreporite absent. )
ORDER :- ARTICULATA (Central disc covered by a movable tegmen having various ossicIt’s. Food grooves
GENUS :- Antedon (The feather star)
It has world-wide distribution found in all seas and at all depths down to 5,800 meters. It is especially found along Atlantic coast in 25 to 500 fathoms from Chesa peake Bay to the banks of Newfoundland. The members are known form lower Cambrian to Recent.
HABIT AND HABITAT
Antedon is marine and occurs about 2 fathoms deep and remains attached to rocks by cirri from central disc. They are gregarious forms and feed on microscopic living organisms.
GENERAL CHARACTERSTICS OF ANTEDON OR FEATHER STAR
- Commonly called on sea-lily or feather star.
- On the aboral side calyx bears a knob-like structure called as centrodorsal plate or stalk.
- The calyx is differentiated into an upper convex oral surface, having mouth and anus and the lower flat aboral surface, into which anus and cirri are inserted.
- On the aboral side calyx bears a knob-like structure, called as stung of the stalk.
- The oral surface is covered by a leathery skin in which numerous calcareous plates are embedded. It is directed upwards.
- Mouth is central and directed upwards which leads into 5 food open grooves or ambulacral grooves, which divide into 10 as they reach near the edge and lead into the anus. The mouth is surrounded by sensory tube feet or podia which are without suckers. The ambulacral grooves give branches into each pinnule and throughout their course contain finger-like, non-prehensile tube feet or podia. Water vascular system is well developed. There is no madreporite.
- There are 10 arms having extensions of viscera and each bears numerous pinnules containing gonads.
- The cirri are emerging from aboral surface and are composed of skeletal ossicles.
- Sea-lily attaches to substratum by cirri. Anus on aboral surface.
- It is one of the living representatives of the class Crinoidea. Sexes are separate. Development includes cystidian and pentacrinoid larva.
The animal contains aboral cirri and all above feature, hence it is Antedon.