CLASSIFICATION OF OPHIODERMA (BRITTLE STAR)
KINGDOM :- ANIMALIA (Multicellular eukaryotic organisms)
PHYLUM :- ECHINODERMATA (Coelomate, pentaradiate and spiny skinned animals with vascular system.)
SUB-PHYLUM :- ELEUTHEROZOA (Non-pedicellate and free-living.)
CLASS :- OPHIUROIDEA (Central disc and arms distinct.)
ORDER :- OPHIURIDA (Arms bent only to lateral sides.)
FAMILY :- OPHIODERMATIDAE (family of brittle stars)
GENUS :- Ophioderma (The brittle star)
It is found along the North Atlantic Mediterranean littoral, tropical and West Indian seas.
HABIT AND HABITAT
GENERAL CHARACTERSTICS OF OPHIODERMA (BRITTLE STAR)
- Commonly called as brittle star.
- Body consists of a small pentagonal disc set by closely set granules. Oral papillae numerous and arranged in a continuous series.
- Body is differentiated into oral and aboral surfaces with distinct central disc and five surpentine arms.
- Arms are covered by arm shields or calcareous ossicles and small spines.
- The oral surface has star-shaped mouth fringed with oral papillae.
- Skin covers the disc which is composed calcareous plates in the disc and typically of articulating ossicles in the arms.
- Internal structures are restricted to central disc only.
- Anus and pedicellariae absent.
- Madreporite is oral. The ambulacral grooves are usually covered. Tube feet lack suckers.
- Most important individual characteristic feature of the genus is the presence of two slits in each bursa, one situated orally and the other peripherally. Larva is Ophiopluteus.
The animal contains distinct rounded disk, serpentine arms with spine and all above features hence it is Ophioderma.