In this article we will discuss about the structure of Brittle Star (Opheolepis) with the help of a diagram.
1. It is commonly known as “brittle star” and is found in shallow sea-waters. It is usually green in colour.
2. Body comprises of a distinct pentagonal disc and 5 narrow flexible jointed and slender arms radiating from it.
3. Animal has a distinct oral and an aboral surface.
4. Disc on the aboral surface bears distinct and large shields or scales which according to their position are categorized into radial, adradial and dermal shields.
5. Oral surface of the disc bears a penta radiate mouth in the centre which is surrounded by large oral papillae and numerous closely set granules.
6. Arms on the aboral surface bear a median row of large radial shields and peripheral rows of small, irregular scales with numerous small inter-sperced spines.
7. Sexes are separate and genital bursae four in each inter-radius.
8. Ambulacral grooves, pedicillariae, branchiae and dermal papillae are absent.
9. The oral surface of each arm bears small tube feets.