Amphioplus gravelyi   James,  1970 (Brittle Star)
Organism information awaits expert curation
Class: Ophiuroidea

Color: Whitish (in rectified spirit)

The disc is five-lobed with numerous small imbricating scales. At the centre of the disc there is a small circular scale. Surrounding this scale and placed radially in position there are five circular scales forming the first circle. Alternating with these five scales there is a second circle of five other scales interradially arranged at some distance from the first circle. The scales surrounding the radial shields are slightly larger than the other scales present on the disc. The scales at the margin of the disc are very small. The radial shields are long, pointed at the proximal end and they remain separated throughout their length. In between each pair of radial shields there is a row of three scales. The interbrachial areas on the ventral side are completely covered with small imbricating scales. There are four oral papillae on each side of the jaw. They are arranged in a row without leaving any space. Of these the infradental papillae are the largest and oval in shape. The distalmost papilla is the smallest of the four and situated on the adoral shield. The middle two papillae are of the same size and are more or less circular in shape. The oral shield is large and pear-shaped. The adoral shields are slightly smaller, three-sided and meet interradially. The dorsal arm plates are broadly elliptical proximally with the proximal and distal margins convex and the distal plates are fan-shaped. The dorsal arm plates are contiguous with the successive plates. The first ventral arm plate is very small and three-sided. The proximal ventral arm plates are rectangular and contiguous. The distal ventral arm plates are pentagonal. There are two tentacle scales for each tentacle pore. The outer tentacle scale lies along the lateral arm plate and is slightly larger than the inner one which lies along the side of the ventral arm plate. The first two free segments have five spines and the next 18 segments have four and the rest three spines. The spines are small, smooth, cylindrical and pointed. When there are four spines the third spine from the upper side is spatulate and when there are three spines the middle spine is spatulate. At the tip of the arm all the three spines are smooth, cylindrical and pointed.

Synonym (s)

Common Name (s)
Economic Importance and Threats



• Tamil Nadu, Krusadai Island INDIA (Record: 09/1925)
• Tamil Nadu, Pamban INDIA (Record: 09/1925)

Literature Source(s)
  • James, DB (1970) Studies on Indian echinoderms - 4 On the brittle-stars Amphioplus gravelyi sp. Nov., and Amphioplus depressus (Ljungman) from the Indian coasts Journal of the Marine Biological Association of India Marine Biological Association of India 12(1-2) 139-145 Available at -
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -

Page last updated on:2011-05-05

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