Ophiactis hirta

F 146354.

Family - Ophiactidae.

Description

The disc is flat, 3 mm diameter. The radial shields are triangular with rounded corners, separated and parallel to one another, with 1 plates between them, with triangular plate separating part of the shields; 1.4–1.6 times long as wide, and length 0.21 times d.d. The dorsal surface is covered by plates, bearing spines/granules, with a visible diameter of 0.15–0.45 mm, overlapping; primary plates not visible. Disc spines or granules of one type, conical. The spines are up to 0.05–0.15 mm long, and 1–3 times high as wide; sparsely distributed (densest toward outer disc margin).

The ventral interradial surface is plated. The oral shields are exposed, circular or fan shaped or diamond, wider than long or as long as wide. The adoral shields are exposed, extending to lateral edge of oral shield, separated radially, meeting interradially. Bursal slits extend from the oral shield to the disc margin, not bordered by spines or papillae. The jaw is longer than wide or as wide as long, with one, pointed or tapering apical papilla or rounded apical papilla, as wide as long or wider than long, with thorns. Oral papillae absent or separated by a gap from apical papillae. The oral tentacle pore is located inside the jaw (out), with distal oral papilla enlarged, and rounded.

The specimen has six arms of equal length (seven), unbranched, moniliform, 3–6 times d.d. Dorsal arm plates, contiguous, without spines/granules; oval, and 0.9–1.1 times long as wide. The second ventral arm plates are contiguous with the third plate, quadrangular, and 1–1.25 times long as wide. Ventral arm plates of the first free segments contiguous, quadrangular or pentagonal (quadrangular or quadrangular with point, triangular proximal edge), and 1–1.35 times long as wide. Tentacle pores along the arm, with one scale, covering the pore, oval. There are 2 arm spines on the first ventral segment, 4 on the first free segments. The spines are erect, extending laterally, subequal, and 0.5–1 times as long as one arm segment, blunt, cylindrical. There are thorns.

Description exported from Delta key and to be finalised when DNA sampling completed. Note species description and image characters may vary slightly in animals of different size within the same species.

Cite this publication as: "T O'Hara (2010). ‘Ophiuroids from deep sea southern Australia. Museum Victoria. Version: 1.0 http://www.museumvictoria.com.au/stars"
Information updated 5 February 2010

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