Ophiochiton fastigatus

F 93153, 93152.

Family - Ophiochitonidae.

Description

The disc is flat, 11 mm diameter. The radial shields are triangular with rounded corners, separated and parallel to one another, with 1 plates between them; 1.5–2.5 times long as wide, and length 0.15–0.24 times d.d. The dorsal surface is covered by plates, no spines/granules, with a visible diameter of 0.05–1 mm, overlapping; primary plates visible.

The ventral interradial surface is plated. The oral shields are exposed, teardrop or diamond (rounded diamond with distal edges concave), wider than long. The adoral shields are exposed, extending to lateral edge of oral shield, separated radially, meeting interradially. Bursal slits reduced or extend from the oral shield to the disc margin, not bordered by spines or papillae. The jaw is wider than long, with one or two, pointed or tapering apical papilla or rounded apical papilla, as wide as long. Oral papillae are present along each jaw angle in a series, pointed. The oral tentacle pore is located inside the jaw, with distal oral papilla similar to other oral papillae or enlarged, and triangular.

The specimen has five arms, unbranched, moniliform, 3–5 times d.d. Dorsal arm plates, contiguous, without spines/granules; diamond or fan-shaped, and 0.5–0.85 times long as wide. The second ventral arm plates are contiguous with the third plate, fan-shaped, notched or concave laterally, and 0.5–0.65 times long as wide. Ventral arm plates of the first free segments separated or contiguous, carinate, fan-shaped (keeled), notched or concave laterally, and 0.5–0.7 times long as wide. Tentacle pores along the arm, with two scales, not covering the pore, quadrangular or oval. There are 2 arm spines on the first ventral segment, 3 on the first free segments. The spines are erect, extending laterally, subequal or longest dorsally, and 1.5–3 times as long as one arm segment, blunt, cylindrical.

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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