Ophiomitrella 5488

F 146337 (holotype), 146335, 82516, 82515, 146334, 146339, 146348.

Family - Ophiacanthidae.

Description

The disc is flat, interradial edge incised (slightly incised), 9.5 mm diameter. The radial shields are triangular with rounded corners, separated and parallel to one another, with 3–4 plates between them; 1.1–2 mm long, 1.7–3.2 times long as wide, and length 0.12–0.21 times d.d. The dorsal surface is covered by plates, bearing spines/granules, with a visible diameter of 0.3–0.45 mm, overlapping, and 10–12 plates from the centre to the disc margin; primary plates not visible. Disc spines or granules of one type, cylindrical (with flat top), with thorns all over. The spines are up to 0.1–0.2 mm long, and 0.5–1 times high as wide; sparsely distributed (1 per plate), not covering the radial shields.

The ventral interradial surface is plated, with spines/granules also covering the surface. The oral shields are exposed, teardrop or diamond, wider than long. 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 wider than long, with one, pointed or tapering apical papilla, longer than wide, with thorns. Oral papillae are present along each jaw angle in a series or separated by a gap from apical papillae, pointed, thorned. The oral tentacle pore is located inside the jaw, with distal oral papilla enlarged, and rounded (on top of jaw edge).

The specimen has five arms, unbranched, moniliform, 4–6 times d.d., longest approximately 45–55 mm long, 3 mm wide at the base tapering to the tip. Dorsal arm plates, separated, without spines/granules (some disc spines on one arm); fan-shaped, 0.6–1.2 mm long, and 0.7–1.4 times long as wide. The first ventral arm plates are contiguous with the second plate (or nearly contiguous), diamond or hexagonal, 0.6–0.9 mm long, and 0.9–1.1 times long as wide. The second ventral arm plates are separated from the third plate, fan-shaped, notched or concave laterally, 0.7–0.9 mm long, and 0.4–0.6 times long as wide. Ventral arm plates of the first free segments separated, heptagonal, notched or concave laterally, 0.9–1 mm long, and 0.7–0.9 times long as wide. The lateral arm plates touch one another laterally, or meet on the dorsal and ventral midlines. Tentacle pores along the arm, with one scale, not covering the pore or covering the pore, pointed (narrow, longer than wide). There are 3 arm spines on the first ventral segment, 7 on the first free segments. The spines are erect, extending around to the dorsal surface, longest dorsally, 2.9–4 mm long, 8–12 times long as wide, and 2–3 times as long as one arm segment, pointed, cylindrical. There are thorns, hapazardly on the spine surface, all along the spine, glassy rough shaft. Distal ventral arm spines with prominent larger thorns haphazardly arranged on the distal half of the spine.

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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