Ophiacantha 4532

F 93291 (holotype), 159759, 144767, 144768, 144769, 82566, 82567, 82556, 82558, 82557, 82568, 168702, 168688, 168093, 168732.

Family - Ophiacanthidae.

Description

The disc is flat, interradial edge slightly incised, 9 mm diameter. The radial shields are covered. The dorsal surface is covered by plates, bearing spines/granules, with a visible diameter of 0.2–0.4 mm, overlapping, and 15–18 plates from the centre to the disc margin; primary plates not visible. Disc spines or granules of one type, cylindrical (with conical base), with multiple, more than 3, terminal points/thorns (usually 4 points), and glassy transparent shaft. The spines are up to 0.2–0.4 mm long, and 3–9 times high as wide; densely distributed (22–28 per sq mm), covering the radial shields.

The ventral interradial surface is plated, with spines/granules also covering the surface. The oral shields are exposed, diamond or arrow head shaped (usually with enlarged distal attachment to ventral interradial surface), 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, rounded apical papilla (occasionally pointed), longer than wide, with thorns. Oral papillae separated by a gap from apical papillae, pointed, thorned. The oral tentacle pore is located inside the jaw (at top of jaw edge), with distal oral papilla similar to other oral papillae.

The specimen has five arms, unbranched, basally constricted (slightly), 6–7 times d.d., longest approximately 55 mm long, 2 mm wide at the base tapering to the tip. Dorsal arm plates, separated, without spines/granules (a few spines at base of arm on first dorsal segment); fan-shaped, 0.5–0.7 mm long, and 0.7–0.9 times long as wide. The first ventral arm plates are separated from the second plate, quadrangular (difficult to distinguish), 0.3–0.4 mm long, and 0.8–0.9 times long as wide. The second ventral arm plates are separated from the third plate, fan-shaped, notched or concave laterally, 0.5–0.7 mm long, and 0.8–0.9 times long as wide. Ventral arm plates of the first free segments separated, heptagonal, notched or concave laterally (some also notched dsitally), 0.5–0.7 mm long, and 0.8–1 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 or two scales, covering the pore, leaf-shaped or pointed (2 or more times long as 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, 2–2.5 mm long, 10–13 times long as wide, and 2–3 times as long as one arm segment, pointed, cylindrical. There are thorns, in longitudinal series on the surface from the base to the tip of the spine, all along the spine, glassy transparent shaft, with hooks. Distal ventral arm spines with a prominent longitudinal series of thorns on one side; spines also ventral spine specialised.

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

MUSEUMVICTORIA