Ophiacantha 4537

F 112613 (holotype), 112612, 111624, 146263, 146266, 93285, 93282, 93284, 93283.

Family - Ophiacanthidae.

Description

The disc is flat, 8 mm diameter. The radial shields are covered. The dorsal surface is covered by plates, bearing spines/granules, with a visible diameter of 0.2–0.5 mm, overlapping, and 18–23 plates from the centre to the disc margin; primary plates not visible. Disc spines or granules of one type, cylindrical, with multiple, more than 3, terminal points/thorns, with thorns all over. The spines are up to 0.3–0.6 mm long, and 4–6 times high as wide; densely distributed (14–20 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, circular or fan shaped (rounded but pointed proximally or swollen fan shape), 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 wider than long, with one, rounded apical papilla (sometimes flattened end with shallow notch), longer than wide, with thorns. Oral papillae separated by a gap from apical papillae, rounded, thorned. The oral tentacle pore is located inside the jaw (at the top of the jaw edge), with distal oral papilla enlarged, and rounded (wider and flatter).

The specimen has five arms, unbranched, moniliform (becoming constricted), 7–9 times d.d., longest approximately 60–70 mm long, 2–3 mm wide at the base tapering to the tip. Dorsal arm plates, separated, with spines/granules, clustered on the basal dorsal arm plates (10–20); fan-shaped, 0.6–0.9 mm long, and 0.6–0.9 times long as wide. The first ventral arm plates are contiguous with the second plate (mostly), fan, 0.4–0.7 mm long, and 0.6–0.8 times long as wide. The second ventral arm plates are separated from the third plate (mostly), fan-shaped, 0.5–0.7 mm long, and 0.5–0.7 times long as wide. Ventral arm plates of the first free segments separated, oval or hexagonal (hexagonal, pointed proximally and rounded distally), 0.9–1.1 mm long, and 0.9–1.3 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, oval (elongated 2 or more times long as wide). There are 5–6 arm spines on the first ventral segment, 9–10 on the first free segments. The spines are erect, extending around to the dorsal surface, longest dorsally, 3.4–4.1 mm long, 16–20 times long as wide, and 3–4 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 or glassy rough 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