Ophiacantha yaldwyni

F 80969, 80972.

Family - Ophiacanthidae.

Description

The disc is flat, 7 mm diameter. The radial shields are covered. The dorsal surface is covered by plates, bearing spines/granules, with a visible diameter of 0.35–0.45 mm, overlapping; primary plates not visible. Disc spines or granules of one type, cylindrical or conical, with 1 terminal point/thorn or 2 terminal points/thorns or 3 terminal points/thorns, with thorns at the tip or thorns in the mid region (occassionally with thorns at tip and middle of shaft). The spines are up to 0.1–0.2 mm long, and 0.8–1.2 times high as wide; densely distributed.

The ventral interradial surface is plated. The oral shields are exposed, fan shaped or bell shaped or diamond (diamond with concave edges), 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 as wide as long, with one, rounded apical papilla, as wide as long, with thorns. Oral papillae are present along each jaw angle in a series, rounded, thorned. The oral tentacle pore is located inside the jaw, with distal oral papilla similar to other oral papillae or enlarged, and rounded.

The specimen has five arms, unbranched, basally constricted, 4–6 times d.d. Dorsal arm plates, separated, without spines/granules; fan-shaped, and 0.85–1 times long as wide. The second ventral arm plates are separated from the third plate or contiguous with the third plate, quadrangular or fan-shaped, and 0.8–0.9 times long as wide. Ventral arm plates of the first free segments separated, pentagonal (square with proximal point), and 0.8–1.2 times long as wide. Tentacle pores along the arm, with one scale, covering the pore, pointed or oval. There are 2–3 arm spines on the first ventral segment, 5–6 on the first free segments. The spines are erect, extending around to the dorsal surface, subequal or longest dorsally, and 0.5–1.5 times as long as one arm segment, blunt, cylindrical. There are thorns, hapazardly on the spine surface, on the tip or on the middle, glassy rough shaft.

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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