Ophioplinthaca incisa

F 80851.

Family - Ophiacanthidae.

Description

The disc is tumid, interradial edge incised, 12 mm diameter. The radial shields are triangular with rounded corners, contiguous distally, divergent proximally, with 1–2 plates between them; 1.2–2 times long as wide, and length 0.28 times d.d. The dorsal surface is covered by plates, bearing spines/granules, with a visible diameter of 0.4–1.2 mm, overlapping; primary plates not visible. Disc spines or granules of one type, cylindrical, with thorns at the tip or thorns in the mid region. The spines are up to 0.2–0.5 mm long, and 1–3 times high as wide; sparsely distributed or restricted to regions of the disc (in the centre).

The ventral interradial surface is plated. The oral shields are exposed, diamond (concaved edges), 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 as wide as long, with one, rounded apical papilla, longer than wide. Oral papillae are present along each jaw angle in a series, pointed. The oral tentacle pore is located inside the jaw (out), with distal oral papilla similar to other oral papillae.

The specimen has five arms, unbranched, moniliform, 5–7 times d.d. Dorsal arm plates, contiguous, with spines/granules, clustered on the basal dorsal arm plates; quadrangular or fan-shaped, and 0.65–0.75 times long as wide. The second ventral arm plates are contiguous with the third plate, fan-shaped, notched or concave laterally, and 0.45–0.65 times long as wide. Ventral arm plates of the first free segments contiguous, fan-shaped, notched or concave laterally, and 0.45–0.6 times long as wide. Tentacle pores along the arm, with one scale or one large scale on top of several smaller scales or several scales as a ring of many scales around the pore, reducing in number, covering the pore, oval. There are 2 arm spines on the first ventral segment, 6 on the first free segments. The spines are erect, extending around to the dorsal surface, longest in middle or longest dorsally, and 3–4 times as long as one arm segment, pointed, cylindrical. There are thorns, hapazardly on the spine surface, all along the spine, 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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