Ophioplinthaca defensor

F 82425, 82452.

Family - Ophiacanthidae.

Description

The disc is tumid, interradial edge incised, 11 mm diameter. The radial shields are triangular with rounded corners, contiguous distally, divergent proximally, with 1 plates between them, with triangular plate separating part of the shields; 1.2–1.6 times long as wide, and length 0.35 times d.d. The dorsal surface is covered by plates, bearing spines/granules, with a visible diameter of 0.5–1 mm, touching; primary plates not visible. Disc spines or granules of one type, cylindrical, with thorns at the tip. The spines are up to 0.05–0.1 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, pentagonal, wider than long. The adoral shields are exposed, extending to lateral edge of oral shield, separated radially, meeting interradially. Bursal slits reduced, not bordered by spines or papillae. The jaw is wider than long, with one, pointed or tapering apical papilla or rounded apical papilla, longer than wide or as wide as long. Oral papillae are present along each jaw angle in a series, pointed or quadrangular. The oral tentacle pore is located inside the jaw, 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, without spines/granules; fan-shaped, and 0.5–0.6 times long as wide. The second ventral arm plates are contiguous with the third plate, fan-shaped, notched or concave laterally, and 0.55–0.65 times long as wide. Ventral arm plates of the first free segments contiguous, oval or fan-shaped, and 0.7–0.9 times long as wide. Tentacle pores along the arm, with one scale, covering the pore, oval. There are 2–3 arm spines on the first ventral segment, 4 on the first free segments. The spines are erect, extending around to the dorsal surface or extending laterally, subequal, and 1–3 times as long as one arm segment, pointed or blunt, cylindrical. There are thorns, in longitudinal series on the surface from the base to the tip of the spine, 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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