Astrobrachion constrictum (Farquhar, 1900)

Mills, V. Sadie & O'Hara, Timothy D., 2013, Ophiuroids (Echinodermata; Ophiuroidea) of biogenic habitats on the continental shelf of New Zealand, Zootaxa 3613 (5), pp. 401-444 : 407

Astrobrachion constrictum (Farquhar, 1900)

( Fig. 2 b)

Ophiocreas constrictus Farquhar, 1900: 405 -406.

Asteroschema (Ophiocreas) constrictum .—Döderlein, 1911: 113.

Ophiocreas constrictum .—Clark, H.L., 1915a: 178.—Mortensen, 1924: 99-102, fig. 1(1), pl. 4(5–6).

Ophiocreas phanerum Clark, H.L., 1916: 79 , pl. 33(1–2).—Clark, H.L., 1946: 176.—Dartnall, 1980: 39, 68 [synonymised by Mortensen, 1924].

Ophiomyxa brevirima .—Bell, 1917: 7 [Non Ophiomyxa brevirima Clark H L, 1915 ; see Mortensen, 1924].

Astrobrachion constrictus .—Döderlein, 1927: 77.

Ophiuropsis sp. —Koehler, 1930: 41–42, pl. 5(4–5) [synonymised by Baker, 1980].

Astrobrachion constrictum .—Mortensen, 1933b: 69, fig. 54.—Fell, 1952: 13.—Fell, 1958: 22.— Baker, 1980: 24–27, figs. 6, 30.—Rowe & Gates, 1995: 358.—McKnight, 2000: 40–42, fig. 17, pl. 16.

Ophiuropsis lymani simplex Mortensen, 1933b: 71 , pl. 6 (31–32) [synonymised by Baker, 1980].

Material Examined. Bay of Islands. TAN0906/3, NIWA 54483 (1). TAN0906/146, NIWA 56330 (1). Far North. TAN1105/9, NIWA 72995 (1).

Diagnosis. Smooth thick skin on dorsal disc and arms. Radial shields are raised ridges beneath skin, extending to disc centre, but do not meet. Oral plates obscured by skin. Four adjacent or alternating lateral arm plates. No arm spines for first 2 segments, then 2 spines. Several colour variations, either a solid dark red-brown, creamy yellow or black and white transverse banded.

Description. See McKnight (2000).

Distribution. New Zealand (3–307 m), Tasman Sea (29–344 m), Kermadec Ridge (122–260 m), south-eastern Australia (18–540 m).

Remarks. Astrobrachion constrictum is often found with its arms coiled on branches of black coral. One specimen (NIWA 72995) has 4 juveniles climbing out of the bursal slit and clinging to the ventral surface.

Figures

FIGURE 2. a: Asteroporpa (Asteroporpa) australiensis Clark, 1909 on host primnoid coral (NIWA 56911, TAN 0906 / 170), scale bar = 3 mm, and b: Astrobrachion constrictum (Farquhar, 1900) on host black coral (NIWA 56330, TAN 0906 / 146), scale bar = 10 mm.