Aquilonastra scobinata ( Livingstone, 1933 )

O, P. Mark, 2006, A systematic revision of the asterinid genus Aquilonastra O Loughlin, 2004 (Echinodermata: Asteroidea), Memoirs of Museum Victoria 63 (2), pp. 257-287 : 283

Aquilonastra scobinata ( Livingstone, 1933)

Figures 1, 3i, 6k

Asterina scobinata Livingstone, 1933: 1–2 , pl. 5 figs 9–12, 15.— H.L. Clark, 1938: 149–150.— Cotton and Godfrey, 1942: 201.—H.L. Clark, 1946: 132.— Dartnall, 1969: 55.— Dartnall, 1970a: 73, 76.— Dartnall, 1970b: 19–20, figs 1, 2.— Dartnall, 1980: 8, 34, 66.— Zeidler and Shepherd, 1982: 412, fig. 10.6e.—OʼLoughlin, 1984: 134.—A.M. Clark, 1993: 213.— Rowe and Gates, 1995: 35.— Waters et al., 2004: 873, 876, figs 1, 2.

Aquilonastra scobinata .—OʼLoughlin and Waters, 2004: 11, 13– 14, fig. 1.— Byrne, 2006: 245, 248, tbls 1, 2, fig. 1.

Material examined. Holotype. Tasmania, AM J1241 .

Other material. Tas., Port Arthur, 25 Nov 1968, NMV F112178 (2); Eaglehawk Neck, J9060 (3); Tamar R. mouth, North Head, 28 Oct 1978, F112176 (1); King I., 10 Mar 1980, F112177 (1); Vic., Inverloch, 28 Mar 1981, F72975 (1); Point Leo, 20 Apr 1935, F58683 (1); Phillip I., NMV F72998 (1); Flinders ocean platforms, 7 Sep 1994, F112180 (3); Cape Otway, 3 Apr 1983, F58682 (2); Killarney, F72997 (10); Port Fairy, F72985 (2); SA, Port MacDonnell, 8 Jan 1988 F112179 (1).

Diagnosis. Non-fissiparous Aquilonastra species; rays 5, wide basally, tapered, narrowly rounded distally, up to R = 18 mm, r = 8 mm; form frequently asymmetrical with one ray shorter; actinal gonopores, hermaphrodite.

At R = 14 mm, r = 7 mm, proximal ray with zig-zag carinal series of singly papulate plates, bordered laterally by subequal non-papulate plates; singly papulate plates in longitudinal series along sides of rays; papulate plates not notched, slightly crescentiform, non-papulate plates round to oval to irregular; rarely 2 papulae per space; secondary plates rare; disc small, variably delineated by 5 long radial 5 short interradial plates; spinelets elongate, thin, pencil-like, splay-pointed sacciform; up to more than 30 per plate, in splayed tuft or crescentiform straight band across plate; superomarginal and inferomarginal plates subequal, in regular series; superomarginal plates with up to about 10 pencil-like splay-pointed spinelets; inferomarginal plates with up to about 20 paxilliform similar spinelets.

Spines per actinal plate up to: oral 7; suboral 6; furrow 6; subambulacral 6; actinal interradial 7; interradial spines long, rugose, digitiform, some pointed distally.

Colour (live). Dark brown to greyish-brown to cream, with some dark flecking (OʼLoughlin, 1984).

Distribution. Tas., Bass Strait, Cape Conran (eastern Vic., NMV collections) to Port MacDonnell ( SA); rocky lower littoral and shallow sublittoral.

Remarks. A. scobinata is provisionally maintained in Aquilonastra because of the arrangement of abactinal plates and papulae, the presence of internal superambulacral plates, and the arrangement of actinal plates. The paxilliform tufts of long thin pencil-like abactinal spinelets and actinal spines, and high numbers of spinelets and spines per plate, are atypical of Aquilonastra . Morphological similarities of A. scobinata to A. rosea and A. rowleyi have been noted above.

Dartnall (1970b) reported actinal gonopores and hermpahrodite reproduction. Mieko Komatsu (pers. comm.) confirmed that a specimen (F112180) was hermaphroditic.