Aquilonastra minor ( Hayashi, 1974 )

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 : 278

Aquilonastra minor ( Hayashi, 1974)

Figures 1, 3d

Asterina minor Hayashi, 1974: 41–44 , fig. 1.—A.M. Clark, 1993: 211.— Fujita and Saba, 2000: 169–170, pl. 3E.— Waters et al., 2004: 873, 876, 877, tbl. 1, figs 1, 2.

Aquilonastra minor .—OʼLoughlin and Waters, 2004: 11, 13–15, fig. 1.— Saba and Fujita, 2006: 270–272, 286, fig. 15.— Byrne, 2006: 245, 251, tbls 1, 2, fig. 1.

Material examined. Japan, NMV F96697 (2).

Diagnosis. Non-fissiparous Aquilonastra species; rays 5, short, broad basally, narrowly rounded distally; up to R = 9 mm; gonopores actinal; direct development into brachiolaria stage ( Hayashi, 1974).

At R = 7 mm, r = 5 mm, rare proximal doubly papulate carinal plates, rare secondary plates, abactinal plates with low domes, spinelets in tufts or bands, subpaxilliform, described as “paxilliform” by Hayashi (1974); up to about 20 spinelets on proximal abactinal plates; spinelets thin, columnar, distally spinous; superomarginal plates smaller than inferomarginals, up to about 8 spinelets per superomarginal plate, up to about 12 spinelets per inferomarginal plate.

Spines per actinal plate up to: oral 6, suboral 4, furrow 5, subambulacral 3, actinal interradial 3; interradial spines digitiform.

Colour (live). “Pale greenish white, pale green or brownish grey with small greenish white patterns and small dark brown scattering spots, and reddish colour intermixed in the marginal zone; madreporite yellowish orange” ( Hayashi, 1974); disc cream, rays and interradii pale mottled pink, brown, cream white (photo from M. Komatsu).

Distribution Japan, southern Honshu, Kushimoto, littoral ( Hayashi, 1974).

Remarks. The largest of the many specimens observed by Hayashi (1974) were up to R = 6 mm. The two specimens donated by Mieko Komatsu to Jon Waters, and subsequently to Museum Victoria, are up to R = 7 mm (preserved). Fujita and Saba (2000) reported R up to 9.4 mm for Takehara (assumed not dried). Saba and Fujita (2006) reported R up to 7.7 mm for Sagami Bay. We wonder whether there is more than one species being referred to A. minor . Distinctive characters for A. minor are: rounded low domes on some abactinal plates; actinal gonopores.