Aquilonastra oharai, O, 2006

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 : 279

Aquilonastra oharai sp. nov.

Figures 1, 3e, 9f

Material examined. Holotype. Japan, Okinawa, Seragaki , under rock on reef, 1–2 m, G. Paulay, 26 Jul 2004, UF 3285 (alcohol).

Paratypes. Type locality and date, UF 3916 (1, alcohol); Kunigami, reef flat, under rock, G. Paulay, J. Geller, M. Malay, Y. Hiratsuka, 4 Jul 2004, UF 3914 (1, alcohol; BOKI–14, d GP 595, 596) .

Diagnosis. Non-fissiparous Aquilonastra species; rays 5, wide basally, tapered, rounded distally; up to R = 12 mm, r = 7 mm; gonopores abactinal.

At R = 12 mm, lacking proximal doubly papulate carinal plates; some secondary plates, frequently 1 per proximal papular space; single large papula per space; spinelets conical, thin, fine point to splay-pointed, subsacciform, in double splayed series across proximal edge of plates, rarely in tufts, up to about 14 spinelets on proximal abactinal plates, up to about 8 on distal interradial plates; superomarginal plates smaller than inferomarginals, superomarginals with up to about 7 spinelets per plate, inferomarginals with up to about 14 spinelets, more stout on inferomarginals.

Spines per actinal plate up to: oral 6, suboral 2, furrow 4, subambulacral 4, actinal interradial 6, predominantly 4–6 proximally; interradial spines conical, thick basally, pointed distally.

Colour (live). Variable, disc dark brown, mottled abactinally with mauve-violet, dark and pale brown, greenish brown, off-white; or disc dark brown, mottled abactinally with pale and dark green, and off-white (photos by G. Paulay).

Distribution. Japan, Okinawa, 0– 2 m.

Etymology. Named for Tim OʼHara, Senior Curator of Marine Invertebrates, Museum Victoria, in appreciation of his contribution to this work and to echinoderm systematics and biogeography.

Remarks. A. oharai is distinguished from A. cepheus and A. limboonkengi by the shorter rays, absence of any proximal doubly papulate carinal plates, absence of clustering of the abactinal spinelets on the plates, and the splay-pointed form of some abactinal spinelets. A. oharai is described from only three specimens, with R up to 12 mm. The morphological characters used to distinguish the new species may be variable within the species, and size related. In the absence of adequate comparative material we have some uncertainty about the status of A. oharai in relation to A. cepheus and A. limboonkengi .