Aquilonastra byrneae, 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 : 270

Aquilonastra byrneae sp. nov.

Figures 1, 2e, 5b, 7e

Aquilonastra new. sp.— Byrne, 2006: 245, 248, 251, tbl. 2.

Material examined. Holotype. NE Australia, Great Barrier Reef, near Heron I., One Tree I., rocky shallows, Maria Byrne, Jan 2002, NMV F98748 (alcohol).

Paratypes.Type locality, Dec 2004, F98747 (1, alcohol); interridal, 12 Apr 2006, F111326 (2, alcohol); 27 May 2004, F109358 (1, dry, dissected).

Other material. Tryon I., 15 Sep 1970, F109373 (2, dry); Mariana Is., Guam I., Asan Point, reef flat, under rock, 11 Apr 1996, UF 894 (dry) .

Diagnosis. Non-fissiparous Aquilonastra species; rays 5, narrow basally, broadly to narrowly rounded distally; up to R = 15 mm, r = 8 mm; gonopores actinal, interradial pairs frequently close, near margin; protandric hermaphrodite (Maria Byrne, pers. comm.).

At R = 15 mm, 0–3 proximal doubly-papulate carinal plates, each with up to 4 tufts with 3–5 spinelets per tuft; numerous proximal secondary plates, 0–3 per space; single large papula per space, rarely 2; disc variably distinctly bordered; spinelets small, short, form variable from conical to digitiform, distally pointed or blunt, some sacciform, not splay-pointed; up to about 16 spinelets across projecting edge of proximal abactinal plates, frequently 1–2 on bare distal mid-plate; up to 12 on proximal surface of distal interradial plates; superomarginal plates smaller than inferomarginals (subequal on Guam specimen), superomarginals with up to about 12 short conical pointed spinelets per plate, inferomarginals with up to about 20 spinelets, more stout and longer on inferomarginals.

Spines per actinal plate up to: oral 7, suboral 6, furrow 7, subambulacral 6, actinal interradial 8, predominantly 5; interradial spines thick, bluntly conical, subsacciform.

Colour (live). Disc sometimes cream centrally surrounded by dark brown ring, abactinally mottled with proximal upper rays predominantly olive-green to greenish-brown, interradii and distal rays predominantly cream; actinal surface cream with green patches (photo and pers. comm. M. Byrne); disc red or brown, thin boundary of white plates, proximal upper rays crimson red, remaining abactinal surface mottled with predominantly dark and pale brown, red and white ( Guam photos by G. Paulay as Asterina cepheus ).

Distribution. NE Australia, Great Barrier Reef, near Heron I., Tryon I. and One Tree I.; (possibly) W Pacific Ocean, Guam; rocky shallows.

Etymology. Named for Maria Byrne, Professor of Developmental and Marine Biology in the University of Sydney, and Director of One Tree Island Research Station on the Great Barrier Reef, in appreciation of her contribution of specimens for this work and her research on life history diversity and evolution in Asterinidae .

Remarks. A significant diagnostic character of A. byrneae is the presence of actinal gonopores. The dominant mottled live colours are green, brown and red, with cream or white. At R = 12 mm, the material from the Great Barrier Reef has predominantly 5 actinal interradial spines per plate, the Guam specimen predominantly 3. This variation (on its own) is judged to be an inadequate basis for separating the material into two species, but this and colour differences suggest the possibility of two species. We identify the Guam specimen as A. byrneae with some hesitation.