Cryptasterina Dartnall, Byrne, Collins and Hart

O’Loughlin, P. Mark & Waters, Jonathan M., 2004, A molecular and morphological revision of genera of Asterinidae (Echinodermata: Asteroidea), Memoirs of Museum Victoria 61 (1), pp. 1-40 : 18-19

Cryptasterina Dartnall, Byrne, Collins and Hart

Figures 1 (clade IV, part), 2f, 11a

Cryptasterina Dartnall et al., 2003: 3–4 .

Diagnosis. Rays 5, form pentagonal to short rays rounded distally; body with noticeable integument; low convex abactinally; abactinal plates in longitudinal series, deeply notched for papulae, many U-shaped more than crescentiform; longitudinal series of predominantly single papulae along sides of rays; non-papulate interradial areas extensive; few (1–3) papulae per papular space; abactinal spinelets granuliform, spaced over plates; lacking pedicellariae; lacking glassy convexities; superomarginal series prominent, longitudinally subrectangular, inferomarginals predominantly project narrowly; non-plated actinal area distal to oral plates frequently present, not extensive; actinal interradial plates in oblique series; actinal spines short conical, predominantly 1 per plate, rarely 2–3 distally; very small superambulacral plates few, never as series; superactinal plates present, sometimes in multiple plate struts.

Type species. Asteriscus pentagonus Müller and Troschel, 1842 (original designation) (junior synonyms: Patiriella pseudoexigua Dartnall, 1971 and Patiriella obscura Dartnall, 1971 , by Dartnall et al., 2003).

Other species. C. hystera Dartnall and Byrne, 2003 ; C. pacifica (Hayashi, 1977) .

Material examined. C. hystera . Paratypes. Queensland, Yeppoon ( Statue Bay ), NMV F96255 (3). Other material. Statue Bay , F 98457 (2); F97057 (6) .

C. pentagona . Queensland, Cairns, NMV F96702 (2); Townsville, F97056 (2); F98452 (8); F98453 (1); Bowen (Airlie Beach), F97055 (4), F98454 (2); Mackay, F95959 (7); Hervey Bay, F98456 (2); Kurrimine, F95961 (2); Bingil Bay, F98455 (2).

Description with species variations. Rays 5 (rarely 4 or 6); interradial margin straight to slightly incurved, form pentagonal to short tapered rays rounded distally; body with noticeable integument; flat actinally, low convex abactinally, sides of rays not steep; size small ( pentagona up to R = 17 mm; hystera up to R = 12 mm); lacking pedicellariae; lacking actinal gonopores; not fissiparous.

Abactinal surface even; plates low, imbricate, deeply notched for papulae, many U-shaped more than crescentiform; plates in longitudinal series; papular spaces fairly large; papulae predominantly single, large ( pentagona ) or small ( hystera ), up to 3 per space; secondary plates 0–3 per papular space; carinal series of doubly or singly notched plates variably present; longitudinal series of papular spaces along sides of rays; disc variably bordered by 5 radial and 5 smaller interradial plates; abactinal spinelets granuliform, short columnar, spaced over plates; denuded abactinal plates with reticulate glassy ridges, not convexities; marginal plates with abactinal-type spinelets, slightly thinner and longer on inferomarginals; superomarginal series distinctive, longitudinally subrectangular; inferomarginal plates less conspicuous, predominantly project narrowly to form margin.

Actinal interradial plates in oblique series; non-plated actinal area distal to oral plates variably present, not extensive.

Actinal spines per plate: oral 5–6 (proximal separated from distal frequently in hystera ); suboral 1–2; furrow 2–3 proximally; subambulacral 1; adradial actinal 0–1; actinal interradial predominantly 1 (rarely 2–3 distally); actinal spines short conical.

Small superambulacral plates few, especially distally, lacking series; superactinal plates present, sometimes in multiple plate struts.

Distribution. Tropical Indo-Pacific; NE Australia, Indonesia, Philippines, Solomon Is, Taiwan, Japan; littoral and shallow sublittoral.

Remarks. In the molecular clade IV of Waters et al. (2004), the label P. pseudoexigua ( Japan) refers to C. pacifica and P. pseudoexigua ( Australia) to C. pentagona (following Dartnall et al., 2003). These sister taxa are on a clade separate from Aquilonastra . Hart et al. (2003) added two additional lineages to this clade ( C. hystera and an undescribed species from Taiwan). Dartnall et al. (2003) erected Cryptasterina and provided a morphological diagnosis for the three species. The principal diagnostic characters of Cryptasterina seen here are: integument cover; pentagonal to short-rayed form; longitudinal series of plates on rays; granuliform spinelets; predominantly single papulae per space; absence of glassy convexities; prominent longitudinally elongate superomarginal plates; narrowly projecting inferomarginal plates; actinal interradial spines predominantly single in mid-ray; some superambulacral plates present; superactinal plates present. The similarities and differences for Cryptasterina and Aquilonastra were discussed under the latter.

Figures

Figure 1. Phylogenetic relationships of asterinid mtDNA sequences (after Waters et al., 2004). Support for particular reconstructions is indicated by bootstrap values (>50%; in bold) and by decay indices (in italics). MtDNA Clades I–VI are identified on the basis of high bootstrap support. Generic assignments made in this paper appear on the right.