Asterina Nardo, 1834

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 : 15-16

Asterina Nardo

Figures 1 (clade VI), 2c, 6a, 8c–e

Asterina Nardo, 1834: 716 .— Clark and Downey, 1992: 177–181.— A.M. Clark, 1993: 206–214.— Liao and Clark, 1995: 129.— Rowe, 1995: 33–35.—O’Loughlin, 2002: 278.— Waters et al., 2004: 874, 875, 877 (part). (For complete synonymy and discussion see Clark and Downey, 1992).

Allopatiria Verrill, 1913: 480 .— Verrill, 1914: 273.— Tortonese, 1965: 174.— Spencer and Wright, 1966: U69.—A.M. Clark, 1983: 372–373.— Clark and Downey, 1992: 172.—A.M. Clark, 1993: 204. New synonym.

Diagnosis. Rays 5; body integument noticeable; interradial margin incurved to varying extents; rays discrete, short, distally broadly or narrowly rounded or pointed; flat actinally, convex abactinally; papular spaces with numerous small papulae and secondary plates; abactinal spinelets opaque, digitiform to conical, rounded distally; actinal plates in oblique and sometimes longitudinal series; actinal interradial spines digitiform to conical, up to 5 per plate; internal contiguous projections from abactinal and actinal plates support margin; lacking superambulacral and superactinal plates.

Type species. Asterias gibbosa Pennant, 1777 (subsequent designation by Fisher, 1906; full treatment by A.M. Clark, 1983) (junior synonym: Asterina crassispina H.L. Clark, 1928 , by Rowe, 1995).

Other species. A. fimbriata Perrier, 1875 ; A. gracilispina H.L. Clark, 1923 ; A. ocellifera ( Gray, 1847) ; A. pancerii (Gasco, 1870) ; A. phylactica Emson and Crump, 1979 ; A. stellifera (Möbius, 1859) (junior synonym: Enoplopatiria siderea Verrill, 1913 , this work).

Material examined. A. fimbriata . Argentina, Comodoro Rivadavia, AM J6411 (3).

A. gibbosa . Mediterranean, Tunisia, USNM E42476 (1); see O’Loughlin (2002).

A. gracilispina . South Africa, Cape Agulhas, BMNH 1975.10.29.47 (1).

A. ocellifera . Mauritania, Cape Lever, BMNH 1969.12.16.13 (1).

A. stellifer . Argentina, AM J6410 (1).

Enoplopatiria siderea . Holotype. Panama (assumed here to be mistaken locality), YPM No. 9830. New synonym.

Description with species variations. Rays 5; interradial margin incurved to varying extents, rays discrete, distally narrowly ( gibbosa ) or broadly ( fimbriata , gracilispina ) rounded, or pointed ( ocellifera , stellifera ); size large ( ocellifera up to R = 81 mm) to small ( phylactica up to R = 7.5 mm); pedicellariae numerous abactinally, predominantly 2 valves, fasciculate ( gibbosa , ocellifera , stellifer a), or absent ( fimbriata , gracilispina ); gonopores abactinal ( fimbriata , gracilispina , ocellifera , stellifera ) or actinal ( gibbosa , phylactica ); not fissiparous.

Extensive abactinal papulate area of weakly notched or shallow crescentiform or rhombic ( ocellifera ) plates, narrow interradial non-papulate margin of proximally rounded plates; upper rays with variably developed carinal series of doubly notched plates ( fimbriata , gibbosa , gracilispina ), or irregular plates ( stellifera ), or rhombic plates ( ocellifera ); up to 4 longitudinal series of plates along each side of rays; papular spaces large, secondary plates and papulae numerous, small secondary plates may partly obscure ( ocellifera ) or encroach on ( stellifera ) primary plates; disc bordered by series of 5 radial and 5 interradial plates ( gibbosa , gracilispina ) or not ( fimbriata , ocellifera , stellifera ); abactinal plates with spinelet-bearing ridges and domes; denuded plates with glassy convexities ( gibbosa , gracilispina , ocellifera , stellifera ) or reticulations ( fimbriata ); abactinal spinelets digitiform or conical, rounded distally; spinelets spaced on plates closely ( stellifera ) or widely ( fimbriata , gibbosa , gracilispina , ocellifera ), not in tufts; interradial plates in short series perpendicular to margin ( ocellifera , stellifera ) or not ( fimbriata , gibbosa , gracilispina ); superomarginal and inferomarginal plates in distinct series, covered with abactinal-type spinelets; projecting inferomarginal plates form marginal edge.

Actinal plates in oblique series (small specimens of A. gibbosa ; longitudinal series in large specimens of A. gibbosa ).

Actinal spines per plate: oral 4–9; suboral 1-4; furrow 2–5 proximally, webbed; subambulacral 1–3; adradial row of actinal plates with complete series of spines; actinal interradial predominantly 2–3 in mid-interradius; interradial actinal spines digitiform to conical.

Lacking superambulacral and superactinal plates; interradial margin supported by contiguous internal tongue-like extensions of abactinal and actinal plates.

Distribution. Atlantic Ocean, Europe, SW and S Africa, SE and S South America; Mediterranean Sea; 0– 250 m.

Remarks. The principal characters in this new diagnosis of Asterina are: papular spaces with numerous small papulae and secondary plates, not predominantly single large papulae; abactinal spinelets opaque, digitiform to conical, not glassy and fine; actinal plates in oblique and longitudinal series; internal contiguous projections from abactinal and actinal plates support the margin; lacking superambulacral and superactinal plates.

Molecular evidence ( Waters et al., 2004, clade VI) places A. phylactica as sister species of A. gibbosa . On the basis of the diagnosis the following species are removed from Asterina to other genera: A. alba , A. anomala , A. aucklandensis , A. batheri , A. burtoni , A. cepheus , A. chilensis , A. corallicola , A. coronata , A. hartmeyeri , A. heteractis , A. inopinata , A. miniata , A. minor , A. pectinifera , A. sarasini , A. scobinata .

A.M. Clark (1983) considered that the rhombic and noncrescentic form of the large primary plates in the radial field, and the proliferation of small secondary plates to the extent that abactinal plates become obscured peripherally, distinguish Allopatiria from Asterina . Clark and Downey (1992) noted superficial similarity of similarly sized specimens of Allopatiria and Asterina . We have found that the form of abactinal plates and number of secondary plates are not generically significant. In diagnosing Allopatiria, Clark and Downey (1992) referred to “additional internal plates” supporting the margin. If such superactinal plates were present they might justify the retention of Allopatiria . But we did not confirm their presence. What could appear to be superactinal plates are long internal projections of distal abactinal and actinal plates. This is a character shared with Asterina , and Allopatiria is judged to be a junior synonym. A.M. Clark (1993) listed Patiria Gray, 1840 and Asterinides Verrill, 1913 as junior synonyms of Asterina . Rowe (1995) and Campbell and Rowe (1997) supported the validity of Asterinides . Patiria is raised out of synonymy in this work.

O’Hara (1998) synonymised Asterina hamiltoni Koehler, 1920 and Cycethra macquariensis Koehler, 1920 with Asterina frigida Koehler, 1917 and assigned A. frigida to Cycethra Bell, 1881 in the Ganeriidae . Rowe (1995) synonymised Asterina crassispina H.L. Clark, 1928 with Asterina gibbosa , and judged the northern Australia locality data to be incorrect. Based on an examination of the type of Asterina spinigera, VandenSpiegel et al. (1998) synonymised it with Asterina coronata .

Clark and Downey (1992) summarised the characters thought to distinguish A. pancerii from A. gibbosa as: flatter and near pentagonal shape; fewer and larger skeletal plates; plates with coarse crystal bodies; and more numerous, usually three, suboral spines. O’Loughlin (2002) noted in A. gibbosa material: some conspicuous glassy convexities around the margin of abactinal plates; and some plates with up to three suboral spines. The near pentagonal body form and relative size of plates have been found to show variation within species in this study. A. pancerii is probably conspecific with A. gibbosa . In the absence of molecular evidence, pancerii is retained here as a species of Asterina .

The holotype of Enoplopatiria siderea was examined and found to conform in all morphological features with Asterina stellifera . The Panama type locality must be an error, since A. stellifera occurs on the east and west coasts of the South Atlantic.

Specimens of Asterina lorioli Koehler, 1910 and Asterina novaezelandiae Perrier, 1875 were not examined. Based on the descriptions, assignment to Asterina could not be confirmed. These species are placed incertae sedis, and discussed below.

All species placed here in Asterina are from the Atlantic and Mediterranean.

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.