Anseropoda 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 : 7-13

Anseropoda Nardo

Figures 2a , 7 , 8 a-b

Anseropoda Nardo, 1834: 716 .— Bell, 1891: 234–235.— Fisher, 1906: 1088.— Clark and Downey, 1992: 174–175.—A.M. Clark, 1993: 204–205.— Liao and Clark, 1995: 128.— Rowe, 1995: 32–33.— McKnight (in Clark and McKnight), 2001: 161. (For complete synonymy and discussion see Clark and Downey, 1992).

Diagnosis. Rays 5–18; body very thin, margin variably curved, rays short or not discrete, broadly rounded or pointed; narrow raised radial areas with single papulae, in scattered or single longitudinal series, sometimes ringed by secondary plates; abactinal plates thin, in longitudinal and oblique series, not notched, each with subpaxilliform glassy, sacciform spinelets, few or tuft; pedicellariae over papulae; actinal plates in longitudinal and oblique series; actinal spines few to numerous per plate, glassy, sacciform; lacking superambulacral plates, superactinal plates present or absent; interradial plates meet internally by long thin articulating projections, extensive in interradii.

Type species. Asterias placenta Pennant, 1777 (subsequent designation by Bell, 1891) (junior synonym: Asterias membranacea Retzius, 1783 , by Bell, 1891).

Other species. A. antarctica Fisher, 1940 ; A. aotearoa McKnight, 1973 ; A. diaphana ( Sladen, 1889) ; A. fisheri Aziz and Jangoux, 1985 ; A. (Palmipes) grandis Mortensen, 1933 ; A. habracantha H.L. Clark, 1923 ; A. insignis Fisher, 1906 ; A. lobiancoi (Ludwig, 1897) ; A. ludovici (Koehler, 1909) ; A. macropora Fisher, 1913 ; A. novemradiata (Bell, 1905) ; A. pellucida (Alcock, 1893) ; A. petaloides (Goto, 1914) ; A. rosacea (Lamarck, 1816) ; A. tenuis (Goto, 1914) .

Material examined. A. placenta . NE Atlantic, off Great Britain, NMV F98043 (2).

A. rosacea . NW Australia, Broome, NMV F95811 (1); AM J7718 (1); Queensland, AM E1814 (1); Tasmania, AM E5037 (1).

Description with some species variations. Body very thin; rays 5 ( grandis , placenta ) or 6 ( insignis ) or 15–18 ( rosacea ), margin variably curved; rays not discrete or short, broad basally, rounded ( grandis , insignis , placenta ) or pointed ( rosacea ); rays slightly elevated as low ridges; size large ( grandis up to R = 130 mm); pedicellariae present ( grandis , placenta , rosacea ); none fissiparous.

Abactinal plates thin, imbricate, narrow raised radial papulate area, extensive interradial non-papulate area; radial plates in regular ( grandis ) or irregular ( placenta ) distribution on narrow upper ray; single papulae scattered on upper ray ( rosacea , placenta ) or in 1–3 longitudinal series along each side of radial midline ( grandis ); papulae may be each surrounded by ring of up to 5 secondary plates ( placenta , rosacea ); interradial plates imbricate, rhombic to fan-shaped, in both longitudinal and oblique series, may be distally perpendicular to margin ( placenta ); disc not bordered; abactinal plates sometimes with proximal low ( placenta ) to high ( rosacea ) spinelet-bearing elevation or dome; subpaxilliform tufts of spinelets (up to about 25 in placenta , up to 3 in grandis ), sometimes multiple tufts per plate ( insignis ); spinelets glassy, sacciform, pointed ( placenta , rosacea ), sometimes more stout over papulae ( grandis , placenta , rosacea ; presumed to be pedicellariae); cleared abactinal plates sometimes with reticulate glassy appearance ( rosacea ), lacking glassy convexities; superomarginal and inferomarginal plates with abactinal-type spinelets, plates slightly larger than adjacent abactinals; margin defined by projecting inferomarginal plates. Actinal plates in longitudinal and oblique series; may be distally perpendicular to margin ( placenta ).

Actinal spines per plate: oral 5–8; suboral 3–10; furrow 4–9 proximally, webbed; subambulacral 2–7; actinal 3–12, webbed, sometimes in fans ( grandis , insignis , placenta ); adradial row of actinal plates with complete series of spines; interradial actinal spines glassy, sacciform.

Superambulacral plates absent; superactinal plates absent ( rosacea ) or present proximally in multiple plate struts ( placenta ); abactinal and actinal interradial plates meet extensively internally by long thin articulating projections.

Distribution. Indo-West Pacific, South Africa, Australia, New Zealand, Antarctic Peninsula, North-East Atlantic, Mediterranean; 10– 600 m.

Remarks. Molecular data are not available for any Anseropoda species. This restricted generic review is based on examination of specimens of A. placenta (type species) and A. rosacea , and original descriptions of A. grandis by Mortensen (1933) and A. insignis by Fisher (1906). Most of the species assigned to Anseropoda have not been examined and their generic placement has not been reviewed. The very thin body, and presence of extensive interradial internal thin projecting articulating supports distinguish Anseropoda from all other asterinid genera. The contrasting internal plate structures and presence or absence of superactinal plates in A. placenta and A. rosacea ( Fig. 7 ) suggest that Anseropoda may not be monophyletic. Clark and Downey (1992) regarded the very small Anseropoda lobiancoi (Ludwig, 1897) from the Mediterranean (R about 8 mm) as being incompatible with Anseropoda .

Figures

Figure 2. Abactinal views of type species of Asterinidae genera. a, Anseropoda placenta (R = 31 mm, AM J10714). b, Aquilonastra cepheus (R = 12 mm, AM J8072). c, Asterina gibbosa (R = 16 mm, AM G11524). d, Asterinides folium (R = 19 mm, USNM E28573). e, Callopatiria granifera (R = 50 mm, NMV F98049). f, Cryptasterina pentagona (R = 11 mm, NMV F95959). g, Disasterina abnormalis (R = 22 mm, WAM Z6754). h, Indianastra sarasini (R = 20 mm, NMV F95802). i, Meridiastra atyphoida (R = 12 mm, AM J9909). j, Nepanthia maculata (R = 73 mm, AM J13918). k, Paranepanthia platydisca (R = 57 mm, holotype, USNM 32644). l, Parvulastra exigua (R = 11 mm, neotype, TM H508).

Figure 7. Longitudinal sections through interradii of Anseropoda species, showing internal contiguous projections from abactinal and actinal plates, and absence (b) of superambulacral plates. a, Anseropoda placenta (R = 56 mm, NMV F98043). b, Anseropoda rosacea (R = 82 mm, NMV F95811).

Figure 8. a, Anseropoda placenta (R = 56 mm, NMV F98043): abactinal plates, spinelets, papulae. b, Anseropoda rosacea (R = 82 mm, NMV F95811): adambulacral and actinal plates and sacciform spines. c–d, Asterina gibbosa (R = 19 mm, NMV F45108): c, actinal interradius with gonopores; d, margin supported by internal contiguous projections from abactinal and actinal plates, absence of superambulacral plates. e, Asterina ocellifera (R = 37 mm, BMNH 1969.12.16.13): margin supported by internal contiguous plate projections, absence of superambulacral and superactinal plates. f–h, Asterinides folium (R = 20 mm, USNM 28573): f, abactinal spinelet clusters and papulae; g, actinal interradius with sacciform spines; h, marginal plates with spinelets. i, Asterinides pompom (R = 14 mm, USNM 47866): abactinal plates with paxilliform elevations.