Nepanthia Gray, 1840

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 : 23-25

Nepanthia Gray

Figures 2j , 4f , 6c , 14a–c

Nepanthia Gray, 1840: 287 .— Sladen, 1889: 386–387.— Verrill, 1913: 480.— Fisher, 1940: 270–271.— Fisher, 1941: 451–155, figs, 20–22, pl. 70 fig. 2.— Spencer and Wright, 1966: U69.— Rowe and Marsh, 1982: 93.—A.M. Clark, 1983: 370.—A.M. Clark, 1993: 220.— Liao and Clark, 1995: 132–133.— Rowe, 1995: 36–37.— McKnight (in Clark and McKnight), 2001: 158.

Asterina (Nepanthia) Perrier, 1875: 320 .

Diagnosis. Rays 4–7, subcylindrical, to varying degrees flat actinally with distinct to slight marginal edge; plates on upper rays irregular in arrangement; secondary plates present; abactinal and actinal interradial plates with dense clusters of thick or thin glassy spinelets, frequently on spinelet-bearing elevations; pedicellariae present; glassy convexities on plates; inferomarginal plates projecting slightly; oblique series of actinal plates variably evident; furrow spines 6 and more per plate; actinal spines predominantly thin, glassy, sometimes sacciform; superambulacral, transactinal and superactinal plates present, embedded in interior resinous lining in most species.

Type species. Nepanthia maculata Gray, 1840 (restriction by Perrier, 1875; subsequent designation by Verrill, 1913).

Other species. N. belcheri ( Perrier, 1875) (junior synonym: N. variabilis H.L. Clark, 1938 by Rowe and Marsh, 1982); N. crassa ( Gray, 1847) ; N. fisheri Rowe and Marsh, 1982 ; N. pedicellaris Fisher, 1913 .

Material examined. N. belcheri . Queensland, Magnetic I., NMV F97721 (1) ; Western Australia, Dampier, F 95806 (1); Exmouth Gulf, F 95805 (1) .

N. crassa . Western Australia, Fremantle, AM J6165 (1); Ludlow Reef, J7418 (1).

N. fisheri . Timor Sea, AM J12649 (1).

N. maculata . Australia, Timor Sea, AM J13918 (2); Gulf of Carpentaria, J7404 (2); J10536 (1); J13063 (1).

N. pedicellaris . Holotype. Philippines, USNM 32643 .

N. variabilis . Paratypes. Western Australia, Broome , AM J6187 (4).

Description with species variations. Rays 4–7, elongate, subcylindrical, equal or unequal lengths, tapering strongly ( fisheri , pedicellaris ) or slightly; large ( maculata up to R = 94 mm) to small ( pedicellaris up to R = 23 mm); integument variably evident; flat actinally, distinct to slight edge at margin; pedicellariae present, 2-valve ( fisheri , maculata , pedicellaris ) or multi-valve ( belcheri , crassa ); fissiparous ( belcheri ) or not.

Abactinal plates strongly imbricating, projecting proximal edge creating uneven surface, irregularly arranged on upper rays, in regular longitudinal sloping series on sides of rays; plates predominantly irregular in shape ( crassa ) or notched ( belcheri , fisheri , maculata , pedicellaris ), with spinelet-bearing curved elevations above notch ( belcheri , pedicellaris ) or raised ridges ( fisheri , maculata ) or domes ( crassa ), lower surface with glassy convexities; disc variably bordered; papulate areas extend to near margin; papular spaces with 1–2 large papulae and 1–8 secondary plates per space; spinelets thin, glassy, variably sacciform ( fisheri , maculata , pedicellaris ), some splay-pointed distally ( belcheri , crassa ), up to more than 40 per plate; variably regular superomarginal plates, inferomarginal series of plates project slightly at margin, covered with spinelets.

Actinal plates with spine-bearing elevations, variably in oblique series.

Actinal spines per plate: oral 9–10; suboral about 10–26, tall and short; furrow 6–10; subambulacral 6–20; complete series of adradial actinal spines; interradial actinal 4–6 or dense subpaxilliform clusters, glassy, thin ( belcheri ), thick and thin ( crassa ), sometimes sacciform ( fisheri , maculata , pedicellaris ).

Superambulacral, transactinal and superactinal plates present, embedded in internal resinous lining or not ( pedicellaris ).

Distribution. N, S, E and W Australia, Lord Howe I., Indonesia, Timor Sea, New Guinea, W Indonesia, Philippines, Vietnam, Burma, Mergui Archipelago, 0– 123 m.

Remarks. Molecular data are not available for any species of Nepanthia and this review is based on a morphological examination. Six species previously assigned to Nepanthia are removed to Pseudonepanthia . The morphological characters which distinguish Nepanthia from Pseudonepanthia are: rays flat actinally, with a marginal edge; presence of secondary plates, pedicellariae and glassy convexities; furrow spines six and more per plate; presence of transactinal and superactinal plates.

Nepanthia pedicellaris Fisher, 1913 was referred by Fisher (1919) to Asterinopsis Verrill, 1913 (a nomen dubium). We return it to Nepanthia .

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 4. Abactinal views, with plates removed and cleared with bleach to show internal morphology. a–b, Parvulastra dyscrita (R = 24 mm, TM H854): a, series of superambulacral plates linking ambulacral and actinal plates; b, superactinal plates linking abactinal and actinal plates to support the interradial margin. c, Meridiastra oriens (R = 28 mm, NMV F73468): margin supported by internal contiguous projections of abactinal and actinal plates (arrow), absence of superambulacral and superactinal plates. d, Patiria miniata (R = 65 mm, NMV F97444): multiple superactinal plate struts supporting interradial margin. e, Pseudonepanthia troughtoni (R = 85 mm, NMV F73013): series of superambulacral plates, and thick internal tisue lining. f, Nepanthia belcheri (R = 40 mm, NMV F95806): transactinal plates extending transversely across actinal inner ray, and thick internal tissue lining.

Figure 6. Forms of abactinal fasciculate pedicellariae. a, Asterina ocellifera (BMNH 1969.12.16.13). b, Indianastra sarasini (WAM Z6836). c, Nepanthia belcheri (NMV F95805).

Figure 14. a–c, Nepanthia pedicellaris (R = 23 mm, holotype, USNM 32643): a, cleared lower lateral ray, and distinct margin; b, abactinal spinelets; c, adambulacral and actinal plates and spines. d, Pseudonepanthia troughtoni (R = 55 mm, NMV F73977): cleared proximal lateral lower ray, margin, and ambulacrum. e, Pseudonepanthia nigrobrunnea (R = 85 mm, NMV F95810): cleared section of ray with single series of superambulacral plates (arrow), and absence of transactinal and superactinal plates. f, Pseudonepanthia gotoi (R = 70 mm, holotype, USNM 36899): internal cleared view of ambulacral plates, with series of superambulacral plates (arrow).