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 .