Orphnurgus insignis Fisher, 1907

Orphnurgus insignis Fisher, 1907 View in CoL sensu stricto

Orphnurgus insignis Fisher, 1907: 702 View in CoL , pl. 73: 1, pl. 77: 1–3.— Ohshima, 1915: 237.—Ohshima,1916–1919: with 3 figures.— Cherbonnier and Féral, 1981: 361, fig. 2a, k.— Thandar, 1992: 173–175 figs 4, 7a.

Orphnurgus glaber Hansen, 1975: 39 View in CoL (part), textfig. 13 (28–33, 40–45).

Non Orphnurgus glaber Walsh, 1891 View in CoL . AM Clark, 1977: 146 (= O. aspersiginis Thandar ).

Material examined. NMV F296867 About NMV * (4) and NMV F296868 About NMV * (6) [IN 2021 V 04 035] ; NMV F296871 About NMV * (1) [IN 2021 V 04 040] ; NMV F296877 About NMV * (3) [IN 2021 V 04 048] ; NMV F308149 About NMV (1) and NMV F308158 About NMV (1) [IN 2022 V 08 105] ; NMV F308167 About NMV (1) [IN 2022 V 08 108] ; NMV F308169 About NMV (1) [IN 2022 V 08 111] ; NMV F308176 About NMV (1) [IN 2022 V 08 113] ; NMV F308212 About NMV (1) [IN 2022 V 08 117] ; NMV F308239 About NMV (1) , NMV F308240 About NMV (2) , NMV F308246 About NMV (1) , NMV F308247 About NMV (1) and NMV F308248 About NMV (1) [IN 2022 V 08 131] ; NMV F308298 About NMV * (1) and NMV F308301 About NMV * (2) [IN 2022 V 08 157] .

Diagnosis of IOT material. Body elongated, sub-cylindrical, raised dorsally and flattened ventrally. Small to medium-sized (e.g. 3.6 mm long [ NMV F308176] to 11.5 cm long [ NMV F308298, tentacles extended]). Salmon-yellow to pink or orange in colour with yellow-brown tips to appendages. White when preserved. Body wall thin, transparent, often rough ventrally. Papillae typically thin, tapered and in single to zigzag series along each dorsal radii, and in lateral series above the ventrolateral tube feet. Of variable length, larger laterally than dorsally. Some specimens with “shaggy” appearance being crowded with papillae, others less so (e.g. 22 or 23 papillae each dorsal radii, and ~13 papillae ventrolateral in NMV F308298, compared to ~13–15 papillae each dorsal radii, and ~9 papillae ventrolateral in NMV F308301, seemingly not size-dependent). Non-retractile ventrolateral tube feet, ~ 16–18 in single to zigzag series along each side. Extended past lateral papillae length in NMV F308298, but typically shorter, wider, more robust, and less tapered than the papillae. Typically bare of tube feet midventrally, but with median line visible. Anus terminal, slightly dorsal. Mouth terminal but turned to ventral with up to 20 non-retractile tentacles. Tentacles usually quite extended in larger specimens, sometimes with obviously shorter ventral tentacles. Peltate tentacle discs with lobed and ramified (branching) processes on the margins. Dorsal body wall ossicles include smooth, nearly straight rods with branched and sometimes spinous extremities (fig. 42g –1). Dominant ventral ossicles (fig. 42m –x) are thick, transformed rods, variable in shape from ellipsoid to dumbbell or sometimes “lumpy” bodies. Visible to the naked eye in smaller specimens (fig. 42f).

Remarks. Hansen’s 1975 synonymy of Orphnurgus insignis with O. glaber was rejected by Cherbonnier and Féral (1981) and subsequent authors. Our identifications here chiefly follow the original description by Fisher (1907) and subsequent examples by Thandar (1992) with smoother branching rods dorsally and thick transformed rods ventrally, though only rare evidence of dorsal cross ossicles was observed (fig 42l). IOT specimens with less-crowded papillae also match Thander’s (1992) South African variety for papillae distribution.

Distribution. Pacific and Indian Oceans including Hawaii, Japan, Philippines, south-east Africa, Australian IOT, off eastern Australia and Tasman Sea.

Full bathymetric range. 222–2435 m (IOT 1019–2435*m).

Type locality. Hawaiian Islands , ~ 222–387 m. This species not previously recorded from Australian IOT in AFD (2024) but recorded from at Lord Howe plateau in the Tasman Sea between Australia and New Zealand (1076–1147 m) , and potentially at upper bathyal depths (<1500 m) off the coast of NSW in ALA (January 2024). This IOT material represents a geographic range extension for the species in Australia .

References. AFD (2024), ALA (2024), Cherbonnier and Féral (1981), Fisher (1907), Hansen (1975), Thander (1992).