Gorgonocephalus cf. dolichodactylus Döderlein, 1911

Nethupul, Hasitha, Stöhr, Sabine & Zhang, Haibin, 2022, New species, redescriptions and new records of deep-sea brittle stars (Echinodermata: Ophiuroidea) from the South China Sea, an integrated morphological and molecular approach, European Journal of Taxonomy 810 (1), pp. 1-95 : 25

Gorgonocephalus cf. dolichodactylus Döderlein, 1911

Figs 11–12

Gorgonocephalus dolichodactylus Döderlein, 1911: 34–36 , pl. 1 figs 4–5, pl. 7 figs 3, 4a–b.

Gorgonocephalus dolichodactylus – Döderlein 1927: 27, 52. — Matsumoto 1915: 73, fig. 20. — Baker 1980: 52, figs 18a, 20, 30. — Liao & Clark 1995: 171, fig. 75. — McKnight 2000: 45–46, pl. 20.

Material examined

CHINA • 1 spec.; South China Sea , Zhongsha Islands, seamount; 13°36.00′ N, 114°34.49′ E; depth 1340 m; 30 Mar. 2020; collection event: stn SC008; MSV Shenhaiyongshi leg.; preserved in -80°C; GenBank: MZ 198760 ; IDSSE EEB-SW0006 .

Remarks

The disc diameter was 67 mm. Our specimen is similar to the holotype description by Döderlein (1911) and the description in Liao & Clark (1995), but showed some morphological variations, especially on the disc ( Fig. 11 ). Therefore, we hesitate to fully associate our specimen with G. dolichodactylus . The original description and the description in Liao & Clark (1995) mention small granules on both the dorsal and ventral disc, but the present specimen is completely naked except for the radial shields ( Fig. 11A–E ), which are covered by scattered granules ( Fig. 11F ).

Pedicellarial bands are formed by approximately 12 articulating tubercles at the curved distal end of the baseplate ( Fig. 12B ), and these articulations have a single foramen ( Fig. 12C ). The distal end of the baseplate internal side becomes curved with perforations on the ventral side of the baseplate ( Fig. 12B–C ). The vertebrae have a streptospondylous articulation with smooth lateral furrows and no oral bridge ( Fig. 12D–H ). The external side of the lateral arm plate has three separate tubercle-shaped articulations with a single opening and one large muscle opening at the edge. Gorgonocephalus dolichodactylus was first recorded from the South China Sea in southeastern Hainan, at a depth of 1100 m, in 1959.

Distribution

146–1357 m depth. South China Sea, Japan, Korea, Philippines, Australia and New Zealand ( Liao 2004; OBIS 2021).

Figures

Fig. 11. Gorgonocephalus cf. dolichodactylus Döderlein, 1911 (IDSSE EEB-SW0006). A. Dorsal aspect. B. Ventral aspect. C. Oral frame. D. Genital slit. E. Ventral disc. F. Radial shield with peripheral plate. G. Dorsal arm. H. Ventral arm. I. Lateral arm. J. Ventral view of arm base. K. Ventral view of first arm branch. L. Ventral view of second arm branch. M. Dorsal view of second arm branch. N. Coiled distal arm branches. O. Pedicellarial band. P. Pedicellariae on pedicellarial band. Abbreviations: ars = arm spine; gs = genital slit; pb = pedicellarial band; rs = radial shield; t = teeth; tp = tentacle pore. Scale bars: A = 22 mm; B = 14 mm; C = 5 mm; D, F–H, J–N = 2 mm; E, I = 1 mm; O = 500 µm; P = 200 µm.

Fig. 12. Gorgonocephalus cf. dolichodactylus Döderlein, 1911, SEM (IDSSE EEB-SW0006). A. Plan view of base plate. B. Distal view of base plate. C. Internal view of base plate. D. Pedicellaria in the pedicellarial band. E–I. Vertebrae. E. Proximal view. F. Distal view. G. Lateral view. H. Dorsal view. I. Ventral view. Abbreviations: ap = articular pad of the base; au = auricle; D = dorsal; Dist = distal; fo = foramen of the base; fs = fossa between adjacent tubercles; hd = head of the apophysis; lp = lateral pores of the blade; mo = muscle opening; pd = pedicel of the apophysis; Prox = proximal; pt = primary tooth of the blade; sh = sheath of the base plate; st = secondary tooth; su = sulcus of tubercle head; V = ventral. Scale bars: A–C, E–F = 300 µm; D = 100 µm; G–I = 500 µm.