Ophiura flagellata ( Lyman, 1878 )

Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, Zootaxa 5259 (1), pp. 1-71 : 22-24

Ophiura flagellata ( Lyman, 1878)

Fig. 4G‒L

Ophioglypha flagellata Lyman, 1878: 69 , pl. 2, figs. 49‒51.

Gymnophiura coerulescens Lütken & Mortensen, 1899: 114‒116 , pl. 7, figs. 4‒6.

Ophiura flagellata . H.L. Clark 1911: 61, fig. 15; 1913: 208.— Koehler 1922: 375‒377, pl. 85, figs. 1, 6, 7, pl. 86, figs. 1‒4, 10.— Paterson 1985: 120, fig. 44.— Lambert & Boutillier 2011: 51, fig. 37.

Material examined. 57 individuals at eight stations. TALUD VIII, Sta. 3, 3 ind. (ICML-EMU-11143-A), and 1 ind. (ICML-EMU-11716). TALUD IX, Sta. 21B, 1 ind. (ICML-EMU-11143-B). TALUD XII, Sta. 9, 12 ind. (ICML-EMU-11140); Sta. 24, 8 ind. (ICML-EMU-11141); Sta. 27, 4 ind. (ICML-EMU-11142-A); Sta. 29, 5 ind. (ICML-EMU-11142-B). TALUD XV, Sta. 5F, 1 ind. (ICML-EMU-11146); Sta. 9, 18 ind. (ICML-EMU-11145) and 4 ind. (ICML-EMU-11692).

Comparative material. Gymnophiura coerulescens Lu ̈tken & Mortensen, 1899, syntypes, 5 ind.: MCZ OPH-786 , USNM 19440 , USNM 19441 (Supplementary file 2).

Description (ICML-EMU-11145). DD = 15 mm. Disc rounded, flat. Dorsal disc covered by minute and imbricated scales. Rays of integument in RS and project from the arms. RS broader than long, circular, separated by numerous scales and the arm width, covering 1/9 of disc radius ( Fig. 4G ). Ventral interradii covered by irregular imbricated scales, larger than dorsal scales. Genital slits with numerous pointed, small genital papillae; projecting dorsally and forming well-developed arm combs with larger papillae ( Fig. 4H ). OSh longer than broad, nearly pentagonal. Madreporite not evident. AdSh longer than broad, elongated, slender, meeting in front of OSh. Jaws bearing 4‒5 papillae at each side; BSc, IPa, 2IPa and TPa oval, pointed, all of similar size. vT pointed and larger than oral papillae. Preceding ossicles separated by a diastema: one AdShSp, 4‒5 2AdShSp. Arms gradually narrowing distally ( Fig. 4I ). DAP broader than long, rectangular, meeting. Longitudinal middle keel along the dorsal arm ( Fig. 4J ). VAP rhomboidal, meeting, separating and decreasing in size distally. LAP with 3‒4 ArSp, very long (approximately two arm segments in length), pointed, dorsalmost the longest. First tentacle pores with 4‒5 oblong TSc; subsequent tentacle pores with up to six TSc, diminishing in number until reaching one distally ( Fig. 4K ). Color pattern beige-whitish ( Fig. 4G‒L ). Radial rays darkening in dorsal disc by a scale-less disc center (ethanol preservation) ( Fig. 4G ).

Habitat and distribution. South Africa, Indonesia, Australia, Japan, Bering Sea, and Alaska. In the eastern tropical Pacific in Mexico and off the Galapagos Islands; 96‒ 2,330 m depth, associated with rocky and muddy bottoms (H.L. Clark 1917; Imaoka et al. 1990; Rowe & Gates 1995; Lambert & Boutillier 2011; Granja-Fernández et al. 2015). The material examined was collected off western Baja California Sur, in the Gulf of California, and off Jalisco, Colima, and Guerrero; 1,035 ‒1,643 m depth.

Remarks. It was impossible to examine the type material of Ophiura flagellata . However, O. flagellata features several morphological differences compared to Gymnophiura coerulescens , including the radial shield shape, the arm spines length, the tentacle scales number, and the length of the spines on the arm combs (H.L. Clark 1911; Koehler 1922). The TALUD material examined matches the morphology of G. coerulescens (distributed in the eastern tropical Pacific; Lütken & Mortensen 1899), which probably corresponds to a valid species, but further studies, including material from the valid and synonymous of O. flagellata , are needed to confirm this. Previously known in the Mexican Pacific off western Baja California Sur and in the Gulf of California ( Granja-Fernández et al. 2015). Samples of O. flagellata collected off Jalisco, Colima, and Guerrero represent new distribution records for these Mexican Pacific areas.

Figures

FIGURE 4. Ophiomusa lymani (Wyville-Thomson, 1873) (ICML-EMU-11078, DD = 23 mm). A, Dorsal disc; B, Ventral disc; C, Mouth; D, Dorsal arm; E, Ventral arm; F, Dorsal view. Ophiura flagellata (Lyman, 1878) (ICML-EMU-11145, DD = 15 mm). G, Dorsal disc; H, Ventral disc; I, Mouth; J, Dorsal arm; K, Ventral arm; L, Dorsal view.