Ophiotreta spectabilis (G.O. Sars, 1872 ) O’Hara & Thuy, 2022

O’Hara, Timothy D. & Thuy, Ben, 2022, Biogeography and taxonomy of Ophiuroidea (Echinodermata) from the Îles Saint- Paul and Amsterdam in the southern Indian Ocean, Zootaxa 5124 (1), pp. 1-49 : 28

Ophiotreta spectabilis (G.O. Sars, 1872) comb. nov.

Fig. 6F

Ophiacantha spectabilis Sars, 1872: 10 .— Lyman 1882: 198.— Mortensen 1933c: 33–34.— Paterson 1985: 41, fig. 18.— Martynov & Litvinova 2008: 96, fig. 11c.

Ophiacantha (Ophiectodia) spectabilis .— Verrill 1899a: 42.

Material examined. MD 50 CP7, MNHN IE.2009.1564 (7). MD 50 CP145, MNHN IE.2009.1565 (1).

Distribution. Arctic (190–1505 m), NW Atlantic (240–366 m), NE Atlantic (530–1830 m), S Australia (780– 1700 m), New Zealand (150–1460 m). SPA (825–1680 m).

Remarks. This species is easily recognised by the large oval tentacle scales (two on basal segments), the multiple (4–8) oral papillae, the pentagonal oral shield that is bordered distally by a fringe of small papillae, and the rod-shaped disc spines that can be terminated by small thorns ( Fig. 6F ). This species has been identified as an associate ( O’Hara et al. 2008) of the colonial deep-water coral Solenosmilia variabilis . Both MD50 samples that contained O. spectabilis (to 8.5 mm dd) also contained S. variabilis (see MNHN online collections database, https:// science.mnhn.fr/institution/mnhn/item/search).

Phylogenetic evidence shows conclusively that this species belongs in the family Ophiotomidae rather than the Ophiacanthidae ( O’Hara et al. 2017) , and consequently it is transferred here to the genus Ophiotreta pending a revision of this family. Many of the existing ophiotomid genera appear to be non-monophyletic. In the phylogeny, it is sister to a clade that includes the tropical Indo-Pacific species Ophiopristis procera ( Koehler, 1904) and Ophiopristis luctosa ( Koehler, 1904) which also have a fringe of papillae on the dorsal margin of the oral shields ( O’Hara & Stöhr 2006).

Figures

FIGURE 6. (A) Ophiacantha veterna, MNHN IE.2009.1562, dorsal outline. (B) MNHN IE.2009.1563, ventral view. (C–E) Ophiosabine cuspidata, MNHN IE.2009.1558, C: dorsal outline, D: dorsal view, E: ventral view. (F) Ophiotreta spectabilis, MNHN IE.2009.1564, dorsal view. (G–H) Ophiolimna bairdi, MNHN IE.2009.1571, G: dorsal and H: ventral views.