Ophiotreta valenciennesi (Lyman, 1879)

Ophiacantha Valenciennesi Lyman, 1879: 57–58, pl. 15(408–410). — Lyman, 1882: 183–184, pl. 26(7–8). — Koehler, 1904: 110–111. — Clark, H.L., 1917: 434.

Ophiotreta valenciennesi . — Koehler, 1922a: 84, pl. 16(4), 93(6). — Mortensen, 1933d: fig. 19b, 21i. — O’Hara & Stöhr, 2006: 62–63, fig. 5a–d, 17p.

STUDY MATERIAL. — MD208: stn DW4894, Walters shoal, Pentes, 33° 8.19´S, 43° 50.3101´E to 33° 8.59´S, 43° 49.75´E, 199–261 m, 5/5/2017: 2 (MNHN IE.2016.1346) (DNA code= IE.2016.1346) .

COMPARATIVE MATERIAL EXAMINED. Ophiotreta rufescens (Koehler, 1896): UF /IZ- 2009-06-10, S of Florida Keys, 24° 13.452´N, 81° 29.004´W, 457 m, 8/6/2009, UF 8999 (DNA code= UF8999). Ophiotreta valenciennesi (Lyman, 1879): ATIMO VATAE / DW3522, secteur de Manantenina, 24° 23´S, 47° 32´E, 154–168 m, 1/5/2010, MNHN IE.2007.4292 (DNA code= IE.2007.4292). BIOPAPUA/DW3719, Vitiaz strait, 6° 3´S, 147° 36´E, 410 m, 7/10/2010, MNHN IE.2023.4066 (DNA code=BP22). EXBODI/DW3940, Récif Pétrie, 18° 35.9´S, 164° 23.9´E, 380–430 m, 27/9/2011, MNHN IE.2023.4075 (DNA code=ex 2007.6848). NA064/017, Galapagos Is marine park, 1° 13.879064´N, 91° 6.803404´W, 354 m, 27/6/2015 (DNA code=NA064-017-01-A). SAYA / DW5434, SW Saya de Malha, 11° 47.436´S, 61° 5.361´E to 11° 47.436´S, 61° 5.435´E, 268–270 m, 15/11/2022, MNHN IE.2023.4193 (DNA code= IE.2023.4193). TARASOC/CP3464, Moorea Island, 17° 34´S, 149° 54´W, 460 m, 20/10/2009, UF 13020 (DNA code= UF13020).

Distribution. NW Pacific (228–512 m), W Indian (133–554 m), E Indo-W Pacific (73–1901 m), E Pacific (332–549 m), S America (370–748 m), S Africa (199–261 m), S Australia (132–700 m), New Zealand (88–883 m).

Remarks. Ophiotreta valenciennesi is a species complex, with considerable genetic divergence between lineages. The most recent common ancestor on our tree dated to approximately 15 MY. The DNA sequence from the Walters Shoal specimen (16 mm dd) is closest to that obtained from a specimen from Madagascar (IE.2007.4292). Both have some slightly elongated granules but not as spine-like as figured for the type of related species O. durbanensis Mortensen, 1933b from eastern South Africa. More samples are required to resolve whether this character is diagnostic. The radial shields are mostly covered by granules (except at their distal tip) and there are spines along the distal edge of the dorsal arm plates. Ophiotreta valenciennesi rufescens (Koehler, 1896) samples are phylogenetically sister to all our Indo-Pacific O. valenciennesi samples and deserves recognition as a separate species, Ophiotreta rufescens .