Breviturma pusilla (Brock, 1888)

Fig. 23

Ophiomastix pusilla Brock, 1888: 499–500 . — Koehler, 1905: 65, pl. 6(6–10), 13(3).

Ophiocoma pusilla . — Clark, H.L., 1921: 131. — Devaney, 1970: 25–28, fig. 26, 29. — Clark, A.M. & Rowe, 1971: 86–87,. — Clark, A.M. & Courtman-Stock, 1976: 174, fig. 190. — Clark, A.M., 1976: 259–260. — Cherbonnier & Guille, 1978: 173– 174, pl. 11(3–4). — Sloan, Clark & Taylor, 1979: 106. — Clark, A.M., 1980: 544. — Price & Rowe, 1996: 77. — Stöhr, 2011: 36–38, fig. 17l–m.

Ophiocoma aegyptica Soliman, 1991: 81–86, fig. 2–6 [according to Olbers & Samyn, 2012].

Breviturma pusilla . — O’Hara et al., 2019a: 74. — Olbers et al. 2019: 169–171, fig. 162–163.

STUDY MATERIAL. — MD208: stn WS03, Walters shoal, Zone sommitale Sud-Ouest, 33° 12.25´S, 43° 50.818´E, 40 m, 30/4/2017: 1 (MNHN IE.2016.1340) (DNA code= IE.2016.1340) . — MD208: stn WB05, Walters shoal, Zone sommitale Sud, 33° 15.12´S, 43° 54.514´E, 26–30 m, 1/5/2017: 1 (MNHN IE.2023.4162) . — MD208: stn WB09, Walters shoal, Zone Sommitale Nord Ouest, 33° 13.767´S, 43° 55.7751´E, 27–30 m, 4/5/2017: 8 (MNHN IE.2023.4165), 1 (MNHN IE.2016.1351) . — MD208: stn WB10, Walters shoal, Zone Sommitale Nord Ouest, 33° 9.131´S, 43° 51.7939´E, 30 m, 6/5/2017: 2 (MNHN IE.2016.1352) .

COMPARATIVE MATERIAL EXAMINED. Breviturma pusilla (Brock, 1888): BIOLUM/18, Lizard Is, Coconut Beach, 14° 40.8´S, 145° 28.5´E, 2–5 m, 25/10/2005 , MV F109823 (DNA code=F109823) . SAYA / YB01, NE Saya de Malha, 10° 22.75´S, 62° 7.75´E, 24 m, 10/11/2022, MNHN IE.2023.4347 (DNA code=IE.2023.4347).

Distribution. W Indian Ocean (0–70 m), E Indo-W Pacific (0–120 m), S Africa (11–20 m), Lord Howe Island (4–21 m), Walters Shoal (26–40 m).

Remarks. These diminutive specimens (maximum 7 mm dd) are identifiable as B. pusilla, having relatively narrow dorsal arm plates, hollow non-alternating arm spines, 3–4 oral papillae and lacking granules near the radial shields (Devaney 1970). The single Indo-Pacific DNA sample we have sequenced is sister to both Indian Ocean samples. Sibling species are common across the Indian Ocean, including in the Ophiocomidae (Boissin et al. 2017; O’Hara et al. 2019a), but more samples are required before species boundaries can be defined in this instance. The name B. aegyptica (type locality Red Sea) is available if all Indian Ocean specimens prove to be conspecific. Breviturma pusilla is a shallow water species and historical records below 100 m need to be verified.