Ophioctenella acies Tyler et al., 1995

Reports for the Azores:

Ophioctenella acies Tyler et al. 1995 — $ St̂hr & Segonzac 2005: 395–396, figs. 2, 7.

Type locality: Mid-Atlantic Ridge.

See: Tyler et al. (1995); St̂hr & Segonzac (2005); Desbruyères et al. (2006: 483, figs. 1–3).

Occurrence: Atlantic, along the Mid-Atlantic Ridge from Lucky Strike (SW Azores, c. 37°17’N, 32°16’W) south to Snake Pit (23°22’N, 44°56’W), westwards from Blake Plateau and Florida Escarpment to south of Barbados.

Depth: 1,626 –3,650 m (Desbruyères et al. 2006), though it seems to reach higher densities at depths greater than 3,000 m (St̂hr & Segonzac 2005); AZO: 1,626 –1,727 m (St̂hr & Segonzac 2005).

Habitat: restricted to chemosynthetic areas, found at hydrothermal vents and methane cold seeps, usually in association with deep-sea mytilid beds (St̂hr & Segonzac 2005).

Larval stage: probable planktotrophic (St̂hr & Segonzac 2005).

Remarks: Ophioctenella acies appears to be the only echinoderm species restricted to active vent sites known to occur in the Azores. In one of the few echinoderm studies from deep-sea reducing environments in the North Atlantic, St̂hr & Segonzac (2005) identify several animals of O. acies from Lucky Strike, but found this species conspicuously absent from hydrothermal vents of Menez Gwen.