Dytaster insignis ( Perrier, 1884 )

Madeira, Patrícia, Kroh, Andreas, Cordeiro, Ricardo, De, António M., Martins, Frias & Ávila, Sérgio P., 2019, The Echinoderm Fauna of the Azores (NE Atlantic Ocean), Zootaxa 4639 (1), pp. 1-231 : 76-77

Dytaster insignis ( Perrier, 1884)

Reports for the Azores:

Dytaster exilis Sladen, 1889 — $ Cherbonnier & Sibuet 1972: 376–377.

Type locality: Gulf of Mexico .

See: Downey (1973: 35–36, pl. 9, figs. C–D); A.M. Clark & Downey (1992: 54, pl. 16, figs. G–H).

Occurrence: Atlantic deep waters, reported from the Gulf of Mexico and Caribbean (A.M. Clark & Downey 1992), eastwards to the Rockall Trough ( Gage et al. 1983) and the Charlie-Gibbs Fracture Zone ( Dilman 2013), south to the Azores ( Cherbonnier & Sibuet 1972): also off Tristan da Cunha (A.M. Clark & Downey 1992).

Depth: 2,515– 3,670 m ( Dilman 2013); AZO : 2,844–3,670 m ( Cherbonnier & Sibuet 1972).

Habitat: soft deep-sea ooze; omnivorous scavenger ( Gage et al. 1983).

Larval stage: planktotrophic ( Tyler & Pain 1982).

Remarks: the geographic distribution of the relatively poorly known asteroid Dytaster insignis is based on a few isolated reports. Cherbonnier & Sibuet (1972) recorded the species Dytaster exilis in the Azores (Jean Charcot, Noratlante cruise: sta P62C03: 36°47’4”N, 27°11’7”W, 3,670 m; sta P65B10: 36°58’2”N, 26°20’W, 2,871 m), remarking that the specimens were close to the variety carinata . A.M. Clark & Downey (1992) listed this variety as a synonym of D. grandis grandis , a subspecies already known from the Azores. However, Cherbonnier & Sibuet (1972) concluded that though close to the variety ‘ carinata ’, the total absence of pedicellaria on the dorsal surface of the disc and arms placed the specimens close as well to the D. exilis type, a species presently accepted as D. insignis ( Downey 1973) . Using the presence/absence of pedicellaria on dorsal surface as diagnosing character alone and comparing with the descriptions by A.M. Clark & Downey (1992) of both D. grandis grandis and D. insignis , we are inclined to include the Azorean specimens under the latter species. Furthermore, Dilman (2014) seems to agree with our conclusions, and listed Cherbonnier & Sibuet (1972) Azorean record under this species. Overall, the record from the Azores together with the reports to the Rockall Trough ( Gage et al. 1983) and to the Charlie-Gibbs Fracture Zone, on the Mid-Atlantic Ridge north of the Azores ( Dilman 2013) further substantiate the presence of this species in the East Atlantic.