Chiridota abyssicola Marenzeller, 1892

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 : 135

Chiridota abyssicola Marenzeller, 1892

Reports for the Azores:

Chiridota abyssicola $ Marenzeller, 1892: 65, 1893: 19 , pl. 1, fig. 5, pl. 2, fig. 7; Perrier 1902: 276; Mortensen 1927a: 437; García-Diez et al. 2005: 52;

p.p. Chiridota laevis (Fabricius) —H.L. Clark 1907: 28–29.

Type locality: North of the Azores (41°40’41”N, 26°44’09”W) .

See: Marenzeller (1893); H.L. Clark (1907: 119–120, as Chiridota laevis ).

Occurrence: known only from the Azores ( Marenzeller 1893).

Depth: AZO: 2,870 m ( Marenzeller 1893).

Habitat: soft substrates (clayish sand; Marenzeller 1893).

Remarks: Marenzeller (1892, 1893) described Chiridota abyssicola based on a single specimen collected by Hirondelle within the archipelago waters (sta 248: 41°40’41”N, 26°44’9”W, 2,870 m). This species is known only from the type specimen. In a review of apodous holothurians, H.L. Clark (1907) united under the name C. laevis several species described from both the Atlantic and Pacific, turning a species previously known only to the Antarctic shallow waters to one of the most widely distributed species of the genus Chiridota , both in terms of geographic and bathymetric range. Notwithstanding, the same author believed that among the shallow and deep-water forms there was more than one species. However, the variability of the diagnostic characters was such (often depending on the age and size of the animal) that H.L. Clark was unable to clearly define each of the species. The decision of making C. abyssicola conspecific with C. laevis did not reunite consensus as the latter was viewed as a cold shallow-water species (e.g., Mortensen 1927a; Deichmann 1930; Heding 1935). Regardless, whether C. abyssicola should be merged with the highly variable C. laevis will depend on future work. For now, we have chosen to retain the historical species, restricted to the Azorean deep waters.