Hygrosoma petersii ( Agassiz, 1880 )

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 : 120

Hygrosoma petersii ( Agassiz, 1880)

Reports for the Azores:

non Phormosomum luculentum ( Agassiz, 1879) — $ Koehler 1895a: 224, 1895b: 228. [misidentified]; non Phormosoma uranus Thomson, 1877 — $ Koehler 1898: 7, 10–15, pl. 1, fig. 1, pl. 3, figs. 5, 6, pl. 9, figs. 49, 50 [misidentified see comments under P. uranus ]; Hygrosoma petersii ( Agassiz, 1880) — $ Mortensen 1903: 176, fig. 11, pl. 11, figs. 4, 27, pl. 12, fig. 42, pl. 13, figs. 8, 13; $ Koehler 1909: 217–218; Mortensen 1927a: 284–285, figs. 156.2, 158. 1, 161; $ Mortensen 1927b: 27; Grieg 1932: 41; Mortensen 1935: 202–208, figs. 118–119, pl. 13, pl. 14, figs. 1–3, pl. 15, figs. 1–2, pls. 16 –17, pl. 18, fig. 2, pl. 19, fig. 2, pl. 78, figs. 1, 3–5, 24, 25; Gage et al. 1985: 180–181; Serafy & Fell 1985: 20, fig. 17; García-Diez et al. 2005: 50; Mironov 2006: 103.

Type locality: Caribbean.

See: Grieg (1932); Mortensen (1935).

Occurrence: Atlantic, from the east coast of the USA to the Caribbean ( Pawson 1982), eastwards from the British Isles to South Africa ( Mortensen 1935), including the Azores ( Koehler 1909), Canaries ( Grieg 1932) and the Atlantis Seamount (Meteor; Mironov 2006); possibly in Bermuda’s deep waters as well ( Mironov 2006).

Depth: 200– 3,800 m ( Mironov 2014); AZO: 1,165 –2,870 (?3,237) m ( Koehler 1909, herein) .

Habitat: opportunistic scavenger, on soft ooze ( Gage et al. 1985).

Larval stage: lecithotrophic ( Emlet 1995).

Remarks: in a preliminary report, Koehler (1895a, 1895b, 1896c, 1898) identified specimens from the Azores and Bay of Biscay (Hirondelle, Princesse Alice and Caudan cruises) as Hygrosoma luculentum (= ‘ Phormosomum luculentum ’) and Tromikosoma uranus (= Phormosoma uranus ). Mortensen (1903) questioned Koehler’s previous identifications based on the examination of a specimen belonging to H. petersii collected in the Azores by Talisman (sta 126: 38°37’00”N, 28°20’46”W, 1,258 m). Subsequently, Koehler (1909) agreed with Mortensen and re-identified the material as H. petersii . During the expedition EMEPC-LUSO (2009, 2008), animals likely to belong to this species were captured on video on the seabed of the Azorean deep waters, between S„o Jorge and Pico islands (38°34'12"N, 28°03'17"W, 1,250 m, Fig. 28D, E ) and near the Hirondelle Seamount (between S„o Miguel and Terceira, 37°56'12"N, 26°10'31"W, 3,237 m, Fig. 28F ).

Figures

FIGURE 28. Echinothuriids in the Azorean deep-waters, most probably belonging to Araeosoma fenestratum (Thomson 1872) (EMEPC–LUSO, 38°42'18"N, 28°01'18"W, 2009.10.02, 900 m: A, B; 36°36'25"N, 28°06'43"W, 2009.10.21, 1,102 m: C) and Hygrosoma petersii (Agassiz, 1880) (EMEPC–LUSO, 38°34'12"N, 28°03'17"W, 2008.11.10, 1,250 m: D, E; 37°56'12"N, 26°10'31"W, 2009.10.08, 3,237 m: F).