Cidaris cidaris ( Linnaeus, 1758 )

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 : 96

Cidaris cidaris ( Linnaeus, 1758)

( Fig. 20 )

Reports for the Azores:

Dorocidaris papillata ( Leske, 1778) — $ Koehler 1895a: 224, 1898: 8, 1909: 214–215, 1921a: 3; Nobre 1938: 104–105, figs. 45, 55;

Cidaris cidaris ( Linnaeus, 1758) — Mortensen 1927a: 272–273, figs. 149, 150–152, 1928: 289–298, pl. 30, figs. 3–4, pl. 31, figs. 1–10, pl. 67, fig. 5, pl. 72, figs. 20–22; $ Cadenat 1938: 363; Harvey 1956: 63; Marques 1980: 104; $ Pérès 1992: 253; García-Diez et al. 2005: 50; Mironov 2006: 98–99; Schultz 2006: 32, fig. 53–55;

See: Mortensen (1928); Mironov (2006); Schultz (2006).

Occurrence: East Atlantic and the Mediterranean Sea, from south of Iceland and Norway south to equatorial West Africa including the Azores, Madeira, Canaries and Cape Verde and Santa Helena ( Koehler 1909, Mortensen 1903, 1928, 1933c, Mironov 2006); also in Gorringe, Josephine and the Meteor seamounts ( Mironov 2006).

Depth: 20–2,010 (?4,275) m ( Mironov 2006, Koukouras et al. 2007); AZO: 165– 1,385 m ( Koehler 1909, herein).

Habitat: mud, fine sand, gravel to hard substrates ( Koehler 1898, 1909); an opportunistic scavenger; feeds also on deep-sea reef building corals such as Lophelia pertusa ( Linnaeus 1758) and Madrepora oculata ( Linnaeus 1758) ( Stevenson & Rocha 2012).

Larval stage: planktotrophic ( Emlet 1995).

Material examined: DOP–2976 (Banco Cavala, AZO, 38°16’12”N, 30°39’00”W, 2008.07.08, 723 m; 1 spm, D = 20 mm); DOP–2977 (Banco Cavala, AZO, 38°16’12”N, 30°39’00”W, 2008.07.08, 723 m; 1 spm, D = 12 mm); DOP–4335 (Banco Princesa Alice, off SW PIX, AZO, 38°00’10.80”N, 29°19’04.80”W, 2010.09.03, 165–219 m; 1 spm, D = 10 mm); DOP–7933 (Banco Princesa Alice, off SW PIX, AZO, 37°58’51.60”N, 29°31’22.80”W, 2011.28.05, 384 m; 1 spm, D = 5 mm); EMEPC-LUSO L09D18B2 (N of SJG, AZO, 38°42’14”N, 28°01’25”W, 2009.10.02, 869 m; 1 spm, D = 52 mm).

Description: test circular, flattened to almost spherical (test height between 55–70%D). Ambulacra distinctly sinuate, about 20% of the interambulacra in width. Marginal series of tubercles regular. The largest specimen (EMEPC-LUSO L09D18B2; D = 52 mm) presented a regular double series of inner tubercles with a distinct naked median line, becoming a single series just near the apical disc. Pore zones sunken; pores of equal size, each pair separated by a narrow wall. Primary tubercles perforated, not crenulate; areoles are rather large and deep, not confluent; subambital areoles distinctly transverse-oval; mamelon rather large, with the boss rather low. Scrobicular tubercles not very conspicuous. Interradial and adradial zones distinct and naked, both conspicuously sunken. Apical disc covered with small tubercles of uniform size in larger individuals (D Ξ 20 mm), leaving a fairly conspicu- ous bare edge between the plates. Apical disc large, dicyclic; genital pores closed in the smaller specimens (D ± 11 mm); Periproct quite flat, covered by moderate number of plates. Peristome smaller than the apical disc, circular to sub-pentagonal. Primary spines rather long, about 2–2.5 times the diameter of the test, cylindrical, thick at the base, tapering very gently, and covered with a fine, spongy coat of anastomosing hairs; oral primaries spines relatively short and flattened with finely serrate edges; scrobicular spines flattened, tapering to a rounded point; marginal ambulacral spines slender, pointed, slightly flattened in the basal part and about half the length of the scrobicular spines. Both large and small globiferous pedicellariae usually present in fair numbers; globiferous pedicellaria with a distinct terminal teeth; large tridentate pedicellaria present on both oral and apical sides. Colour (in ethanol): generally of a uniform light brown to white; spines white or cream; occasionally some of the primary spines are pinkish to dark brown red colour (e.g., DOP 2976); some of the larger spines of the largest individuals (EMEPC-LUSO L09D18B2) are encrusted with serpulids and cirripeds.

Remarks: among the five cidaroids reported from the Azores, Cidaris cidaris is the only species known to occur with certainty in the extant waters of the archipelago. Though highly variable this species is easily distinguished from the remaining species by the presence of a coat of hairs covering the primary spines and by the presence of enlarged terminal teeth in the globiferous pedicellaria.

Historically, abundant material from the Azores identified as C. cidaris (as Dorocidaris papillata ) is listed in the cruises reports of Princesse Alice and Hirondelle ( Koehler 1898, 1909, 1921a), from depths of 500 and 1,200 m. Cadenat (1938) in his report of the expedition of the Président Théodore-Tissier also recorded this species in the archipelago from a similar depth. This species appears to be quite common in the Azores at this depth range as the footage by ROV LUSO (EMEPC, 2009 expedition) seems to exemplify. They show cidaroids most likely belonging to C. cidaris in practically any kind of environment from sediment to vertical walls ( Figs. 20 D–F).

Figures

FIGURE 20. Cidaris cidaris (Linnaeus, 1758) (DOP 2976: A–C; EMEPC–LUSO L09D18B2: D). Aboral view (A); oral view (B); lateral view (C); animal in situ (38°42'14"N, 28°01'25"W, 2009.10.02, 869 m: D); cidaroids possible belonging to C. cidaris in situ in the Azores deep-waters (EMEPC–LUSO, 38°31'45"N, 27°56'16"W, 2009.10.04, 869 m, E; 38°14'07"N, 26°33'27"W, 2009.10.09, 815 m: F).