Zoroaster fulgens (Wyville Thompson 1873)

FIGURE 2A–C

Thomson, 1873: 153; For complete synonymy see Mah 2007: 196.

Diagnosis

Body strongly stellate (R/r>15.0). Disc small, arms elongate, tapering in some. Abactinal and marginal plates lobate, carinal plates overlapping adradial plates. Single marginal plate series, overlapping adradials. Prominent, sharp spines variably present on carinal and marginal plates. Marginals with a single spine and small ensacculate spinelets. Adambulacral plates alternatively with distinct adradial extensions (also described as “carinate”), furrow spines two, long and slender each bearing pedicellariae, many small straight pedicellariae or a large subambulacral spine. Subambulacral spines three. Modified from Clark & Downey (1992).

Comments

The numerous species synonymies summarized in Mah (2007) is indicative of a wide range of morphological variation among populations of Zoroaster throughout the Atlantic. These have been argued as a single species, Zoroaster fulgens (Downey, 1973) . However, three distinct morphotypes have been observed and subsequently supported by molecular data (Howell et al. 2004) suggesting greater diversity than is reflected by “ Zoroaster fulgens . ” The numerous Atlantic species synonymized by Downey (1973) should be re-visited, testing different regional and bathymetric populations.

In Situ Observation

Figure 2A–C shows Zoroaster fulgens buried within the subsurface sediments partially buried in different localities (e.g. Benfield & Kupchick 2020). Mah (2007) reported several Atlantic zoroasterids with small mollusks present in the oral region and that this area also demonstrated a high abundance of straight pedicellariae, especially on oral spines. These observations are consistent with prior reports of Zoroaster fulgens as an infaunal predator and/or perhaps a detritivore (Gale et al. 2013), digging into the sediment and utilizing spines and pedicellariae on its actinal surface, especially around the mouth to facilitate predation of gastropods and/or bivalves.

Carinal and marginal spines oriented in upward directions (Figs 1A–C) suggests a defensive function.

Occurrence

North Atlantic (off Massachusetts), Faroe Channel, Rockall Trough (north-east Atlantic), to Bahamas, Gulf of Mexico, and Surinam. South Atlantic to Shag Rocks, South Georgia Sea, to Indian Ocean (South Africa) 220–4810 m.

Images Observed

Puerto Rico, 17.76096, -66.75684, 2018.5738 m

EX1502L3_IMG_20150416T124927Z_ROVHD_ASR.jpg

Key West Scarp, North Atlantic 23.969688 -81.799899, 1154 m

EX2107_IMG_20211110T155722Z_ROVHD.jpg

Northern Gulf of Mexico (BOEM study 2020-022), 27.22 N 90.05 W 2099 m, 22 Dec 2015. (from Benfield & Kupchick 2020) (Fig. 1A).