Earleria panicula

Earleria panicula (G.O. Sars, 1874)

Campanulina panicula: Cornelius, 1995a: 190–192, fig. 43.

Opercularella panicula: Christiansen, 1972: 291–292; Leloup, 1974: 4–6, fig. 3; Ramil & Iglesias, 1988: 79–81, figs. 1–2; Ramil & Vervoort, 1992: 25–27, fig. 3.

Opercularella denticulata: Gili et al. 1989: 75–76, fig. 6A.

Racemoramus panicula: Calder, 2012: 26, fig. 24.

Earleria quadrata: Schuchert et al. 2017: 177, figs. 5–6.

Material examined. MAURIT-0911, stn MUDR02, 16º08´50”N, 16º57´01”W, 462 m, 5-XII-2009: one colony, badly damaged, no gonothecae.

MAURIT-0911, stn MUDR07, 18º35´40”N 16º43´12”W, 460 m, 12-XII-2009: one colony, without gonothecae.

Biology. The species can colonize a great variety of substrata, such as hydroids, brachiopods, pennatulids, bivalves, dead corals, polychaete tubes and ascidians (Cornelius 1995a; Calder 2012). Fertile colonies have been found in April, June, August, November and December (Ramil & Vervoort 1992; Gili et al. 1989; Cornelius 1995a; Gil & Ramil 2017a).

Gonothecae were not found in our material.

Distribution. Earleria panicula, including its synonyms Campanulina denticulata Clarke, 1907 and Campanulina indivisa Fraser, 1948, was considered to be widely distributed in the Atlantic, Pacific and Indian Oceans at moderately deep to deep waters (Ramil & Vervoort 1992). Nevertheless, Calder (2012) considered the material from the Pacific and Indian Oceans to be a different species (Racemoramus denticulata), and, in consequence, the current distribution of E. panicula is restricted to the East Atlantic, from Trondheimfjord, Norway (Calder 2012) to at least Namibia [Gili et al. 1989, as Opercularella denticulata (Clarke, 1907)]. In West Africa, it was collected from Morocco [Ramil & Vervoort 1992, as Opercularella panicula (Sars, 1874)] and Mauritania (Gil & Ramil 2017a). The bathymetric distribution of the species ranges from 30 to 2100 m (Christiansen 1972; Ramil & Vervoort 1992).

Our material was collected from depths of 460 to 462 m.

Remarks. The material was composed of two colonies with monopodial growth and a cluster of monosiphonic, unsegmented and straight branches with badly damaged terminal hydranths. This morphology was consistent with the typical structure of E. panicula, a species previously recorded in Mauritanian soft bottoms (Gil & Ramil 2017a, as R. panicula). Moreover, the Mauritanian material is identical to those reported by Ramil & Vervoort (1992) from the Alboran Sea and Ibero-Moroccan Gulf to off Casablanca.

Recently, Schuchert et al. (2017) used DNA barcoding and found that Earleria quadrata (Hosia & Pagès, 2007) is the medusa of E. panicula. However, differences in the geographical distribution of the medusa, only known in deep waters of Korsfjord (Norway), and the polyp phase, which is widely distributed in the East Atlantic, led Schuchert et al. (2017) to consider the identity of E. panicula ambiguous, since it could represent a species complex. Nevertheless, samples of Racemoramus panicula from the Alboran Sea and Gulf of Cádiz showed 16S sequences almost identical to that of E. quadrata (Schuchert et al. 2017), which seems to supports its co-specificity in at least the Northeast Atlantic. Despite Schuchert et al. (2017) hesitate to synonymise both names, currently they are considered the same species (Schuchert 2018).