Halecium sibogae marocanum: Ramil & Vervoort, 1992: 86–90, figs. 21a–e, 22a–b; Ramil et al., 1998: 7–8, fig. 1; Medel et al., 1998: 39–41, fig.5; Peña Cantero & García Carrascosa, 2002: 74–75, fig. 15.
Material examined. MAURIT-0911, stn MUDR01, 16º08´24”N, 16º57´12”W, 488 m, 5-XII-2009: three colonies badly damaged, without gonothecae.
MAURIT-0911, stn MUDR07, 18º35´40”N, 16º43´12”W, 460 m, 12-XII-2009: one colony, no gonothecae.
MAURIT-1011, stn MUDR20, 16º08´11”N, 16º56´08”W, 405 m, 7-XII-2010: one colony 15 mm high, no gonothecae.
MSM 16/3, stn GeoB 14908–1, ROV, 17°40.213’– 17°40.191’N, 16°40.829’– 16°40.289’W, 463–574 m, 16- XI-2010: six colonies 6–7 mm high, three colonies growing on Lophelia pertusa, one on cirriped and two on Sertularella gayi; one colony with gonothecae.
Biology. This species has been reported to grow on rocks, pebbles, shell fragments, algae, other hydroids, gorgonians and worm tubes. The gonothecae have been observed in March, June, July, August (Peña Cantero & García Carrascosa 2002) and December (Gil & Ramil 2017a).
Our colonies were found growing on L. pertusa, S. gayi and cirripeds; the female gonothecae were recorded in November.
Distribution.Halecium sibogae marocanum has an Atlantic-Mediterranean distribution from the Galicia Bank (Ramil et al. 1998) to Cape Verde Islands (Medel & Vervoort 2000) and Alboran Sea in the Mediterranean (Ramil & Vervoort 1992; Peña Cantero & García Carrascosa 2002). In West Africa, this species was found in Morocco (Patriti 1970; Ramil & Vervoort 1992; Vervoort 2006), Canary Islands (Medel & Vervoort 2000), Mauritania (Gil & Ramil 2017a) and Cape Verde Islands (Medel & Vervoort 2000). Bathymetric distribution from 16 (Peña Cantero & García Carrascosa 2002) to 756 m (Ramil et al. 1998).
Our material was collected from depths of 405 to 574 m.
Remarks. The presence of a perisarc fold at the base of the primary hydranthophore, the rim strongly everted and the female gonothecae are characteristics of H. sibogae marocanum and help in identifying the colonies to the species level (Ramil et al. 1998).