Plumularia setacea: Ramil & Vervoort, 1992: 191–193, fig. 47F–I; Ansín Agís et al., 2001: 238–245, fig. 91; Peña Cantero & García Carrascosa, 2002: 117–119, fig. 21C–D; Vervoort, 2006: 259; Ansín Agís et al., 2014: 824, fig. 22.
Material examined. MAURIT-0911, stn MUDR 01, 16º08´24”N, 16º57´12”W, 488 m, 5-XII-2009: six colonies, one colony growing on Lophelia pertusa and two on Aglaophenia lophocarpa; one colony with gonothecae.
MAURIT-0911, stn MUDR02, 16º08´50”N, 16º57´01”W, 462 m, 5-XII-2009: one colony, no gonothecae.
MAURIT-1011, stn MUDR20, 16º08´11”N, 16º56´08”W, 405 m, 7-XII-2010: one colony on Nemertesia sp., without gonothecae.
MSM 16 /3, stn GeoB 14801–1, 20°14.762’N, 17°40.173’W, 568 m, 3-XI-2010: three colonies on Aglaophenia lophocarpa, no gonothecae.
Biology.Plumularia setacea usually grows attached to other hydroid species, but it can also colonize a wide range of other substrata (Peña Cantero & García Carrascosa 2002). Fertile material has been found throughout the year (Ansín Agís et al. 2014).
Our colonies were attached to the hydroids A. lophocarpa and Nemertesia sp. and the scleractinian coral L. pertusa; fertile material has been found in December.
Distribution. This species has a circumglobal distribution with a bathymetric range from 0 to 1513 m (Ansín Agís et al. 2001; Gil & Ramil 2017a). In West Africa, it was collected from Morocco (Billard 1906b; Patriti 1970; Ansín Agís et al. 2001), West Sahara (Vervoort 1946), Mauritania (Ansín Agís et al. 2001; Gil & Ramil 2017a), Cape Verde Islands (Bedot 1921b; Ansín Agís et al. 2001), Senegal (Picard 1951), Guinea-Bissau (Gili et al. 1989), Ghana (Buchanan 1957), Angola (Broch 1914; Bouillon et al. 1995) and Namibia (Broch 1914; Gili et al. 1989).
The material studied by us was collected from depths of 405 to 568 m.
Remarks. This species is well-known and does not require further comments. Schuchert (2014) analysed the genetic diversity within P. setacea by using a set of worldwide samples, and the results suggested a species complex; however, they could also be considered as a single species with an extensive population subdivision.