Filellum, Hincks, 1868

Soto, Joan J. & Peña, Álvaro L., 2019, Benthic hydroids (Cnidaria, Hydrozoa) from the Weddell Sea (Antarctica), Zootaxa 4570 (1), pp. 1-78 : 22

Filellum cf. bouvetensis Marques, Peña Cantero, Miranda & Migotto, 2011

( Fig. 6h )

Material examined. ANT XXI/2: PS65/39, some hydrothecae, on Sc. nana ; PS65/121, several hydrothecae, on Sc. nana and B. subrufa ; PS65/278, some hydrothecae, on A. elongatus .

Remarks. The size spectrum of both the hydrotheca and the nematocysts are in agreement with the description of the species (cf. Marques et al. 2011). However, the absence of coppinia precludes a proper identification.

Cnidome composed exclusively of microbasic mastigophores [range 6.5–9.0 x 3.0–3.5 µm, mean 7.4±0.7 x 3.2±0.3 µm (n=21)].

Ecology and distribution. Previously reported in Antarctic waters at a depth of 122–134 m [ Peña Cantero & Gili 2006, as Filellum contortum ( Nutting, 1905) ]. Rare species only reported twice: from its type locality at Bouvet Island ( Peña Cantero & Gili 2006) and from Gough Island , Tristan da Cunha archipelago, in the South Atlantic ( Galea 2015). If confirmed, present record would constitute the first evidence of the species from both the Weddell Sea and High Antarctica .

Figures

FIGURE 6. a–b Acryptolaria frigida: a stem; b hydrotheca; c–f Filellum antarcticum: c hydrotheca; d coppinia; e section of a coppinia showing gonothecae and eggs; f detail of gonothecal aperture. g Filellum cf. magnificum: hydrotheca. h Filellum cf. bouvetensis: hydrotheca. i–j Lafoea dumosa: i stem; j detail of the stem showing hydrothecal arrangement. k Lafoea gaussica: hydrotheca. l-m Abietinella operculata: l stems; m detail of the stem showing hydrothecal arrangement. n Hebella cf. plana: hydrotheca.