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. magnificum Peña Cantero, Svoboda & Vervoort, 2004

( Fig. 6g )

Material examined. ANT XV/3: 48-150, some hydrothecae, on E. scotti ; 48-220, some hydrothecae, on Sy. exochus ; 48-276, several hydrothecae, on Sc. nana ; ANT XXI/2: PS65/166, numerous hydrothecae, on O. erratum ; PS65/274, numerous hydrothecae, on Staurotheca nonscripta Peña Cantero, Svoboda & Vervoort, 1997 .

Remarks. In spite of the absence of coppinia, the size of the hydrotheca and the size of the nematocysts perfectly agree with previous reports ( Peña Cantero 2010, Peña Cantero et al. 2004, Soto Àngel & Peña Cantero 2015). However, in agreement with Peña Cantero et al. (1998), the identification of infertile material of Filellum is tentative.

Cnidome consisting of large microbasic mastigophores [range 17.5–19.0 x 4.5–6.0 µm, mean 18.1±0.6 x 5.4±0.8 µm (n=4)] and small microbasic euryteles [range 6.0–7.5 x 2.5–3.5 µm, mean 6.9±0.4 x 2.8±0.3 µm (n=13)].

Ecology and distribution. Previously known from 85 ( Peña Cantero 2010) to 640 m (Peña Cantero et al. 2004); present material collected at depths from 236 to 758 m. Only known from Peter I Island ( Peña Cantero 2010) and the Weddell Sea (Peña Cantero et al. 2004; material examined).

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.