Campanularia sp.

Peña Cantero, Álvaro L., 2021, Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica), Zootaxa 4966 (3), pp. 321-336 : 325-326

Campanularia sp.

( Fig. 1F–G )

Material examined. TAN 0602/420, several hydrothecae, on S. compressa ( NIWA 144251).

Description. Stolonal hydrorhiza giving rise to erect, slightly sinuous, smooth pedicels provided with a single distal hydrotheca.

Hydrotheca elongated, bell-shaped ( Fig. 1F ), 800–1050 µm high, resting on a basal spherule, 60 µm high and

70 µm wide, and provided with a distinct diaphragm ( Fig. 1G ), 110 µm in diameter, delimiting a basal chamber 70 µm high ( Fig. 1G ). Distinct inflexion point at diaphragm ( Fig. 1G ); hydrothecal diameter markedly increasing just above basal chamber, only slightly afterwards (maximum diameter at aperture, 340–520 µm). Hydrothecal aperture circular; rim provided with 16 blunt cusps ( Fig. 1F ), slightly directed inwards and separated by deep embayments.

Larger microbasic mastigophores around 10 x 2.5 µm.

Remarks. The material seems to be conspecific with material reported from other Antarctic waters (e.g. Peña Cantero et al. 2004; Peña Cantero 2013). The absence of gonothecae, here and in previous records, prevent the identification to species level.

Ecology and distribution. Present material, which represents the first record for the area, collected at a depth of 103−108 m off Sturge Island, epibiotic on S. compressa .

Figures

FIGURE 1. Filellum antarcticum (Hartlaub, 1904): A, part of a coppinia showing gonothecal arrangement; B–C, distal part of gonothecae showing aperture (arrows). Lafoea dumosa (Fleming, 1820): D, hydrotheca and pedicel. Phialella belgicae (Hartlaub, 1904): E, hydrotheca and pedicel. Campanularia sp.: F, hydrotheca; G, distal part of pedicel, basal spherule and basal chamber with diaphragm. Antarctoscyphus elongatus (Jäderholm, 1904): H, internode with hydrotheca. Scale bar: 100 µm (B, C, G), 200 µm (A, D–F, H).