Campanularia

Campanularia sp.

(Fig. 3L–Q, Z1)

Campanularia norvegiae — Stepanjants, 1979: 30, pl. 5, figs 2A, B [not Orthopyxis norvegiae (Broch, 1948)].? Peña Cantero, 2006 (pro parte): 944, fig. 5D [not fig. 5B, C = O. norvegiae (Broch, 1948)].

Material examined. Stn. RAS — 21.ii.2011, Ant.14/2011 (20–30 m): male and female colonies on a seaweed (MHNG-INVE-79664)

Description. Colonies arising from creeping, branching, anastomozing hydrorhiza. Pedicels 680–1460 µm high, 90–140 µm wide, distinctly spirally twisted throughout. Hydrotheca cup-shaped, 715–910 µm high, 340–490 µm wide in middle, flattened fronto-dorsally, with laterally thickened perisarc, basally delimiting an ovoid subhydrothecal chamber, distally forming a thick, prominent, conspicuously arched margin, the latter prolonged by short (15–30 µm high), thin perisarc sheet, forming an even, slightly everted rim; aperture diameter 280–320 µm (measured at the distal part of the lumen of hydrotheca). Between hydrotheca and pedicel, a subhydrothecal spherule. Colonies dioecious. Gonothecae ovoid to bottle-shaped in frontal view, strongly flattened laterally, borne on moderately long pedicels (140–220 µm), the latter constricted just below insertion of gonotheca; aperture circular, borne on a terminal tube, comparatively longer and asymmetrical in female; gonophores, sessile sporosacs; male gonotheca 630–970 µm long, 335–665 µm wide in middle and 50–60 µm at aperture, containing a rounded, homogenous mass of sperm cells around blastostyle; female gonotheca 970–1120 µm long, 685–830 µm wide in middle and 110–130 µm at aperture, carrying 3– 6 eggs or developing embryos; egg diameter 180–200 µm. Nematocysts: possibly microbasic mastigophores (though none was observed discharged) in two size classes, with large (12.8–15.0) × (3.4–3.8) µm and small (6.0–6.3) × (1.7–2.0) µm capsules.

Remarks. The trophosome of Campanularia sp. superficially resembles that of Orthopyxis norvegiae (Broch, 1948), a species with which it often occurs on the same substrates, but their gonothecae are markedly different in shape, size and the nature of their gonophores (see below).

The hydrothecae described and illustrated by Stepanjants (1979) (Pl. 5 Fig. 2A, B) have a distinctly arched margin and are said to have an "oval aperture", thus coming closer to our material of Campanularia sp. than to O. norvegiae. The gonothecae described and figured by Peña Cantero (2006) are similar to those of the present species (see discussion under O. norvegiae).

Geographical distribution. Only known from the South Shetland islands: King George Is. (Stepanjants 1979, present study) and Livingston Is. (Peña Cantero 2006).