Symplectoscyphus magellanicus ( Marktanner-Turneretscher, 1890 )

Galea, Horia R. & Schories, Dirk, 2012, Some hydrozoans (Cnidaria) from Central Chile and the Strait of Magellan, Zootaxa 3296, pp. 19-67 : 51-52

Symplectoscyphus magellanicus ( Marktanner-Turneretscher, 1890)

(plate 4A–C, fig. 6G–J)

Symplectoscyphus magellanicus — Vervoort, 1972: 158, figs 51A–C, 52, 53. — Galea, 2007: 69, fig. 16J–L.

Material examined. Stn. FSI — 04.i.2011, S27 (40 m): four stems, 1.8–5.6 cm high, the two smaller monosiphonic, the two larger polysiphonic, as well as several monosiphonic colony fragments and numerous broken cladia, several specimens bear gonothecae (MHNG-INVE-79636); S28 (40 m): a few sterile, monosiphonic fragments, the larger one attaining 2 cm high and 3.2 cm wide; S29 (40 m): a fragmentary, sterile stem with incipient polysiphony, fragments assembled together attain 3.2 cm in height, basal part missing; S33 (30 m): three sterile, monosiphonic fragments, 0.9–1.8 cm high, rather badly preserved, with only the perisarc left; S35 (20 m): a polysiphonic stem, 4.4 cm high, basal most cladia also polysiphonic, as well as several smaller fragments, all sterile (MHNG-INVE-79638); S36 (40 m): a broken, sterile colony composed of two main parts: a basal, 4.2 cm high, strongly polysiphonic part comprising the stolonal mass, and an upper part, 3.4 cm high, profusely ramified (plate 4A), with branches polysiphonic basally, as well as numerous smaller, monosiphonic fragments and cladia (MHNG-INVE-79637); S38 (25 m): a polysiphonic stem, 4.5 cm high, as well as several monosiphonic fragments (the bigger one is 2.5 cm high) and broken cladia, larger specimens bearing gonothecae; S44 (40 m): a large, polysiphonic colony broken into three main pieces and a few broken cladia, assembled together totalling 15 cm in height, gonothecae absent; S47 (30 m): a fragmentary, polysiphonic stem, 4.0 cm high, devoid of basal part, with numerous, long (up to 4.3 cm), broken cladia, all sterile; 08.i.2011, S04 (30 m): several fragmentary colonies, ca. 4.5 cm high, all strongly polysiphonic, as well as numerous smaller, monosiphonic fragments and broken cladia, all sterile (MHNG-INVE-79639).

Remarks. For descriptions of this species, see Vervoort (1972) and Galea (2007). While most of the earlier accounts are based on relatively small, often fragmentary colonies with monosiphonic stems (Marktanner- Turneretscher 1890, Nutting 1904, Vervoort 1972), the present material comes as large (up to 15 cm high), polysiphonic colonies, occasionally bearing gonothecae (plate 4A–C). The length of the free adcauline wall is highly variable, as illustrated in the fig.6G, H. Specimens in samples S27 and S38 are fertile, allowing the first description of the gonotheca of this species.

Gonothecae large (2330–2450 µm long, 1240–1345 µm wide), ovoid, tapering basally into imperceptible pedicel, distally provided with 3 or 4 conspicuous transverse ridges, fading off towards base, distal end truncate and provided with short terminal tube; the latter 265–305 µm long, 230–260 µm wide, widening further on at level of aperture (315–325 µm wide); the latter circular, with smooth rim.

Distribution in Chile. The northernmost record is from Canal Pitt Chico (Galea 2007). The present material originates from the Strait of Magellan.

World records. See Galea (2007).

PLATE 4. A–C: Symplectoscyphus magellanicus ( Marktanner-Turneretscher, 1890) —two polysiphonic colonies (A, B) and a monosiphonic fragment (C). D, E: Symplectoscyphus patagonicus sp. nov. — holotype (D) and upper fragment of a colony (E), both bearing gonothecae.