Sertularella curvitheca Galea & Schories, 2012a

Horia R. Galea, Dirk Schories, Verena Häussermann & Günter Försterra, 2017, Taxonomic revision of the genus Sertularella (Cnidaria: Hydrozoa) from southern South America and the subantarctic, with descriptions of five new species, Revue suisse de Zoologie 124 (2), pp. 255-321 : 273

Sertularella curvitheca Galea & Schories, 2012a

Fig. 8A, B ; Table 7

Sertularella curvitheca Galea & Schories, 2012a: 38 , pl. 3E, fig. 4A-E.

Sertularella gayi. – Galea, 2007: 62. – Galea et al., 2007b: 161. – Galea et al., 2007c: 312 [non Sertularella gayi ( Lamouroux, 1821) ].

Sertularella polyzonias . – Leloup, 1974: 32, fig. 26. – Galea, 2007: 64, fig. 15A-D. – Galea et al., 2007b: 161. – Galea et al., 2007c: 312 [non Sertularella polyzonias ( Linnaeus, 1758) ].

Material examined: MHNG-INVE-79665; Chile, Región de los Lagos, Caleta la Arena, Caleta Yerbas Buenas, -41.67263° -72.65650°, 20 m, coll. D. Schories, lot #05; 25.04.2007; colony composed of several profusely-branched, polysiphonic stems, up to 10 cm high, some bearing male gonothecae (holotype). – HRG-1178; Chile, Región de Aysén, Isla Waller, -46.7648° -75.2312°, 20 m, coll. HSFS, HF24, lot #128; 20.04.2015; three colonies with polysiphonic stems, 4.5, 5.8, and 7.0 cm high, the latter bearing a male gonotheca.

Description: Colonies erect, up to 10 cm high, arising from creeping, branching stolon. Stems either mono- or polysiphonic. Basal part of monosiphonic stems of varied length, not constricted above origin from stolon, ahydrothecate, with smooth perisarc; remainder of stem composed of a succession of moderatelylong, slightly geniculate internodes delimited by rather indistinct, oblique nodes sloping in alternate directions. A hydrotheca, or a hydrotheca and a short, lateral apophysis immediately below its base, confined to the distal end of each internode. Branching pattern alternate and coplanar, with generally 3 hydrothecae between successive side branches, but possibly 1 to 9; up to 3rd order branching observed; branches with similar structure as the stem, though 1 st internode comparatively longer than subsequent ones. Hydrothecae tubular, distinctly curved outwards, adnate for about half their length to the corresponding internode; abaxial wall straight for 3/4th its length, conspicuously curved outwards below rim; free adaxial wall slightly convex, perisarc smooth to wavy, in the latter case provided with 2-3 indistinct undulations, more conspicuous proximally; hydrothecal aperture expanding just below rim; the latter provided with 4 acute cusps separated by moderately-deep, semi-circular embayments; operculum composed of 4 triangular flaps, with concentric, closely-set striae. Gonothecae arising from below the hydrothecal bases; male and female similar, though of slightly different size; broadly ovoid, with 6-7 transverse ribs, the 3-4 distalmost well-marked, becoming obsolete towards base; aperture mounted on short, terminal collar, truncate distally and provided with 4 blunt perisarc projections; female with acrocysts.

Dimensions: See Table 7 .

Remarks: The typical shape of the colonies of this species is illustrated in Galea & Schories (2012a, pl. 3E, fig. 4A), and its gonothecae in both Galea (2007, fig. 15B, D) and Galea & Schories (2012a, fig. 4E).

Distribution: Chile – Región de los Lagos [Fjord Comau ( Galea, 2007, as both S. gayi and S. polyzonias ), Gulf of Ancud ( Leloup, 1974, as S. polyzonias ), Seno de Reloncaví ( Galea & Schories, 2012a)]; Región de Aysén [Canal Puyuhuapi ( Galea et al., 2009, as S. cf. gayi ); Isla Waller (present study)]; Región de Magallanes y de la Antártica Chilena [Canal Adalberto and Isla Camello ( Galea, 2007, as S. gayi ), Canal Fallos ( Galea, 2007, as S. polyzonias )].

Figures

Fig. 8. (A, B) Sertularella curvitheca Galea & Schories, 2012 a. Portion of colony from MHNG-INVE- 79665 (A), and hydrotheca from HRG- 1178 (B). (C-I) Sertularella fuegonensis El Beshbeeshy, 2011. Colony portions from ZMH C 11884 (C), HRG- 0 0 0 9 (D) and Vervoort (1972, as S. picta) (E). Hydrothecae from ZMH C 11884 (F, G), HRG- 0009 (H) and Vervoort (1972, as S. picta) (I). (J): Sertularella gaudichaudi (Lamouroux, 1824) (part), colony fragment from ZMH C 04172. Scale bars: 200 μm (B, F-I), 1 mm (A, C-E, J).