Sertularella mediterranea Hartlaub, 1901

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 : 289-291

Sertularella mediterranea Hartlaub, 1901

Fig. 14 A-E; Table 16

Sertularella mediterranea Hartlaub, 1901: 86 , pl. 5 figs 10- 11, 15-16. – Genzano, 1990: 47, figs 13-15. – Blanco, 1994: 199. – Genzano & Zamponi, 2003: 308.

Sertularella uruguayensis Mañé Garzón & Milstein, 1973: 21 , fig. 1 (syn. nov.). – Milstein, 1976: 85, figs 25, 28, 29, 36.

Sertularella picta . – Blanco, 1967: 112, pl. 3 figs 1-7 [non Ser-

tularella picta ( Meyen, 1834) ].

Material examined: HRG-0001; France, La Ciotat, 43.174850° 5.611921°, 0.5 m, coll. H.R. Galea; 16.03.2003; male colony composed of numerous stems, up to 4 cm high.

Description: Stems erect, up to 1.5 cm high, monosiphonic, sparingly and irregularly branched. Internodes rather short, delimited by deep, oblique constrictions of the perisarc, basally with a more or less marked bulge; first internodes of side branches comparatively longer than subsequent ones, with 2-3 basal twists; distally a hydrotheca to each internode. Hydrothecae flask-shaped, adnate for less than half their length, swollen basally (notably on adaxial side), constricted below aperture; rim with 4 cusps, abaxial one conspicuously produced, adaxial one the shortest, and recurved outwards; rim not thickened; 3 internal, submarginal projections of perisarc (2 lateroadaxial, 1 abaxial). Gonothecae arising from below the hydrothecal bases, broadly ovoid, walls with 6-9 transverse ridges, aperture surrounded by 4 (rarely 5) pointed cusps.

Dimensions: See Table 16.

Remarks: The description given above is based on Argentinean material, and combines both Blanco’s (1967, as S. picta ) and Genzano’s (1990) accounts. Blanco (1994) regarded her earlier record as conspecific with the present species, although El Beshbeeshy (2011) still believed that it belonged to Meyen’s hydroid.

The occurrence of S. mediterranea Hartlaub, 1901 in Argentina is plausible, as additional remote records are, for instance, from South Africa ( Millard, 1975).

There are no objective reasons to separate specifically S. uruguayensis Mañé Garzón & Milstein, 1973 from the Argentinean hydroid. Both form colonies composed of short, erect, sparingly branched stems, their internodes are short, and each bears a flask-shaped hydrotheca, conspicuously swollen adaxially, and provided with a produced abaxial, marginal cusp, as well as with 3 internal, submarginal perisarc projections [Mañé Garzón & Milstein (1973); Genzano (1990)]. In addition, the measurements given by these authors for their respective materials are comparable (see Table 16 herein), and both originate from localities close to one another.

Distribution: Uruguay – Cabo Polonio (Mañé Garzón & Milstein, 1973, as S. uruguayensis ). Argentina – Provincia de Buenos Aires [Mar del Plata ( Blanco, 1967, as S. picta ; Genzano 1990)]. Elsewhere – widely distributed in the Mediterranean and the eastern Atlantic, from Spitzbergen to South Africa ( Ramil et al., 1992).