Taxonomic revision of the genus Sertularella (Cnidaria: Hydrozoa) from southern South America and the subantarctic, with descriptions of five new species Author Horia R. Galea Author Dirk Schories Author Verena Häussermann Author Günter Försterra text Revue suisse de Zoologie 2017 2017-09-30 124 2 255 321 journal article 31805 10.5281/zenodo.893519 10de215a-77ca-4e81-8c6b-a603108c4181 0035-418 893519 Sertularella novarae Marktanner-Turneretscher, 1890 Fig. 14 J-L; Table 19 Sertularella novarae Marktanner-Turneretscher, 1890 : 226 , pl. 4 figs 3, 3A, 3B. – Bedot, 1916 : 208. Sertularella polyzonias . – p.p. Vanhöffen, 1910 : 322, fig. 39 [non S. polyzonias ( Linnaeus, 1758 ) ]. Material examined: ZMB Cni944; French Southern and Antarctic Lands, St. Paul I., coll. Deutsche Südpolar ( Gauss ) Expedition 1901-1903, stranded on beach; 26.03.1903; six stems and fragments, 0.5-1.4 cm high, of which four bear one gonotheca each [material studied by Vanhöffen (1910) , as S. polyzonias ]. Description: Upright, up to 2.5 cm high, monosiphonic, sparingly-branched stems arising from filamentous hydrorhiza; divided by faintly-indicated, oblique nodes into moderately-long, geniculate internodes with 1-2 basal twists and a hydrotheca distally; terminal stolonization occurs. Side branches arising irregularly from below the bases of stem hydrothecae, as well as from within their lumena; up to 2nd order branching, giving the colonies a somewhat bushy appearance. Hydrothecae biseriate, alternate, long, about 1/3rd adnate, tumid proximally, tapering distally, with 4 triangular marginal cusps separated by shallow embayments; 5 internal, submarginal cusps (2 lateroadaxial, 2 latero-abaxial, and 1 abaxial). Gonothecae arising from below the hydrothecal bases; elongatedovoid, transversely wrinkled, tapering abruptly below into indistinct pedicel, aperture surrounded by 3-4 blunt, apical projections. Dimensions: See Table 19 . Remarks: As noted by Vanhöffen (1910) , there is no doubt that his material from St. Paul belongs to the present species. Indeed, both the measurements of the hydrothecae and the illustration provided by him are in agreement with the original account on this species. However, his specimens from Kerguelen, also assigned to it, were reexamined and proved to belong to both S. contorta Kirchenpauer, 1884 and S. gaudichaudi ( Lamouroux, 1824 ) (see under these species). Table 18. Measurements of Sertularella mixta Galea & Schories, 2012a , in μm.
Galea et al . (2009), as S. sanmatiasensis Galea & Schories (2012a)
Internode
- length 540-790 745-1170
- diameter at node 210-280 240-320
Hydrotheca
- free adaxial length 380-445 400-450
- adnate adaxial length 305-415 400-455
- abaxial length 630-690 670-725
- maximum width 315-380 330-355
- diameter at aperture 250-290 305-330
Gonotheca
- total length 1770-1820 (♀) 1730-2105
- maximum width 840-930 (♀) 775-865
Table 19. Measurements of Sertularella novarae Marktanner-Turneretscher, 1890 , in μm.
Marktanner-Turneretscher (1890) Vanhöffen (1910), as S. polyzonias (Linnaeus, 1758) Present study, ZMB Cni944
Internode
- length 920-1200 - 455-735
- diameter at node - - 110-140
Hydrotheca
- total length 440-500 480-520 480-520
- free adaxial length - - 330-350
- adnate adaxial length - - 210-235
- abaxial length - - 455-485
- maximum width 210-260 240-260 230-255
- width at aperture ca . 150 - 185-205
Gonotheca
- total length 1500-1700 1500-1700 1350-1715
- maximum width 600-900 780-880 590-770
Curiously, Vanhöffen overlooked the rather obvious specific differences between a number of closely-related subantarctic species [ viz . S. allmani Hartlaub, 1901 , S. antarctica Hartlaub, 1901 , S. contorta Kirchenpauer, 1884 , S. novarae , S. paessleri Hartlaub, 1901 , S. picta ( Meyen, 1834 ) , and S. protecta Hartlaub, 1901 ], and assigned them all to the synonymy of S. polyzonias ( Linnaeus, 1758 ) , a species not known to occur in the study area (see Appendix I). As underlined by him, the present species is a true Sertularella , in possessing 4 hydrothecal cusps, not 3, as erroneously stated by Marktanner-Turneretscher (1890) . A typical colony of this species is accurately illustrated by Vanhöffen (1910, p. 325, fig. 39) .
Distribution: French Southern and Subantarctic Lands – St. Paul ( Marktanner-Turneretscher, 1890 ; Vanhöffen, 1910 , as S. polyzonias ).