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
).