Some hydrozoans (Cnidaria) from Central Chile and the Strait of Magellan
Author
Galea, Horia R.
Author
Schories, Dirk
text
Zootaxa
2012
3296
19
67
journal article
10.5281/zenodo.280882
e115374e-5859-427c-b28f-74d469b2cf3a
1175-5326
280882
Sertularella
?
lagena
Allman, 1876
(fig. 4K, L)
Sertularella lagena
Allman, 1876
: 114
. —
Allman, 1879
: 283
, fig.
not
Sertularella lagena
—
Stechow, 1925
: 475
, fig. 34 (=?
S. antarctica
Hartlaub, 1901
).
Material examined
.
Stn. FSI
—
04.i. 2011
, S25 (
40 m
): three minute sterile stems, epizoic on
Symplectoscyphus patagonicus
sp. nov.
Description
. Three monosiphonic, unbranched stems,
ca
.
3 mm
high, with 3, 4, and 5 hydrothecae, respectively, arising from creeping hydrorhiza. Basal part, of varied length, with several wrinkles just above origin from stolon, then perisarc smooth; remainder of stem divided into internodes by means of twin, oblique constrictions of perisarc; internodes slender, 595–790 µm long, 130–155 µm wide at node; widening gradually towards distal end, where they bear a hydrotheca. Hydrothecae flask-shaped, distinctly swollen basally (maximum width 290–315 µm), narrowing distally to form a short neck region, then widening again at aperture; adnate for about 1/3rd of their adcauline length (205–265 µm); free adcauline wall 295–400 µm long, sigmoid, convex below, concave distally, perisarc smooth; abcauline wall
420–580 m
long, concave below, though not as much as its free adcauline counterpart, then convex distally; aperture 210–270 µm wide, facing outwards and upwards, provided with 4 marginal cusps, the abcauline one most developed; cusps separated by moderately deep, semi-circular embayments; aperture composed of four triangular plates forming a pyramidal roof; internal projections of perisarc missing. Gonothecae absent.
Remarks
. The small habit of the present specimens, along with the characteristic shape of their hydrothecae and the twin, basal constrictions of the perisarc delimiting the stem internodes, place them close to
S. lagena
Allman, 1876
. However, the brief description, the limited illustrations and the lack of measurements in the account by
Allman (1879)
prevent us from determining whether they are conspecific or not, and examination of the
type
of
S. lagena
is required.
Stechow’s (1925) record of the species is suspect: the intrathecal perisarcal projections observed by him may, indeed, have been overlooked by Allman when he described
S. lagena
, but the characteristic position of the hydrothecae (the two rows being shifted unidirectionally so as to form an angle of
ca
. 90°), would certainly have not been overlooked. Additionally, the short branches springing alternately left and right from the stem resemble the characteristic habit of young colonies of
S. antarctica
Hartlaub, 1901
(see plate 3D).
Hartlaub (1901)
placed, with a query, Allman's species in the synonymy of
S. contorta
Kirchenpauer, 1884
, stating that a number of internodes observed by him in specimens originating from the Le Maire Strait, completely matched those originally illustrated for
S. lagena
. He also added that
S. contorta
was clearly distinguishable from
S. picta
(Meyen, 1834)
. However, from the account by Kirchenpauer,
S. contorta
appears similar to the
type
of
S. gaudichaudi
(Lamouroux, 1824)
examined by
Billard (1909
,
1922
), a species suspected by us to be a junior synonym of
S. picta
(Meyen, 1834)
8.
It becomes clear that, in order to solve these difficult taxonomic issues, a re-examination of the
types
of all the nominal species from the subantarctic is urgent and necessary.
Distribution in
Chile
. Strait of Magellan (present study).
World records
. Kerguelen (
Allman 1876
,
1879
).