New species and new records of hydroids (Cnidaria: Hydrozoa) from Chile
Author
Galea, Horia R.
Author
Schories, Dirk
Author
Försterra, Günter
Author
Häussermann, Verena
text
Zootaxa
2014
3852
1
1
50
journal article
http://dx.doi.org/10.11646/zootaxa.3852.1.1
2fb83006-f93c-4492-aed0-f5f0707f553e
1175-5326
286956
7DE3BCBA-E5F0-4F0D-B2FD-B5B59E4DAE51
Halecium humeriformis
Galea & Schories
,
sp. nov.
(
Figs
2
E, F;
3
D;
4
C,
Table
4
)
?
Halecium gracile
―
Jäderholm,
1903
:
266
, pl.
12
Figs 2
, 3. not
Halecium gracile
Bale,
1888
:
759
, pl.
14
Figs
1
–3.
Material examined
. Taltal, lat. -
25.38333
, long. -
70.51667
,
24
.iv.2012
, 12‒
20 m
, sample
27
: numerous stems, up to
9 mm
high, on bryozoan covered barnacle, with male and female gonothecae (
holotype
: MHNG-INVE-
86222
); sample
50
: numerous female stems, up to
8 mm
high, on barnacle (
paratype
: MHNG-INVE-
86223
).
Description
. Stems monosiphonic, scarcely branched, up to
9 mm
high, arising from creeping, branching hydrorhiza. A constriction above origin from stolon, then stem broken up into slightly geniculate to almost collinear internodes, each of which of moderate length, with bulges at both ends, and a latero-distal hydrophore supporting a terminal hydrotheca (
Fig.
2
E1, 3). Hydrophores long, with a pseudodiaphragm on adaxial side; hydrotheca deep, with everted margin; renovations common (
Fig.
2
F). Side branches, when present, given off singly from the primary hydrophores (
Fig.
2
E
2
); structure identical to the stem. Gonothecae arising from the primary hydrophores, from within the primary hydrotheca, or as a replacement of it, as well as from the stolon. Female laterally flattened, broadly ovoid in frontal view, tapering abruptly below into short pedicel; distally there are two lateral, earlike outgrows, in the middle of which there is a circular, notched aperture (Fig.
3
D
1–3
).
Male
gonothecae ovoid, borne of short pedicel (Fig.
3
D
4
). Cnidome (
Fig.
4
C
): small heteronemes [(
3.1–3.4
) ×
1.7
µm], microbasic mastigophores [(
5.7
–6.0) ×
1.7
µm], and conspicuously curved heteronemes [(
8.3–9.2
) ×
2.3
µm].
Remarks
.
Male
and female stems are found together on the same substrate, a barnacle, but, since the latter is overgrown with an encrusting bryozoan, it is impossible to check whether the same stolon unites stems of both sexes.
The female gonotheca of
H. humeriformis
resembles that of the South African material assigned by
Millard (
1957
)
to a new variety,
magnum
, of
H. parvulum
12
Bale,
1888
. However, her material has much larger dimensions compared to ours. It seems therefore justifiable, as already remarked by
Schuchert (
2005
, p.
630
)
, to raise this variety to species, as
H. magnum
Millard,
1957
.
The cnidome of the new species includes a peculiar, large, banana-shaped heteroneme (
Fig.
4
C
), and therefore differs from the homologous capsules found in the other species described herein. It will be shown below that another congener,
H. tristaniensis
sp. nov.
, possesses an unusual capsule, too, suggesting that the knowledge of the cnidome in haleciids may represent a useful tool for discriminating between the species.
Etymology
. The specific name is a fusion between two Latin words,
viz
.
humerus
(pl.
-i
), meaning shoulder(s), and
forma
(meaning shape), making reference to the latero-distal diverticles of the female gonotheca.
Distribution in
Chile
. Only known from Taltal (present record).