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
Symplectoscyphus
sp.
(Plate
3
E;
Fig.
8
E–H)
Material examined
. HF
9
,
Isla
Magel, lat. -
54.92655
, long. -
67.41338
,
19
.xii.2010
, 6 m, sample C
281
: colony on seaweed, composed of several stems (up to
4.5 cm
high) and smaller fragments, and a single gonotheca.
Description
. Colony
4.5 cm
high, fan shaped, delicate (Pl.
3
E). Stems monosiphonic with a few annuli above origin from stolon, then regularly divided into oblique internodes by constrictions of the perisarc. Each internode with
3
alternate hydrothecae and a lateral apophysis given off from below the distalmost hydrotheca, the latter becoming axillar (
Fig.
8
E); presence of apophysis introduces a bent in the structure of the stem. Cladia borne of corresponding stem apophyses, junction marked by transverse node. Cladia given off in same plane as the stem, conferring the whole colony a planar appearance; divided into regular internodes by oblique nodes, each carrying a distally placed hydrotheca. Cladia almost straight, unless the presence of a lower order branch introduces a bend, like in the stem; up to
4
th order branches, lower order ones given off irregularly. Hydrothecae alternate on both stem and branches, and rather distant; tubular, adnate for half their adaxial length; abaxial wall slightly swollen basally, becoming convex distally; free adaxial wall almost straight (
Fig.
8
F); aperture with three triangular cusps separated by rather deep embayments; a conspicuous abaxial, submarginal cusp projects to a varied degree into the lumen of hydrotheca (
Fig.
8
G). A single gonotheca, of undetermined sex, arises from below the base of a stem hydrotheca; immature, with distal part incomplete; wall with nine free, independent ribs (
Fig.
8
H).
Remarks
. This species somehow resembles
S. filiformis
(
Allman,
1888
)
in the colony structure and the shape of hydrotheca. Its gonotheca, though incomplete, recalls also that of Allman’s species. However, the presence of a prominent abaxial, submarginal cusp is not a feature met with in any of the numerous specimens of
S. filiformis
examined so far. Its identification to species is pending the discovery of specimens with fully formed gonothecae.
Distribution in
Chile
. Magel
Island
(present study).