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
36804
10.11646/zootaxa.3852.1.1
2fb83006-f93c-4492-aed0-f5f0707f553e
1175-5326
286956
7DE3BCBA-E5F0-4F0D-B2FD-B5B59E4DAE51
Sertularella pauciramosa
Galea & Schories
,
sp. nov.
(Plate 3B; Fig. 6F, H; 7D;
Table 8
)
Material examined
. Taltal, Punta Morada, lat. -25.36667, long. -70.45000,
20.iv.2012
, 15 m, sample 13: up to
4 cm
high, female colony on worm tube (
paratype
: MHNG-INVE-86234). Taltal, lat. -25.38333, long. -70.46667,
21.iv.2012
, 20 m, sample 07: up to
3.5 cm
high, sterile colony on algae (
paratype
: MHNG-INVE-86233);
23.iv.2012
, 22 m, sample 17: up to
6 cm
high, male colony on worm tube (
holotype
: MHNG-INVE-86235).
Description
. Colonies arising from creeping, branching, anastomosing hydrorhiza. Stems erect, monosiphonic, slightly geniculate to almost straight (Pl. 3B), perisarc rather thick, almost transparent; a varied number of basal annuli above origin from stolon, followed by a short, smooth part; remainder of cauli divided into internodes by oblique constrictions of the perisarc, slightly marked to indistinct, slanting in opposite directions. Each internode rather short, carrying a latero-distal hydrotheca; adaxial cusp of one hydrotheca almost reaching the base of following one. Side branches, when present, arising irregularly from below bases of stem hydrothecae, generally laterally (giving the colony a coplanar appearance) or, more rarely, slightly in front or rear side of the colony (Fig. 6F). Base of branch delimited from stem by a rather distinct node; first internode generally longer than subsequent ones. Hydrothecae (Fig. 6H) alternate, flask shaped, slightly curving outwards; adnate for 2/5th their adaxial length; free adaxial wall smooth to wavy (in which case provided with 2–3 weak undulations); abcauline wall varied in shape, from slightly concave, to straight, to rarely convex; aperture perpendicular to long axis of hydrotheca, constricted below rim; four pointed triangular cusps separated by shallow embayments; operculum of four triangular plates. Gonothecae of both sexes given off from below the bases of stem hydrothecae; ovoid, walls undulated to occasionally rather smooth; male longer and slightly slender than female (compare Fig. 7D1 and 7D2); aperture mounted on short neck provided with 3–4 distal horns flanking the aperture; female containing up to 20 large oocytes.
Remarks
. The general appearance, the mode of branching, the shape of both hydro- and gonothecae recall the widely-spread
S. polyzonias
(Linnaeus, 1785)
. A comparison with specimens of the latter from Brittany,
France
(Fig. 6G), showed −however − that
S. pauciramosa
is a smaller species, with less adnate hydrothecae [about 2/5th, compared to 1/2 or less in
S. polyzonias
, this feature being also evident from the accounts of Ramil & Vervoort (1992) and Ramil
et al
. (1992)].
Etymology
. The specific name results from the fusion of two Latin words,
pauci
(meaning few) and
ramus
(meaning branch), and illustrates the rather scarce branching pattern of the colonies.
Distribution in
Chile
. Only known from around Taltal (present study).
TABLE 8.
Comparison of
Sertularella pauciramosa
sp. nov.
with
S. polyzonias
(Linnaeus, 1758)
; measurements in µm.
Sertularella pauciramosa
sp. nov.
S. polyzonias
(Linnaeus, 1758)
Reference
Present study Present study Ramil
et al
. (1992)
Internodes
- length 815–1140 |
890–1170 |
816–912 |
- diameter at node 195–230 |
230–310 |
260–302 |
Hydrotheca
|
- free adaxial wall 390–425 |
445–535 |
330–375 |
- adnate adaxial wall 315–380 |
405–435 |
475–490 |
- abaxial wall 635–690 |
670–730 |
576–605 |
-
maximum
width 335–365
|
400–425 |
– |
- diameter at aperture 220–275 |
275–290 |
303–345 |
Gonotheca
|
- length 1710–1965 (
♂)
1490–1710 (
♀)
|
Not seen |
1770–1950 |
- width 660–730 (
♂)
660–805 (
♀)
|
Not seen |
740–850 |
Symplectoscyphus flexilis
(Hartlaub, 1901)
(Fig. 7E, F)
|
Material examined
. Corral, Chaihuin/Huiro, lat. -39.95000, long. -73.61667,
17.x.2011
, 18 m, sample 01: fertile colony on sponge, stems up
3.5 cm
high (MHNG-INVE-86241);
22.iii.2012
, 6 m, sample 13: fertile colony on sponge, stems up to 3.0 cm high (MHNG-INVE-86242).
Remarks
. Besides its discovery in
Chile
by
Hartlaub (1901b)
, the second record from the country (
Galea & Schories 2012a
) was based on sterile specimens. The present material, with gonothecae, is in agreement with earlier descriptions [
Blanco (1967a)
, as
S. glacialis
(
Jäderholm, 1904
)
;
Blanco (1976)
, as
S. modestus
(Hartlaub, 1901)
;
Blanco (1980)
], and confirms our previous identification.
Distribution in
Chile
. Calbuco (Hartlaub 1901), Punta de Choros (
Galea & Schories 2012a
), and Corral (present record).
World records
.
Argentina
(see
Galea & Schories 2012a
).