Species of Staurotheca Allman, 1888 (Cnidaria: Hydrozoa: Sertulariidae) from US Antarctic expeditions, with the description of three new species
Author
Cantero, A. L. Peña
Author
Vervoort, W.
text
Journal of Natural History
2003
2003-11-30
37
22
2653
2722
http://dx.doi.org/10.1080/00222930210155701
journal article
10.1080/00222930210155701
1464-5262
Staurotheca vanhoeffeni
(Peña Cantero and García Carrascosa, 1994)
(figure 18)
Dictyocladium affine
: Vanhöffen, 1910: 331
, figure 44a–c.
Thuiaria affinis
: Stepan’yants, 1979: 95, pl. 18 figure 1, pl. 24 figures D, E, I.
Selaginopsis vanhöeffeni
Peña Cantero, 1991: 83–86
, pls 9, 43, pl. 65 figure a.
Selaginopsis vanhoeffeni
Peña Cantero and García Carrascosa, 1994: 121
, figure 3j–n; 1995: 32–35, figures 9A–J, 10A–E, 61D; Peña Cantero
et al
., 1996: 1–10, figures 1–3.
Staurotheca vanhoeffeni
: Peña Cantero
et al
., 1997: 337
, 373–375, figure 12; 1999: 160; Peña Cantero and García Carrascosa, 1999: 212
et seq
.
Material examined. 12
/
1002
, one extremely fragmented stem (largest fragment
ca
90 mm
long), with female gonothecae (
USNM
1003287; RMNH-Coel. 30325;
MNCN
2.03/296);
12
/
1003
, numerous fragments up to
60 mm
long (
USNM
1003288; RMNH-Coel. 30326);
32
/
1995
, two fragments up to
7 mm
long (
USNM
1003289);
46
/
5042
, several fragments and stems up to
85 mm
high, with male gonothecae (
USNM
1003290; RMNH-Coel. 30327;
MNCN
2.03/297);
6
/
418
, four fragments up to
18 mm
long (
USNM
1003291).
Description
. Material in fragmentary state, largest fragment up to
60 mm
long, with polysiphonic stem and branches. Branching in one plane, alternate or irregular; with anastomoses.
Hydrothecae arranged in decussate verticils of three to four hydrothecae (figure 18A) forming six to eight longitudinal rows. Hydrothecae (figure 18A–F) immersed into the stem and branches for approximately half their volume and adnate for almost full adcauline length. In lateral view hydrotheca cylindrical and slightly curved outwards. In frontal view maximum hydrothecal diameter at the hydrothecal base, from where diameter smoothly decreasing towards the aperture. Abcauline hydrothecal wall slightly concave. Hydrothecal aperture circular and tilted downwards, forming an acute angle with long axis of stem. Rim of hydrotheca even, frequently with a few, short renovations. Diaphragm mushroom-shaped, with two abcauline projections pointing towards the hydrothecal lumen.
F. 18.
Staurotheca vanhoeffeni
(Peña Cantero and García Carrascosa, 1994)
. (A) Fragment of branch showing arrangement of hydrothecae in verticils; (B–F) hydrothecae; (G) female gonotheca; (H) male gonotheca. (A, C–G: Stn 12/1002; B, H: Stn 46/5042.) Scale bar: 1 mm (A), 900 Mm (G, H), 400 Mm (B–F).
Both male and female gonothecae present, originating at the hydrothecal base. Proximal part of female gonotheca (figure 18G) cone-shaped, distally with a wide neck bearing a strongly laterally depressed aperture due to the presence of two lips of approximately equal development. Male gonotheca fusiform (figure 18H), provided with a distal neck bearing a small, circular aperture.
Ecology and distribution
.
Staurotheca vanhoeffeni
is a shelf species (Peña Cantero
et al.
, 1997), having been found from depths between 100 (Stepan’yants, 1979) and
400 m
(Peña Cantero and García Carrascosa, 1994) on bottoms of pebbles (Vanhöffen, 1910; Peña Cantero and García Carrascosa, 1994) and stones (Peña Cantero
et al.
, 1997). We found it from
210 to 426 m
on gravel. Fertile colonies were collected in January (Peña Cantero and García Carrascosa, 1994), February and March (Peña Cantero
et al.
, 1997) and April (Vanhöffen, 1910; Stepan’yants, 1979); in our material colonies collected in January and March have gonothecae.
Staurotheca vanhoeffeni
has a circum-Antarctic distribution (Peña Cantero and García Carrascosa, 1994), being known from both East and West
Antarctica
. In the former it is known from the Davis Sea (Vanhöffen, 1910; Stepan’yants, 1979). In West
Antarctica
,
S. vanhoeffeni
has been reported from off Graham Land (Stepan’yants, 1979), the South Shetland Islands (Stepan’yants, 1979; Peña Cantero and García Carrascosa, 1994), Elephant Island (Peña Cantero and García Carrascosa, 1994) and the eastern part of the Weddell Sea (Peña Cantero
et al.
, 1997). It is also known from off
Heard Island
(Stepan’yants, 1979) at the limits of the Antarctic region. Our material comes from the region of the Antarctic Peninsula (off Elephant Island, north-east of Joinville Island and north of d’Urville
Island
), from east of Cape Hallett (Victoria Land), from the Ross Sea, and from west of
Heard Island
.