Benthic hydroids (Cnidaria, Hydrozoa) from bathyal and abyssal depths of the Northeast Atlantic held in the modern Discovery Collections
Author
Peña Cantero, Álvaro L.
Author
Horton, Tammy
text
Zootaxa
2017
2017-11-10
4347
1
1
30
journal article
31577
10.11646/zootaxa.4347.1.1
49a11228-6c4d-478f-b958-52610eaab951
1175-5326
1044772
176D72B0-0DD6-4D51-83CA-D47C2268A3CF
Schizotricha profunda
(
Nutting, 1900
)
(
Fig. 8
)
Plumularia profunda
Nutting, 1900
: 66
–67, pl. 8 figs 2–3.
Not
Polyplumaria profunda
—
Broch, 1918
: 60
–62, figs 28–29 [=
Schizotricha variabilis
(Bonnevie, 1899)
].
Schizotricha profunda
—
Peña Cantero & Vervoort, 1999
: 368
–371, fig. 3.
Material examined. 54907#3
, four stems up to
18 mm
high, on coral, with gonothecae.
Description.
Stems polysiphonic, up to
18 mm
high. Stem with alternately arranged cauline apophyses giving rise to hydrocladia (
Fig. 8F
). Stem divided into internodes with one to two cauline hydrothecae. Each at axil between cauline apophysis and internode and with three associated nematothecae (
Fig. 8A–B
): two flanking hydrothecal aperture and one under the hydrotheca. Cauline apophyses with one basal nematotheca (
Fig. 8B
). Hydrocladia unbranched, heteromerously divided into internodes with one or two hydrothecae. Each hydrocladial hydrotheca with three associated nematothecae (
Fig. 8C–D
): two flanking hydrothecal aperture and one infrathecal nematotheca. Hydrotheca elongate (
Fig. 8E
), length slightly increasing along hydrocladia (e.g. abcauline length from 230 to 290 µm).
Gonothecae inserted on cauline and hydrocladial internodes through a small pedicel (
Fig. 8E–F
); up to two gonothecae per internode (
Fig. 8E
). Gonotheca inverted pear-shaped (
Fig. 8F
), with circular diaphragm at basal fifth delimiting a basal chamber. Two nematothecae inserted at diaphragm. Gonothecal aperture wide, subterminal and adcaudally directed. Gonotheca 400 µm high and 240 µm in maximum diameter.
Remarks.
Schizotricha profunda
is the only species of the genus with unforked hydrocladia. These are typically branched once or several times in the remaining species of
Schizotricha
.
Peña
Cantero and Vervoort (1999
: 369), who re-described the species after examining the
type
material, discussed the differences with the morphologically closest species of the genus.
Ecology and distribution.
This is a bathyal species (
Peña Cantero & Vervoort 1999
), previously reported from
491 to 792 m
depth (
Nutting 1900
); present material collected at
1060 m
, distinctly increasing its lower bathymetric limit, on coral, and with gonothecae in May.
Hitherto
, only known off the east coast of
Florida
(
30°44’N
79°26’W
and
30°53’N
79°42’30’’W
) (
Nutting 1900
). Our material, which represents the second record for the species, comes from the Porcupine Seabight.