The genera Egmundella Stechow, 1921 and Cyclocanna Bigelow, 1918 (Cnidaria, Hydrozoa) in waters of Northwest Africa
Author
Gil, Marta
0000-0002-8985-332X
Departamento de Ecoloxía e Bioloxía Animal, Facultade de Ciencias do Mar e Centro de Investigación Mariña (CIM-UVigo), Universidade de Vigo. Campus Lagoas-Marcosende. 36310 Vigo. Spain. & martag @ uvigo. gal; https: // orcid. org / 0000 - 0002 - 8985 - 332 X
martag@uvigo.gal
Author
Ramil, Fran
0000-0002-9146-8201
Departamento de Ecoloxía e Bioloxía Animal, Facultade de Ciencias do Mar e Centro de Investigación Mariña (CIM-UVigo), Universidade de Vigo. Campus Lagoas-Marcosende. 36310 Vigo. Spain. & framil @ uvigo. gal; https: // orcid. org / 0000 - 0002 - 9146 - 8201
framil@uvigo.gal
text
Zootaxa
2023
2023-04-17
5264
4
490
504
http://dx.doi.org/10.11646/zootaxa.5264.4.2
journal article
10.11646/zootaxa.5264.4.2
1175-5326
7836965
3C867D94-E8FC-4A19-A275-2DCA88590BEE
Cyclocanna producta
(G.O.
Sars, 1874
)
(
Fig. 6
;
Table 5
)
Cyclocanna producta
—
Schuchert
et al
., 2017: 177
, fig. 7.
Lovenella producta
—
Fraser, 1944: 175
, pl. XXXI fig. 149;
Cornelius, 1995: 166–168
, fig. 37;
Schuchert, 2001: 54
, fig. 39;
Calder, 2012: 22–23
, fig. 21.
Egmundella producta
—
Schuchert, 2016: 219–224
, figs 1A–D, 2A–C, 3A–F.
Material examined.
Morocco
.
MAROC-0411, stn MO31, 34º28′56″–
34º27′33″N
, 7º12′22″–
7º11′02″W
,
1722– 1824 m
,
24-XI-2004
: a colony,
4 mm
high, growing
on
Halecium delicatulum
, without gonothecae
.
MAROC-0411, stn MO56, 33º32′05″–
33º31′60″N
, 8º26′43″–
8º28′34″W
,
1556–1620 m
,
02-XI-2004
: two colonies,
1–5 mm
high, one growing on
Halecium delicatulum
, the other on
Stegolaria geniculata
; both without gonothecae.
Western Sahara
.
MAROC-0611, stn MO189, 21º09′04″–
21º12′24″N
, 17º42′06″–
17º42′18″W
,
556–564 m
,
14- XI-2004
: a colony, 1.9 mm high, growing on an unidentified hydrozoan, without gonothecae
.
MAROC-0611, stn MO235, 23º12′00″–
23º14′27″N
, 17º11′16″–
17º12′27″W
,
909–913 m
,
27-XI-2006
: a colony, 0.6 mm high, growing on
Halecium
sp
, without gonothecae.
MAROC-0611, stn MO260, 24º31′21″–
24º33′03″N
, 16º51′04″–
16º48′12″W
,
1429–1440 m
,
05-XII-2006
: a colony,
4 mm
high, growing on
Lafoea gracillima
, without gonothecae.
Mauritania
.
MAURIT-0811, stn
MU89
,
20
º20′50″–
20º18′23″N
, 17º53′30″–
17º52′03″W
, 1012–
1000 m
,
20-XI-2008
: three colonies up to
4 mm
high, one growing
on
Eudendrium ramosum
, another on an unidentified hydrozoan, and the last one on a
plastic net
; all with gonothecae
.
MAURIT-0911, stn
MU195
,
20
º24′31″–
20º26′10″N
, 18º03′31″–
18º06′10″W
, 1236–
1214 m
,
23-XI-2009
: two colonies growing on bivalves, without gonothecae
.
FIGURE 6.
Cyclocanna producta
(G.O.
Sars, 1874
)
, stn MU89;
a
, a portion of colony with hydrothecae;
b
, gonotheca seen frontally;
c
, nematothecae. Scale bar:
a–b =
1 mm; c = 0.3 mm.
Guinea
Bissau
.
CCLME 2011-410
, stn
GR-
04,
10º26′47′′N
,
17º22′43′′W
,
504 m
,
28-X-2011
: a colony growing on a worm tube, without gonothecae.
Description.
Colonies stolonal, with hydrothecae, nematothecae and gonothecae arising irregularly from filiform hydrorhiza. Hydrothecae borne on long, smooth pedicels, with some short basal undulations and some others irregularly-placed along its length. Hydrotheca deeply campanulate, elongated, tapering basally where it is provided with a transverse, thin diaphragm; walls parallel, widening distally, rim not apparent, aperture closed by a conical operculum composed of 10–12 triangular flaps that can be folded either inwards or outwards, and in this case, the rim is distinctly-marked. Nematothecae arising between the hydrothecae, egg-shaped, borne on short pedicels, aperture apical, circular.
Gonothecae fan-shaped, strongly flattened “dorso-ventrally”, borne on short, slightly undulated pedicels, aperture distal, large, spanning from one side to the other.
Biology.
This species has been found growing on various hydroids, notably
Tubularia indivisa
Linnaeus, 1758
(
Calder 2012
), dead
Lophelia
corals (
Cornelius 1995
), polychaete tubes and ascidians (
Schuchert 2016
). Gonothecae have been found in April (
Schuchert 2016
) and November (
Gil & Ramil 2017
).
In our material, colonies were growing on the hydroids
Lafoea gracillima
,
Eudendrium ramosum
(Linnaeus, 1758)
and
Halecium
sp.
, as well as on bivalves, a worm tube and a plastic net. One colony with gonothecae was found in November.
Distribution.
This species has a North-Atlantic distribution, from the Lofoten Islands to Øresund and southwest
Ireland
in the East, and from northern
Canada
to Cape Cod in the West (
Calder 2012
).
Fraser’s (1944)
record from the Pacific coast of North America was considered doubtful by
Schuchert (2016)
. We also agree with him regarding the exclusion of the material from the Bay of Biscay reported by
Vervoort (1985)
, due to its gonothecae being very different from the flattened ones described in
C. producta
by
Schuchert (2016
, as
E. producta
) and those reported upon by
Gil & Ramil (2017)
from Mauritanian material. Its previously-known bathymetric distribution ranges from
6 to 750 m
(
Schuchert 2016
).
Our material was collected from
Morocco
to
Guinea
Bissau
at depths of
504 to 1440 m
.
Remarks.
DNA barcoding of
Cyclocanna welshi
Bigelow, 1918
and
Egmundella producta
(Sars G.O. 1874)
, prompted
Schuchert
et al
. (2017)
to conclude that the first nominal species is the medusa of the second. Because the distributions of the polyp and medusa, restricted to the cool waters of the North Atlantic, matched, the authors synonymised both names under the new combination,
Cyclocanna producta
(G.O.
Sars, 1874
)
. Our records of typical colonies of ‘
E. producta
’ from deep waters of West Africa expand its southern limit of distribution from Southwest Ireland (
Calder 2012
) to
Guinea-Bissau
.
The presence of gonothecae in the material collected from
Mauritania
and the morphology of the trophosome, with long hydrothecal pedicels and stolonal nematothecae, allowed us to identify this material as
C. producta
(see also Gil 2017).
TABLE 5.
Measurements of
Cyclocanna producta
(G.O.
Sars, 1874
)
, in µm.
MAURIT-0811
St. 10 (MU89) Pedicel, length from base to ‘diaphragm’ 1925–10000 diameter of pedicel 102–235 Hydrotheca, length ‘diaphragm’-rim, excluding. operculum 551–918
idem
, including operculum 673–1102
diameter at rim 205–530
diameter at ‘diaphragm’ 143–230 Nematotheca, length including pedicel 56–72
maximal diameter 36–46 Gonotheca, length including pedicel 1150–2725 maximum width 938–2850