Hydroids (Cnidaria, Hydrozoa) from Mauritanian Coral Mounds
Author
Gil, Marta
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. & Instituto Español de Oceanografía, Centro Oceanográfico de Vigo. Subida Radio Faro 50. 36390 Vigo. Spain.
Author
Ramil, Fran
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. es
Author
Agís, José Ansín
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. & ansinjose @ gmail. com
text
Zootaxa
2020
2020-11-16
4878
3
412
466
journal article
7931
10.11646/zootaxa.4878.3.2
288c6fc9-269b-468f-8811-d79d4350f6e4
1175-5326
4425132
4F59F5B2-CFDB-4819-AF83-0EF232328F8D
Filellum
cf.
serratum
(
Clarke, 1879
)
(
Fig. 2
C–E)
Filellum serratum
:
Millard, 1975: 178
, fig. 59A–C;
Millard, 1978: 177
;
Hirohito, 1995: 110–112
, fig. 31a–c; Calder, 1998: 1852–1853;
Peña Cantero
et al
., 1998: 304–308
, fig. 1–2;
Marques
et al
., 2011
.
Filellum
cf
serratum
:
Ramil & Vervoort, 1992: 54–55
;
Vervoort, 2006: 231–232
.
Material examined.
MAURIT-0911, stn
MUDR
01,
16º08´24”N
,
16º57´12”W
,
488 m
,
5-XII-2009
: 26 colonies, 9 attached to bryozoans, five to
Eudendrium
sp. and one to
Aglaophenia lophocarpa
; no coppiniae.
MAURIT-0911, stn
MUDR02
,
16º08´50”N
,
16º57´01”W
,
462 m
,
5-XII-2009
: one colony
on
Sertularella gayi
, without coppiniae
.
MAURIT-0911, stn
MUDR07
,
18º35´40”N
,
16º43´12”W
,
460 m
,
12-XII-2009
: three colonies,
on
Turritopsis
sp., without coppiniae
.
MAURIT-1011, stn
MUDR20
,
16º08´11”N
,
16º56´08”W
,
405 m
,
7-XII-2010
: three colonies, growing
on
Lafoea gracillima
and bryozoans, no coppiniae
.
MSM
16/3, stn GeoB 14801–1, BG,
20°14.762’N
,
17°40.173’W
,
568 m
,
3-XI-2010
: six colonies, four on
Aglaophenia lophocarpa
and one on
Nemertesia freiwaldi
n. sp.
, no coppiniae.
MSM 16
/3, stn GeoB 14802–1, BG,
20°14.791’N
,
17°40.188’W
,
595 m
,
3-XI-2010
: one colony attached to coral, without coppiniae
.
MSM 16
/3, stn GeoB 14886–1, ROV, 18°39.013’–
18°38.476’N
, 16°43.580’–
16°43.757’W
,
484–640 m
,
12- XI-2010
: one colony
on
Sertularella gayi
, no coppinia
.
MSM
16/3, stn GeoB 14908–1, ROV, 17°40.213’–
17°40.191’N
, 16°40.829’–
16°40.289’W
,
463–574 m
,
16- XI-2010
: nine colonies, three attached to
Halecium sibogae marocanum
, two to
Sertularella gayi
, two growing on
bivalvia
, two on unidentified hydroids, no coppiniae.
FIGURE 2.
A,
Turritopsis
sp. (stn MUDR07), part of colony. B,
Acryptolaria conferta minor
Ramil & Vervoort, 1992
(stn MUDR01), part of hydrocladium. C–E,
Filellum
cf.
serratum
(
Clarke, 1879
)
(stn GeoB 14908–1), hydrothecae. Scales: a, 0.5 mm; b, 1 mm; c–e, 0.3 mm.
MSM 16
/3, stn GeoB 14911–1, CKG,
17°28.910’N
,
16°41.509’W
,
450 m
,
16-XI-2010
: two colonies, on a bryozoan, without coppiniae
.
MSM 16
/3, stn GeoB 14914–1, ROV, 17°08.203’–
17°07.898’N
, 16°49.478’–
16°48.878’W
,
417–514 m
,
17-XI- 2010
: one colony growing
on
Sertularella gayi
, without coppiniae
.
Biology.
Filellum serratum
has been found growing on several substrata, mainly on hydroids but also on bryozoans, anthozoans, worm tubes and algae (
Peña Cantero
et al.
1998
;
Vervoort 2006
). Fertile material has been found in March, July and August (
Peña Cantero
et al
. 1998
).
The colonies studied here were mainly growing on bryozoans and the hydroids
A. lophocarpa
Allman, 1877
,
N. freiwaldi
n. sp.
,
H. sibogae marocanum
,
S. gayi
,
Eudendrium
sp.,
Turritopis
sp. and
L. gracillima
. No coppiniae were found.
Distribution.
It is a circumglobal species (
Peña Cantero
et al
. 1998
); however, most identifications are based on sterile material, and, in consequence, its actual distribution remains uncertain (
Vervoort 2006
). In West Africa, it was collected from Canary Islands (
Vervoort 2006
),
Mauritania
(
Gil & Ramil 2017a
) and
Cape Verde
Archipelago (
Vervoort 2006
). The bathymetric distribution ranges between 0 and
2000 m
(
Millard 1978
; Calder 1998).
Our material was collected from depths of
405 to 640 m
.
Description.
Colonies stolonal, hydrorhizal stolons giving rise to tubular hydrothecae with the adnate part with fine transversal striae or corrugations on its upper surface; free part curving away from the adnate part, resulting in an erect distal part of variable length, varying between one-third to three-fourth of hydrothecal length. Hydrothecal rim circular, smooth and slightly everted. Renovations of hydrothecae are common and on occasion numerous, oscillating between one and eight. Coppinia not observed.
Remarks.
Identification of the different species of
Filellum
requires the study of its coppiniae (
Marques
et al.
2011
); however, all the material studied by us was sterile. The hydrothecae showed the characteristic transverse striae of
F. serratum
, the only species with the hydrothecal wall striated in the Atlantic; consequently, we identified it tentatively
F.
cf.
serratum
.
Filellum antarcticum
(Hartlaub, 1904)
,
Filellum magnificum
Peña Cantero, Svoboda & Vervoort, 2004
and
Filellum nitidum
Watson, 2005
also have striated hydrothecae, but they are only known in the Antarctic and
South Africa
, Antarctic and
Australia
, respectively. Nevertheless, some differences in coppinia morphology within the fertile material assigned to
F. serratum
by several authors suggest that several species could be involved in its current definition (see
Peña Cantero
et al.
1998
and
Marques
et al.
2011
).