Rissoidae gastropods of the outer continental shelf and slope off Galicia (NW Spain)
Author
Oliver, Joan Daniel
Alcorisa 83 - 12 C, 28043 Madrid, Spain. joandanieloliver @ hotmail. com
Author
Gofas, Serge
Departamento de Biología Animal, Universidad de Málaga, E- 29071 Málaga, Spain.
Author
Urgorri, Victoriano
Estación de Bioloxía Mariña da Graña, REBUSC, Universidade de Santiago de Compostela, Spain.
Author
Díaz-Agras, Guillermo
Estación de Bioloxía Mariña da Graña, REBUSC, Universidade de Santiago de Compostela, Spain.
Author
Templado, José
Museo Nacional de Ciencias Naturales (CSIC), José Gutiérrez Abascal 2, 28006 Madrid, Spain.
text
Zootaxa
2022
2022-10-18
5196
1
1
45
journal article
170600
10.11646/zootaxa.5196.1.1
e1042177-7e89-413a-b10b-3803d000d20d
1175-5326
7224080
1B12892E-D68F-4BFE-8E9A-7F19E220E73D
Alvania xelae
Oliver & Urgorri
sp. nov.
(
Fig. 14
)
Alvania electa
—
Bouchet &Warén, 1993: 663–636
(in part), figs. 1416–1417.
Type material.
Holotype
:
SPAIN
• 1 emPty shell (
Figs. 14d–h
);
43° 57.030′N
,
008° 54.795′W
to 43° 57.248′N, 008° 54.133′W; 1191–
1132 m
;
08–15 SeP. 2002
; DIVA-Artabria I
AT-1000
;
MHNS
, dePosit number: MHN-USC-10117
.
Paratypes
:
SPAIN
• 2 sh (
ParatyPes
1 and 2);
43° 51.265′N
,
008° 54.480′W
to 43° 51.498′N, 008° 53.123′W; 827–
819 m
;
08–15 Sep. 2002
; DIVA-Artabria I
DRN-800
;
MNCN 15.05
/200227
•
1 sh;
43° 52.823′N
,
008° 56.151′W
to 43° 52.837′N, 008° 55.597′W; 988–
920 m
;
08–15 SeP. 2002
; DIVA-Artabria I
DRN-1000
•
2 sh;
43° 47.188′N
,
008° 53.053′W
to 43° 55.312′N, 008° 53.101′W;
770–842 m
;
08–15 SeP. 2002
; DIVA-Artabria I
AT-800
•
1 spc + 22 sh;
43° 57.030′N
,
008° 54.795′W
to 43° 57.248′N, 008° 54.133′W; 1191–
1132 m
;
08–15 SeP. 2002
; DIVA-Artabria I
AT-1000
•
1 sPc + 1 sh;
43° 53.575′N
,
008° 56.868′W
to 43° 54.015′N, 008° 56.959′W;
965–974 m
;
10–20 SeP. 2003
; DIVA-Artabria I
DRN-1000
•
12 sPc + 3 sh;
43° 48.587′N
,
008° 51.402′W
to 43° 49.545′N, 008° 51.197′W; 610–
598 m
;
10–20 Sep. 2003
; DIVA-Artabria I
EBS-600
•
12 sh;
43° 51.873′N
,
008° 53.683′W
to 43° 53.120′N, 008° 53.301′W; 802–
788 m
;
10–20 SeP. 2003
; DIVA-Artabria I
EBS-800
•
1 sh;
Polygon
delimited by
Points
44° 10.000′ N
,
009° 00.000′ W
/44° 10.000′ N, 008° 35.000′ W/44° 00.000′ N; 009° 00.000′ W/44° 07.000′ N; 008° 35.000′ W;
720 m
; SARRIDAL (2006–2007) SARRI-1
•
14 sh;
44° 11.652′N
,
008° 58.152′W
to 44° 11.539′N, 008° 57.574′W;
908–1106 m
;
15–24 Jul. 2008
; A
SELVA
DRN-7
•
2 sh;
44° 08.65′N
,
008° 55.305′W
to 44° 08.771′N, 008° 55.104′W; 581–
566 m
;
15–24 Jul. 2008
; A
SELVA
DRN-7
C
•
1 sh;
43° 34.86′N
,
009° 21.95′W
to 43° 36.44′N, 009° 20.71′W;
1010–1112 m
;
15–30 SeP. 2008
; DIVA-Artabria II
EBS-04
.
Type
locality:
Ferrol Canyon
off
Galicia
coast (43° 57.030′-
43° 57.248′N
,
008° 54.795′W-
00854.133′W,
1132–1191 m
)
.
Derivatio nominis
:
This species is dedicated to Dra. Xela Cunha Veira who has participated in the collection of samples in all oceanographic campaigns and for the custody and handling of the samples studied.
Description.
Shell with a moderately high sPire with conical outline, aPical angle of about 45° and a blunt aPex, somewhat solid, with conspicuous reticulated sculpture (
Fig. 14a
).
Holotype
(
Fig. 14d
) of 1.6 x 1.0 mm with four convex whorls. Adult shells studied up to 1.7 x
1.2 mm
. Well-marked, somewhat channeled suture. Colour white. Aperture pyriform, pointed at union with penultimate whorl, height
0.56 mm
(about 46% of total height). Umbilical area with chink and coarse growth lines. About 20 sharP, orthocline axial ribs, at about 10° with sPire axis, narrower than interspaces on the body whorl and disappearing toward the base. Thick spiral cords, also narrower than interspaces, more developed on the periumbilical area of the body whorl. Entire surface covered by regularly distributed spiral threads, much narrower than their interspaces, often interrupted where crossing growth lines (
Fig. 14e
). Outer lip slightly opisthocline with a thin edge, thickened externally and not thickened inside. Inner lip thin, bordering a narrow umbilicus.
Radulae, operculum and soft parts have not been described since they show great uniformity in species of this genus. Specimens are kept for possible future studies.
Protoconch of 1.25 convex whorls (
Figs.
14g
–h
) whose surface is covered by minute granules irregularly arranged (
Fig. 14c
) overlapping wide, diffuse spiral cords (
Fig. 14b
).
Remarks.
About 75 shells and specimens were found in 10 samples collected between 400 and
1200 m
. Most of the shells with soft parts were found in a sample at around
600 m
depth in sandy bottom. No notable variability was observed.
Alvania xelae
sp. nov.
has been believed to fall within the variability of
A. electa
, and corresponds to one of the shells illustrated under that name by
Bouchet & Warén (1993
, figs. 1416–1417 from THALASSA st X362 at
385–600 m
off north
Spain
coasts).
Alvania xelae
sp. nov.
differs from
A. electa
by its more convex whorls, not so deeply channelled suture and especially by its protoconch with wide diffuse spiral cords (
Fig. 14b
) instead of fine striae (
Figs. 9b–c
). This sculpture of the protoconch also differentiates it from the other species of the group of
A. electa
(
A. porcupinae
,
A. adinogramma
,
A. cancapae
and
A. candasae
sp. nov.
). On the other hand,
A. seinensis
from the Seine seamount has a shell protoconch similar to that of the new species but its teleoconch has much finer and more numerous ribs (more than 40 on the penultimate whorl) and a less marked spiral sculpture (
Gofas 2007
, fig. 7E–F).