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 electa
(
Monterosato, 1874
)
(
Fig. 9
)
Material examined. (
4 empty shells and 6 with soft parts, in 6 samples):
SPAIN
•
1 sPc;
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
•
2 sPc + 2 sh;
43° 36.544′N
,
009° 03.064′W
to 43° 36.816′N, 009° 04.339′W;
601–619 m
;
17–28 SeP. 2004
; VERTIDOS
GA-EBS-600
•
1 spc;
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;
417–668 m
; SARRIDAL (2006–2007) SARRI-4
•
1 sh;
44° 08.516′N
,
008° 40.788′W
to 44° 09.688′N, 008° 39.721′W; 436–
428 m
;
15–24 Jul. 2008
; A
SELVA
EBS-11
•
1 sPc + 1 sh;
44° 08.516′N
,
008° 40.788′W
to 44° 09.688′N, 008° 39.721′W; 436–
428 m
;
15–24 Jul. 2008
; A
SELVA
EBS-11-2
•
1 spc;
43° 48.252′N
,
008° 51.427′W
to 43° 49.707′N, 008° 51.164′W;
575–584 m
;
15–24 Jul. 2008
; A
SELVA
EBS-30-1
.
FIGURE 9.
Alvania electa
(
Monterosato, 1874
)
(VE:GA-EBS-600).
a
Shell (1.8 mm);
b–c
Protoconch from a and detail of its microsculpture;
d–e
Details of microsculpture of the teleoconch of figure a;
f
Shell (1.7 mm);
g–h
Lateral view of the protoconch from f and detail of its microsculpture;
i
Apical view of another protoconch.
Remarks.
This species has been recorded from the southern part of the Bay of Biscay to off the
Canaries
and Mediterranean Sea (where the
type
locality is located) in a wide depth range, normally in
150–800 m
and occasionally deeper down to
2770 m
(
Bouchet & Warén 1993
). We have found six shells with soft parts and four empty shells in samples collected between 400 and
700 m
in muddy sand bottoms.
Alvania electa
is a rather variable species, as was pointed out by
Bouchet & Warén (1993)
, and a cryptic species-complex may be involved. Its complex synonymy was unraveled by
Oliverio
et al
. (1992)
. This species is characterized by its deeply channeled suture, low number of sharp axial ribs, narrow umbilical chink, and large and blunt apex (
Figs. 9a, d–f
). Protoconch sculpture with irregular microgranules separated by about six equidistant fine riblets (
Figs. 9b, c, g–i
).
The specimens here studied match with those figured by
Gofas & Warén (1982
, figs. 24 and 32 as
Alvania deliciosa
(
Jeffreys, 1884
)
,
Oliverio
et al.
(1992
, figs. 17–20) and
Bouchet & Warén (1993
, figs. 1412, 1415 and 1420).
In
Figure 10 a–d
we show for comparison a shell (as
Alvania
sp.
) from the
Djibouti
Bank (Alborán Sea) whose protoconch is like that of
A. electa
, but because its convex whorls and the higher number of axial ribs it resembles
Alvania porcupinae
Gofas & Warén, 1882
. On the other hand, the Mediterranean
Alvania elegantissima
(
Monterosato, 1875
)
has sometimes been confused with
A. electa
, but according to
Oliverio
et al.
(1992)
its convex whorls and protoconch without sculpture allow differentiate both species.
Figure 10e–g
shows a shell from off the Italian coast of the Tyrrhenian Sea that may be
Alvania elegantissima
by having opisthocline axial ribs and a protoconch lacking sculpture.