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
Pusillina inconspicua
(
Alder, 1844
)
(
Fig. 20
)
Material examined.
(12 empty shells and 23 with soft parts in 8 samples):
SPAIN
• 1 sPc;
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
•
5 spc (1 juv);
43° 35.451′N
,
008° 34.432′W
to 43° 34.810′N, 008° 35.407′W; 153–
151 m
;
08–15 SeP. 2002
; DIVA-Artabria I
EBS-150
•
1 sh;
43° 26.703′N
,
008° 30.669′W
to 43° 27.452′N, 008° 29.612′W; 103–
102 m
;
10–20 SeP. 2003
; DIVA-Artabria I
EBS-100
•
1 sh;
43° 40.250′N
,
008° 43.755′W
to 43° 40.760′N, 008° 42.120′W; 207–
197 m
;
10–20 Sep. 2003
; DIVA-Artabria I
EBS-200
•
5 sPc;
43° 29.412′N
,
008° 28.362′W
to 43° 29.779′N, 008° 28.240′W;
110– 111 m
;
17–28 Sep. 2004
; VERTIDOS GA-AT-110
•
10 sPc + 10 sh;
42° 30.391′N
,
009° 19.517′W
to 42° 29.428′N, 009° 17.924′W;
147–148 m
;
17–28 SeP. 2004
; VERTIDOS AG-EBS-150
•
1 sPc:
42° 31.176′N
,
009° 23.380′W
to 42° 32.132′N, 009° 24.151′W;
242–248 m
;
17–28 SeP. 2004
; VERTIDOS AG-EBS-250
•
1 sPc;
42° 50.507′N
,
009° 25.773′W
to 42° 48.810′N, 009° 25.198′W; 151–
148 m
;
17–28 SeP. 2004
; VERTIDOS CA-EBS-150
.
FIGURE 20.
Pusillina inconspicua
(
Alder, 1844
)
(VE:AG-EBS-150).
a
Shell (1.5 mm);
b
Shell (1.2 mm);
c
Lateral view of the protoconch;
d
Detail of the embryonic/larval protoconch transition (arrow);
e
embryonic protoconch.
f
Variable sculpture of wide axial ribs very weak or almost totally missing;
g
Spiral micro-cord close to the suture of the protoconch.
Remarks.
A species-complex can hide under the name
Pusillina inconspicua
(
Gofas & Oliver 2011
)
due its variability, its discontinuous geographic distribution along the eastern Atlantic from
Norway
to
Angola
, including the Mediterranean, and due the different habitats where the species supposedly lives, from sublittoral to bathyal bottoms below
100 m
depth, and even in brackish lagoon areas (
Gofas & Oliver 2011
).
Cordeiro & Ávila (2015)
also recorded
P. inconspicua
in the Azores.
The shells found in the samples studied exhibited a remarkable variability ranging from weak axial ribs, thickened lip, curved columella and closed umbilicus (
Fig. 20a
), to almost smooth surface with incised peripheral lines, thin lip, straightened columella and narrow umbilicus (
Fig. 20b
). The protoconch bears a characteristic spiral microcord close to the suture (
Figs. 20c, g
). Transition between protoconch I and II well delimited (
Figs. 20d–f
).
Shells with soft parts have been found in samples collected between
111–248 m
depth on muddy sand bottoms, and
one specimen
at
920 m
.
It should be noted that some micromolluscs living in coastal algae could be swept by the currents away from the coast.