Deep-water Raphitomidae (Mollusca, Gastropoda, Conoidea) from the Campos Basin, southeast Brazil
Author
Figueira, Raquel Medeiros Andrade
Author
Absalão, Ricardo Silva
text
Zootaxa
2012
3527
1
27
journal article
10.5281/zenodo.210977
8eba0512-d65c-4c36-8c30-6d629fabfff8
1175-5326
210977
Famelica mirmidina
Dautzenberg & Fischer, 1896
(
Figs. 3–4
)
Pleurotoma mirmidina
Dautzenberg & Fischer, 1896
: 413
, pl. XVII, fig. 13;
Dautzenberg & Fischer (1897b: 146)
;
Dautzenberg (1927: 68, pl. III, fig. 23)
.
Famelica mirmidina
:
Bouchet & Warén (1980: 90, figs. 188, 280, 281)
;
Absalão
et al
. (2005
: 35
, figs. 105, 117);
Rios (2009: 353, species 916)
.
Type
material
: In Museé Océanographique de
Monaco
.
Type
locality
: Azores, Princesse Alice (1895) sta. 46 (
37°42,40’N
,
27°27,30’W
),
1385 m
.
Material examined
: 18443 [1] B # 32; 18444 [4] OP I # 47; 18445 [6] OP I # 48; 18446 [4] OP I # 52; 18447 [4] OP I # 53; 18448 [4] OP I # 58; 17060 [1] OP I # 59; 18449 [1] OP I # 60; 18450 [3] OP I #61; 18451 [4] OP I # 62; 18452 [4] OP I # 63; 18453 [1] OP I # 75; 18454 [1] OP I # 78; 18455 [1] OP I # 83; 16965 [3] OP II # 45; 18456 [5] OP II # 48; 18457 [2] OP II # 50A; 18458 [2] OP II # 52; 18459 [11] OP II # 53; 18460 [2] OP II # 58; 18461 [1] OP II # 60; 18462 [2] OP II # 61; 18463 [6] OP II # 62; 18464 [4] OP II # 63; 18465 [6] OP II # 68; 18466 [3] OP II # 73; 18467 [1] OP II # 75; 18468 [1] OP II # 77; 18469 [1] OP II # 82; 18470 [2] OP II # 83; 18471 [1] OP II # 84; 18472 [1] OP II # 86; 18473 [2] OP II # 87.
Description
: Shell high, slender, white, up to
8.68 mm
long. Protoconch with five whorls, light yellow. Protoconch 1 granulose and slightly darker. Protoconch 2 with a middle keel, straight, evenly spaced axial riblets below it, a subsutural row of large nodules and several smaller nodules between the axial riblets and the subsutural row. Clear-cut transition from protoconch to teleoconch. Teleoconch with four whorls of convex profile. Slight and low rounded spiral cord below the upper 1/3 of each whorl and several fine faint axial scars cross the entire surface of the whorls. Scars curved in a C shape below the spiral cord and inverted above it. Suture moderately deep. Base smooth except for the axial scars. Inner lip not entirely pressed against the parietal wall, forming a narrow chink. Anterior siphonal canal short.
Geographic distribution
: Northeast Atlantic: Azores (
Dautzenberg & Fischer, 1896
;
Dautzenberg & Fischer, 1897b
;
Dautzenberg, 1927
) Azores and
Portugal
(
Bouchet & Warén, 1980
). Southwest Atlantic: Espírito Santo and Bahia States,
Brazil
(
Absalão
et al
., 2005
); Campos Basin, Rio de Janeiro (this paper).
Bathymetry
:
750 m
(
Absalão
et al
., 2005
)–
3360 m
(
Bouchet & Warén, 1980
).
Discussion:
The shell in this species is extremely thin and fragile. In all specimens studied here, the outer lip is broken, making it impossible to describe the aperture or the anal sinus. The
holotype
is broken in the same manner, and apparently so was the material studied by
Bouchet & Warén (1980: 89, fig. 188)
.
Four species of
Famelica
are assigned to the western Atlantic (
Rosenberg, 2009
):
Famelica mirmidina
(
Dautzenberg & Fischer, 1896
)
,
F. monoceros
(
Watson, 1881
)
,
F. scipio
(
Dall, 1889
)
and
F. catharinae
(
Verrill & Smith, 1884
)
.
Bouchet & Warén (1980)
mentioned the narrow chink as a unique feature that differentiates
F. mirmidina
from all other known
Turridae
from the eastern Atlantic, in which the inner lip is completely pressed against the parietal wall, precluding the formation of the chink. The same difference applies to the western Atlantic
Famelica
, among which
F. mirmidina
is the only one that has the chink. Also,
F. mirmidina
has a faint spiral cord, unlike the other species, which show abundant spiral ornamentation.
Famelica mirmidina
was reported in
Brazil
for Bahia and Espírito Santo States (13°–19°S). Its distribution is here expanded further South to include Rio de Janeiro (21°–22°).