The deep-sea species of Triphoridae (Gastropoda, Triphoroidea) from Guadeloupe, sampled by the Karubenthos 2 expedition
Author
Fernandes, Maurício Romulo
3B8B864F-3300-45B2-8D1F-61F282F83CDE
Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Estado do Rio de Janeiro (UNIRIO), Av. Pasteur, 458, Urca, 22290 - 240, Rio de Janeiro, Brazil.
mauriciofernandes14@hotmail.com
text
European Journal of Taxonomy
2024
2024-12-11
972
1
52
https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2763/12649
journal article
307386
10.5852/ejt.2024.972.2763
e5b6b78f-bbae-487d-a563-a2a2de92aa2b
2118-9773
14506799
5571E5E4-47CC-43FB-B5AC-7388E403A73E
Strobiligera
cf.
delicata
Fernandes & Pimenta, 2014
Fig. 17C–H
Strobiligera delicata
Fernandes & Pimenta, 2014: 166
, fig. 1b–k.
Type material
Holotype
BRAZIL
• sh; off
Espírito Santo State
;
19°36′ S
,
38°53′ W
; depth
640 m
;
MNHN
IM-2000-27528.
Paratypes
See
Fernandes & Pimenta (2014)
.
Material examined
GUADELOUPE
(
Karubenthos 2 expedition
) • 1 sh; stn DW4556;
MNHN
•
1 sh; stn DW4577;
MNHN
•
1 spec.
stored dry; stn DW4635;
MNHN
.
Emended description
Shell sinistral, conical-fusiform, single complete shell up to 7.0 mm long (incomplete shells up to
8.9 mm
long) and
1.5 mm
wide, length/width ratio 4.7, apical angle of early whorls 18–20°; one shell with a distinct change in width on 13
th
teleoconch whorl, becoming broader. Protoconch multispiral, 3.5– 4.0 whorls,
0.50–0.53 mm
long,
0.34–0.37 mm
wide; first whorl dome-shaped, with minute granules; subsequent whorls with two spiral cords, situated at 35% and 68% of whorl height; incomplete axial ribs (~33 ribs per whorl), with a smooth spiral zone above adapical spiral cord; abrupt transition to teleoconch. Teleoconch with up to 17 whorls (incomplete); three main spiral cords, with median and abapical cords continuous with those of protoconch; adapical spiral cord initially narrow, but gradually enlarging and reaching nearly same size as other cords between 11
th
and 13
th
whorls; shallow suture, almost indistinct, with a very narrow, smooth sutural cord; 18–19 orthocline axial ribs on 14
th
whorl; medium-sized to moderately large, nearly rounded to slightly elliptical nodules; wide, smooth subperipheral cord, two smooth basal cords, adapical one prominent and close to subperipheral one, abapical cord narrow and more distant; no evident supranumerical cords; elliptical aperture, 1.0 mm long,
0.69 mm
wide, length/ width ratio 1.5; open, very short anterior canal,
0.14 mm
long,
0.20 mm
wide, length/width ratio 0.7. Protoconch light brown, teleoconch white to dirty-white.
Fig. 17. A–B
.
Strobiligera
cf.
georgiana
(
Dall, 1927
)
, MNHN, stn DW4550, 15.1 mm.
C–H
.
Strobiligera
cf.
delicata
Fernandes & Pimenta, 2014
.
C
. MNHN, stn DW4556, 8.9 mm.
D
. MNHN, stn DW4577, 8.9 mm.
E–H
. MNHN, stn DW4635, 7.0 mm. Scale bars: A, C–E = 1 mm; B, F–H = 500 µm.
Remarks
Shells of
S
. cf.
delicata
from
Guadeloupe
are very similar to the
type
material from SE
Brazil
, and their planktotrophic development could allow such a wide geographic range. The single adult shell from
Guadeloupe
is 7.0 mm long and incomplete shells reach up to
8.9 mm
, contrasting with adult shells from
Brazil
, reaching only
5.8 mm
. This difference in length might be related to the later development of the adapical spiral cord on the teleoconch in shells from
Guadeloupe
, reaching nearly the same size as other cords between the 11
th
–13
th
whorls vs the eighth–tenth whorl in the
type
material. More adult shells from
Guadeloupe
are required in order to evaluate the importance of these differences.
The most similar species to
S
. cf.
delicata
in
Guadeloupe
is
S
. cf.
georgiana
, which has a much reduced adapical spiral cord, fewer axial ribs on the teleoconch, a slightly opisthocline orientation of the axial ribs (vs orthocline in
S
. cf.
delicata
) and a larger and more conical shell. These differences were already pointed out by
Fernandes & Pimenta (2014)
when they compared the
types
of both species.
One atypical shell of
S
. cf.
delicata
has a distinct change in width on the 13
th
teleoconch whorl, becoming broader (
Fig. 17D
). This is also observed in
S
.
torticula
(
Rolán & Fernández-Garcés 2008
;
Fernandes & Pimenta 2015b
), which in contrast is much larger (incomplete shell reaching up to 25.0 mm in length –
Rolán & Fernández-Garcés 2008
) than
S
. cf.
delicata
. In addition, the protoconch of
S
.
torticula
has almost five whorls and it is
0.64 mm
long and
0.45 mm
wide (
Fernandes & Pimenta 2015b
) vs 3.5–4.0 whorls,
0.50–0.53 mm
long and
0.34–0.37 mm
wide in
S
. cf.
delicata
.
Geographic distribution
Guadeloupe
(this study);
Brazil
: off
Espírito Santo
and
Rio de Janeiro
(
Fernandes & Pimenta 2014
).
Bathymetric distribution
Empty shells previously known from
607–940 m
(
Fernandes & Pimenta 2014
). This study:
358–428 m
(empty shells),
265–268 m
(live specimen).