Revision of the deep-sea Eulimidae (Gastropoda, Caenogastropoda) from off Northeast Brazil
Author
Souza, Leonardo Santos De
Setor de Malacologia, Departamento de Invertebrados, Museu Nacional-Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Author
Pimenta, Alexandre Dias
Setor de Malacologia, Departamento de Invertebrados, Museu Nacional-Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil. & alexpim @ mn. ufrj. br; http: // orcid. org / 0000 - 0001 - 7001 - 5820
alexpim@mn.ufrj.br
Author
Barros, José Carlos Nascimento De
Laboratorio de Malacologia, Departamento de Pesca e Aqüicultura, Universidade Federal Rural de Pernambuco, Recife, PE, Brazil. mundovan 6 @ yahoo. de; http: // orcid. org / 0000 - 0002 - 8476 - 6171
mundovan6@yahoo.de
text
Zootaxa
2021
2021-02-16
4927
4
451
504
journal article
8069
10.11646/zootaxa.4927.4.1
065cd936-3e5f-45f8-ac7f-2d530aab8b4e
1175-5326
4542923
AED51D9E-1751-4010-A8E1-B72AE428821A
Melanella paraabida
sp. nov.
urn:lsid:zoobank.org:act:
8D796B06-259E-445F-8C87-B6C4FF5BE506
(
Figure 13
A–H)
Type material.
Holotype
MNRJ 35262
† (
Figure 13
A–H).
Type
locality.
Brazil
:
Off
Pernambuco
, REVIZEE
Nordeste
(
08°42′06″S
34°44′06″W
,
465 m
), coll.
RV
Natureza
,
25/iii/2000
.
FIGURE 13.
A–H.
Melanella paraabida
sp. nov.
: holotype, MNRJ 35262. D. Detail of the teleoconch surface. G. Detail of protoconch, frontal view. H. Detail of protoconch, apical view. Scale bars: A–C= 1.0 mm; D= 100 µm. E, F= 200 µm; G, H= 50 µm.
Etymology.
Named after its similarity to
Melanella abida
Dall, 1927
.
Description (
Holotype
).
Shell conical, curved, reaching about
3.4 mm
long,
1.1 mm
wide. Larval shell whitish, conical, consists of 2.5 whorls,
220 µm
in wide, smooth, transition to teleoconch marked by distinct incremental scar. Teleoconch with about 7.5 whorls, flat outline; suture slightly demarcated, almost straight; subsutural zone indistinct; surface sculptured by axial lines, intervals about
25 µm
in the penultimate whorl; incremental scars well demarcated, appearing at intervals of about 1.0 whorl in the last three whorls, stepped. Last whorl about 45% of the shell length; base rounded. Aperture short, pear shaped, acute posteriorly and rounded anteriorly; outer lip relatively thick, opisthocline, sinuous, slightly retracting near the suture and slightly projecting in the uppermost third; inner lip sinuous, sloping, reflected and well demarcated. Not umbilicate. Shell vitreous, colorless.
Measurements.
Holotype
MNRJ 35262†, 10 whorls, SL=
3.4 mm
; BWL=
1.5 mm
; AL=
0.8 mm
; SW=
1.1 mm
; AW=
0.5 mm
.
Remarks.
Despite having only a single shell, we describe
Melanella paraabida
based on the combination of consistent shell features that enable us to discriminate this species from the other eulimids known to the Atlantic. The
holotype
was destroyed during the fire in the MNRJ.
FIGURE 14.
A–F.
Melanella abida
Dall, 1927
: A. Holotype of
Melanella abida
Dall, 1927
, USNM 108030. B, F. Holotype of
Melanella corrida
Dall, 1927
, USNM 108376. C–E. Paratypes of
M. corrida
, USNM
108376. F. Detail of protoconch, apical view. Scale bars: A–E= 1.0 mm; F= 75 µm. Credits: A, B, F, courtesy of USNM.
Melanella paraabida
sp. nov.
closely resembles
M. abida
Dall, 1927
(
Figure 14A, B
), known only from off
Georgia
,
USA
.
Dall (1927)
cited the type locality of
M. abida
as “off Fernandina,
Florida
” but the label of the holo-type (USNM 108030) clearly indicates “RV
Albatross
stn. 2668”, thus the correct locality is off
Georgia
.
Melanella corrida
Dall, 1927
(
Figure 14
C–F), from the same locality, is a synonym of
M. abida
(MolluscaBase Eds. 2020b)
.
Melanella paraabida
sp. nov.
can be distinguished from
M. abida
mainly by the presence of microsculpture on the teleoconch (
Figure 13D
) and the less protruding outer lip. Additionally, the protoconch of
M. paraabida
sp. nov.
has a smaller number of whorls and diameter.
Melanella paraabida
sp. nov.
has a protoconch
210 µm
wide with 2.5 whorls, while the
holotype
of
M. corrida
(USNM 108376) (
Figure 14F
) has a protoconch
260 µm
wide with 3.5 whorls.
Melanella paraabida
sp. nov.
resembles
M. orphanensis
Clarke, 1974
(
Figure 17K
), from the North Atlantic, and
M. scarifata
Gofas & Rueda, 2014
(
Gofas
et al.
2014
), from the Alboran and Mediterranean sea, by the teleoconch sculpture.
Melanella paraabida
sp. nov.
differs from
M. orphanensis
by the narrower apex (
Figure 13G
), which is dome shaped in the latter (
Figure 17K
).
Melanella paraabida
sp. nov.
differs from
M. scarifata
by the smaller dimensions of the protoconch (2.5 whorls,
210 µm
wide
vs.
3.5 whorls,
350 µm
wide in
M. scarifata
) and the less protruding outer lip (
Figure 13F
).
Melanella paraabida
sp. nov.
resembles
Melanella spiridioni
(
Dautzenberg & Fischer, 1896
)
, from Northeast Atlantic and Mediterranean, by the curved spire but differs by the presence of microsculpture of axial lines.
Geographical distribution.
Only known from the
type
locality.
Bathymetric distribution.
465 m
.