Deep-sea “ cephalaspidean ” heterobranchs (Gastropoda) from the tropical southwest Pacific
Author
Valdés, Ángel
John T. Huber
text
Mémoires du Muséum national d'Histoire naturelle
2008
196
587
792
journal article
978-2-85653-614-8
1243-4442
Cylichna consobrinoides
Kuroda & Habe, 1952
Figs 31E, F, 34, 35A, B
Cylichna consobrinoides
Kuroda & Habe, 1952: 50
.
Cylichna consobrina
A.
Adams, 1862: 152
[
non
Cylichna consobrina
Gould, 1859
].
TYPE
MATERIAL
. —
Not
examined
.
TYPE
LOCALITY
. —
C. consobrina
: west coast of
Jesso
, western
Hokkaido
,
Japan
. —
C. consobrinoides
: Mino-Sima
[= Mishima],
Japan
,
115 m
.
MATERIAL
EXAMINED. —
Coral Sea
.
CHALCAL 1: stn D
Norfolk
Ridge.
MUSORSTOM 4: stn
DW 225
,
22°52’S
, 63,
Banc Nova
,
22°11’S
,
159°14’E
,
305 m
, 1 dd
. —
MUSORS-
167°52’E
,
590-600 m
, 1 dd
. —
SMIB 3
: stn
DW 21
,
22°59’S
,
TOM 5
: stn 255,
Banc Capel
,
25°15’S
,
159°55’E
, 280-295
167°19’E
,
525 m
, 1 dd
. —
SMIB 8
: stn
DW 193-196
,
22
°59-23’S, m, 1 dd; stn 265,
25°21’S
,
159°45’E
,
190-260 m
, 2 dd (
Figs
168°21-23’E,
491-558 m
, 1 dd.
35A, B); stn 291, Banc Argo,
23°08’S
,
159°28’E
,
300 m
, 1 dd;
New Caledonia
proper
.
BATHUS 2
: stn
DW 724
,
Ile des Pins
, stn 302, Banc Nova,
22°10’S
,
159°23’E
,
345-360 m
, 1 dd;
22°48’S
,
167°26’E
,
344-358 m
, 1 dd
. —
Grand Récif Sud
,
200 m
, stn 341,
Chesterfield Islands
,
19°46’S
,
158°43’E
, 620-630
5 November 1976
, 1 dd
.
m, 1 dd; stn 376,
19°51’S
,
158°30’E
,
280 m
, 1 dd; stn 380,
Loyalty Ridge
. MUSORSTOM 6: stn
DW
391,
20°47’S
,
19°38’S
,
158°44’E
,
555-570 m
,
1 lv
, dissected (Figs 31E, F);
167°06’E
,
390 m
, 1 dd.
stn 388,
20°45’S
,
160°54’E
,
500-510 m
, 5 dd. —
CORAIL 2:
Fiji
. MUSORSTOM 10: stn
DW 1376
,
S of Viti Levu
,
18°19’S
, stn DE 16,
Bancs Lansdowne-Fairway
,
20°48’S
,
160°56’E
,
178°09’E
,
497-504 m
, 1 dd
.
500 m
, 1 dd.
Tonga
.
BORDAU
2: stn
DW
1531,
Eua
,
21°12’S
,
174°56’W
, 970-
North of
New Caledonia
.
BATHUS
4: stn
DW
918, Grand Pas-
983 m
, 1 dd.
sage,
18°49’S
,
163°16’E
,
613-647 m
, 1 dd.
DISTRIBUTION
. —
Reported
from the
Japan
Sea
in
74-115 m
(Hori 2000b).
Records
herein from the
Coral Sea
,
Fiji, New Caledonia
and
Tonga
(Fig. 34), in
200-970 m
, live in
550-570 m
.
DESCRIPTION. —
Shell morphology
. Length
17 mm
, width
6 mm
(largest specimen examined). Shell solid, elongate, with nearly parallel sides (Fig. 35A). Only 1 whorl visible, forming nearly the entire shell, with the exception of a small visible portion of the spire. Apex rounded, deeply umbilicate (Fig. 35B), with the aperture lip rising from the left side and forming a short, triangular wing. Anterior end of the shell rounded. Aperture as long as the shell, wider anteriorly and narrowing gradually at about 1/4 of its length. Columellar margin conspicuously thickened. Columella simple, with no folds. Umbilicus closed. Sculpture of about 5 simple spiral grooves near the posterior end and about 8 grooves near the anterior end. These grooves are absent from the central part of the shell, which is covered with faint growth lines. Colour uniform shiny white.
Anatomy
. The digestive system contains 3 smooth gizzard plates similar in shape and size. All the plates are oval and elongate (Fig. 31F). The radular formula is 16 x 2.1.1.1.
2 in
a specimen from the Coral Sea (MUSORSTOM 5 stn 380). The rachidian teeth are broad, with a number of sharp denticles decreasing in size towards the laterals of each plate (Fig. 31E). There is a gap with no denticles on the centre of each rachidian tooth. The innermost lateral teeth are hook-shaped, with a long, strong cusp with 15-20 denticles. The 2 outermost teeth of each row are much smaller, also hook-shaped and lack denticles.
Reproductive system unknown.
REMARKS. —
Cylichna consobrina
was described by A.
Adams (1862)
from
Japan
in
115 m
, with no illustrations. Because this name was preoccupied by
Cylichna consobrina
Gould, 1859
, also from
Japan
, Kuroda & Habe (1952) proposed the replacement name
Cylichna consobrinoides
.
This species was redescribed and illustrated by Hori (2000b) who placed it in
Adamnestia
with no apparent justification. Iredale (1936) introduced the genus
Adamnestia
with a short description, for species similar to
Cylichna
and with a radula similar to that of
Haminoea
. Subsequent authors (Kuroda
et al.
1971) broadened the concept of
Adamnestia
to include other species with a similar shell morphology to
Adamnestia peroniana
Iredale, 1936
, the
type
species. Anatomical examination of a specimen of
C. consobrinoides
shows that the radula morphology is similar to other species of the genus
Cylichna
, with a rachidian tooth, a large and denticulate innermost lateral tooth, and several smaller outer laterals. Therefore this species is maintained in the genus
Cylichna
.
Cylichna consobrinoides
differs from other species of
Cylichna
here examined in having an elongate shell with the aperture lip rising from the left side and forming a short, triangular wing.