Coralliophilinae (Neogastropoda: Muricidae) from the southwest Pacific
Author
Oliverio, Marco
John T. Huber
text
Mémoires du Muséum national d'Histoire naturelle
2008
196
481
586
journal article
978-2-85653-614-8
1243-4442
Mipus alis
n. sp.
Figs 138, 139, 197
TYPE MATERIAL. —
Holotype
(dd)
MNHN 20241
and
2 paratypes
(dd)
MNHN 20242-20243
.
TYPE
LOCALITY. —
Tonga
,
23°23’S
,
176°18’W
,
407-443 m
[BORDAU 2: stn DW 1631]
.
MATERIAL EXAMINED. —
New Caledonia
proper
. BATHUS 2: stn DW 731,
Passe
de Kouaré
,
22°49’S
,
166°45’E
,
300-370 m
, 1 dd
.
Tonga
. BORDAU 2: stn DW 1631,
23°23’S
,
176°18’W
, 407-
443 m, 2 dd (
holotype
MNHN
20241, Figs 138, 197 and
paratype
MNHN
20242); stn DW 1543,
21°16’S
,
175°18’W
,
427-436 m
, 1 dd (
paratype
MNHN
20243, Fig. 139).
DISTRIBUTION. —
Known only from the
type
locality (
Tonga
) and
New Caledonia
, empty shells in
370-427 m
.
DESCRIPTION — Shell of medium size for the genus,
holotype
height 16.8 mm, width 7.8 mm, of moderate thickness, turriculate, stepped below suture, whitish, aperture and parietal callus bright white.
Protoconch of 1.8 conical whorls, 520 Μm high, 710 Μm wide at base. Protoconch-I of about 0.8 whorls, entirely sculptured with pustules. Protoconch-II of about 1 whorl, with 2 spiral keels, sculptured with a series of subsutural prosocline threads, a series of tubercules over each keel, and a series of opisthocline threads between the second abapical keel and the suture.
Teleoconch of 6.3 whorls. Spire high, conical, constricted at base. Shoulder crest directed adapically. Subsutural ramp flat, narrow, whorls convex below keel. Aperture of medium size, 4.5 by
3 mm
, subquadrangular. Outer lip incised corresponding to the shoulder keel. Inner lip curved, callous. Siphonal canal long (30% of total height), open, straight. Umbilicus closed with low siphonal fasciole. Teleoconch axial sculpture of 10 broad, rounded ribs on first whorls and 9 on last whorl, and of squamous growth lines over entire shell. Spiral sculpture of cords, covered with densely packed imbricate scaly spines. First spiral cord appearing on first teleoconch whorl becomes cord of shoulder keel, covered by imbricate scaly spines adapically directed. One additional cord adjoining below keel on each whorl, resulting in 6 spiral cords visible on penultimate whorl above aperture. Last whorl bearing 25 cords and 5 irregularly set cordlets. Suture not incised, undulate. Sutural ramp bearing 4 spiral cords on last whorl, commencing as 1 cord on second teleconch whorl.
Animal and operculum unknown.
REMARKS. — This new species is very similar to
Mipus mamimarumai
(Kosuge, 1981)
. It differs in its marked shoulder keel and resulting sutural ramp, its axial sculpture and its straight siphonal canal.
Mipus matsumotoi
Kosuge, 1985
also lacks the axial ribs and the shoulder keel, resulting in a more slender shell.
Mipus sugitanii
Kosuge, 1985
has axial ribs and many specimens develop a keel (the corresponding spiral cord is the first one developing on the teleoconch, and therefore possiby homologous with the keel of
M. alis
), but the whorls remain rounded, the sutural ramp is never flat, and the keel is not abapically oriented.
Mipus intermedius
Kosuge, 1985
and
M. eugeniae
(Bernardi, 1853)
are larger and have more strongly convex whorls with the suture more incised.
Mipus gyratus
(
Hinds, 1844
)
and
M. vicdani
(
Kosuge, 1980
)
also develop a keel on the periphery, but are larger and the keel is not adapically oriented.
ETYMOLOGY. — The epithet
alis
refers to the R/V
Alis
, which was employed for the BORDAU 2 and BATHUS 2 expeditions in the southwest Pacific. It is used as a noun in apposition.