Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species
Author
Fallon, Phillip J.
text
Zootaxa
2016
4090
1
1
363
journal article
10.11646/zootaxa.4090.1.1
e6b35f5a-435e-4473-b29e-1e4d842f84b0
1175-5326
263299
203BAC25-B542-48FE-B5AD-EBA8C0285833
Leptadrillia flavomaculata
,
new species
(
Plate 105
)
Type
material.
Holotype
11.2 x
3.5 mm
(USNM 1199825); 3
paratypes
, all from
type
locality: 10.6 x
3.5 mm
(USNM 1199824); 12.3 x 3.4 & 11.8 x
3.7 mm
(USNM 1199826). All
types
were recovered from in bottles, M. Harasewych! aboard submersible
Curasub
,
23 May 2012
.
Type
locality.
Off Sea Aquarium, Bapor Kibra, Willemstad,
Curaçao
,
Netherlands Antilles
,
12°04.87'N
,
68°53.75'W
, in glass bottles collected at
130–
288 m
.
Other material examined.
An additional
13 specimens
were examined: 11.2 x 3.5, 9.8 x 3.4, 12.1 x 3.8, 10.9 x 3.3, 11.6 x 3.4, 11.9 x 3.4, 10.1 x 3.3, 10.5 x 3.2, 10.1 x 3.1, 9.9 x 3.2, 9.7 x 3.1, 9.8 x 3.2, 7.9 x 2.6 & 6.3 x
2.5 mm
, in old bottle at
244–274 m
, off Sea Aquarium, Bapor Kibra, Willemstad,
Curaçao
,
Netherlands Antilles
,
12°04'59.51"N
,
68°53'56.61"W
, C. Baldwin! aboard submersible
Curasub
,
8 Feb 2013
(USNM 1231403).
Range and habitat.
Netherlands Antilles
(SE coast of
Curaçao
). Dead-collected from inside discarded beverage bottles at
130–
288 m
. The
13 specimens
appear to have been sequestered by an octopod. It is likely that the shells were first occupied by hermit crabs.
Description.
Shell
small (to
12.3 mm
in total length), glossy, partially translucent, narrowly fusiform; whorls flat on shoulder and convex below, number up to about 10¼, the last approximately 54% of total length, with a narrow aperture only slightly wider than the anal sinus and anterior canal.
Protoconch
of 2 round glossy-smooth whorls.
Axial sculpture
of narrow, slightly opisthocline ribs that run from suture-to-suture on spire whorls, to anterior fasciole on last; ribs narrower than their interspaces, number 8–11 on penultimate, 6–10 on last whorl to varix.
Varix
rib-like in profile, about twice their height and width; straight, not opisthocline, positioned ⅓–½-turn from the edge of outer lip.
Spiral sculpture
absent on most of shell surface, limited to 6–7 low faint threads on anterior fasciole.
Sulcus
absent; ribs narrower on shoulder, flat in longitudinal profile, curved by slight hollow on trailing side of ribs formed by previous positions of the anal sinus.
Outer lip
thin, translucent, edge forming an arc from the anal sinus to anterior canal, strengthened by curved axial folds parallel to lip edge; edge bent upward at junction with anal sinus; curved outward along anterior canal.
Anal sinus
deep, apex round, sides straight, offset from shell axis by parietal callus on one side and outward curve of outer lip on the other, appearing spout-like.
Inner lip
narrow, margined, erect on anterior canal, formed into a parietal callus posteriorly; depositional layers visible on margin.
Anterior canal
long, open, only slightly narrower than aperture, turned right when viewed ventrally; end unnotched.
Color
light golden brown, anterior and first few whorls lighter; nucleus (tip of the protoconch) violet-colored; violet hue on some ribs, especially on post-varical axial folds; and yellow patch on leading side of varix and on anterior fasciole.
PLATE 105.
Leptadrillia flavomaculata
,
new species
.
Upper panel.
Figs. 1–3: holotype,
Curasub
Sta. 4, off Sea Aquarium, Curaçao, Netherlands Antilles (USNM 1199825). Fig. 1: ventral, lateral & dorsal views; Fig. 2: enlarged view of protoconch (not to scale); Fig. 3: apical view, V = varix, L = edge of outer lip.
Lower Panel.
Figs. 4–16: off Sea Aquarium, Curaçao, Netherlands Antilles. Fig. 4:
Curasub
Sta. 1 (USNM 1199824); Figs. 5–6: paratypes,
Curasub
Sta. 4 (USNM 199826); Figs. 7– 16:
Curasub
Sta. 13-04 (USNM 1231403).
Remarks.
Taxonomy.
Leptadrillia flavomaculata
has all of the distinguishing characteristics of
Leptadrillia
: a long, spindle-shaped shell with a narrow aperture and long anterior canal, ribs that extend from suture-to-suture without a sulcus, and no spiral sculpture except on the anterior fasciole.
Variability.
The
17 specimens
have an average total length of
10.38 mm
(
6.3–12.3 mm
), and W/
L ratio
of 0.313.
Identification.
Leptadrillia flavomaculata
is unique in possessing narrow, widely spaced ribs, and for its combination of colors. Its violet hue is reminiscent of
L. violacea
,
new species
but that species has wide ribs, wider than their interspaces.
Leptadrillia flavomaculata
differs from
L. luciae
,
new species
, with which it was found, in possessing narrower ribs and shell profile.
Etymology.
The Yellow spot
Leptadrillia
. From the Latin adjectives
flavus
meaning yellow, combined with
maculata
, meaning spot. Named for the large yellow spot on the leading side of its varix and on the anterior fasciole of the freshest specimen.