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
Fenimorea fabae
,
new species
(
Plates 65
, Figs. 5, 6 &
Plate 76
)
Type
.
Holotype
10.1 x
4.4 mm
(ANSP 370199); 15
paratypes
originally from the same lot as the
holotype
, 9 measured: 10.4 x 4.5, 9.6 x 4.1, 10.4 x 4.7, 9.6 x 4.3, 10.3 x 4.4, 9.6 x 4.3, 10.0 x 4.6, 10.0 x 4.5 & 8.7 x 4.0 mm (ANSP 464999). All
types
, J. Worsfold!
Type
locality.
Caravel Beach (John Jack Point), Freeport, Grand
Bahama
I.,
Bahama
Is.,
26°29'30''N
,
078°41'45''W
, in shallow water.
Other material examined.
An additional
18 specimens
were examined: 1 spec., 8.3 x
3.6 mm
, in
12 m
, Kings Bay (Dundee Bay), Grand
Bahama
I.,
Bahama
Is.,
26°29'15"N
,
078°43'30"W
, J. Worsfold! (ANSP 373187); 14 spec., 8.2 x 3.8, 9.4 x 4.0, 9.0 x 4.0, 8.6 x 3.9, 9.1 x 3.9, 8.1 x 3.6, 8.4 x 3.7, 7.8 x 3.5, 8.5 x 3.7, 7.7 x 3.8, 8.3 x 3.6, 8.7 x 3.6, 7.5 x 3.6, 7.3 x
3.3 mm
, in
9 m
,
Bahama
Club slipway, Kings Bay Jetty, Kings Bay, Dundee Bay, Grand
Bahama
I.,
26°29'15''N
,
078°43'30''W
, J. Worsfold! (ANSP 369088); 1 spec., 10.2 x
4.5 mm
, in
11 m
, Borco pipeline,
5 mi
[
8 km
] W of Freeport, Grand
Bahama
I.,
26°30'30''N
,
078°46'30''W
, J. Worsfold!
Jun 1982
(ANSP 370942); 2 spec., 8.8 x 4.4 & 9.2 x
4.7 mm
, in beach wash, Millar’s Beach, Eleuthera I.,
Bahama
Is., M. Williams!
6 May 1998
(author’s coll.).
Range and habitat.
Bahama
Is. (Grand
Bahama
I.; Eleuthera I.), in shallow water to
12 m
.
Description.
Shell
small (to
10.4 mm
), bullet-shaped, of up to 7¾ impressed whorls, last whorl large, approximately 66% of total length. Spire short, slightly acuminate at its tip; whorls straight-sided except for sutural impressions, and slight creases marking the anterior boundary of the sulcus.
Protoconch
of 2 smooth glossy-white whorls.
Axial sculpture
of crowded minute ribs on the first 1½ whorls of the teleoconch, obsolete on the remaining whorls.
Varix
hump-like, approximately ¼- to ⅓-turn from the edge of the outer lip.
Spiral sculpture
absent; shell surface packed with microscopic growth striae and spiral incised lines, so close that under a dissecting microscope the shell’s surface appears velvety.
Sulcus
slightly convex, not excavated, but is marked by a slight spiral crease at its anterior margin.
Outer lip
thin, edge smooth, without scalloping, and without a stromboid notch. Lip edge, from the anal sinus to midway point flexed slightly into the aperture.
Anal sinus
is deep, round at its apex, lies next to the suture, except for the opening, which is skewed anteriorly by the parietal callus.
Inner lip
margined, and mostly a faint with a narrow wash of enamel; callus is present posteriorly on the parietal wall; columella is straight.
Anterior canal
is short, open, and slightly notched at its tip. Anterior fasciole not swollen; without spiral threads or ridges.
Color
white, with narrow orange-brown band below whorl periphery; patches on varical hump, and sporadically on whorls’ shoulder.
PLATE 76.
Fenimorea fabae
,
new species
.
Upper panel.
Fig. 1: holotype, Caravel Beach, Freeport, Grand Bahama I., Bahama Is. (ANSP 370199), ventral lateral & dorsal views.
Lower panel.
Figs. 2–10: paratypes from the type locality (ANSP 355001). Fig. 11–25: Kings Bay (Dundee Bay), Grand Bahama I., Bahama Is. Fig. 11: ANSP 373187; Figs. 12–25: ANSP 373188.
Remarks.
Taxonomy.
Fenimorea fabae
is the most aberrant of the
fucata
-like species [
Fenimorea fucata
(Reeve, 1845)
]. The characteristic shell microsculpture of
Fenimorea
is present but is compressed—spiral threads and growth striae are closer together producing a felt-like surface when viewed under a dissecting microscope. High magnification SEM photographs of the microsculpture of
F. f a ba e
are compared with similar photographs of
F. janetae
Bartsch, 1934
, and
F. fucata
(Reeve, 1845)
in
Plate 65
, two species that exhibit the typical pattern of the genus. The presence of axials from suture-to-suture, although only present on early teleoconch whorls, a varical hump, in addition to the typical shell microsculpture allies this species with
Fenimorea
. The near absence of axial ribs is probably a secondary loss, perhaps an environmental adaptation.
Variability.
The 26 measured specimens have an average total length of
8.99 mm
(
7.3–10.4 mm
), and average W/
L ratio
of 0.445.
Identification.
Fenimorea fabae
resembles the dwarf ecotypes of
F. f u c at a
(Reeve, 1845) that have the same color pattern, which are also found on Grand
Bahama
I., but possesses axial ribs, a more distinct sulcus, a straight, not acuminate spire tip, and a less dense “
Fenimorea
-like” microsculptural pattern. Dwarf specimens of
F. f uc a t a
are depicted in the plates included in that section.
Fenimorea fabae
is also similar to
F. culexensis
Usticke, 1969
,
F. jongreenlawi
,
new species
,
F. caysalensis
,
new species
,
F. glennduffyi
,
new species
, and
F. biminensis
,
new species
. It differs from
F. culexensis
in possessing a round last whorl, not square, in lacking fimbriations at the suture, and in having a different coloration. From
F. jongreenlawi
it differs in lacking ribs, a distinct sulcus, in being stockier, and in its color pattern. From
F. caysalensis
,
F. glennduffyi
, and
F. biminensis
it differs in lacking ribs, a distinct sulcus, and spiral grooves that end in “teeth” at the edge of the outer lip.
Etymology.
The Bean
Fenimorea
, from the Latin noun
fabae
(feminine form) meaning resembling a bean. The small, squat smooth almost oval shell has inspired the name.