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
Clathrodrillia tryoni
(Dall, 1889)
(
Plate 48
)
Drillia tryonii
Dall, 1889a: 83
[also spelled “
tryoni
”].
Drillia tryoni
[sic] Dall, 1889: Sander & Lalli (1982: 317).
“
Crassispira
”
tryoni
[sic] (Dall, 1889): Kaicher (1984: card 3927 [photo of USNM 87449, the
lectotype
]).
Clathrodrillia tryonii
(Dall, 1889)
: Williams (2005 species 1546, 1547 [L photo pair only]).
Not this species or unverified extralimital reports.
Clathrodrillia tryonii
(Dall, 1889)
: Williams (2005; 2009: species 1546 [R photo pair only =
Calliclava
sp.]); Daccarett & Bossio (2011: 129, fig. 787 [=
Calliclava
sp.]).
Type
material.
The 12.6 x
4.7 mm
specimen from near
Grenada
(USNM 87449) is in best condition and is here designated as
lectotype
. There are 3 known
paralectotypes
: 1 spec., 10.9 x
4.1 mm
, R/V
Blake
Sta. 262 near
Grenada
in 92 fms [
168 m
] (MCZ 7056); 1 spec., 11.4 x
4.4 mm
, in 76–100 fms [
139–183 m
], R/V
Blake
Sta. 272 near
Barbados
(MCZ 7057); and 1 spec., 10.6 x 4.0 mm, in 95 fms [
174 m
], R/V
Blake
Sta. 231 near
St. Vincent
(MCZ 7055).
Type
locality.
R/V
Blake
Sta. 262 near
Grenada
, 12°01′45″N, 61°47′25″W, in 92 fms [
168 m
].
Other material examined.
An additional
13 specimens
were examined: 1 spec., 8.6 x
3.1 mm
, in
80 m
, Port- Louis, Grand Cul-de-Sac Marin,
Guadeloupe
KARUBENTHOS 2012 Sta. GD23,
16°25.0'N
,
61°32.8'W
,
14 May 2012
(MNHN IM-2013-20797) was sequenced and has the following barcode accession numbers:
MNHN Catalog Number |
Station |
GenBank accession number |
BOLD accession number |
IM-2013-20797 |
GD23 |
KT782753
|
TEMPO034-15 |
1 spec., 8.6 x
3.3 mm
(juv.), in
146 m
, off
Barbados
(USNM 900049); 1 spec., 11.3 x
4.1 mm
, in
137–146 m
, off Lazaretto,
Barbados
, J.B. Henderson, Jr., SUI (State University of Iowa) Expedition of 1918 Sta. 85 (USNM 502548); 1 spec., 10.3 x
3.7 mm
, in
137–146 m
, off Payne’s Bay Church,
Barbados
, J.B. Henderson, Jr., SUI Expedition of 1918 Sta. 41 (USNM 502554); 1 spec., 10.2 x
3.7 mm
, in
60 m
, off Pelican I.,
Barbados
, J.B. Henderson, Jr., SUI Expedition of 1918 Sta. 51 (USNM 502551); 3 spec., 9.9 x 3.6, 11.9 x 4.3 & 12.9 x
4.5 mm
, in
155–174 m
, off Holetown, St. James,
Barbados
(
13°10'52''N
,
059°38'30''W
) F. Sander! (ANSP 353516); 1 spec., 13.5 x
4.8 mm
, in
155–174 m
, off Holetown, St. James,
Barbados
(
13°10'52''N
,
059°38'30''W
) F. Sander! (ANSP 353517); 1 spec., 7.6 x
2.8 mm
, in
155–174 m
, off Holetown, St. James,
Barbados
(
13°10'52''N
,
059°38'30''W
) F. Sander! (ANSP 353518); 3 spec., 13.6 x 4.7, 11.8 x 4.3 & 10.6 x
4.1 mm
, in
183 m
, off St. James,
Barbados
, F. Sander! 1978 (UF 470286).
Range and habitat.
Guadeloupe
; SVG (near
St. Vincent
);
Barbados
;
Grenada
. Dall believed this to be a shallow water species, that specimens were adventitious in deep water samples (
139–183 m
) from the R/V
Blake
offshore of
St. Vincent
,
Barbados
and
Grenada
localities on account of their “injured” condition. However Sander & Lalli (1982: 317) report live specimens from
155–174 m
depths off Holetown, St. James,
Barbados
(Pl. 48, Figs. 7–8), and some specimens taken from off
Barbados
during the SUI Expedition of
1918 in
60–146 m
appear to have been fresh-taken (Pl. 48, Figs. 12–13). The specimen from Grand Cul-de-Sac Marin,
Guadeloupe
, was live-taken at
80 m
and its tissue processed for molecular analysis. Data from fresh specimens suggests their habitat as moderately deep water (
60–183 m
), not shallow water as surmised by Dall.
Description.
Shell
small (to
13.6 mm
), narrowly fusiform, translucent between sculptural elements, to approximately 10 slightly convex (early teleoconch) to straight-sided turreted whorls, the last whorl approximately 57% of total length. Sculptural elements of axial cords and spiral threads; aperture narrow.
Protoconch
glossysmooth, translucent, of approximately 1¾–2 rounded whorls, the first partially immersed in the second such that the apex appears blunt.
Axial sculpture
of straight, narrow ribs that stretch from suture-to-suture on the spire whorls, and evanesce on shell base, their width about the same as the interspaces; approximately 17–20 on penultimate, and 7–14 to varix on last whorl. Ribs are reduced abruptly at sulcus producing a right-angled shoulder, then continue to suture much reduced and curved, reflecting the trace of the anal sinus. Fine axial folds are present on the outer lip.
Varix
narrow, protruding, positioned about ⅓-turn from the edge of the outer lip.
Spiral sculpture
of evenly spaced heavy spiral threads, roughened by growth striae, spaced 2–4 times their width that override ribs producing a beaded effect on rib crests, and the shell surface a reticulate appearance.
Sulcus
strongly demarcated by abruptly reduced ribs at its edge, producing a right-angled shoulder; about 5 spiral threads present; growth striae tend to become lamellate.
Outer lip
thin, flattened from the varix to lip edge, which is bent inward posteriorly; no evidence of a stromboid notch in examined specimens. Edge of lip smooth, forms a flattened arc from anal sinus to anterior canal; without teeth or scalloping.
Anal sinus
U-shaped with a round apex, slightly offset from the shell’s axis by the parietal callus and inflection of the outer lip below it. Inner edge of sinus flared, such that it appears spout-like.
Inner lip
emarginated, thick, wide, erect anteriorly; parietal callus present at its posterior end.
Anterior canal
moderately long, shallow, open, unnotched. Anterior fasciole not swollen; with spiral cords.
Color
white; some with a golden-brown patch on shoulder of varix.
Remarks.
Nomenclature.
Dall spelled the
minor
epithet with and without the second “i” in the original species description (Dall, 1889a: 83).
As
First Revisor (ICZN 2000 Article 24.2.3) the spelling “
tryoni
”, with a single ending “i”, is herein fixed as the correct spelling.
Taxonomy.
Clathrodrillia tryoni
was described without illustration. A photograph of a
type
specimen was not published until much later—in Kaicher (1984: card 3927). The protoconch, which was not described by Dall, is missing from all of the
types
and resulted in some confusion between this and species of
Calliclava
that have a distinctively carinate one. Intact specimens of
C. tryoni
have a protoconch of about 2 glossy-smooth whorls (Pl. 48,
Fig. 2
).
Clathrodrillia tryoni
is typical for the genus in possessing numerous ribs and heavy spiral elements, a somewhat spout-like anal sinus, and heavy varix.
Variability.
The average length of
17 specimens
is
10.96 mm
(
7.6–13.6 mm
); their average W/
L ratio
is 0.367. The examined shells appear fairly uniform in most other respects.
Identification.
Clathrodrillia tryoni
has been confused with
Calliclava
spp. because of their similarity in size and shell sculpture. The latter is easily distinguished by its carinate protoconch, presence of spiral threads between ribs, not overriding them as in
C. tryoni
, therefore a smooth not coarse feel, and sometimes more colorful shell. Only white specimens of
C. tryoni
have been observed, some with a golden-brown color patch on the shoulder of the varix.
Clathrodrillia tryoni
is very similar to
C. wolfei
(Tippett, 1995)
but differs in having more ribs (17–20 versus 8–10 on the penultimate whorl).