Clathrodrillia guadeloupensis, Fallon, Phillip J., 2016

Fallon, Phillip J., 2016, Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species, Zootaxa 4090 (1), pp. 1-363 : 99-101

Clathrodrillia guadeloupensis , new species

( Plate 43 )

Type material. Holotype, live taken, 14.7 x 5.8 mm, 16 May 2012 (MNHN IM-2013-7812); 1 paratype: 9.2 x 4.2 mm, in 95 m, KARUBENTHOS 2012 Sta. GD60, E Petite-Terre, Guadeloupe, 16°12.1'N, 61°03.9'W, 26 May 2012 (MNHN IM-2013-9051). Barcode accession numbers of the sequenced holotype paratype are tabularized below: Type locality. Port-Louis, Grand Cul-de-Sac Marin, Guadeloupe, 16°25.0′N, 061°32.8′W, in 85 m (KARUBENTHOS 2012 Sta. GD31).

Additional material examined. 1 spec., 20.7 x 8.0 mm, in 18 m, Hollandes Cays, San Blas Is., Panama, G. Mackintosh! (M. Williams coll.).

Range and habitat. Guadeloupe & Panama (San Blas Is.: Hollandes Cays). Reported from 18–85 m depths.

Description. Shell small (to 20.7 mm in total length), fusiform with a high turreted spire possessing a slightly acuminate tip and truncated anterior; up to 11 whorls with strong axial ribs, the last whorl approximately 56% of total length. Aperture narrow. Protoconch of approximately 2–2½ glossy-smooth round whorls, the first partially immersed in the second. Axial sculpture of strong, broad axial ribs that run from suture-to-suture on the spire whorls, and evanesce on the shell base; ribs number 7–9 on the penultimate and 4–5 on the last whorl to varix, and are reduced at the sulcus becoming lower creating acutely angled shoulders. Strong growth striae are present overall, raise, fimbriated on rib crests and cupped by intercostal cords, curved in the sulcus reflecting past positions of the anal sinus. Varix hump-like, about ⅓-turn from outer lip edge. Spiral sculpture of regularly spaced cords that progressively increasing from 2 to 4 on spire whorls, 5 more on last whorl below suture line, and 6 on the anterior fasciole. Cords are cut by the growth striae and appear made up of minute compressed beads. Sulcus is flat, with low round-crested ribs, and growth striae. Outer lip thin, strengthened by 5 narrow fimbriated axial folds. Lip edge produced in a low arc from anal sinus to stromboid notch, scalloped by ends of spiral cords. Stromboid notch moderately deep and wide. Anal sinus a deep notch, round, set off at an angle from the shell’s axis by the parietal lobe and outward flex of the outer lip, spout-like, entrance slightly constricted by upward projection of outer lip; inner edge of sinus flared up. Inner lip porcellaneous, moderately wide, margined, detached anteriorly where a shallow false umbilicus appears; and posteriorly formed into a lobe. Anterior canal distinct, of moderate length, slightly notched, bent dorso-laterally at anterior end; anterior fasciole not swollen. Color off white with a faint brown band at suture and another narrow darker brown spiral band between ribs at level of first spiral cord on shoulder; a patch of the same dark brown color lies on the leading side of the varix shoulder.

Remarks. Taxonomy. At first sight, with its prominent spiral cords and moderately long anterior canal, Clathrodrillia guadeloupensis resembles a Compsodrillia , perhaps C. eucosmia (Dall, 1889) , but it differs from that species and other members of that genus in some significant ways that are characteristic of Clathrodrillia : the anal sinus is spout-like, much more so than in Compsodrillia ; the varix is ⅓-turn behind the outer lip edge, not just behind it as in Compsodrillia ; a subsutural cord is lacking; and its shell is more robust, not slim as in Compsodrillia . Clathrodrillia guadeloupensis , differs from most of its congeners in that the spiral elements are cord-like, rather than spiral grooves and ridges, or flattened cords aligned plank-like. Also, unlike most of its congeners, its rib crests are round, not ridged. Variability. The three examined specimens have an average total length of 14.9 mm (9.2–20.7 mm) and an average W/ L ratio of 0.413. The specimen from Panama is larger, which is reflected in its greater number of whorls, 11 versus the holotype’s 10. Identification. Clathrodrillia guadeloupensis is most similar to C. masinoi , new species. It differs in number of protochonch whorls (2–2½ versus 1½–1¾ whorls), in lacking shorter intercostal auxiliary ribs on the last whorl, and in the presence of dark brown maculations in the sulcus between ribs. From C. garciai , new species it differs in having more convex whorls and coarser spiral sculpture. From C. wolfei (Tippett, 1995) , it differs in being larger (20.5 versus 16.6 mm maximum total length), as well as possessing more robust ribs with heavier spiral sculpture.

Etymology. The Guadeloupe Clathrodrillia is named after the country of its type locality.

Figures

PLATE 43. Clathrodrillia guadeloupensis, new species. Figs. 1 – 3: holotype, Grand Cul-de-Sac Marin, Guadeloupe (MNHN IM- 2013 - 7812). 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. Figs. 4 – 5: paratypes. Fig. 4: juvenile specimen, Grand Cul-de-Sac Marin, Guadeloupe (MNHN IM- 2013 - 9051); Fig. 5: Hollandes Cays, Panama (P. Williams coll.).