Clathrodrillia garciai, 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 : 93-96

Clathrodrillia garciai , new species

( Plate 41 )

Clathrodrillia minor auct. non Dautzenberg, 1900: is a misidentification by Altena (1975: 7, pl. 7, figs. 1, 2) that is likely this species.

Clathrodrillia phasma auct. non (Schwengel, 1940): is a misidentification by García (2012a: 65–66) that is likely this species.

Type material. Holotype, live-taken, 27.0 x 9.6 mm, 28 Jul 2014 (MNHN IM-2013-55984); 24 paratypes: 1 spec., live-taken, 27.4 x 9.3 mm, in 64–65 m, GUYANE 2014 Sta. CP 4350, off French Guiana, 05°10.8'N, 51°28.3'W, 28 Jul 2014 (MNHN IM-2013-55955). Barcode accession numbers of the sequenced holotype and paratype are tabularized below:

Other paratypes are, French Guiana: 1 spec., 16.4 x 6.1 mm, in 130–131 m, GUYANE 2014 Sta. CP4379, 06°33'N, 52°28'W, 25 Jul 2015 (MNHN IM-2013-56495); 2 spec., 19.1 x 6.7 & 21.3 x 7.4 mm, in 50 m, GUYANE 2014 Sta. CP4355, 06°17.2'N, 53°07.4'W, 30 Jul 2014 (MNHN IM-2000-31087); 2 spec., 9.0 x 3.6 & 11.1 x 4.5 mm, in 130–131 m, GUYANE 2014 Sta. CP4379, 06°33'N, 52°28'W, 4 Aug 2014 (MNHN IM-2000-31088); 1 spec., 20.7 x 7.3 mm, in 94 m, GUYANE 2014 Sta. DW4359, 06°52.2'N, 53°02.6'W, 30 Jul 2014 (MNHN, IM- 2000-31089); 1 spec., 30.3 x 10.7 mm, in 47 m, GUYANE Sta. CP4344, 05°08.7'N, 51°08.7'W, 26 Jul 2014 (MNHN IM-2000-31090). Louisiana: 4 spec., 21.8 x 8.5 (USNM 1291332), 18.3 x 6.9, 20.1 x 8.0 & 17.6 x 6.4 mm (EFG 28614), in 109–110 m, Ewing Bank, 28°05.009'N, 91°09.093'W to 28°05.348'N, 91°11.365'W, E. García! aboard R/V Pelican, 24 Aug 2008; 2 spec., 22.9 x 8.8 & 19.5 x 7.3 mm, dredged in 99–100 m offshore, 28°04.147'N, 91°46.845'W to 28°04.438'N, 91°45.163'W, E. García! aboard R/V Pelican, 24 Aug 2008 (EFG 28636); 1 spec., 19.1 x 7.4 mm, dredged in 100–104 m, offshore, 28°04.675'N, 91°38.545'W to 28°05.020'N, 91°36.140'W, E. García! aboard R/V Pelican, 24 Aug 2008 (EFG 28624); 2 spec., 15.7 x 6.0 & 14.4 x 5.4 mm, dredged in 100–101 m, offshore, 28°03.080'N, 91°58.641'W to 28°02.623'N, 91°56.393'W, E. García! aboard R/V Pelican, 24 Aug 2008 (EFG 28643); 1 spec., 12.5 x 5.2 mm, in 99–101 m, offshore, 28°06.78'N, 90°55.58'W, E. García! aboard R/V Pelican, 8 Jul 2006 (EFG 27905). Mississippi: 4 spec., 20.9 x 7.5, 19.1 x 7.4, 21.1 x 7.7 & 19.9 x 6.6 mm, dredged in 82–84 m off Mississippi R delta, 29°16.245'N, 88°37.233'W to 29°08.900'N, 88°39.768'W, E. García! aboard R/V Pelican, 23 Apr 2011 (EFG 30172). Campeche, Mexico: 1 spec., 21.5 x 7.8 mm, in 63–65 m, ca. 13 km SW of Triángulos Reef, 20°51.49'N, 92°21.44'W, E. García! aboard R/V Pelican, 10 Jun 2005 (EFG 26532); 1 spec., 18.2 x 7.4 mm, in 94–124 m, ca. 20 km SW of Triángulos Reef, (20°51.09'N, 92°27.10'W) E. García! aboard R/V Pelican, 10 Jun 2005 (EFG 26695).

Type locality. Off French Guiana, 05°13.9'N, 51°41.7'W, in 60 m ( GUYANE 2014 Sta. CP4352).

Other material examined. An additional 13 specimens not included in the type series were examined: 1 spec., 15.7 x 5.7 mm, in 72–74 m, Mississippi-Alabama Shelf, Alabama, 29°24.43'N, 87°58.63'W, E. García! aboard R/V Pelican, 29 Jun 2006 (EFG 27706); 2 spec., 15.6 x 6.9 & 17.0 x 6.7 mm, in 116–117 m, dredged offshore Louisiana, 28°07.188'N, 90°52.812'W to 28°07.867'N, 90°49.896'W, E. García! aboard R/V Pelican, 21 Apr 2011 (EFG 30161); 1 spec., 20.0 x 7.3 mm, dredged in 62–63 m, off Mississippi R delta, Mississippi, 29°20.683'N, 88°27.136'W to 29°20.883'N, 88°30.016'W, E. García! aboard R/V Pelican, 23 Apr 2011 (EFG 30136); 1 spec., 21.5 x 8.0 mm, in 55 m, Snellius OCPS Sta. F41, off Paramaribo, Suriname, 06°54.8′N, 56°28.6′W, 6 May 1966 (ANSP 324007); 1 spec., 23.9 x 8.6 mm, in 49.5 m, Snellius OCPS Sta. D32, off Paramaribo, Suriname, 06°44.5′N, 55°59.6′W, 3 May 1966 (ANSP 324005); 4 spec., 4.6 x 1.9, 7.9 x 3.2, 8.9 x 4.9 & 13.9 x 4.9 mm, in 94 m, GUYANE 2014 Sta. DW4359, off French Guiana, 06°52.2'N, 53°02.6'W, 30 Jul 2014 (MNHN not cataloged); 1 spec., 10.7 x 3.9 mm, in 19–21 m, GUYANE 2014 Sta. CP4389, off French Guiana, 05°20'N, 52°33.2'W, 5 Aug 2014 (MNHN IM-2013-43507); 1 spec., 21.9 x 7.2 mm, off Cabo Orange, Amapá, Brazil, 04°30'N, 051°30'W (ANSP 355310); 1 spec., 17.4 x 6.8 mm, in 30 m, off Cabo Orange, Amapá, Brazil, 04°30'N, 051°30'W, E.C. Rios! May 1968 (ANSP 357891).

Range and habitat. Alabama (Gulf coast); Mississippi; Louisiana; Campeche Bank, Mexico; Suriname (off Paramaribo); French Guiana; and Brazil (off Amapá). Odé (1991: 23–24) states that several lots from off Port Isabel, Texas and in the mud lump fauna off the Mississippi River belong to Clathrodrillia , which he did not identify further. If they prove to be this species, then it would extend its range northwestward to Texas. Reported depths are 15– 131 m.

Description. Shell small (to 23.9 mm in total length), fusiform, spire tall and acuminate toward tip, last whorl large, approximately 55% of total length of shell; base well rounded, constricted below, with a narrow, twisted anterior canal. Suture impressed; whorls up to 12¼ in number, slightly convex; sculpture of numerous axial ribs, interspaces with spiral threads. Aperture only slightly wider than anal sinus and anterior canal. Protoconch of 2½– 3 smooth whorls; the first partially immersed in the second, the last whorl slightly less in diameter than second such that the protoconch appears somewhat beehive-like in outline. Axial sculpture of numerous narrow, slightly opisthocline ribs; 14–19 on penultimate and 11–15 on last whorl to varix; crests ridged, not round, lower and curved in the sulcus reflecting the outline of anal sinus. Ribs abruptly lower and narrower in sulcus, producing a well demarcated shoulder, terminating at anterior fasciole on shell base. Varix hump-like, close to anal sinus, about ¼-turn from the edge of outer lip. Spiral sculpture of threads spaced 2–4 times their width; threads crowded together in sulcus, obsolete on rib crests; microscopic growth striae visible between threads. Sulcus about ⅓-height of spire whorls, with curved narrow ribs and closely set spiral threads between them. Outer lip flattened from the varix to lip edge with up to 6 strengthening axial folds; edge a flat arc from anal sinus to stromboid notch; stromboid notch distinct. Anal sinus deep, U-shaped, open, not constricted, laterally offset from shell axis by parietal lobe on one side, and by the outward flex of the outer lip on the other; and together with inner rim of sinus flared out, appearing spout-like. Inner lip moderately wide, erect anteriorly, recumbent posteriorly with a parietal lobe along one side of anal sinus. Anterior canal relatively long for genus, tapering gradually from aperture, open, twisted to the right when viewed ventrally, and turned dorsally; tip notched. Anterior fasciole swollen; dorsal half of fasciole surface sculptured with spiral threads, as in shell base; ventral half with notch growth increments; the two sides separated by a distinct ridge. Color white or off-white; color patch on varix, typical for the genus, is absent.

Remarks. Taxonomy. Clathrodrillia garciai fits the diagnosis of the genus in possessing a tall spire, numerous axial ribs and a strong spiral sculpture, a hump-like varix, and a deep anal sinus that projects out from the axis of the shell spout-like. Also, it possesses a moderately long anterior canal with a slightly swollen fasciole. The 3- whorl protoconch is unique; all other described species in Clathrodrillia have protoconchs with 2½ or less whorls. It also lacks a strong turreted outline, a characteristic it shares with C. wolfei (Tippett, 1995) and C. tryoni (Dall, 1889) . Variability. 36 specimens have an average total length of 18.04 mm (4.6–30.3 mm) and an average W/ L ratio of 0.375. Two were not included in these statistics because of broken apices. Specimens are fairly uniform in form and color. Identification. Clathrodrillia garciai is unique among its congeners in possessing an approximately 3-whorl protoconch. It also differs from C. wolfei in having more ribs (14–19 versus 8–10 on the penultimate whorl), a larger shell (average total length of C. wolfei is 12.68 mm) and rounder body whorl. From C. dautzenbergi (Tippett, 1995) it also differs in being smaller (average total length of 67 specimens of C. dautzenbergi is 27.00 mm). From C. tryoni (Dall, 1889) it also differs in being larger (average total length of 17 specimens of C. tryoni is 10.96 mm).

Etymology. Emilio García’s Clathrodrillia . Named for Dr. Emilio F. García in recognition of his diligent and persistent effort to collect and preserve specimens from the Gulf of Mexico for study, many of his drilliids included here and elsewhere in this work.

Figures

PLATE 41. Clathrodrillia garciai, new species. Figs. 1 – 3: holotype, GUYANE 2014 Sta. CP 4352 French Guiana (MNHN IM- 2013 - 55984). Fig. 1: ventral, lateral & dorsal views; Fig. 2: enlarged view of 2 protoconchs, holotype on the left, paratype (in Fig. 13) on right (neither to scale); Fig. 3: apical view, V = varix, L = edge of outer lip. Figs. 4 – 19 paratypes. Fig. 4: an exceptionally large specimen, GUYANE 2014 Sta. CP 4344, French Guiana (MNHN not cataloged). Paratypes. Fig. 5: GUYANE 2014 Sta. CP 4350, French Guiana (MNHN IM- 2013 - 55955); Figs. 6 – 8: GUYANE 2014 Sta. CP 4379, French Guiana (MNHN IM- 2000 - 31088); Fig. 9: GUYANE 2014 Sta. CP 4355, French Guiana (MNHN IM- 2000 - 31087); Fig. 10: GUYANE 2014 Sta. DW 4359, French Guiana (MNHN IM- 2000 - 310089); Fig. 11: off Mississippi R delta, Mississippi (EFG 30172); Fig. 12: offshore, Louisiana (EFG 28636); Fig. 13: Ewing Bank, Louisiana (USNM 1291332); Fig. 14: offshore, Louisiana (EFG 28636); Fig. 15: ca. 13 km SW of Triángulos Reef, off Campeche, Mexico (EFG 26532); Fig. 16: offshore Louisiana (EFG 28624); Fig. 17: off Cabo Orange, Amapá, Brazil (ANSP 355310); Figs. 18 – 19: off Paramaribo, Suriname (ANSP 324007 & ANSP 324005, respectively).