Splendrillia karukeraensis, 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 : 304-305

Splendrillia karukeraensis , new species

( Plate 155 )

Type material. Holotype 11.7 x 4.6 mm, (ANSP 313863); 3 paratypes: 2.0, 4.7 x 2.2 & 11.9 x 4.6 mm, in 1.2–1.8 m, 1.6 km NW of Pointe des Chateaux, Grande-Terre, Guadeloupe, R.A & V. O. Maes! Feb 1967 (ANSP 465005). Type locality. 1.6 km NW of Pointe des Chateaux, Grande-Terre, Guadeloupe, in 1.2–1.8 m.

Range and habitat. Guadeloupe (Grande-Terre). Reported from 1.2–1.8 m depths, in sand around coral.

Description. Shell small (to 11.9 mm total length), fusiform, truncated anteriorly, glossy, with 7½ whorls; whorl profile with convex ribs below sulcus, shoulders round to slightly shouldered; last whorl approximately 60% of shell length, suture appressed; aperture oval. Outer lip beyond varix not developed type specimens. Protoconch of approximately 1¾ smooth, round whorls, first not immersed in second. Axial sculpture of 11–12 on penultimate, 9–10 to varix on last whorl low, round-crested opisthocline ribs that begin at the margin of the sulcus and evanesce below whorl peripheries, before the anterior fasciole on the shell base. Spaces between ribs less than to about as wide as the ribs; growth striae fine, strongest on last whorl, especially on varix. Vari x strong and humplike. Spiral sculpture of fine threads and ridges on shell base and about 7 ridges on anterior fasciole. Microsculpture of closely packed, very faint microscopic lines over entire shell surface. The faint lines resolve into rows of joined punctae in SEM images (1,000x). Between the lines are a few rows of more widely spaced punctae (see Pl. 141, Figs. 1 –4). It is not known if this pattern holds for all members of the species. Outer lip undeveloped on type specimens. Anal sinus undeveloped on type specimens. Sulcus is flat to slightly excavated; ribs evanesce at sulcus margin. Anterior canal short, open, unnotched; anterior fasciole not swollen. Inner lip margined and slightly erect anteriorly along the columella, unemarginate on parietal wall. Posterior callus or lobe lacking in type specimens. Color creamy white base with 3 light golden brown bands, the posterior-most one interrupted by white rib crests; aperture white; shoulder of varix with a golden brown patch.

Remarks. Taxonomy. Splendrillia karukeraensis has characteristics of the genus: a glossy-smooth shell, with a bare sulcus, and opisthocline ribs. The form of the anal sinus has yet to be described since the types are not fully developed. Variability. The average length of the two largest specimens (not fully adult) is 11.80 mm (11.7, 11.9 mm) and their average W/ L ratio is 0.390. Identification. Splendrillia karukeraensis is similar to S. cruzensis , new species, S. coccinata (Reeve, 1845) , and S. compta , new species. From S. cruzensis it differs in having slightly longer ribs on spire and last whorls, a slightly wider shell (average W/L = 0.390 versus 0.361), and a different color (light golden brown versus brownish rose with deep rose markings). From S. coccinata it differs in being larger (average total length 11.80 versus 7.88 mm) and having a more rounded last whorl, unlike the tapered one of S. coccinata . From S. compta it differs having a wider, smoother sulcus and lower ribs.

Etymology. The Karukera Splendrillia , after the Arawak name for Guadeloupe, the type locality.

Figures

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.

PLATE 155. Splendrillia karukeraensis, new species. Figs. 1 – 4: holotype and paratypes, 1.6 km NW of Pointe des Chateaux, Grande-Terre, Guadeloupe. Fig. 1: holotype, ventral, lateral, & dorsal views (ANSP 313863); Fig. 2: same specimen, apical view, V = varix; Fig. 3 – 4: paratypes from type locality (ANSP 465005).