Bellaspira tricolor, 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 : 44-45

Bellaspira tricolor , new species

( Plate 15 )

Type material. Holotype 6.8 x 3.3 mm, 25 May 2012 (MNHN IM-2012-28007); 4 paratypes, 3 from original type lot: 6.2 x 2.8, 3.2 x 1.7 & 2.4 x 1.3 mm (MNHN IM-2000-31082); 1 spec., 2.5 x 1.4 mm, in 29 m, KARUBENTHOS 2012 Sta. GS31, Grand Cul-de-Sac Marin, Guadeloupe, 16°21.6'N, 61°34.7'W, 24 May 2012 (MNHN IM-2012-28059).

Type locality. Behind Fajou Islet, Grand Cul-de-Sac Marin, Guadeloupe, 16°22.7'N, 61°35.0'W, in 95 m (KARUBENTHOS 2012 Sta. GD58).

Range and habitat. Guadeloupe (Grand Cul-de-Sac Marin). Reported from 29– 95 m.

Description. Shell very small (to 6.8 mm total length), broadly fusiform, truncated anteriorly, surface glossy; whorls flat to slightly concave, the last approximately 47% of total shell length; sculpture of ribs; aperture narrow. Protoconch of two smooth round translucent whorls, the first partially immersed in the second so that the shell appears to have a round tip when viewed from its side. Axial wrinkles present near the end of the last whorl of the protoconch. Axial sculpture of narrow ribs that run from suture-to-suture on spire whorls, evanesce below periphery on last; number 8 on penultimate, 7–8 on last, are narrower, slightly curved on shoulder with ridged crests, wider with round crests near suture of succeeding whorl; intercostal spaces wider than ribs. Ribs tend to align whorl-to-whorl. Varix incompletely formed on holotype, absent on paratype. Spiral sculpture of low, very fine well-spaced threads over entire shell surface, irregular, faint growth striae visible between threads. Sulcus absent; lower, narrower, and slightly curved ribs on whorl shoulder mark former positions of the anal sinus. Outer lip thin, without the shallow indentations that typically mark the anal sinus and stromboid notch (usually weak in this genus) of fully grown specimens. Anal sinus not formed on type specimens, which are incompletely developed; edge of lip thin, straight, without an indentation in sinal area. Inner lip recumbent, thin, narrow; pinched up on anterior end of columella. Parietal callus also not yet formed on type specimens. Anterior canal short, open, unnotched. Color a light caramel wash with a white spiral band below mid-whorl and extending axially over rib crests; a narrow brown spiral band above the white one, occasionally interrupted in intercostal spaces. Protoconch, aperture and columella white.

Remarks. Taxonomy. Bellaspira tricolor is similar to most other members of Bellaspira in possessing a midwhorl spiral color band, but more importantly has the characteristic spiral groove microsculpture of the genus and ribs that run suture-to-suture that are little changed in the sulcal area. While a fully formed anal sinus, which is also diagnostic of the genus, is lacking in the examined specimens, the other characteristics place this species in the genus. Variability. The average total length of the two largest type specimens is 6.50 mm and their average W/ L ratio is 0.308. Identification. Bellaspira tricolor is close in size to B. hannyae (Jong & Coomans, 1988) but that species has more numerous and closely spaced ribs, and a narrower shell profile. B. tricolor is similar in profile to B. pentagonalis (Dall, 1889) , B. amplicostata , new species, and B. aurantiaca , new species. It is generally smaller and has more ribs than B. pentagonalis (7–8 versus 5), is about the same size as B. amplicostata but has narrower ribs, and from B. aurantiaca it also differs in possessing narrower ribs. The color pattern of B. tricolor differs from all three species.

Etymology. The Three-colored Bellaspira , from the Latin adjective combination tri+color, meaning three color. Named for the white, light caramel, and brown color pattern of its shell.

Figures

PLATE 15. Bellaspira tricolor, new species. Figs. 1 – 3: holotype, Grand Cul-de-Sac Marin, Guadeloupe (MNHN IM- 2012 - 28007). Fig. 1: ventral, lateral & dorsal views; Fig. 2: enlarged view of protoconch (not to scale); Fig. 3: apical view, L = edge of lip. Figs. 4 – 7: paratypes, Grand Cul-de-Sac Marin, Guadeloupe. Figs. 4, 6 – 7: MNHN IM- 2000 - 31082; Fig. 5: MNHN IM- 2012 - 28059.