Fasciolaria tephrina, De & Souza, 2002

De, Paulino J. S. & Souza, 2002, A new bathyal Fasciolaria (Mollusca: Caenogastropoda) from the southwestern Caribbean, Zootaxa 49, pp. 1-7 : 2-5

Fasciolaria tephrina sp. nov.

Fig. 1­5

Type material: Holotype (fig. 1­3): MZSP 35048 (length 187.4 mm, width 73.8 mm). Type locality: North of Quita Sueño Bank, Colombia (off Nicarágua), 14º 40’ N 81º 25’ W, 480 m, viii.1957 ( fig. 12 ) . Paratype (fig. 4) MNRJ 8668 (length 160.1 mm, width 70.9 mm) this shell has the protoconch missing and the siphonal canal partially broken, from type locality .

Other Material: KSC (fig.5) off Roatan Isl., Honduras, 420 m, collected in fish trap (length 155 mm, width 68. 4 mm).

Diagnosis: Large bathyal species, with ashen white surface lacking spiral grooves, long siphonal canal, large deviated protoconch.

Description: Shell large, fusiform, spire high. Surface somewhat glossy, ashen white in color, marked with axial growth lines, sculptured by 4 or 5 spiral grooves on concave area just anterior to suture. Protoconch (fig. 3) large (approximately 5.5 mm in height), paucispiral, deviated, rounded with 1 whorl. Teleoconch with 7 highly convex whorls, early whorls with obsolete wide ribs (10 on first whorl) and 4 spiral cords, gradually fading, disappearing at 4th whorl; very faint spiral grooves appearing on the final third of body whorl. Aperture slightly prosocline posteriorly, otherwise orthocline, rounded, wide, internally glossy with cream colored enamel; outer wall with numerous, thin, weak lirae; outer lip unthickened with 6 weak, posteriorly set denticles. Parietal wall smooth; columella with 2 moderately strong, oblique plications, not apparent at aperture; anteriormost plication blending with the inner lip of siphonal canal. Siphonal canal very long (24.6 % of total shell length), open, slightly sinuous.

Discussion: Fasciolaria tephrina shares many characters with its congeners, warranting its inclusion in the genus. The general shape of the shell is similar to other Fasciolaria . The columellar plications agree in number and position; the subsutural grooves, labial denticles, and internal lirae are present in other tropical western Atlantic species. The large deviated protoconch (i.e. the protoconch coiling axis forms roughly a right angle with that of the teleoconch) is not typical of other West Atlantic species, but this type of protoconch is also present in the African F. rutila ( figs. 11 , 12 ).

Fasciolaria rutila is distinguishable from F. tephrina by its slender shape, spiral sculpture formed by numerous shallow grooves, short siphonal canal (approximately 16% of total shell length), lack of denticles on the external lip, and low but distinct callus on parietal wall.

Fasciolaria tulipa ( figs. 9, 10 ) and F. hollisteri ( Weisbord, 1962: pl. 31, fig. 1­2) have mottled color pattern of dark brown and cream with several dark spiral lines, their surfaces are sculptured with spiral grooves, and the subsutural grooves are much deeper and wider. The whorls of F. tulipa and F. holisteri are less convex, their apertures more elongate and their siphonal canals shorter (approximately 15 % of total shell length). The protoconch ( fig. 10 ) of F. tulipa and F. hollisteri are mammilated and much smaller (approximately 2.5 mm in height) than that of F. tephrina .

Fasciolaria lilium lilium ( figs. 7, 8 ), F. lilium hunteria and F. bullisi are somewhat smaller (approx. 65 – 130 mm in length) and have color patterns of a few dark brown lines over a mottled background of cream and light brown (see Abbott, 1974: p. 228, fig. 2505 and plt. 10, figs. 2501, 2502), their surfaces are smooth and lack the subsutural spiral grooves but have a few obsolete spiral cords over the siphonal canal. The whorls of F. lilium lilium , F. lilium hunteria and F.bullisi are less convex, their apertures more elongate and their siphonal canals shorter (15 – 19 % of total shell length). Internally the apertures of F. lilium lilium , F. lilium hunteria and F. bullisi have a low keel at the posterior part of their parietal walls, also the columellar plications are visible at their apertures. Their protoconch ( fig. 8 ) are smaller (approximately 3 mm in height) and mammilated.

Fasciolaria insularis is much smaller (25 – 28 mm in length), the shell surface is tessellate with numerous raised thin spiral cords, crossed by thin ribs, the siphonal canal is much shorter, and the protoconch is much smaller and cylindrical ( Fernández, 1977: 28, figs. 1­2) than that of F. tephrina .

Etymology: This species is named for its ashen white coloration, from the Greek tephrinos that means ash­colored.

Figures

FIGURE 12. Map of the coasts of Honduras and Nicaragua. Star indicates type locality, arrow indicates Roatan Island, where KSC specimen was collected.

FIGURES 1 ­ 5. Fasciolaria tephrina sp. nov. 1, Holotype, MZSP 35048, ventral view (length 187.4 mm, width 73.8 mm); 2, Detail of protoconch, scale 5 mm. 3, Holotype, dorsal view; 4, Paratype MNRJ 8668, ventral view (length 160.1 mm, width 70.9 mm); 5, KSC specimen, ventral view (length 155 mm, width 68.4 mm).

FIGURES 6­11. 6­7. Fasciolaria lilium ANSP 234370. 6, Ventral view (length 123.5 mm, width 50.4 mm); 7, Detail of protoconch, scale bar 5 mm. 8­9. Fasciolaria tulipa. 8, ANSP 216226 ventral view (length 182.8 mm, width 80.6 mm); 9, MZSP 35530 detail of protoconch, scale bar 5 mm. 10­11. Fasciolaria rutila ANSP 244337. 10, Ventral view (length 123.3 mm, width 43.6 mm); 11 detail of protococh, scale bar 5 mm.