Aclis cf. pulchra Souza, Araújo & Pimenta

Souza, Leonardo Santos De, Araújo, Tarciso Almeida De & Pimenta, Alexandre Dias, 2024, Taxonomic review of Aclis Lóven, 1846 (Gastropoda, Eulimidae) from Brazil with notes on other congeners from the western Atlantic and Saint Helena, Zootaxa 5433 (4), pp. 451-499 : 468-469

Aclis cf. pulchra Souza, Araújo & Pimenta (present study)

Fig. 9

Material examined. Brazil: Rio de Janeiro state: HAB 13 sta. H3; MNRJ 16811 [1†]; HAB 16 sta. H3; MNRJ 34072 [2†].

Characterization. Shell tall, conical, spire angle 15°, reaching 3.0 mm long, 1.0 mm wide, eight whorls, colorless. Protoconch subcylindrical, dome-shaped, about 2.0 whorls, 320 μm high, surface smooth. Teleoconch with strongly convex whorls, surface glossy presenting faint microscopical spiral striae and strong incremental scars with irregular intervals. Body whorl about 40% of the total length, base rounded; aperture high, about 67% of body whorl length, strongly expanded laterally, rounded anteriorly, acute posteriorly; outer lip thin, strongly orthocline, sinuous, moderately advanced close to distal area; inner lip thin, reflected. Wide umbilicus present, bordered by a rounded edge.

Measurements. MNRJ 34072: 6 whorls; SL= 3.0 mm; BWL= 1.2 mm; AL= 0.8 mm; SW= 1.0 mm; AW= 0.6 mm.

Geographic Distribution. Brazil: Rio de Janeiro. From 71 m to 73 m.

Remarks. These shells ( Fig. 9 ) are similar to A. pulchra sp. nov ( Figs 7 , 8 ) described herein in relation to shell shape, dimensions of the protoconch and convexity of teleoconch whorls. However, shells with this tentative identification (‘cf.’) reach a higher number of whorls, has a more regular increase in diameter, which results in a more turriform shape, besides a less advanced outer lip, a slightly smaller aperture compared to the total length (0.25 vs. 0.30) and a slightly narrower umbilicus. We avoid describing these specimens as a new species due to the scarcity of studied material that hampers a proper comparison of shape variability with A. pulchra sp. nov.

Figures

FIGURE 7. Aclis pulchra sp. nov. A–C, F–I. Holotype, MNRJ 16825. D–E, J. paratype, MNRJ 26601. A, C–D. Shell in frontal view. B, E. Shell in lateral view. F–G. Detail of teleoconch surface; square in F indicates detail in G. H. Detail of body whorl in frontal view. I. Detail of apical whorls. J. Protoconch in apical view. Scale bars: A–E. 1 mm; F–G. 50 μm; H. 500 μm; I–J. 200 μm.

FIGURE 8. Aclis pulchra sp. nov. A. Paratype, MNRJ 16323. B, F, H. Paratype, MNRJ 17713. C. Paratype, MNRJ 30872. D, G, I. paratype, MORG 39469. E. Paratype, MNRJ 26601. A–D. Shell in frontal view. E–G. Detail of apical whorls. H–I. Detail of body whorl in frontal view. Scale bars: A–D. 1 mm; E–G. 200 μm; H–I. 500 μm.

FIGURE 9. Aclis cf. pulchra: MNRJ 34072. A, C. Shell in frontal view. B. Shell in lateral view. D. Detail of teleoconch surface. E. Detail of apical whorls. F–G. Detail of body whorl in frontal view. Scale bars: A–C. 1 mm; D. 20 μm; E. 200 μm; F–G. 500 μm.