Aclis macrostoma Barros, Lima & Francisco, 2007

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 : 474

Aclis macrostoma Barros, Lima & Francisco, 2007

Aclis macrostoma Barros, Lima & Francisco, 2007: 62 , Fig. 7–9 : Rios (2009: 198, Fig. 490); Cavallari et al. (2016: 35) .

Type material. Holotype: MZSP 77988 ; R/ V Natureza col., 26/xi/2001 . Paratypes: Brazil: Rio Grande do Norte: Revizee Nordeste ; 04°51′00″S, 35°06′46″W, 375 m; 24/xi/2001; R/ V Natureza; MZSP 77989 [2]; Revizee Nordeste ; 06°14′24″S, 34°52′06″W, 500 m; 26/xi/2001; R/ V Natureza; MZSP 77990 [1]: LMUFRPE 022 [1].

Type locality. Brazil: Rio Grande do Norte; Revizee Nordeste ; 06°14′04″S, 34°52′33″W, 510 m.

Material examined. Only the holotype.

Measurements. Holotype, MZSP 77988: 3 whorls; SL= 1.08 mm; BWL= 0.80 mm; AL= 0.54 mm; SW= 0.74 mm; AW= 0.50 mm. Paratype LMUFRPE 022: 3 whorls; SL= 1.08 mm; BWL= 0.81 mm; AL= 0.54 mm; SW= 0.71 mm; AW= 0.50 mm.

Remarks. Aclis macrostoma is known only by the type series and has conspicuous characteristics among the taxa of the present study, such as the broad elliptical aperture, having about half the total size of the shell, and the outer lip vastly expanded in comparison to the other species ( Barros et al. 2007: Figs. 1 , 5 ). Although type specimens have a tiny size, the expanded aperture, well-formed inner lip and the relatively sizeable umbilical fissure indicate that this may represent an adult specimen.

Geographic Distribution. Brazil: Rio Grande do Norte ( Barros et al. 2007). From 375 to 510 m.

Figures

FIGURE 1. Terminology of some of the shell features used in descriptions in the present study. A. Microscopic spiral striae of the teleoconch indicated by arrows. B. Spiral keels of the teleoconch indicated by arrows. C. Umbilical fissure indicated by arrow. D. Umbilicus indicated by arrow.

FIGURE 5. Aclis kanelaAbsalão, 2009. A, D–G. MNRJ 28293. B–C. MNRJ 26713. A–C. Shell in frontal view; rectangle in A indicates detail in E. D. Detail of body whorl in frontal view. E, F. Detail of teleoconch sculpture; rectangle in E indicates detail in F. G. Detail of apical whorls. Scale bars: A–C. 1 mm; D. 500 μm; E–F. 50 μm; G. 200 μm.

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.