Aclis anaglyptica, Souza & Araújo & Pimenta, 2024

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 : 477-479

Aclis anaglyptica sp. nov.

Fig. 14

Type material. Holotype: MNRJ 23777 , R/ V Ocean Stalwart col. 28/ix/2019 . Paratypes. Brazil: Rio de Janeiro state: PADCT sta. 6541; MNRJ 28199 [5†].

Type locality. Brazil: Santos Basin , off Rio de Janeiro state; PCR BS 4 sta. G6; 23°48′57.96″S, 42°40′31.8″W, 404 m.

Material examined. The types and: Brazil: Rio de Janeiro state: PADCT sta. 6541: MNRJ 28205 [10†]; PADCT sta. 6627: MNRJ 28203 [1†]; São Paulo state: Revizee Sul sta. 6662: MNRJ 28210 [2†]; Revizee Sul sta. 6669: MNRJ 28211 [1†]; Revizee Sul sta. 6660: MNRJ 28209 [1†]; PADCT sta. 6625: MNRJ 28208 [2†]; Revizee Sul sta. 6674: MNRJ 28212 [1†]; Paraná state: Revizee Sul sta. 6703: MNRJ 28213 [2†]; PADCT sta. 6641: MNRJ 28214 [1†]; Santa Catarina state: PADCT sta. 6595: MNRJ 28207 [14†]; Revizee Sul sta. 6672: MNRJ 28206 [1†]; PADCT sta. 6635: MNRJ 28204 [1†]; PADCT sta. 6601: MNRJ 28200 [2†]; PADCT sta. 6606: MNRJ 28201 [2†]; PADCT sta. 6608: MNRJ 28202 [2†].

Etymology. The specific epithet is a Latin singular feminine adjective in the nominative case meaning carved or engraved in bas-relief, which refers to the teleoconch sculpture.

Description. Shell whitish, tall, conical, with an obtuse apex, spire angle about 16°, reaching about 4.3 mm long, 1.4 mm wide. Protoconch globose, subcylindrical, about 2.0 whorls, about 320 μm high and 260 μm wide, presence of microscopic spiral lines regularly spaced, transition to teleoconch marked by an abrupt incremental scar and onset of spiral keels. Teleoconch up to seven whorls, moderately convex outline, crenulated; suture slightly deep, well impressed, sloping; presence of microscopic spiral striae in whole surface of each whorl; presence of sharp, pronounced spiral keels, two since the onset of teleoconch, reaching three at the body whorl; incremental scars strongly demarcated, appearing at irregular intervals. Last whorl about 40% of total length; base carinated, flattened below. Aperture elliptical in shape, about 55% of body whorl length, slightly expanded laterally, rounded or pointed anteriorly, acute posteriorly; outer lip thin, orthocline in adults, prosocline in juveniles, gradually advancing forward, slightly sinuous, maximum projection close to distal region, retracted at distal region; inner lip thin, reflected. Umbilical fissure present.

Measurements. Holotype, MNRJ 23777: 9 whorls; SL= 4.3 mm; BWL= 1.7 mm; AL= 1.0 mm; SW= 1.4 mm; AW= 0.8 mm. Paratype, MNRJ 28199: 7 whorls; SL= 3.0 mm; BWL= 1.2 mm; AL= 0.7 mm; SW= 1.0 mm; AW= 0.6 mm. Paratype, MNRJ 28199: 6 whorls; SL= 2.4 mm; BWL= 1.0 mm; AL= 0.5 mm; SW= 0.9 mm; AW= 0.5 mm.

Remarks. Aclis anaglyptica sp. nov. presents the microscopic spiral striae, which are very numerous and thin ( Fig. 14G, H ). The aperture is relatively short and slightly expanded laterally ( Fig. 14B ) like in other Aclis species. Aclis anaglyptica can be easily recognized by its short, globular protoconch with microscopic spiral lines ( Fig. 14I–K ), presence of sharp and strongly pronounced spiral keels beginning since the onset of teleoconch in all shells examined ( Fig. 14A–J ). These features are the most conspicuous to recognize this species.

Aclis anaglyptica sp. nov. differs from A. marplatensis ( Fig. 13A–I ) by the fewer number of spiral keels in the body whorl (3 vs. 5), which are more pronounced and sharper than in A. marplatensis . Furthermore, the spiral keels of A. anaglyptica sp. nov. starts at the onset of teleoconch whorls, earlier than in A. marplatensis .

Aclis anaglyptica sp. nov. differs from A. eolis ( Fig. 19A–D ) and A. hendersoni ( Fig. 19E–F ) by the less advanced aperture anteriorly and laterally. Additionally, A. anaglyptica sp. nov. differs from A. eolis by the more pronounced spiral keels and A. hendersoni by the homogeneous development of the spiral keels, while the latter has a single well pronounced spiral keel in the upper region of each whorl and the remaining ones are weaker. Aclis anaglyptica sp. nov. resembles Aclis maoria Powell, 1937 , from New Zealand, but the former is more elongated and with a more advanced outer lip.

Geographic Distribution. Brazil: Rio de Janeiro, São Paulo, Paraná, Santa Catarina. From 101 m to 980 m.

Figures

FIGURE 13. Aclis marplatensis (Castellanos & Landoni, 1984). A, B. MZSP 85401. C. MZSP 88368. D. MNRJ 15963. E–I. MNRJ 15964. A–C, E. Shell in frontal view; rectangle in E indicates detail in H. D. Shell in lateral view. F. Detail of body whorl in frontal view. G. Detail of apical whorls. H, I. Detail of teleoconch surface; rectangle in H indicates detail in I. Scale bars: A–E. 1 mm; F. 500 μm; G. 100 μm; H, I. 20 μm.

FIGURE 14. Aclis anaglyptica sp. nov. A, B. Holotype, MNRJ 23777. C–K. Paratypes, MNRJ 28199. A, C. Shell in frontal view. B, D. Shell in lateral view. E, F. Shell in dorsal view; rectangles in F indicates details in G (lower rectangle) and H (upper rectangle). G, H. Detail of teleoconch surface; arrows indicate the suture. I, J. Detail of apical whorls; square in J indicates detail in K. K. Detail of protoconch surface. Scale bars: A–F. 1 mm; G–H. 50 μm; I–K. 100 μm.

FIGURE 19. A–D. Aclis eolis Bartsch, 1947: Holotype, USNM 573617. A. Shell in frontal view. B. Shell in lateral view. C. Detail of apical whorls. D. Detail of the body whorl in frontal view. E–F. Aclis hendersoni Dall, 1927: E, F. Holotype, USNM 333465; E. Shell in frontal view. F. Protoconch in apical view. G–H. Aclis georgiana Dall, 1927: Holotype, USNM 108020. G. Shell in frontal view. H. Protoconch in apical view. Scale bars: A, B, E, G. 1 mm; C, F, H. 200 μm, D. 500 μm. Credits: E–H. USNM.