Aclis watsoni 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 : 461-462

Aclis watsoni Barros, Lima & Francisco, 2007

Fig. 4

Aclis watsoni Barros, Lima & Francisco, 2007: 65 , Fig. 7–9 : Rios (2009: 198, Fig.491); Cavallari et al. (2016: 52) .

Type material. Holotype (herein examined): MZSP 77991 ; R/V Natureza coll., 28/x/2000 . Paratypes (herein examined): Brazil: Sergipe state: type locality; MZSP 77992 [3]; Revizee Nordeste; 11°35′30″, 37°12′18″W, 510 m; R/V Natureza col., 30/x/2000: MZSP 77993 [4].

Type locality. Brazil: Sergipe state; Revizee Nordeste , 10°41′24″S, 36°18′42″W, 365 m.

Material examined. The types and: Brazil: Sergipe state: MARSEAL SED 3 sta. HN4; CZUFS GAS-00105 [1].

Measurements. Holotype, MZSP 77991: 7 whorls; SL= 4.29 mm; BWL= 1.72 mm; AL= 1.02 mm; SW= 1.44 mm; AW= 0.86 mm. Paratype MZSP 77993: 7 whorls; SL= 4.26 mm; BWL= 1.73 mm; AL= 1.02 mm; SW= 1.5 mm; AW= 0.89 mm.

Remarks. Aclis watsoni has been reported only on the coast of northeastern Brazil, based on few specimens. We report new material from the same region, which consists of a single shell with a worn surface but still exhibiting the strong spiral keels.

Aclis watsoni closely resembles A. sarissa ( Figs 2–3 ) in the general shape and dimensions of the shell. However, the holotype and paratype figured by Barros et al. (2007: Fig. 7–9 ) have a remarkable spiral sculpture since the third teleoconch whorl, which gives a truncated outline in the teleoconch whorls. The types of A. sarissa ( Fig 2 ) have a more rounded outline, with a weaker spiral sculpture usually notable in the last teleoconch whorls. In view of the preservation status of the type series of A. sarissa and the possible variation in the expression of the spiral keels, one could suspect a possible synonymy of A. sarissa and A. watsoni , in which the types of A. sarissa would be eroded specimens. Additional specimens would be necessary to confirm the synonymy.

Aclis watsoni resembles Aclis eolis Bartsch, 1947 ( Fig. 19A–D ), from Florida, but differs by the more truncated outline of the teleoconch whorls. Furthermore, A. watsoni can be distinguished from A. eolis by the pattern of the teleoconch sculpture, the former has a single and pronounced spiral keel in the posterior whorls and reaches three pronounced spiral keels at the anterior whorls. All spiral keels are restricted to the lower half region of the whorls. In contrast, A. eolis has three weak spiral keels since the initial teleoconch whorls that are distributed through the whole surface of each whorl, equally spaced ( Bartsch 1947) ( Fig. 19A–D ).

Geographic Distribution. Brazil: Sergipe state. From 365 m to 510 m.

Figures

FIGURE 2. Aclis sarissa Watson, 1881. A–C, E. Lectotype, NHMUK 1887.2.9.1576, herein designated; D. Paralectotype, NHMUK 1887.2.9.1576; F–I. Paralectotype, NMW 1955.158.26255; J–K. Holotype of Aclis carolinensis, USNM 83743. A, D, F, J. Shell in frontal view; B, G, K. Shell in lateral view. C, H. Shell in dorsal view. E, I. Body whorl in frontal view. Scale bars: A–D, F–H, I–J. 1 mm; E, I. 500 μm. Credits: A–E. NHMUK photographic unit; F–I. NMW.

FIGURE 3. Aclis sarissa Watson, 1881. A–B, H–K. MORG 49199. C–D. CZUFS GAS-00102. E–G. CZUFS GAS-00104. A, C, E. Shell in frontal view; square in A indicates detail in I. B, D, F. Shell in lateral view. G–H. Detail of the body whorl in frontal view. I–J. Detail of teleoconch surface; rectangle in I indicates detail in J. K. Detail of apical whorls; arrow indicates the transition protoconch–teleoconch. Scale bars: A–F. 1 mm; G–H. 500 μm; I–J. 50 μm; K. 200 μm.

FIGURE 4. Aclis watsoni Barros, Lima & Francisco, 2007. A–B. CZUFS GAS-00105. A. C. Shell in frontal view. B. Shell in lateral view. Scale bar: 1 mm.

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.

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.