Ampullaria scalaris, d'Orbigny, 1835

Cowie, Robert H. & Héros, Virginie, 2012, Annotated catalogue of the types of Ampullariidae (Mollusca, Gastropoda) in the Muséum national d’Histoire naturelle, Paris, with lectotype designations, Zoosystema 34 (4), pp. 793-824 : 817

scalaris d’Orbigny, 1835 , Ampullaria

( Fig. 6G )

Ampullaria scalaris d’Orbigny, 1835a: 31 [1838: 369, pl. 50, figs 1-3].

CURRENT TAXONOMIC STATUS. — Pomacea (Pomacea) . Valid species.

TYPE SPECIMENS. — Lectotype (here designated) MNHN 23088 (ex 4627); paralectotypes MNHN 4626 (4 spms), 4627 (3 spms); possible paralectotype MNHN 4629 (1 spm, the smaller of the two shells).

TYPE LOCALITY. — “Rio Parana ( republica Argentina) […] Guarayos (republica Boliviana) […] provincia Santa-Cruz de la Sierra (republica Boliviana)”.

REMARKS

Some of these shells are sharply-carinate and purplish, usually considered the typical Ampullaria scalaris form, while others tend more towards less carinate, greenish and yellowish forms.Those of MNHN 4626 are close to Pomacea diffusa Blume, 1957 , being less carinate. Those of MNHN 4627 (from which the lectotype here designated was selected) are typical Ampullaria scalaris . The two specimens in MNHN 4629 differ considerably from each other.One is large, pale greenish-yellowish and strongly reminiscent of Ampullaria bridgesii Reeve, 1856 (the oldest label in fact says “ A. bridgesii ”), but the other shell is of the typical Ampullaria scalaris form. The original description of the species included three varieties, although none was illustrated or named. However, the labels of MNHN 4629 identify it (presumably the larger Ampullaria bridgesii -like shell) as “var. B. major viridescens”.D’Orbigny (1835a: 31) did note a “Var. B. major, viridescens” but did not formally name it. It is possible that the Ampullaria scalaris -like shell in this lot has been misplaced in this lot as it is very similar to the shells in MNHN 4627. The later illustration of d’Orbigny (1838: pl. 50) shows only the sharply-carinate, purplish form, and his account of the species (d’Orbigny 1838: 369-371) adds little to the original description. To stabilise the name, we here designate as the lectotype the largest shell among the four specimens that formerly constituted MNHN 4627. The remaining specimens in MNHN 4627 and those in MNHN 4626 then become paralectotypes. The larger Ampullaria bridgesii -like shell in MNHN 4629 has no type status, as we consider it to be referable to d’Orbigny’s “Var.B” (see ICZN 1999b: art. 72.4.1). However, as the smaller shell in MNHN 4629 may have been misplaced in this lot, we treat it as a possible paralectotype.

Figures

FIG. 6. — A, Ampullaria physis Hupé,1857,lectotype MNHN 23084, 41.4 mm; B, Ampullaria prunella Hupé,1857,syntype MNHN 4620, 25.7 mm; C, Ampullaria puntaplaya Cousin, 1887, lectotype MNHN 4622, 35.6 mm; D, Ampullaria pygmaea Récluz, 1851, syntype MNHN 4623, 7.0 mm; E, Meladomus pyramidalis Bourguignat,1879,syntype MNHN 4624, 42.5 mm; F, Ampullaria reyrei Cousin,1887, possible syntype MNHN 23087, 60.3 mm; G, Ampullaria scalaris d’Orbigny, 1835, lectotype MNHN 23088, 48.9 mm; H, Ampullaria schrammi Crosse, 1876, lectotype MNHN 4630, 41.7 mm.