Austropeplea cf. brazieri (E. A. Smith, 1882)

Figs 4 B, D, F, 5 B, D, 6 B, D, 7 B

Material examined.

Artificially bred specimens in the lab, which were originally from Werribee South, Victoria, Australia.

Description.

Shell (Fig. 4 B) medium in size (≤ 14.7 mm in height in lab condition), high-conical, with relatively narrow and high spire and moderately inflated body whorl. Shell thin but somewhat solid, in some specimens almost translucent. Whorls (4–4.5 in number) rounded, convex, slowly increasing, separated by deep and oblique suture. Shell surface smooth, light brown, covered by collabral growth lines. Aperture pyriform, with evenly rounded basal and palatal margins. Peristome sharp, not expanded but columellar lip slightly reflexed. Parietal callus thin but distinct, extending a little over the parietal wall. Columellar fold weakly developed. Umbilicus covered by inner lip, closed or very narrow (slot-like).

Head-foot (Fig. 4 D, F) typical of family. Foot broad, fully extended approximately equal to shell height, light grey with dense white freckles (observed when living). Tentacle elongated triangular, length equal to width (observed when living). Mantle light grey with large black blotches on pallial roof. Mantle collar slightly reflexed and attached to aperture margin (Fig. 4 F). Mantle covering visceral coil unpigmented (Fig. 4 D).

Central nervous system (Fig. 5 B) typical of family. Cerebral ganglia with irregular-borders, pale yellow in fresh material. Commissural lobule distinct, white, notably smaller in size than cerebral ganglia.

Pulmonary roof (Fig. 5 D) with heart and kidney in typical positions for family. Kidney spindle-shaped, thin-walled, with transversely pleated lining of sinuate tube visible through translucent wall, proximal part opposite to anterior pericardium. Ureter short, urinary opening not observed.

Prostate fusiform, with single internal fold. Sperm duct short, almost invisible in natural position. Praeputium (Fig. 6 B) light greyish white, cylindrical, tapers towards proximal end, distal part near opening folded. Bulbous termination of praeputium distinct in lighter colour to white, narrowest across praeputium. Penis sheath narrow, shorter than praeputium, proximal part slightly inflated. Index of copulatory apparatus (ICA) 1.12 to 2.21. Spermatheca (Fig. 6 D) ellipsoid. Spermatheca duct shorter than length of spermatheca, width approx. quarter of length, proximal external side somewhat adherent to the vaginal duct.

Radula of the haplolateral multidentate type (Fig. 7 B). Radular formula 28 - C- 28 to 38 - C- 38. Teeth in same row approximately aligned horizontally. Central tooth small, bicuspid, asymmetrical, right cusp significantly larger than left. Lateral teeth pairs 1–11 ~ 13 tricuspid, middle cusp largest, left cusp larger than right, rarely with denticle situated on the right basal side; pairs 12 ~ 14–28 ~ 38 with four or five cusps. A variant individual observed among examined specimens (Fig. 7 C), with lateral teeth pairs 1–13 tricuspid, middle cusp largest, left cusp larger than right, rarely left cusp absent; pairs 14–17 tricuspid, left cusp largest, right two cusps gradually reduced; pairs 18–28 with 3–6 cusps.

Remarks.

We use the species-group name A. cf. brazieri for our Victorian specimens because both molecular and morphological data indicate clear differences from typical Austropeplea brazieri (E. A. Smith, 1882: 274, pl. 5, fig. 15, from Glebe Point, Sydney, New South Wales). The currently recognised distribution of A. brazieri is broad (Ponder et al. 2024), and our analysis and that done previously by Puslednik et al. (2009) have shown that it does not form a monophyletic group. To reflect this taxonomic uncertainty, we follow our earlier usage (Sukee et al. 2024) in applying the provisional name A. cf. brazieri to the Victorian population.

There are three additional names available for this taxon, all from New South Wales (Glacilimnaea gelida Iredale, 1943: 214, Blue Lake, Mt Kosciusko, NSW; Simlimnea morbida Iredale, 1944: 119, figs 5-4, Walcha, NSW; and Simlimnea aegrifer Iredale, 1944: 119, fig. 5-5, Bombala, NSW), but based on the molecular data of species from representative location of above (Fig. 3), none are applicable to the Victorian taxon.

Distribution.

Victoria, Australia.