40 Zootecus pullus (Gray, 1834)

Figs 17 D – H, 18, Table 1

Bulimus pullus Gray, 1834: 66. Type locality: India Orientali ad ripas Gangis [Eastern India, banks of the Ganges River]. Pfeiffer 1848: 162. Reeve 1849 b: Bulimus pl. 67, species 476. Blanford 1865: 94.

Bulimus (Opeas) pullus — Albers 1850: 175.

Pupa (Cylindrus) pulla — von Martens 1860: 297.

Bulimina (Mastus) pulla — Pfeiffer and Clessin 1881: 293.

Rumina pulla — Ancey 1886: 61.

Stenogyra pulla — von Martens 1895: 106, 107, pl. 8, figs 7, 8.

Zootecus insularis var. pullus — Pilsbry 1906: 110, pl. 26, figs 26–28.

Zootecus pullus — Gude 1914: 371, 372. Raheem et al. 2014: 118, 119, fig. 74 e, f.

Type specimens.

Lectotype NHMUK 1986252 / 1 (Fig. 17 D; designated in Raheem et al. 2014) . Paralectotype NHMUK 1986252 (1 shell; Fig. 17 E) from Banks of the Ganges, South Asia.

Other material.

Dhammayazaka Pagoda, Pwasaw Village, Bagan City, Mandalay Region, Myanmar (21 ° 08 ' 40.3 " N, 94 ° 52 ' 58.0 " E): CUMZ 13081 (70 shells; Fig. 17 F – H), CUMZ 13082 (20 specimens in ethanol).

Description.

Shell subcylindrical, solid, glossy, pale grey colour, slightly thick, and with 8–9 ½ whorls. Apex slightly elevated; protoconch ~ 2 whorls, dome-shaped and nearly smooth with fine radial striations; subsequent whorls with dense but fine, wavy, radial striations, stronger near suture. Spire grows evenly; whorls flatly convex; suture wide and shallow. Aperture nearly rounded and wide; columella straight; peristome relatively thickened, expanded, and white. Umbilicus narrowly opened.

Genitalia (n = 5). Atrium undifferentiated. Penis very narrow, slender, almost same length with vagina, and slightly bulging at base. Penial retractor slender, long and attached at junction of penis and vas deferens. Epiphallus very short or indistinct. Vas deferens long, slender tube, and connected between penis / epiphallus to free oviduct (Fig. 18 A, B).

Vagina much larger than penis and cylindrical shape. Gametolytic duct short and slender tube; gametolytic sac distinct and bulbus shape. Free oviduct almost the same diameter as vagina; spermoviduct enlarged.

Radula. Each row contains ~ 43 + teeth with half-row formula: central-lateral-marginal teeth (1 – (11–13) – (6–7 +)). Central tooth relatively small, tricuspid with pointed central cusp, and small, rounded, lateral cusps. Lateral teeth bicuspid: endocone large rhomboid in shape and with pointed to dull tip; ectocone small, pointed tip and located at middle of tooth height. Marginal teeth asymmetrically tricuspid starting approximately at tooth number 11–13: mesocone large, triangular, and curved to blunt tip; endocone small and located near tip of mesocone; ectocone triangular, pointed tip and located near tooth base. Outermost teeth small and polycuspid (Fig. 18 C).

Distribution.

Apart from Myanmar, this species is likely to occur in India and Bangladesh (Raheem et al. 2014).

Remarks.

In Myanmar, the previous records of Z. pullus were from ‘ Ava’ [Innwa in Mandalay Region]. Our newly collected specimens from Bagan (~ 150 km southwest of Innwa) are identified as this species, but they present some differences such as having a long and narrower shell and a blunt apex. Zootecus pullus has a penis nearly equal in length to the vagina, and the penis is slightly enlarged with a conical shape at base near the atrium (Fig. 18 A, B), while Z. insularis possesses a penis shorter than the vagina, and the evenly slender penis (see Schileyko 1999: fig. 678 from a near type locality in the Red Sea). Further investigation is required to determine whether these two Myanmar species are distinct or simply demonstrate variation in shell morphology.