Amplirhagada vialae, Köhler, 2011

Köhler, Frank, 2011, Descriptions of New Species of the Diverse and Endemic Land Snail Amplirhagada Iredale, 1933 from Rainforest Patches across the Kimberley, Western Australia (Pulmonata: Camaenidae), Records of the Australian Museum 63 (2), pp. 167-202 : 179-180

Amplirhagada vialae n.sp.

Type locality. Western Australia, NW Kimberley, Bonaparte Archipelago, Montague Sound, Scott Strait, 8.3 km E of Savage Hill ; 14°37'15"S 125°15'15"E (RFS-05–2; coll. V. Kessner, 05 Jun 1987) ( Fig. 1 ) .

Type material. Holotype WAM S34719 (preserved specimen) (Pl. 1.6; Table 1) . Paratypes AM C.472925 (2 preserved specimens), WAM S34720 (5 preserved specimens) , FMNH 220066 (9 preserved specimens) , AM C.472926 (4 shells), WAM S34721 (10 dried shells) , FMNH 220065 (12 shells) .

Etymology. Named in honour of Marlene Vial in recognition for her help with SEM and other work.

Description

Shell (Pl. 1.6; Fig. 17 A–D ). Semi-globose with highly elevated spire. Solid, not translucent. Periphery well rounded to slightly compressed, occasionally slightly angulate; upper sector of whorl flattened to slightly shouldered underneath suture, basal sectors rounded. Umbilicus completely concealed by columellar reflection. Background colour pale yellowish brown to horn; peripheral band conspicuous, well developed, moderately broad, clearly visible on last whorls; sub-sutural band broad, diffuse to well developed, brown, clearly visible on last whorls; both bands may blend into each other covering shell with a dark brown tone; outer and inner lip colour white, conspicuously contrasting shell colour. Protoconch 3.4 mm in diameter, comprising about 1.5 whorls, with weak radially elongated pustulations. Teleoconch with faint, regular axial growth lines, evenly distributed across shell. Angle of aperture about 30 degrees; outer lip moderately thick, well rounded, slightly expanded, not reflected; basal node absent or weak. Parietal wall of inner lip inconspicuous. Average shell size 17.1±1.8 × 19.8±1.0 mm ( Table 1).

Radular and jaw morphology ( Fig. 17 E–G ). Tooth formula C + 14–16 + 4 + 20–22, with 160 rows of teeth (n = 1). Jaw with 10 plates.

Genital morphology ( Figs 18–19 ). Penis curved, medially inflated, about as long as anterior part of oviduct. Penial sheath very delicate. Length of penial retractor muscle equivalent to about 1/3 of length of penial complex. Penial verge elongately conical, with pointed tip, short, extending about 1/10 of length of penial chamber. Inner penial wall entirely covered by well-developed, elongate pustules densely arranged in longitudinal rows. Main stimulatory pilaster huge, cone-shaped comprising 3/4 of length of inner penial wall; with regular lateral corrugations that support dense and regular rows of hooks. Vas deferens thick, not undulating, entering penial sheath close to penial apex. Vagina long, inflated; inner vaginal wall and wall of bursa copulatrix with smooth longitudinal pilasters. Bursa copulatrix reaching base of spermoviduct. Free oviduct rather long, tubular, comprising about half of length of anterior part of oviduct. Spermoviduct not much longer than anterior part of oviduct.

Aestivation strategy: Free sealer.

Remarks. Anatomical description based on dissections of two specimens. Listed by Solem (1991) as “ Amplirhagada NSP 22”. The “bee-hive” shaped shell is similar to that of A. decora Köhler, 2010 (Bigge Island) and A. boongareensis Köhler, 2010 (Boongaree Island), but these species differ in shell colour. All three species are characterized by a huge, cone-shaped main pilaster and by their inner penial wall being densely covered with large pustules. Amplirhagada boongareensis differs by possessing two additional pilasters and A. decora Köhler, 2010 has a shorter bursa copulatrix. The present species occurs in sympatry with A. discoidea n.sp. being described in the following.

Figures

Figure 1. Distribution of Amplirhagada species described in the present work. (A) A. atlantis n.sp. (B) A. carsoniana n.sp. (C) A. alicunda n.sp. (D) A. davidsoniana n.sp. (E) A. vialae n.sp. and A. discoidea n.sp. (F) A. forrestiana n.sp. (G) A. inusitata n.sp. and A. epiphallica n.sp. (H) A. lindsayae n.sp. (I) A. angustocauda n.sp. (K) A. moraniana n.sp. (L) A. gardneriana n.sp. (M) A. bendraytoni n.sp. (N) A. coffea n.sp. (P) A. carinata Solem, 1981. When species occur at more than one locality, the type locality of newly described taxa is marked with an asterisk.

Figure 17. Amplirhagada vialae n.sp. SEM of shell (AM C.472926), radula and jaw (AM C.472925). (A) Protoconch and first teleoconch whorls viewed from above. (B) Detail of first teleoconch whorls viewed from above. (C) Lateral view of shell. (D) Lateral view of last whorl. (E) Jaw. (F) Central and inner lateral teeth viewed from above. (G) Marginal teeth viewed from above. Scale bars: A, 200 µm, B–D, 1 mm; E, 100 µm, F, 20 µm; G, 10 µm.

Figure 18. Genitalia of Amplirhagada vialae n.sp. (AM C.472925). For labelling of structures see Fig. 3. Scale bar = 10 mm.

Figure 19. Penial anatomy of Amplirhagada vialae n.sp. (AM C.472925).For labelling of structures see Fig.4. Scale bar = 3 mm.