Amplirhagada berthierana, Köhler, 2010

Köhler, Frank, 2010, Uncovering Local Endemism in the Kimberley, Western Australia: Description of New Species of the Genus Amplirhagada Iredale, 1933 (Pulmonata: Camaenidae), Records of the Australian Museum 62 (2), pp. 217-284 : 244

Amplirhagada berthierana n.sp.

Type locality ( Fig. 1 ). Western Australia, northwestern Kimberley, Bonaparte Archipelago, Berthier Island , 14°29'49"S 124°59'34.1"E (leg. C. Whisson, 11 November 2006) .

Type material. Holotype WAM S34611 (Pl. 1.17) . Paratypes AMS C463754 (8 preserved specimens), WAM S33029 (10 preserved specimens) .

Etymology. In reference to Berthier Island, where this species occurs.

Sealing strategy. Rock sealer.

Shell ( Fig. 41A–C , Pl. 1.17). Globose to broadly conical with medium high spire; thick. Whorls evenly rounded. Umbilicus open, forming a chink, 95 percent concealed by columellar reflection. Background and ventral colour cream; banded. Sub-sutural band well defined, red-brown. Mid-whorl band well marked, red brown, moderately broad, visible on entire shell becoming more diffuse on upper whorls, blends with sub-sutural band to cover entire surface of whorl in reddish brown towards tip of shell; outer lip colour white; inner lip translucent, white. Protoconch c. 2.2 mm in diameter, comprising 1.7 whorls, with fine, indistinct axial lirae. Teleoconch with strong axial growth lines.Angle of aperture 45°; outer lip rounded, moderately thick to thick, slightly expanded, slightly reflected; basal node of lip weak; palatal node absent. Parietal wall of inner lip inconspicuous.

Pallial morphology. Pallial cavity moderately deep, extending 3 ⁄ 4 whorl. Pigmentation on mantle comprising sparsely distributed, dark brown spots. Kidney extending more than half of pallial cavity.

Genital morphology ( Figs. 39–40 ). Penis curved, thick, more or less of same length as anterior part of oviduct. Vas deferens coils once before entering penis. Penial retractor muscle stubby to short. Penial sheath evenly thick. Penial verge short (<1 ⁄ 4 penial chamber), broad with rounded tip. Penial wall pustules small, arranged in rows over entire length of inner penial wall. Main stimulatory pilaster welldifferentiated, elongated, cone-shaped, sculptured by smooth horizontal ridges, comprising apical two thirds of penial chamber. Vas deferens entering penial sheath in upper third. Vagina moderately thick, medially inflated; inner vaginal wall with undulating longitudinal pilasters. Spermatheca long, clearly extending over base of spermoviduct. Spermathecal duct wide, internally with undulating longitudinal pilasters. Spermathecal head elongately inflated, connected with oviduct by connective tissue, internally smooth with delicate wall. Free oviduct comprising more or less half of anterior part of oviduct, straight. Spermoviduct longer than anterior part of oviduct. Talon embedded in albumen gland at junction with spermoviduct.

Radular morphology ( Fig. 41E–G ). Rectangular. Tooth formula C+13–15+3–4+20–24. In average 133±5.0 rows of teeth, 29.2±0.2 rows per mm (n = 2). Central teeth with sharply pointed, triangular to ovate mesocones, shorter than base of tooth; ectocones vestigial. Lateral teeth with sharply pointed, triangular mesocones, length equal to base of tooth; ectocones and endocones vestigial. Marginal teeth with triangular mesocones; ectocones shorter and narrower than mesocones; endocones reduced in size.

Comparative remarks. Distinctive species; its broadly conical, almost dome-like shell with widely rounded, almost depressed last whorl with pronounced spiral banding, and the corrugated, large main pilaster are diagnostic.

Figures

Figure 1. Distribution of Amplirhagada species in the Kimberley region, northwestern Australia. (1) A. euroa n.sp., Adolphus Island. (2) A. solemiana n.sp., Middle Osborn Island. (3) A. indistincta n.sp., Southwest Osborn Island, Kidney Island. (4) A. combeana, Cassini Island. (5) A. mckenziei n.sp., Oliver Island. (6) A. ponderi n.sp., Kingsmill Island. (7) A. montesquieuana n.sp., Fenelon Island. (8) A. descartesana n.sp., Descartes Island. (9) A. katerana, Katers Island. (10) A. puescheli n.sp., unnamed island near Prudhoe Island. (11) A. decora n.sp., A. kessneri n.sp., Bigge Island. (12) A. berthierana n.sp., Berthier Island. (13) A. lamarckiana n.sp., Lamarck Island.(14) A. anderdonensis n.sp., unnamed island, Anderdon Islands. (15) A. tricenaria n.sp., Prince Frederick Harbour, north of Hunter River mouth. (16) A. regia n.sp., A. boongareensis n.sp., A. gibsoni n.sp., and Amplirhagada sp., Boongaree Island. (17) A. yorkensis n.sp., Coronation Island. (18) A. buffonensis n.sp., Buffon Island. (19) A. uwinsensis n.sp., Uwins Island. (20) A. sphaeroidea n.sp., St. Andrews Island. (21) A. basilica n.sp., and A. camdenensis n.sp., Augustus Island. (22) A. kimberleyana n.sp., NW of Wilson Point. (23) A. gemina n.sp., 1.5 km SE of Hall Point. (24) A. dubitabile n.sp., Steep Island. (25) A. napierana, north Napier ranges. (26) A. percita, Napier ranges. (27) A. castra, A. mitchelliana, and A. varia, Mitchell Plateau.

Figure 39. Genitalia of Amplirhagada berthierana n.sp., paratype AMS C463754 (11 November, scale 10 mm). Compare with Fig. 3 for labelling of structures.

Figure 40.Interior of penial chamber of Amplirhagada berthierana n.sp., paratype AMS C463754 (11 November, scale 5 mm). Compare with Fig. 4 for labelling of structures.

Figure 41. SEM photographs of Amplirhagada berthierana n.sp., paratype AMS C463754. (A–C) Shell: (A) apical whorl viewed from above (scale 200 µm); (B) sculpture on second to forth whorl viewed from above (scale 200 µm); (C) sculpture on upper part of last whorl (scale 200 µm). (D) Jaw (scale 100 µm). (E–G) Radula: (E) central and lateral teeth (scale 20 µm); (F) close-up of lateral teeth (scale 20 µm); (G) outer lateral and inner marginal teeth (scale 20 µm).