Amplirhagada regia, 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 : 251-253

Amplirhagada regia n.sp.

Type locality ( Fig. 1 ). Western Australia, Kimberley, Bonaparte Archipelago, central section of Boongaree Island , 15°04'15"S 125°11'14"E; KIS 1-30. Dry vine thicket on west facing sandstone scree below escarpment, under rocks (leg. M. Shea, 9.8.2007) .

Type material. Holotype WAM S34615 (Pl. 1.21) . Paratypes AMS C463705 (4 preserved specimens, as holotype), WAM S36647 (3 preserved specimens, as holotype), WAM S36449 (6 preserved specimens, 15°04'00"S 125°11'11"E) , AMS C463704 (6 shells, 15°04'31"S 125°11'07"E), WAM S36480 (12 shells, 15°04'31"S 125°11'07"E) .

Additional, non-type material. WAM S36479 , WAM S36481 –5, WAM S36648 (Boongaree Island).

Etymology. From regia (Latin = royal), referring to fact that this species is among the largest of the genus.

Sealing strategy. Free sealer.

Shell ( Fig. 53A–D , Pl. 1.21). Globose with medium high to high spire; solid to thick. Periphery angulated; upper sector of whorls rather flattened, basal sector rounded. Umbilicus forming chink or narrowly winding opening, 60–100 percent concealed by columellar reflection. Background colour uniform, creamish horn; outer lip purple; inner lip pale purple. Protoconch c. 2.2 mm in diameter, comprising 1.5 whorls, sculpture almost smooth. Teleoconch smooth except for faint axial growth lines. Angle of aperture 45; outer lip simple rounded; moderate; slightly expanded; not reflected, or slightly reflected; basal node of lip present; weak; palatal node absent. Parietal wall of inner lip inconspicuous.

Pallial morphology. Pallial cavity deep, extending one whorl. Pigmentation on mantle comprising brownish grey spots. Kidney extending about half of pallial cavity.

Genital morphology ( Figs. 51–52). Penis straight, more or less of same length as anterior part of oviduct. Vas deferens forms simple loop before entering penis. Penial retractor muscle shorter than or equal to penis length. Penial sheath evenly thin. Penial verge short (<1 ⁄ 8 penial chamber), slender to spatulate, with pointed tip. Penial wall pustules absent. Main stimulatory pilaster absent. Two longitudinal pilasters present at basal portion of penial chamber, two additional weakly developed pilasters visible at apical portion. Vas deferens entering penial sheath in upper third. Vagina short to moderately long, tubular. Inner vaginal wall with smooth longitudinal pilasters. Spermathecal duct moderately wide, internally with smooth longitudinal pilasters. Spermathecal head globular to elongately inflated, connected with oviduct by connective tissue, internally entirely smooth, with delicate wall. Free oviduct comprising about half of anterior part of oviduct, more or less straight. Spermoviduct of same length as anterior part of oviduct. Talon embedded in albumen gland close to anterior end of albumen gland.

Radular morphology ( Fig. 53F–H ). Rectangular. Tooth formula C+20+3+20. In average with 147±2.5 rows of teeth, 29.6±1.7 rows per mm (n = 2). Central teeth with sharply pointed, triangular 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 elongate mesocones; ectocones shorter and narrower than mesocones; endocones greatly reduced in size.

Comparative remarks. Diagnostic features are the broadly conical to dome-shaped shell, smooth inner penial wall with lack of pustulation and main pilaster.

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 53. SEM photographs of Amplirhagada regia n.sp.(A–D) Shell, paratypeAMS C463704: (A) apical whorl viewed from above (scale 200 µm); (B) sculpture on second to forth whorl viewed from above (scale 1 mm); (C) surface of last whorl (scale 1 mm); (D) close-up showing axial growth lines on last whorl (Scale 100 µm). (E) Jaw, paratype WAM S36647 (scale 100 µm). (E–G) Radula, paratype WAM S36647: (E) close-up of lateral teeth (scale 10 µm); (F) close-up of central and inner lateral teeth (scale 10 µm); (G) close-up of middle marginal teeth (scale 10 µm).