Uncovering Local Endemism in the Kimberley, Western Australia: Description of New Species of the Genus Amplirhagada Iredale, 1933 (Pulmonata: Camaenidae)
Author
Köhler, Frank
text
Records of the Australian Museum
2010
2010-11-24
62
2
217
284
http://dx.doi.org/10.3853/j.0067-1975.62.2010.1554
journal article
10.3853/j.0067-1975.62.2010.1554
2201-4349
5239086
749A271A-6942-4D4C-B0DF-B968462BFF0C
Amplirhagada yorkensis
n.sp.
Careening Bay
;
15°06'41"S
125°01'53"E
; KC-040),
WAM
S37376
–8
,
WAM
S36980
–6
,
WAM
S37394
–404
, AMS C463712–4 (
Coronation Island
, southern section)
.
Etymology
. In reference to York Sound, where this species occurs on islands and likely adjacent mainland.
Sealing strategy. Free sealer.
Shell
(
Fig. 62A–B
, Pl. 2.4–5).
Broadly
conical to almost flat with low spire; thin (translucent).
Periphery
evenly rounded to slightly angulate; upper and basal sectors of whorls rounded.
Umbilicus
open, narrowly winding, 30–90 percent concealed by columellar reflection.
Background
and ventral colour brownish horn; sub-sutural band absent; mid-whorl band absent or diffuse, light yellowish brown, thin, generally not very pronounced, only visible on last whorl(s); outer lip colour same as shell; inner lip translucent, whitish.
Protoconch
c.
2.7 mm
in diameter, comprising 2 whorls, with fine, indistinct axial lirae.
Teleoconch
smooth except of axial growth lines.
Angle
of aperture 30°; outer lip rounded, sharp, expanded to largely expanded, reflected; basal and palatal node absent.
Parietal
wall of inner lip inconspicuous.
Type
locality
(
Fig. 1
).
Western Australia
,
northwestern Kimberley
,
Bonaparte Archipelago
,
York Sound
,
Coronation Island
, southern section,
15°01'52"S
124°56'56"E
; KIS- 3–085.
Vine
thicket on upper slopes of a volcanic hill behind mangroves, under rocks (leg.
V
. Kessner,
30 May 2008
)
.
Type material
.
Holotype
WAM
S34619
(Pl. 2.4)
.
Paratypes
AMS C463711 (24 preserved specimens),
WAM
S36979
(42 preserved specimens)
.
Figure 61. Genitalia of
Amplirhagada yorkensis
n.sp.
, paratype AMS C463711 (30 May, scale 5 mm). Compare with Fig. 3 for labelling of structures.
Additional, non-type material
.
WAM
S41477
,
FMNH
219151 (12 preserved specimens, Port
Nelson
,
5 km
N of Mt. Knight, c.
3 km
E of
Figure 62. SEM photographs of shell, jaw and radula of
Amplirhagada yorkensis
n.sp.
, paratype AMS C463711: (
A
) apical whorl viewed from above (scale 200 µm); (
B
) sculpture on second to forth whorl viewed from above (scale 200 µm); (
C
) jaw (scale 100 µm); (
D
) close-up of central and inner lateral teeth (scale 10 µm); (
E
) outer lateral and inner marginal teeth (scale 10 µm); (
F
) close-up of middle marginal teeth (scale 10 µm).
Pallial morphology
. Pallial cavity moderately deep, extending
3
⁄
4
whorl; mantle pigmentation spotted, black. Kidney extending about half of pallial cavity.
Genital morphology
(
Figs. 61
,
63
). Penis curved to sharply bent, more or less of same length as anterior part of oviduct. Vas deferens coils once before entering penis. Penial retractor muscle very short, stubby. Penial verge very short, slender to spatulate, with pointed tip. Penial wall pustules of average size, arranged in rows over entire length of inner penial wall. Main stimulatory pilaster well-differentiated, large, cone-shaped, sculptured by horizontal ridges that support little hooks, comprising about
3
⁄
4
of length of penial chamber. Vas deferens entering penial sheath in upper third. Vagina moderately wide, posteriorly inflated; inner vaginal wall with smooth longitudinal pilasters. Spermathecal duct wide, internally with smooth longitudinal pilasters. Spermathecal head pyriform, connected with oviduct by connective tissue, internally smooth with thing wall. Free oviduct comprising about half of anterior part of oviduct, more or less straight. Spermoviduct longer than anterior part of oviduct. Talon embedded in albumen gland at junction with spermoviduct.
Radular morphology
(
Fig. 62D–F
). Rectangular. Tooth formula C+13–14+3+18. In average with 122±1.5 rows of teeth, 32.4±2.0 rows per mm (n = 2). Central teeth with sharply pointed, triangular mesocones, shorter than base of tooth; ectocones vestigial. Lateral teeth with bluntly pointed, triangular to ovate mesocones, length equal to base of tooth; ectocones and endocones vestigial. Marginal teeth with triangular to elongate mesocones; ectocones shorter and narrower than mesocones; endocones reduced in size.
Figure 63. Interior of penial chamber of
Amplirhagada yorkensis
n.sp.
, paratype AMS C463711 (30 May, scale 3 mm). Compare with Fig. 4 for labelling of structures.
Comparative remarks
. The shell is low spired with a rounded periphery and light colouration; penis with a comparatively large main pilaster. This species was referred to as “
Amplirhagada
sp.
34” by Solem (1991).