A morphological phylogenetic analysis and generic revision of Australian Helicarionidae (Gastropoda: Pulmonata: Stylommatophora), and an assessment of the relationships of the family 2462
Author
Hyman, Isabel T.
Author
Ponder, Winston F.
text
Zootaxa
2010
2010-05-14
2462
1
1
148
https://biotaxa.org/Zootaxa/article/view/zootaxa.2462.1.1
journal article
10.11646/zootaxa.2462.1.1
11755334
5312710
Mysticarion porrectus
(
Iredale, 1941
)
Figures 5B
,
6C
,
7F
,
8F
,
9F
,
12C
,
13C
,
15D–F
,
16A
Helicarion porrectus
(
Iredale, 1941
) 1992: 234
.
Material examined.
New South Wales
,
Australia
:
Probable
holotype
:
AM
C101136
(one shell measured, photographed), NW of
Sydney
,
Blue Mountains
,
Mt. Irvine
(
33º29' S
,
150º28' E
), pre 1941,
M. Ward
.
Other material:
AM
C165048
(
one specimen
dissected), NW of
Sydney
,
Blue Mountains National Park
, N of
Katoomba
,
Mount Wilson
(
33º31' S
,
150º22' E
), on tree ferns,
9 Feb. 1991
,
G.A. Clark
,
R
. deKeyzer;
AM
C205296
(
one specimen
dissected, radula examined),
Forest Rd.
, at the entrance to the
Mountaineer Trail
,
Barrington Tops National Park Wilderness Area
(
32º07.56’ S
,
151º40.68’ E
), mixed beech and
Callicoma
forest, in trees, on bark and the underside of leaves,
9 Feb. 2002
,
M. Shea
,
I. Hyman
,
C. Urquhart
;
QMMO29298
(
two specimens
dissected, one radula examined),
Robertson Nature Reserve
,
Robertson
(
34º36' S
,
150º36' E
), warm temperate rainforest, on leaves of trees,
4 Jan. 1990
,
J. Stanisic
,
J. Chaseling
;
QMMO20281
(
one specimen
dissected),
Point Lookout
,
New
England
National Park
, rainforest, crawling on trees,
7 Jan. 1989
, J.
Stanisic
, J.
Chaseling
;
QMMO37006
(
one specimen
dissected),
Kookaburra
Walking Trail, ca.
0.5 km
NW of Kookaburra Forestry Camp
,
Carrai State Forest
, NW
Kempsey
(
31º01'25'' S
,
152º20'05'' E
), warm temperate rainforest, on trees feeding on lichen and moss,
10 Jan. 1992
,
J. Stanisic
,
J. Chaseling
;
QMMO27296
(
one specimen
dissected),
Gibraltar
Range National Park
,
W of Grafton
(
29º31' S
,
152º25' E
), on leaves of trees in rainforest,
4 Mar. 1990
,
D. & N. Potter
.
Queensland
,
Australia
:
QMMO24253
(
one specimen
dissected), summit
Mt. Superbus,
1300 m
,
8 Feb. 1990
,
G. Monteith
,
G. Thompson
,
H. Janetski
.
FIGURE 15.
Radulae. SEM.
A–C
Helicarion mastersi
, AM C
334204.
D–F.
Mysticarion porrectus
, QMMO
29298.
G–I.
Mysticarion hyalina
, AM C
128630.
J–L.
Parmavitrina planilabris
, AM C
334357.
M–O.
Peloparion helenae
, AM C
205295.
P–R.
Brevisentis jacksoniensis
, AM C
205293. Scale bars 20 mm (A–I, M–R); 50 mm (J–L).
Description.
External morphology
: Shell (
Figures 7F
,
8F
,
9F
,
16A
) reduced, 3.3–3.6 whorls, orangebrown, spire flat, apex slightly raised, shape and sculpture as for genus. Animal (
Figure 5B
) cream. Mantle laps wide at base, moderately long, rounded, not fused, uniform in colour. Right and median mantle lobes of medium size, left mantle lobe small. Caudal horn small to medium; caudal foss vertical or diamond-shaped slit in tail.
Mantle cavity
: As for genus. Pigmentation of few white spots sometimes present.
Digestive system
: As for genus.
Genital system
(
Figures 12C
,
13C
): As for genus. Free oviduct moderately long; internal longitudinal pilasters absent. Penis moderately short; epiphallus enters penis through short verge (about a quarter of penis length or less); penis internally covered in irregular longitudinal ridges, two longitudinal penis pilasters present. Epiphallus shorter than penis, internally with two longitudinal pilasters.
Radula
(
Figure 15D–F
): As for genus. Central tooth mesocone slightly longer than tooth base. Marginal teeth subdivided into three to five extra teeth towards outer edge. Radular formula (106.12.1.12.106) × 126 rows (QMMO 29298); (86.11.1.11.86) × 130 rows (AM C205296), (~100.12.1.12.~100) × 128 rows (AM C165048).
Range and habitat.
The range of
Mysticarion porrectus
was previously thought to be quite narrow, including only the Blue Mountains region in
New South Wales
. However, in the current study, specimens from around Barrington Tops, Wauchope, Dorrigo and Casino (just south of the New South Wales-Queensland border) have been included in this species, dissections having shown their anatomy to be identical to the Blue Mountains species. Populations from the Wyong and Olney State Forests in mideastern
New South Wales
may also belong to
M. porrectus
(J. Stanisic, pers. comm.) but were not examined in the current study. There is also a single specimen in the Australian Museum from southwest of Narooma in southern
New South Wales
. Thus
M. porrectus
appears to have a wide but apparently discontinuous range.
Mysticarion porrectus
usually occupies rainforest, but can also be found in vine thickets and open eucalypt forest. The species is arboreal and is most commonly found on tree trunks and the underside of leaves and fern fronds. It is also occasionally found in leaf litter and on mossy rocks.
Another species belonging to this genus,
Mysticarion insuetus
, was not examined in the current study but was described from around Scone. It is probably sympatric with Barrington Tops populations of
M. porrectus
. However, it is usually found in drier habitats (Stanisic
et al.
, in preparation).
Mysticarion insuetus
can be distinguished from
M. porrectus
by its smaller size and slightly raised spire. No anatomical information is available for
M. insuetus
.
Remarks.
Specimens from several widely dispersed and isolated regions were examined, with the expectation that these might have diverged into separate species. Instead, these specimens were found to be identical to
M. porrectus
in every detail, including the internal structure of the penis; for this reason all populations examined have been provisionally included in
M. porrectus
pending DNA studies.
Populations of
Mysticarion porrectus
from the Beaury State Forest in northern
New South Wales
are sympatric with
M. hyalina
.
Mysticarion porrectus
can be distinguished from
M. hyalina
by its more reduced shell and anatomically by the presence of two penial pilasters (
M. hyalina
has only one) and a shorter penial verge.