The millipede genus Tasmaniosoma Verhoeff, 1936 (Diplopoda, Polydesmida, Dalodesmidae) from Tasmania, Australia, with descriptions of 18 new species
Author
Mesibov, Robert
Queen Victoria Museum and Art Gallery, Launceston, Australia
text
ZooKeys
2010
2010-03-26
41
4
31
80
journal article
10.3897/zookeys.41.420
ea2c4da4-3899-41cd-80f4-b7df9302da79
1313–2970
576649
FC5CFE57-05F9-4685-BC02-BB82AB9E4894
Tasmaniosoma
gerdiorivum
sp. n.
urn:lsid:zoobank.org:act:
6333E909-8104-403A-B6C3-50FB376FB357
Fig. 17; map
Fig. 26
Holotype
.
Male
,
Australia
,
Tasmania
,
Weavers Creek area
,
41°25'37"S
147°22'16"E
(
EQ
309136
) ±
100 m
,
540 m
,
23 March 1995
,
R
. Mesibov,
QVM 23
:51667.
Paratypes
.
6 males
,
1 female
, details as for
holotype
,
QVM 23
:46675
;
1 male
,
1 female
, same details but
41°26'00"S
147°21'55"E
(
EQ
304129
) ±
100 m
,
700 m
,
4 August 1994
,
QVM 23
:46667
;
3 males
,
4 females
, same locality but
41°24'09"S
147°22'59"E
(
EQ
319163
) ±
100 m
,
970 m
,
8 January 1995
,
R
. Mesibov &
T
. Moule,
QVM 23
:46669
;
2 males
, same details but
41°26'58"S
147°22'47"E
(
EQ
316111
) ±
100 m
,
470 m
,
22 March 1995
,
R
. Mesibov,
QVM 23
:46671
;
1 male
, same details but
41°27'01"S
147°23'04"E
(
EQ
320110
) ±
100 m
,
530 m
,
QVM 23
:46672
;
2 males
, same details but
41°27'27"S
147°23'13"E
(
EQ
322102
) ±
100 m
,
440 m
,
QVM 23
:46673
;
1 male
, same details but
41°26'19"S
147°22'04"E
(
EQ
306123
) ±
100 m
,
710 m
,
23 March 1995
,
QVM 23
:46674
.
Other
material examined.
66 males
and
15 females
from 39 other sites (see Appendix).
Diagnosis
.
Metatergites with three weakly developed, transverse rows of low tubercles, gonopod telopodite apex divided into cluster of four processes including broad, flattened solenomere, the most lateral process directed bent laterally.
Description
.
Male/female approximate measurements: length 10/
11 mm
, ring 12 paranota width 0.9/1.0 mm. Live colour very pale yellow with sparse, reddish mottling and reticulation on metatergites, mainly along posterior margin, antennae light brown and head pinkish-red dorsally; in alcohol, pale yellowish-brown or completely decoloured.
Male as for
T. armatum
in most non-gonopod details, but overall widths tergite 6>head>5>4>(3,2)>collum, antennomere 3 longest, leg 6 tarsus 1.5 × as long as femur, femur longer than prefemur, prefemoral swellings not apparent posterior to ring 11. Ring 12 paranota 1.3 × as wide as prozonite; paranotum with distinct shoulder anteriorly, almost quadrate, lateral margin almost straight; metatergite almost completely covered with three transverse rows of 10–12 large, very low tubercles, each with small seta near posterior edge, but tubercles hard to detect with light microscopy. Ring 6 ster-
Figure |7.
Tasmaniosoma gerdiorivum
sp. n.
,
paratype
males ex QVM 23:46675.
A
Posterior view of gonopods in situ
B
medial view of left gonopod telopodite. Setation not shown in
B
dashed line marks course of prostatic groove. Scale bars =
0.1 mm
. In
A
, the bends in the three flattened terminal processes are a preparation artifact; in wet specimens the bent portions seen in (A) are nearly planar.
nite as for
T. armatum
but with marginal band of fine setae along anterior edge of sternite; at high magnification, band is seen to consist of four evenly spaced, loose clusters.
Gonopod telopodite (Fig. 17) straight, stout, slightly flattened anteroposteriorly; base extended posteriorly and laterally as shelf, concave upwards, with thickened margin; anterior surface with gently convex medial extension at ca 1/2 telopodite height. Telopodite divided at ca 3/4 height into four processes: (a) mediolaterally flattened, tab-like solenomere arising medially, the distal edge subtriangular; (b) anteroposteriorly flattened process arising just lateral to solenomere with acute apex and short, shelf-like posterior extension at base; (c) long, blade-like, bluntly acute, mediolaterally flattened anterolateral process; (d) rod-like, acute process arising just anterolateral to anterolateral process. Sparse tract of fine setae running from basal shelf anterodistally to ca 1/2 telopodite height on lateral surface; a few fine setae on posterolateral surface at ca 1/2 telopodite height. Prostatic groove running on medial surface more or less directly to solenomere base and terminating at apex of triangle on distal solenomere edge.
Female with posterior margin of epigynum produced as rectangular process almost as long as posterior margin.
Distribution
.
Sometimes locally abundant in wet eucalypt and subalpine forest over ca
1500 km
2
in
northeast
Tasmania
from
80 m
to at least
1050 m
elevation (
Fig. 26
). Th e western limit of this distribution coincides approximately with the biogeographical boundary known as the East Tamar Break (
Mesibov 1994
,
1997
).
T. gerdiorivum
occurs ca
5 km
from the sea in the north of its range; it has not yet been found east of Mt Saddleback or south of the North Esk River. It co-occurs with
T. armatum
and
T. clarksonorum
sp. n.
in the west of its range, and may be parapatric with
T. cacofonix
sp. n.
and
T. decussatum
sp. n.
in the east.
A male of
T. gerdiorivum
has been found at Gardners Ridge in north central
Tasmania
, at least
60 km
west of all other known localities. Th is specimen may be from a translocated population, or it may indicate a natural disjunction in the
T. gerdiorivum
range. A similar northeast-north central disjunction has been found in the distribution of
Lissodesmus devexus
Mesibov 2006
(
Mesibov 2006
).
Etymology
.
Latin
gerdius
, “weaver”, +
rivus
, “stream”, noun used as adjective, after the
type
locality, Weavers Creek.