Tasmaniosoma hickmanorum, Mesibov, 2010

Mesibov, Robert, 2010, The millipede genus Tasmaniosoma Verhoeff, 1936 (Diplopoda, Polydesmida, Dalodesmidae) from Tasmania, Australia, with descriptions of 18 new species, ZooKeys 41 (4), pp. 31-80: 66-68

publication ID

http://doi.org/ 10.3897/zookeys.41.420

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scientific name

Tasmaniosoma hickmanorum

sp. n.

Tasmaniosoma hickmanorum   sp. n.


Figs 1E, 1I, 5D, 19; map Fig. 23 View Figure 23

Holotype. Male, Australia, Tasmania, Mossy Marsh Creek , 42°18'34"S 146°22'44"E ( DP 487155 View Materials ) ± 100 m, 630 m, 18 February 1994, R. Mesibov, QVM 23 View Materials :51669. GoogleMaps  

Paratypes. 6 males, details as for holotype, QVM 23 View Materials :46089   ; 3 males, Tarraleah, Tas, 42°18'19"S 146°25'52"E ( DP 530160 View Materials ) ± 10 km, May 1952, V. V. Hickman, from dead fern leaves, QVM 23 View Materials :46042 GoogleMaps   ; 1 male, same details but under logs, QVM 23 View Materials :46043   ; 8 males, 6 females, same details but 26 December 1952 to 2 January 1953, QVM 23 View Materials :46044   ; 5 males, Tarraleah, Tas, 42°18'44"S 146°21'48"E ( DP 474161 View Materials ) ± 100 m, 690 m, 16 April 1992, R. Mesibov, plot 1, QVM 23 View Materials :46057 GoogleMaps   ; 2 males, same details but 42°18'11"S 146°21'48"E ( DP 474162 View Materials ) ± 100 m, 700 m, plot 3, QVM 23 View Materials :46058 GoogleMaps   ; 1 male, 1 female, same details but 42°17'58"S 146°21'48"E ( DP 474166 View Materials ) ± 100 m, 710 m, 18 April 1992, plot 11, QVM 23 View Materials :46060 GoogleMaps   ; 1 male, 1 female, same details but 42°16'27"S 146°21'35"E ( DP 471194 View Materials ) ± 100 m, 750 m, 2 May 1992, plot 47, QVM 23 View Materials :46065 GoogleMaps   ; 1 male, same details but 42°16'21"S 146°21'36"E ( DP 471196 View Materials ) ± 100 m, 760 m, plot 45, QVM 23 View Materials :46066 GoogleMaps   ; 2 males, same details but 3 May 1992, plot 52, QVM 23 View Materials :51668   ; 1 male, same details but 42°16'08"S 146°21'40"E ( DP 472200 View Materials ) ± 100 m, 790 m, plot 50, QVM 23 View Materials :46068 GoogleMaps   ; 2 males, same details but 4 May 1992, plot 55, QVM 23 View Materials :46069   ; 1 male, same details but 42°16'24"S 146°21'57"E ( DP 476195 View Materials ) ± 100 m, 720 m, 8 May 1992, plot 73, QVM 23 View Materials :46071 GoogleMaps   .

Other material examined. 154 males, 67 females, 3 stadium VI males and 1 stadium VI female from 120 other sites (see Appendix).

Diagnosis. Metatergites with three transverse rows of large, low, contiguous tubercles; leg 7 sternal tab with dense brush of stout, rod-like setae; gonopod telopodite with central, flattened process notched into three parts, a single comb of long, stout, rod-like, setae on posterior surface, and anteromedial process lying obliquely against central process.

Description. Male/female approximate measurements: length 16/ 16 mm, ring 12 paranota width 1.7/ 1.7 mm. Freshly preserved specimens finely mottled or reticulated reddish-brown (Fig. 1E); head reddish above, antennae dark brown, legs pale, reddish distally; prozonite with paired paramedian yellowish patches contrasting with adjoining dark brown patches; metatergites sometimes with paired paramedian, yellowish patches near anterior edge; rings laterally (Fig. 1I) finely mottled reddishbrown with small, pale patch under paranotal margin. In alcohol, pale reddish or decoloured.

Male as for T. armatum   in most non-gonopod details, but overall widths 6>5>(4,head)>(3,2,collum), antennomere 3 longest, ring 12 paranota 1.4 × as wide as prozonite, leg 6 tarsus 1.4 × as long as femur. Anterior margin of metatergite smoothly curving into lateral edge of paranota (shoulder less distinct than in T. armatum   ); metatergite almost completely covered with three transverse rows of 10–12 large, low tubercles, each with small seta near posterior edge. Ring 6 sternite ( Fig. 5D View Figure 5 ) with no

Figure |9. Tasmaniosoma hickmanorum   sp. n. A Posterolateral view of gonopods in situ, voucher male ex QVM 23:46055 B anterior view of tip of left gonopod telopodite, paratype male ex QVM 23:46065 C anterior view of left gonopod telopodite, paratype male ex QVM 23:46057. Setation not shown in C dashed line marks course of prostatic groove. Scale bars: A, C = 0.2 mm, B = 0.1 mm.

leg 6 tab; leg 7 tab long, thickened, with brush of stout setae; anterior margin without setae but with medial notch, about 1/3 width of margin.

Gonopod telopodite (Fig. 19) straight, in cross-section with posterior, anterolateral and anteromedial longitudinal ridges, divided at ca 3/4 telopodite height into tight cluster of four processes: (a) small, slender, acute, medial solenomere, directed distally but curving laterally; (b) large, anteroposteriorly flattened laminate process divided by notches into three acute portions, their lengths decreasing from anteromedial to posterolateral; (c) large, blade-like, acute lateral process curving laterally; (d) blade-like, acute process arising near medial edge of anterior surface, directed distolaterally and closely pressed to anterior surface of laminate process. Sparse group of fine setae near base posterolaterally; ca 20 fine setae laterally from ca 2/3 to ca 3/4 telopodite height; two dense, adjoining clusters of stout, rod-like setae on posterior surface ridge at ca 2/3 telopodite height, the basal cluster of 10–15 setae directed mainly posterobasally, the distal cluster of ca 30 setae directed distally with a few outlying setae in line extending towards base of lateral process. Prostatic groove running along medial surface more or less directly to solenomere base.

Female with sternites as wide as long, legs 2 usually missing (Mesibov, in preparation).

Distribution. Often locally abundant in wet eucalypt forest (with or without a cool temperate rainforest understorey), riparian tea-tree forest and coastal dune scrub over the whole of western Tasmania (ca 28 000 km 2), from the northern part of King Island (northwest of the main island of Tasmania) to Melaleuca in the far south, with an elevation range from sea level to at least 940 m ( Fig. 23 View Figure 23 ). Part of the eastern range boundary is congruent with the Mersey Break, a major biogeographical divide in north central Tasmania ( Mesibov 1999; species coded as Tasmaniosoma   sp. 2). T. hickmanorum   is sympatric with T. fasciculum   sp. n., broadly parapatric with T. armatum   along the Mersey Break, and at some localities tightly parapatric with T. compitale   sp. n. (Mesibov, in preparation), with an overlap zone less than 500 m wide.

T. hickmanorum   is remarkably abundant in Eucalyptus globulus   and E. nitens   plantations established on sites converted from native forest. I have not yet found it in plantations established on former pasture.

Etymology. In honour of V. V. Hickman (1894–1984) and his son J. L. Hickman (1926–2007), Tasmanian invertebrate zoologists and collectors of this millipede species and many others.

Remarks. This species varies a little in size and colouration over its large range, and in some populations females are smaller than males. Gonopod structure, however, is nearly constant.

Long-preserved, decoloured females of T. hickmanorum   sp. n. and T. compitale   cannot be separated. Live and freshly preserved females can be distinguished by colour: T. hickmanorum   reddish-brown with only a small yellowish patch under paranotal margin (Fig. 1I), T. compitale   yellowish-brown with a large, prominent yellowish patch just under the paranotal margin (Fig. 1G).


Departamento de Geologia, Universidad de Chile


Royal British Columbia Museum - Herbarium


Mykotektet, National Veterinary Institute