Tasmaniosoma fasciculum, 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: 58-60

publication ID

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

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scientific name

Tasmaniosoma fasciculum

sp. n.

Tasmaniosoma fasciculum   sp. n.


Figs 1D, 1H, 5C, 15; map Fig. 26 View Figure 26

Holotype. Male, Australia, Tasmania, Little Claytons Rivulet , 41°12'24"S 146°12'07"E ( DQ 330378 View Materials ) ± 25 m, 100 m, 27 December 2009, R. Mesibov & T. Moule, QVM 23 View Materials :51664. GoogleMaps  

Paratypes. 1 male, same locality as holotype but 41°12'28"S 146°12'12"E ( DQ 331377 View Materials ) ± 100 m, 100 m, 30 November 1997, R. Mesibov & T. Moule, QVM 23 View Materials :46644 GoogleMaps   ; 2 males, 1 stadium VI male, 2 stadium VI females, same details as holotype, QVM 23 View Materials :51665   .

Other material examined. 20 males and 3 females from 17 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, anvil-shaped process and two comparably sized combs of long, stout, rod-like setae on posterior surface, both directed distally.

Description. Male/female approximate measurements: length 12 / 11 mm, ring 12 paranota width 1.2/ 1.2 mm. Live and freshly preserved specimens with reddishbrown head and antennae and complex pattern of strongly contrasting yellow and brown patches on most rings (Figs 1D, 1H): prozonites have paired paramedian yellow patches with brown patches medially and laterally, metazonites have paired paramedian yellow patches anteriorly and posteriorly, strongly contrasting with dark brown patches marginally on paranota and more diffuse paramedian brown bands along posterior margin and just anterior to transverse furrow. Live specimens similarly coloured but yellow not so intense; in alcohol, long-preserved specimens completely decoloured.

Figure |5. Tasmaniosoma fasciculum   sp. n., paratype males. A Right posterolateral view of gonopods in situ (ex QVM 23:46638) B lateral and slightly anterior and C medial views of left gonopod telopodite (ex QVM 23:46635). Scale bars = 0.2 mm.

As for T. armatum   in most non-gonopod details, but relative widths tergite 6>5>(4,head)>(3,2)>collum, leg 6 tarsus 1.5 × as long as femur. Metatergite almost completely covered with three transverse rows of 10–12 large, low tubercles, each with a small seta near posterior edge. Ring 2 pit not apparent except as slight concavity near anterior margin of ring. No setae on anterior margin of ring 6 ( Fig. 5C View Figure 5 ); leg 6 tab short, with a few fine setae; leg 7 tab long, thickened, with brush of stout setae.

Gonopod telopodite (Fig. 15) arching anteriorly, strongly narrowed at ca 1/4 telopodite height, tip divided into four processes: (a) small, subcylindrical, distally tapered solenomere arising on medial surface and directed distally, curving medially near tip; (b) thick, tab-like bulge arising posterolaterally and bearing a tight cluster of 6–8 long, stout, rod-like setae directed anterodistally and slightly laterally; (c) anvilshaped process arising on anteromedial surface, flattened anteroposteriorly, rounded medial end and pointed lateral end of “anvil” both curving posteriorly; (d) long, blade-like, acute process arising on anterolateral surface and directed distally. Second tight cluster of ca 15 stout, rod-like setae arising on posterior surface just basal to division of telopodite into processes, setae reaching almost as far distally as solenomere; sparse fine setae on posterior surface near base and along lateral surface to level of telopodite division into processes. Prostatic groove running on medial surface directly to solenomere base.

Female with sternites as wide as long.

Distribution. Known from eucalypt forest over ca 2000 km 2 in north central Tasmania to 550 m elevation ( Fig. 26 View Figure 26 ). Not yet found west of the Dial Range, south of Maggs Mountain or east of the Birralee Road. Co-occurs with T. hickmanorum   sp. n.

Etymology. Latin fasciculus, diminutive of fascis, “sheaf”, adjective, for the tight sheaf of stout, rod-like setae on the tip of the gonopod.

Remarks. I have not been able to recognise species-diagnostic features in long-preserved, decoloured females of T. fasciculum   . As a result, I cannot confidently assign to T. fasciculum   a number of possible female specimens from localities within the known range (in the QVM collection) because no there are no associated males. The description of the female (above) is based on three specimens found close to sites in the Gog Range and Dial Range where I have also collected males.

I may also have overlooked T. fasciculum   outside its known range in north central Tasmania. In the field, an adult of this uncommon species can easily be mistaken for a stadium V or VI juvenile of the co-occurring T. hickmanorum   sp. n.


Departamento de Geologia, Universidad de Chile


Tavera, Department of Geology and Geophysics


Mykotektet, National Veterinary Institute