Research Article |
Corresponding author: Robert Mesibov ( robert.mesibov@gmail.com ) Academic editor: Sergei Golovatch
© 2015 Robert Mesibov.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Mesibov R (2015) Three new species of Tasmaniosoma Verhoeff, 1936 (Diplopoda, Polydesmida, Dalodesmidae) from northeast Tasmania, Australia. ZooKeys 488: 31-46. https://doi.org/10.3897/zookeys.488.9460
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The small-range millipedes Tasmaniosoma anubis sp. n., T. interfluminum sp. n. and T. nicolaus sp. n. are described, and the colour of live T. barbatulum Mesibov, 2010 is documented.
Diplopoda , Polydesmida , Dalodesmidae , millipede, Australia, Tasmania
When reviewing Tasmaniosoma Verhoeff, 1936 several years ago I wrote that “more small-range species may remain to be discovered” (
“Male” and “female” in the text refer to adult (stadium 7) individuals. All specimens are stored in 75–80% ethanol in their respective repositories. Gonopods were cleared in 80% lactic acid and temporarily mounted in a 1:1 glycerol:water mixture for examination by optical microscopy. Body measurements were estimated with a Nikon SMZ800 binocular dissecting microscope using an eyepiece scale. Colour photographs were taken with a Canon EOS 1000D digital SLR camera mounted on the same microscope fitted with a beam splitter. The colour images in Figs
A, D, E Tasmaniosoma anubis sp. n., paratype ex QVM 23:53817 B T. interfluminum sp. n., paratype ex QVM 23:52247 C T. nicolaus sp. n., paratype ex QVM 23:53860 A, B, C Ventral views of male ring 6 D Left lateral view of midbody spiracles E Limbus on lateral portion of midbody ring. Scale bars: A–C = 0.25 mm, D, E = 0.05 mm.
The Suppl. material
Abbreviations in text: QVMAG = Queen Victoria Museum and Art Gallery, Launceston, Tasmania, Australia; Tas = Tasmania; WAM = Western Australian Museum, Perth, Western Australia, Australia.
Tasmaniosoma
Tasmaniosoma armatum Verhoeff, 1936, by monotypy.
T. alces Mesibov, 2010, T. anubis sp. n., T. aureorivum Mesibov, 2010, T. australe Mesibov, 2010, T. barbatulum Mesibov, 2010, T. bruniense Mesibov, 2010, T. cacofonix Mesibov, 2010, T. clarksonorum Mesibov, 2010, T. compitale Mesibov, 2010, T. decussatum Mesibov, 2010, T. fasciculum Mesibov, 2010, T. fragile Mesibov, 2010, T. gerdiorivum Mesibov, 2010, T. hesperium Mesibov, 2010, T. hickmanorum Mesibov, 2010, T. interfluminum sp. n., T. laccobium Mesibov, 2010, T. maria Mesibov, 2010, T. nicolaus sp. n., T. orientale Mesibov, 2010, T. warra Mesibov, 2010.
Male, Trevallyn Nature Recreation Area, Tas, -41.4417 147.0800 ±25 m (Google Earth), 150 m a.s.l., 21 June 2014, R. Mesibov, QVM 23:53863 (ex QVM 23:53817)
15 males, 28 females, details as for holotype, QVM 23:53817.
41 males and 51 females (see Suppl. material
Nominate member of the “anubis group” within Tasmaniosoma (see Discussion), distinguished from T. clarksonorum, T. compitale, T. fasciculum, T. hickmanorum and T. nicolaus sp. n. by the absence of a distally directed cluster of stout, rod-like setae on the posterior surface of the gonopod telopodite; from T. barbatulum by the presence of a lateral apical process and by the absence of a setal cluster on the anterior telopodite surface; from T. fragile by the absence of a setal cluster on the anterior telopodite surface; and from all other “anubis group” members by the presence of an anteromedially directed tab on the anterior telopodite surface.
Male/female approximate measurements: length 10/10 mm, midbody paranota width 1.2/1.1 mm, maximum vertical diameter 1.1/1.1 mm. Live and freshly preserved adults with reddish brown head and antennae; body (Fig.
Male with head sparsely setose; antennal sockets slightly impressed, separated by ca 2× socket diameter; antennal groove short and shallow. Antenna slender, slightly clavate, when manipulated reaching back to ring 3; antennomere 6 widest, relative antennomere lengths (2,3,6)>(4,5). Collum from above reniform, convex anteriorly, posterior corner rounded. Tergites 2-4 distinctly narrower than more posterior metatergites; overall ring widths 6>(5,head)>(2,4)>(3,collum); rings 6–15 about same width, 16-18 narrowing. In lateral view, margin of ring 2 tergite slightly lower than margins of collum and ring 3 tergite. Ring 2 ventrally on either side without obvious pit. Ring suture and waist distinct on diplosegments (Fig.
Gonopore on distomedial bulge of leg 2 coxa, protected by tall, thin cowl. Short brushes of setae on sternite between legpairs 4 and 5. Legs 6 and 7 bases (Fig.
Gonopod aperture ovoid, ca 1/2 as wide as ring 7 prozonite, posterolateral margin raised. Gonocoxa short, subcylindrical, slightly tapering distally. Telopodites (Fig.
Female with legs more slender and prefemora and femora not swollen. Epigynum ca 1/3 width of ring 2, posterior margin produced medially as small, rounded triangle with irregular margin. Cyphopods not examined. (See also Remarks, below.)
Eucalypt forest and woodland within a range envelope of <12 km in the city of Launceston, Tasmania, with a core habitat area of <6 km2 (Figs
A Museum specimen localities to 15 February 2015 of Tasmaniosoma anubis sp. n. (blue markers). Base map from http://maps.thelist.tas.gov.au/listmap/app/list/map; for general location see index map, Fig.
A The main island of Tasmania (Mercator projection) showing locations of Launceston (T. anubis sp. n. range) and the Nicholas Range area (rectangle; ranges of T. interfluminum sp. n. and T. nicolaus sp. n.) B Anubis, as illustrated by Jeff Dahl (Creative Commons Attribution-ShareAlike license, GNU Free Documentation License; http://commons.wikimedia.org/wiki/File:Anubis_standing.svg) C Posterior and slightly ventral view of distal portion of right gonopod of T. interfluminum sp. n., ex QVM 23:52262. Dotted line marks course of prostatic groove.
Greek “Anubis”, a jackal-headed god of ancient Egypt; noun in apposition. The tip of the gonopod telopodite in posterolateral view resembles popular representations of the head of Anubis (Fig.
The core habitat area for T. anubis sp. n. includes the 440 ha Trevallyn Nature Recreation Area (TNRA; Fig.
T. anubis sp. n. has not been found more than ca 1.5 km from the South Esk River near its confluence with the Tamar River at Cataract Gorge in the city of Launceston (Fig.
Unlike the similar-sized, co-occurring dalodesmid Atrophotergum pastorale Mesibov, 2004 and unlike most Tasmaniosoma species, T. anubis sp. n. do not usually run away rapidly when disturbed, but remain “crouched” and stationary on the bark, leaf or wood pieces among which the animals are sheltering.
As with Tasmaniosoma compitale Mesibov, 2010 and T. hickmanorum Mesibov, 2010 (
Nicholas Range, Tas, -41.5417 148.0786 ±25 m (GPS), 570 m a.s.l., 14 May 2012, W. Clarkson and L. Clarkson, QVM 23:53867 (ex QVM 23:52247).
3 males, details as for holotype, QVM 23:52247.
21 males and 4 females (see Suppl. material
Very similar to T. decussatum, but without a setose sternal tab adjoining leg 7, with the anterolateral telopodite process prominently notched, with the solenomere tabs curving posteriorly and less deeply separated, and with the medial process tongue-like and curving posterobasally, rather than forming a rounded, mediolaterally flattened, tab-like solenomere extension as in T. decussatum.
Male/female approximate measurements: length 12/11 mm, midbody paranota width 1.4/1.4 mm, maximum vertical diameter 1.1/1.1 mm. Live and freshly preserved adults with yellowish ground colour (Figs
Non-gonopodal features in males mostly as for T. anubis sp. n., but head moderately setose; antennal sockets separated by ca 1.5× socket diameter; overall ring widths 6>5>(4,head)>2>3>collum; rings 8-16 distinctly elongated; ring 2 ventrally on either side with wide, shallow pit, the anterolateral margin well-defined; metatergites with indistinct low tubercles medially; midbody legs with tarsus ca 1.8× as long as femur; brush setae on coxa/trochanter, prefemur and femur of anterior legs; legs 6 and 7 bases (Fig.
Gonopod aperture ovoid, ca 1/2 as wide as ring 7 prozonite, posterolateral margin raised. Telopodites (Figs
Female about as robust as male but shorter, with posterior rings not elongated; legs more slender and prefemora and femora not swollen. Epigynum ca 1/3 width of ring 2, posterior margin produced medially as low trapezoid with irregular margin. Cyphopods not examined.
Eucalypt forest over ca 100 km2 north and east of Fingal, Tasmania, with an outlying record near the town of Scamander on the east coast (Figs
Known localities (blue markers) to 15 February 2015 of Tasmaniosoma interfluminum sp. n. (A) and T. nicolaus sp. n. (B). Base map from http://maps.thelist.tas.gov.au/listmap/app/list/map; for general location see index map, Fig.
Latin inter (between) + fluminum (genitive plural of flumen = river); adjective. The largest populations of this species are found between the upper South Esk and Break O’Day Rivers.
The gonopod telopodite structure of T. interfluminum sp. n. is remarkably similar to that of T. decussatum, the two differing only in the details noted above in Diagnosis. Another difference is a setose sternal tab adjoining the base of leg 7: present in T. decussatum, absent in T. interfluminum sp. n. I am unable to distinguish the two species in the field.
Male, Catos Road, Tas, -41.5350 148.0842 ±50 m (GPS), 520 m a.s.l., 9 February 2015, R. Mesibov, QVM 23:53864 (ex QVM 23:53860).
18 males, details as for holotype, QVM 23:53860.
5 males and 3 females (see Suppl. material
Member of the “anubis group” within Tasmaniosoma (see Discussion); distinguished from T. anubis sp. n., T. barbatulum and T. fragile by the absence of a basally directed cluster of stout, rod-like setae on the posterior surface of the gonopod telopodite; from T. clarksonorum, T. compitale and T. hickmanorum by the absence of a lateral process on the telopodite apex; and from T. fasciculum by the telopodite apex extending as a mediolaterally flattened process in the shape of a bird’s head pointed posteriorly.
Male/female approximate measurements: length 11/10 mm, midbody paranota width 1.3/1.2 mm, maximum vertical diameter 1.0/1.0 mm. Live and freshly preserved adults (Figs
Non-gonopodal features in males as for T. anubis sp. n., but overall ring widths 6>5>(4,head)>(3,2)>collum; prefemoral swellings to about leg 20. Legs 6 and 7 bases (Fig.
Telopodites (Fig.
Female with legs more slender and prefemora and femora not swollen. Epigynum ca 1/3 width of ring 2, posterior margin produced medially as small, rounded triangle with irregular margin. Cyphopods not examined. (See also Remarks, below.)
Eucalypt forest over <40 km2 on the Nicholas Range and the Mt Elephant area at the eastern end of the Fingal Valley in northeast Tasmania, on both north- and south-facing slopes at ca 300–500 m a.s.l. (Figs
Latinised “Nicholas” for the Nicholas Range, type locality of this species; noun in apposition.
All of the known T. nicolaus sp. n. collection sites are in forest patches with evidence of past logging and burning, and part of the known range of T. nicolaus sp. n. is within the ca 800 ha Nicholas Range Regional Reserve. Like T. anubis sp. n., T. nicolaus sp. n. can be locally abundant: I found most of the 19 type specimens in bark litter under two Eucalyptus trees.
My identification of three females as T. nicolaus sp. n. (QVM 23:53635) is tentative. Two of the three females are missing legs 2.
Alcohol-preserved specimens of T. barbatulum are almost entirely decoloured, i.e. more or less uniformly pale white (
The new species Tasmaniosoma anubis sp. n. and T. nicolaus sp. n. join T. barbatulum, T. clarksonorum, T. compitale, T. fasciculum, T. hickmanorum and probably T. fragile in a well-defined group within Tasmaniosoma, first recognised in
The relationships of T. interfluminum sp. n. are uncertain, but it is clearly very close to T. decussatum and the two species may be parapatric in northeast Tasmania.
Wade and Lisa Clarkson (Riverside, Tasmania) diligently searched for the new species described in this paper. I am very grateful to the Clarksons for their enthusiastic and voluntary efforts in the field, and to Julianne Waldock of the Western Australian Museum for the loan of a T. anubis sp. n. specimen. SEM images were acquired with the help of Sandrine Feig of the Central Science Laboratory, University of Tasmania. I thank reviewers Cathy Car and Sergei Golovatch for recommending improvements to the draft manuscript. This study was funded by the author.
Specimen records of Tasmaniosoma species.
Data type: Tab Separated Value File (tsv).
Explanation note: Specimen records of Tasmaniosoma species as of 15 February 2015.