Research Article |
Corresponding author: Robert Mesibov ( robert.mesibov@gmail.com ) Academic editor: Sergei Golovatch
© 2017 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 (2017) A new and unusual species of Amastigogonus Brölemann, 1913 from Tasmania, Australia (Diplopoda, Spirostreptida, Iulomorphidae). ZooKeys 687: 45-51. https://doi.org/10.3897/zookeys.687.14872
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Amastigogonus insularis sp. n. is described from Schouten and Tasman Islands off the east coast of Tasmania, and a key is presented for the identification of males of Tasmanian Amastigogonus species. The new species differs from the 10 previously described species of Amastigogonus in having a reduced coxite process on the anterior gonopod.
Millipede, gonopod
In a previous paper (
In this paper I describe a new Amastigogonus species in which the coxite process is reduced (Fig.
Specimens are stored in 80% ethanol in the Queen Victoria Museum and Art Gallery, Launceston, Australia (
Male, Tasman Island, Tasmania, 55G 581536 521818 (GDA94) [-43.2419 148.0042 ±100m], 210m a.s.l., 19 November 2005, S. Bryant + Hamish Saunders Memorial Island Survey Program personnel, pitfall, cliff mosaic, 5A,
Tasmania: 1 male, 4 females, 1 juvenile, Schouten Island [-42.3131 148.2850 ±2km], 23–26 September 1993, R. Taylor,
Male leg 7 coxa not noticeably elongated or distally swollen; coxite process on anterior gonopod much shorter than telopodite, not protecting pseudoflagellum; pseudoflagellum as in A. peninsulensis Mesibov, 2017 but longer, extending just past telopodite tip.
As for the genus description (
A Amastigogonus tasmanianus Brölemann, 1913 (type species of Amastigogonus),
Male with cardo not deeper posteriorly (Fig.
Coxite process on anterior gonopod (Fig.
Schouten and Tasman Islands off the east coast of Tasmania (Fig.
Latin insularis, insular; adjective.
As with the two known males, the Schouten Island females are smaller than their Tasman Island counterparts: (51+2)–(59+1) rings, 1.5–2.3 mm midbody diameter from Schouten Island, (47+2)–(63+1) rings, 2.3–2.7 mm from Tasman Island. Further, the pseudoflagellum tip in the holotype male from Tasman Island is slightly longer, broader and more medially directed than the tip in the Schouten Island paratype. These are minor differences and I regard the two forms as conspecific.
I doubt that A. insularis sp. n. is restricted to its two widely disjunct localities, ca 105 km apart. However, the only iulomorphid so far collected on Forestier and Tasman Peninsulas, just north of Tasman Island (Fig.
1 | Coxite process of anterior gonopod truncate with apical fossa; cardo deeper in posterior half | A. danpicola Mesibov, 2017 |
– | Coxite process laminate with broadly rounded apex; cardo deeper in anterior half | 2 |
2 | Coxite process much shorter than telopodite; no legs with elongated coxae | A. insularis sp. n. |
– | Coxite process almost as long as telopodite; elongated coxae on leg 7 only, or on legs 7, 10 and 11 | 3 |
3 | Pseudoflagellum tapering to sharp point | 4 |
– | Pseudoflagellum bluntly rounded, expanded or apparently bifid at tip | 7 |
4 | Pseudoflagellum with distinct anterior shoulder, prostatic groove making sharp S-bend to reach tip; dense field of short, fine setae on telopodite behind pseudoflagellum | A. fossuliger Verhoeff, 1944 |
– | Pseudoflagellum without anterior shoulder, prostatic groove without S-bend; only sparse, stout setae behind pseudoflagellum | 5 |
5 | Pseudoflagellum broad at base, abruptly truncate apically, continued as sharp, pointed tip bent over laterally or medially | A. hellyeri Mesibov, 2017 |
– | Pseudoflagellum not truncate apically | 6 |
6 | Pseudoflagellum broad at base, gradually tapering to sharp point, not as long as telopodite | A. hardyi (Chamberlin, 1920) |
– | Pseudoflagellum narrow at base, very gradually tapering to sharp point, much longer than telopodite | A. tasmanianus Brölemann, 1913 |
7 | Pseudoflagellum with tip strongly curving posterobasally and with small tooth on apicodistal margin, thus appearing bifid | A. elephas Mesibov, 2017 |
– | Pseudoflagellum with bluntly rounded or expanded tip | 8 |
8 | Pseudoflagellum with tip strongly curving posterobasally | A. verreauxii (Gervais, 1847) |
– | Pseudoflagellum with tip directed distally or slightly posteriorly | 9 |
9 | Pseudoflagellum with tip slightly expanded apically and truncate, with small tooth medially on distal margin | A. orientalis Mesibov, 2017 |
– | Pseudoflagellum gradually narrowing to bluntly rounded tip | 10 |
10 | Pseudoflagellum with tip directed slightly posteriorly and with posterobasal margin extended as bulge | A. peninsulensis Mesibov, 2017 |
– | Pseudoflagellum with tip directed distally and with prominent sharp tooth on posterobasal margin | A. michaelsae Mesibov, 2017 |
I am grateful to Ben Clark, Luke Gadd and Sue Robinson (Department of Primary Industries, Parks, Water and Environment, Tasmania) and to Lyndon O’Grady, Rohan O’Grady and Ian Ross (Friends of Tasman Island) for their efforts in searching for millipedes on Tasman Island in 2016 and 2017. I also thank reviewer Nesrine Akkari for helpful suggestions.