Research Article |
Corresponding author: Nesrine Akkari ( nesrine.akkari@nhm-wien.ac.at ) Academic editor: Pavel Stoev
© 2022 Henrik Enghoff, Nesrine Akkari.
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:
Enghoff H, Akkari N (2022) A new species of the hitherto monospecific genus Pleonoporus Attems, 1938 (Diplopoda, Spirostreptida, Odontopygidae). ZooKeys 1117: 189-202. https://doi.org/10.3897/zookeys.1117.87765
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The hitherto monospecific genus Pleonoporus is revised based on the syntypes of P. robustus Attems, 1938, housed in Naturhistorisches Museum Wien (NHMW), as well as on specimens of what we interpret as a new species of the genus, Pleonoporus tanzanicus sp. nov., collected in Tanzania and housed in the Museum of Nature – Zoology, Leibnitz Institute for the Analysis of Biodiversity Change (ZMH) for more than a century. Both species are described based on habitus and gonopod structures and illustrated with micrographs, whereas scanning electron microscope images are also provided for the new species. This paper further highlights the importance of natural history collections for taxonomic research and studies on species diversity in general.
Africa, gonopods, natural history collections, new species, syntypes, taxonomy
In his work on “Diplopoden des Belgischen Congo”,
In this work, we describe a new species of the genus Pleonoporus, P. tanzanicus sp. nov., based on material collected from Tanzania and housed in ZMH, and document the type species of the genus, P. robustus, based on the syntypes housed in NHMW. Both species are described, illustrated and compared, and the genus Pleonoporus is redefined.
The specimens on which the new species is based were collected by “Ostafrika-Expedition der Hamburger Geographischen Gesellschaft in 1911.”
The syntypes of Pleonoporus robustus were examined using a Nikon SMZ25 stereomicroscope and images were obtained with a Nikon DS-Ri2 camera mounted on the same stereomicroscope, using NIS-Elements Microscope Imaging Software (version 5.02) with an Extended Depth of Focus (EDF) patch (Nikon Corporation, Tokyo, Japan). A male of the new species was studied by scanning electron microscopy (SEM): body parts were cleaned with ultrasound, transferred to 96% ethanol, then to acetone, air dried, mounted on aluminium stubs or on triangles of flexible aluminium tape in turn mounted on a stub, coated with platinum/palladium and studied in a JEOL JSM-6335F scanning electron microscope. Images were processed in Adobe PhotoShop CS6 and assembled into figure plates with InDesign CS6 or Microsoft Publisher.
Morphological terminology mostly follows
Specimens are kept in the following collections:
NHMD Natural History Museum of Denmark
ZMH Museum of Nature – Zoology, Leibnitz Institute for the Analysis of Biodiversity Change, Bonn
Class Diplopoda De Blainville in Gervais, 1844
Order Spirostreptida Brandt, 1833
Family Odontopygidae Attems, 1909
Subfamily Archepyginae Manfredi, 1939
Differs from all other genera of Archepyginae by having ozopores on body ring 5, a condition paralleled in the subfamily Peridontopyginae (see
Pleonoporus robustus Attems, 1938, by monotypy
Pleonoporus tanzanicus sp. nov.
Differs from P. robustus, its only congener, by having a long, slender, disto-laterad hooked spine on the gonopodcoxa; in P. robustus, there is no trace of such spine.
(total 5 ♂♂, 1 (juvenile) ♀). Holotype. Tanzania • ♂; Singida Region, Manyoni District, Kilimatinde; 05°50'S, 34°58'E; 26 Jan. – 08 Feb. 1911; E. Obst leg.; verbatim label text: “Ostafr.-Exp. d. Hamb. Geogr. Ges. Kilimatinde, Landschaft Ugogo Dr, E. Obst leg., 26.I –8.II. 1911. Geogr-. Ges. ded. 3.x.1912”; (ZMH) Paratypes. Tanzania • ♂; Singida Region, Manyoni District, Saranda-Sawa [here understood as the village of Saranda ca. 14 km N of Kilimatinde]; 05°43'S, 34°59'E; 15–16 Feb. 1911; E. Obst leg. ZMH-A0016675; NHMD 621850; verbatim label text: “Ostafr.-Exp. d. Hamb. Geogr. Ges. Ugogo und Turu, Saranda-Sawa, Dr. E. Obst leg., 15.–16.II. 1911, Geogr-. Ges. ded. 3.x.1912”; additional labels: “Spinotarsus?, R.L. Hoffman det. 1966”, “Odontopygidae: ?n.gen. oder viell. Spinotarsus?” [label by Krabbe?] • ♂; Singida Region, Manyoni District, Mahalala [here understood as the village of Muhalala ca. 11 km WNW of Kilimatinde]; 05°47'S, 34°53'E; 12–14 Feb. 1911; E. Obst leg.; ZMH-A0016676; verbatim label text: “Ostafr.-Exp. d. Hamb. Geogr. Ges. Mahalala, Landschaft Ugogo leg. Obst, 12/14.II. 1911” • 2 ♂♂, 1 (juvenile) ♀; same collection data as holotype, ZMH- A0016676; 1 ♂, same collection data as holotype,
(males). Size. Length ca. 8 cm. Diameter 5.5–6.0 mm. 60–62 podous rings, no apodous rings in front of telson.
Colour
(Fig.
Head . Area below supralabral setae vertically wrinkled, otherwise smooth; parietal furrow distinct, interocular furrow very faint; supralabral setae abraded and uncountable in most specimens, but six setae/sockets can be seen in some; eyes extending to medial tangent to antennal sockets. Mandibular stipes with a not very pronounced disto-ventral lobe; distal margin very shallowly emarginated.
Collum . With rectangular lateral lobes; a marginal furrow and one further furrow extending almost halfway to dorsal midline, two short furrows between them.
Body rings
. Unvaulted; prozonites with fine, finely punctate ring furrows; suture straight, simple; metazonites with rather dense, deep longitudinal furrows in ventral part; on anterior body rings the furrows reach almost to ozopores level, further back they stop well below the pores and are not so deep. Ozopores starting on ring 5, visible as black dots (Fig.
Pleonoporus tanzanicus sp. nov., paratype, ♂ (NHMD 621850) A, B sternum 9 A anterior view B ventral view C–E first pair of legs C anterior view D sublateral view E ventral view F limbus. Abbreviations: APS = mesapical prefemoral setae; CXS = coxosternal setae; LPS = lateral prefemoral setae. Scale bars: 0.2 mm (A–E); 0.02 mm (F).
Telson
(Fig.
Legs . Length ca. 0.8 × body diameter. Prefemoral and tibial pads present on all legs from pair 6 backwards.
First pair of legs
(Fig.
Sternum 9
(Fig.
Gonopod coxa
(Fig.
Pleonoporus tanzanicus sp. nov., paratype, ♂ (NHMD 621850), left gonopodcoxa A anterior view B posterior view C mesal view. Abbreviations: CU = cucullus; hu = lateral hump; LCS = lateral coxal spine; MF = metaplical flange; mk = metaplical knob; MP = metaplica; ms = metaplical shelf; msp = metaplical spine; mst = metaplical shelf tooth; mts = metaplical transverse spine; PP = proplica. Scale bars: 0.2 mm.
Gonopod telopodite
(Fig.
Pleonoporus tanzanicus sp. n., paratype, ♂ (NHMD 621850), left gonopod telopodite A аnterior view B posterior view (basomere partly covered by mounting tape (orange)) C ventral (apical) view D basal (dorsal) view E mesal view F tip of solenomere. Abbreviations: al = anterior lobe of telomere; ARC = arculus; fl = basal flap of solenomere; pl = posterior lobe of telomere; SLM = solenomere; TL I = torsotope lobe; TM = telomere; TT = torsotope. Scale bars: 0.2 mm (A–E); 0.02 mm (F).
Very similar to Pleonoporus tanzanicus sp. nov., from which it differs by the absence of the lateral coxal spine (LCS) on the gonopods.
Syntypes
: 6 ♂♂ (four of them broken in halves), 1♀ (
Pleonoporus robustus Attems, 1938. Syntype ♂ (
It was not possible to find the specimen from which Attems dissected and extracted the gonopods. However, the gonopod illustrations (
Pleonoporus robustus Attems, 1938. Syntypes ♂ gonopods A gonopod block (
Pleonoporus robustus Attems, 1938. Syntype ♂ gonopods (
The new species from Tanzania described here is very similar to P. robustus from the Democratic Republic of the Congo, but although there is really only one distinguishing character, i.e., the lateral coxal spine present in P. tanzanicus sp. nov. and absent in P. robustus, this spine is so conspicuous that we consider the Tanzanian specimens different from the Congolese ones at the species level. The geographical distance between the type localities of the two species is 1000 km, which in itself suggests (but does not prove) that different species are involved.
Another long-distance disjunction involving odontopygids was recorded by
Natural history collections continue to play a pivotal role as a source of undescribed species. A high number of unknown taxa are housed in museum collections, awaiting to be studied and described. An average shelf life of 20.7 years (range 0–206 years) was estimated for all species described in 2007 (
In other instances, species have randomly been discovered when studying related taxa and recovered among the type material of another previously described species. The relatively recently described species Annamina attemsi Golovatch, Geoffroy & Akkari 2017 is an example of such a species, which was described based on specimens mixed with the syntypes of Annamina xanthoptera Attems, 1937 housed in
Thanks to Danilo Harms (ZMH) for kindly loaning the specimens of the new species, and to Sree Gayathree Selvantharan (NHMD) and Oliver Macek (