Chaleponcus nesrineae, Enghoff, 2022

Enghoff, Henrik, 2022, Mountains of millipedes. The family Odontopygidae in the Eastern Arc Mountains of Tanzania (Diplopoda, Spirostreptida), European Journal of Taxonomy 803, pp. 1-136 : 42-46

Chaleponcus nesrineae sp. nov.

urn:lsid:zoobank.org:act:CC0353E8-0641-40FE-951E-6A7F74FB0268

Figs 26–28

Diagnosis

Differs from other species of Chaleponcus by the combination of a coarsely serrate distal telomeral lamella (tml3) and a limbus without lobes.

Etymology

After Nesrine Akkari, Tunisian myriapodologist, former resident of ‘Hotel Dolichoiulus’.

Material examined (total 1 ♂, 1 ♀)

Holotype TANZANIA • ♂; Morogoro region and district, near Maskati mission, west side of Nguru Mountains, 20 km west of Turisani; 1900 m a.s.l.; 1986?; Jan Kielland leg.; moist evergreen forest; VMNH110628 .

Referred non-type specimen

TANZANIA • 1 ♀; same collection data as for holotype; VMNH110629 .

Description (male)

SIZE. Length 44 mm, diameter 2.8 mm, 50 podous rings, no apodous rings in front of telson.

COLOUR. After?32 years in alcohol faded, all straw yellow.

SUPRALABRAL SETAE. 4.

MANDIBULAR STIPES. Distal margin bilobed.

ANAL VALVES. Anval valves with well-developed dorsal spine, no ventral spine or ‘corner’; margin raised, 4–5 sessile setae per valve, (exceptional, but maybe teratological since one valve is slightly damaged; the female in the sample has 3 setae per valve as normal).

LIMBUS ( Fig. 26I ). Not lobed, marginal cells striate, their free margin with minute (<0.001 mm) spinules.

LEGS. Ventral pads on postfemur and tibia from leg-pair 4 backward, diminishing and eventually disappearing towards hind end.

FIRST PAIR OF LEGS ( Fig. 26A–C ). Prefemoral lobes relatively long, slender-triangular in ventral view. Four to five coxosternal setae (CXS) of different length close to lateral margin of coxosternum, well separated from prefemoral lobes. Prefemora with two short mesapical setae (APS) but apparently without further setae or sensilla.

STERNUM 9 ( Fig. 26H ). Pointed pentagonal.

GONOPOD COXA ( Fig. 26D–G ). Basally with subparallel margins, cucullus (CU) broadly rounded, apical ⅓ with rounded lateral lobe (lcs). Proplica (PP) simple, proplical lobe hidden from view by anterior metaplical process. Metaplica (MP) with well-differentiated metaplical flange (MF) ending in distinct process (MFP); metaplica with large transverse fold (mtf) at ca ⅔ of its length and with large, broadly rounded, basad anterior process (amp).

GONOPOD TELOPODITE ( Figs 27–28 ). Arculus 90°. Torsotope (TT) moderately compact; no post-torsal spine. Post-torsal narrowing (PN) very pronounced. Solenomere (SLM) slender, whiplike, longer than telomere, making several turns, without a basal spine, tip ( Fig. 27E ) simple. Telomere a highly convoluted irregular lamella featuring a proximal rounded, folded lobe (tml1), a distal triangular, curved lobe (tml2) and a distal large main lobe (tml3) with coarsely serrate margins.

Figure 28 shows as ‘360° tour’ of the telopodite in order to convey a better impression, especially of the highly complicated, three-dimensional telomere.

Descriptive notes (female)

SIZE. Length 45 mm, diameter 3.4 mm, 48 podous rings, no apodous rings in front of telson. Conspecificity with males indicated by general appearance and the characteristic limbus.

Distribution and habitat

Known only from the type locality in moist evergreen forest in the Nguru Mts; altitude 1900 m a.s.l.

Remarks

In the key of Kraus (1966) C. nesrineae sp. nov. runs to Tibiomus Chamberlin, 1927 because of the unlobed limbus. However, the value of the limbus as a genus-defining character has been challenged: whereas Kraus (1960) included a simple, serrate limbus in the diagnosis of Chaleponcus, Enghoff (2014 : fig. 4) found many different limbus types in species of the C. dabagaensis group, including a completely unlobed type similar to that of C. nesrineae sp. nov. The gonopods of C. nesrineae sp. nov. show a general similarity to those of Tibiomus species although C. nesrineae sp. nov. has no post-torsal spine (“Femoraldorn”) as in Tibiomus species except T. eurypeza Attems, 1953, and also has no spine at the base of the solenomere (“Tibialdorn”). However, the gonopods of the new species are clearly of a typical Chaleponcus shape: the gonopod cucullus is pronouncedly hood-like, the slender solenomere is much longer than the telomere, and the telomere is divided into several diverging lamellae.

Figures

Fig. 26. Chaleponcus nesrineae sp. nov., holotype, ♂ (VMNH110628). A–C. First pair of legs. A. Sublateral view. B. Anterior view. C. Ventral view. D–G. Right gonopod coxa. D. Anterior view. E. Mesal view. F. Posterior view. G. Lateral view. H. Sternum 9. I. Midbody dorsal limbus. Abbreviations: amp=anterior metaplical process; APS =mesapical prefemoral setae;CXS =coxosternal setae; lcs =lateral coxal lobe;MF =metaplical flange; MFP=metaplical flange process; mtf =metaplical transverse fold; MP=metaplica; PP =proplica. Scale bars: A–H=0.2 mm; I =0.005 mm.

Fig. 27. Chaleponcus nesrineae sp. nov., holotype, ♂ (VMNH110628). Right gonopod telopodite. A. Anterior view.B. Mesal view.C. Posterior view.D. Lateral view.E. Tip of solenomere.Abbreviations: PN = post-torsal narrowing; SLM =solenomere; tml =telomeral lamellae (numbered); TT =torsotope. Scale bars: A–D =0.2 mm; E=0.05 mm.

Fig. 28. Chaleponcus nesrineae sp. nov., holotype, ♂ (VMNH110628). Right gonopod telopodite, ‘360° tour’. A. Anterior view. B. Meso-anterior view. C. Mesal view. D. Meso-posterior view. E. Posterior view. F. Latero-posterior view. G. Lateral view. H. Latero-anterior view. Scale bar =0.2 mm.