Chaleponcus circumvallatus, Enghoff, 2014

Enghoff, Henrik, 2014, A mountain of millipedes I: An endemic species-group of the genus Chaleponcus Attems, 1914, from the Udzungwa Mountains, Tanzania (Diplopoda, Spirostreptida, Odontopygidae), European Journal of Taxonomy 100, pp. 1-75 : 41-44

Chaleponcus circumvallatus sp. nov.

urn:lsid:zoobank.org:act:67292AA6-2D3C-4DE4-BCF0-55719766C6E7

Figs 4–6 , 9 , 21

Diagnosis

Large. Gonopod coxa ( Fig. 9 ) without a lateral process; metaplical shelf-spine long. Telomere with a smooth anterior lamella and a posterior lamella ending in two long spines. Claws of walking legs surrounded by ‘palisade’ of setae, a character shared only with C. ibis sp. nov.

Etymology

The name is a Latin adjective meaning ”surrounded by palisade” and refers to the ‘palisade’ of setae surrounding the claws.

Material studied (total: 2 ♂♂)

Holotype

TANZANIA: ♂, Tanzania, Iringa Region, Udzungwa Mts, Udzungwa Scarp FR, above Chita village , 1600–1650 m, 8– 12 Nov. l984, montane rain forest, N. Scharff leg. ( ZMUC).

Paratype

TANZANIA: 1 ♂, Iringa Region, Iringa District, West Kilombero Scarp FR, 07°50’ 38.4” S, 36°22’ 17.6” E, montane forest, 1390–1410 m asl, plot Paradiso, 18 Nov. 2000, Frontier Tanzania UMPS leg. (ZMUC).

Type locality

TANZANIA: Tanzania, Iringa Region, Udzungwa Mts, Udzungwa Scarp FR, above Chita village, 1600–1650 m, montane rain forest.

Description (male)

DIAMETER. 2.8 mm, 48 podous rings.

COLOUR. After 14 years in alcohol uniform straw yellow, metazonites slightly darker, no traces of a dorsal light band.

ANAL VALVES ( Fig. 6B ). Each with a very long and stout, slightly curving dorsal spine and a very long and slender ventral one; marginal rim raised; setiferous tubercles well developed, on small ‘ravelins’.

LIMBUS ( Fig. 4J ). Almost rectilinear, with just the slightest indication of lobes.

TARSAL SETATION ( Fig. 5 B–C). Unusual: claws surrounded and almost hidden by numerous stiff setae, accessory claw much longer than claw.

GONOPOD COXA ( Figs 9 , 21 ). Stout, ca. 3 × as long as wide. Lateral margin slightly convex in basal 2/3, then straight, then continuing in smooth curve in apical margin; cucullus (cu) hence regularly rounded. Metaplical flange ending in long triangular process (mfp); metaplica posterior-mesally with large triangular process (mp), delimiting semicircular sinus together with base of metaplical shelf. Metaplical shelf (ms) regularly rounded, projecting mesad as well as posteriad. Metaplical shelf-spine (mss) originating from anterior-mesal end of ms, massive, long, regularly curved, first anteriad, then distomesad.

GONOPOD TELOPODITE ( Fig. 21 ). Solenomere with a very long, straight, mesad proximal spine (ps). Telomere distally with two branches, both curving anteriad:

• a rounded anterior lamella (al) with small, rectangular accessory lamella (al’) on its mesal surface, • a posterior lamella (pl) ending in an apicad and a basad-anteriad spine.

Distribution and habitat

Known from West Kilombero Scarp FR and Udzungwa Scarp FR. Altitudinal range 1390–1650 m asl. Habitat: montane forest.

Coexisting species

C. hamerae sp. nov. and C. nikolajscharffi sp. nov. also occur in Udzungwa Scarp FR. In West Kilombero Scarp FR C. netus sp. nov. was found in the same sample as C. circumvallatus sp. nov. In addition, C. basiliscus sp. nov., C. gracilior sp. nov., C. ibis sp. nov. and C. tintin sp. nov. occur in West Kilombero Scarp FR.

Notes

Resembles the smaller C. nectarinia sp. nov. and the similar-sized C. krai sp. nov. in gonopod morphology, including in the possession of a telomeral lobe with a long spine. Differs from these species in the detailed shape of this lobe. Differs from all other species in the C. dabagaensis group except C. ibis sp. nov. by the peculiar distal setation of the walking leg tarsi. Although females are generally not considered in this study, it deserves mention that a female specimen found together with the male C. circumvallatus sp. nov. from West Kilombero Scarp FR and sharing its size and general morphology, also has the strange tarsal setation. The function of this is uncertain; maybe it is an adaptation for walking on soft substrates (I.B. Enghoff pers. comm.).

Figures

Fig. 4. Limbus types in Chaleponcus species, SEM micrographs, external view, except I: internal view. — A. Lobes pointed, more than twice as long as broad (C. scopus sp. nov.). B. Lobes pointed, slightly less than twice as long as broad (C. howelli sp. nov.). C. Lobes pointed, almost equilateral triangles (C. netus sp. nov.), D. Lobes rounded, slightly longer than broad (C. dabagaensis Kraus, 1958). E. Lobes broadly rounded, slightly shorter than broad (C. hamerae sp. nov.). F. Lobes spatulate (C. gracilior sp. nov.). G. Lobes rounded, broader than long, spinose, ridged (C. krai sp. nov.). H. Lobes ca. 3 times as broad as high, rounded, spinose (C. teres sp. nov.). I. Lobes rounded, much broader than high, smooth (C. malleolus sp. nov.). J. No lobes (C. circumvallatus sp. nov.). Scales: 0.01 mm (A– F, J), 0.001 mm (G–I).

Fig. 5. Chaleponcus spp., tip of tarsus and claw of walking legs. — A. C. mwanihanensis sp. nov. as an example of normal setation. B–C. C. circumvallatus sp. nov. with the claw surrounded by a ’palisade’ of setae. Scales 0.1 mm.

Fig. 6. Telson types in Chaleponcus species. — A. Dorsal and ventral anal valve spines well developed (C. nectarinia sp.nov.).B.Spinesverylong(C.circumvallatussp.nov.).C.Dorsal spinewell developed, ventral spinebarelyindicated(C.mwabvuisp.nov.).D.Nospines(C.teressp.nov.).E.Setiferoustuberclesonravelins (C. nectarinia sp. nov.). F. With setiferous tubercles, not on ravelins (C. mwabvui sp. nov.). Scales 0.1 mm.

Fig. 9. Chaleponcus spp., outline of coxite of left gonopod, posterior view. (The ’transverse’ plane of the gonopod is usually slightly at angles with the exact transverse plane of the millipede, so it may be necessary to tilt the gonopod slightly in order to obtain the view shown on the drawings.) The stippled lines indicate the place where the telopodital basomere emerges from the coxal cavity. Not to scale.

Fig. 21. Chaleponcus circumvallatus sp. nov., left gonopod. A. Anterior view. B. Mesal-anterior view. C. Posterior view. D. Mesal-posterior view. al = anterior lobe of telomere, al’ = accessory lamella, cu = cucullus, mfp = metaplical flange process, mp = mesal metaplical process, ms = metaplical shelf, mss = metaplical shelf-spine, pl = posterior lobe of telomere, ps = proximal spine of solenomere. Scales 0.1 mm.