Chaleponcus howelli, 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 : 63-65

Chaleponcus howelli sp. nov.

urn:lsid:zoobank.org:act:F7D97CB8-4791-4584-AD89-F2BCC6589590

Figs 4 , 9 , 30

Diagnosis

Medium-sized. Gonopod coxa ( Fig. 9 ) without a lateral process; cucullus small. Distinguished from other species, i.a., by the presence of a spine (sts) on the main stem of the telomere in combination with the large distal spine (als) on the anterior telomeral lamella.

Etymology

The name honours Kim Howell in recognition of his huge efforts to increase the knowledge of Tanzanian millipedes.

Material studied (total: 100 ♂♂)

Holotype

TANZANIA: ♂, Iringa Region, Udzungwa Mts, Mufindi, Kigogo Forest Reserve , 1900 m, 7–15 Oct. 1984, pitfall traps in montane rain forest, N. Scharff leg. ( ZMUC).

Paratypes

TANZANIA: 61 ♂♂, Iringa Region, Udzungwa Mts, Mufindi, Kigogo Forest Reserve, 1700 m, 8–10 Oct. 1984, pitfall traps in montane rain forest, N. Scharff leg. (ZMUC); 38 ♂♂, same data as holotype (ZMUC).

Type locality

TANZANIA: Iringa Region, Udzungwa Mts, Mufindi, Kigogo Forest Reserve, 1900 m, montane rain forest.

Description (male)

DIAMETER. 2.0– 2.2 mm, 44–47 podous rings.

COLOUR. After 30 years in alcohol almost uniform pale brown, with faint traces of a light dorsal stripe, sometimes with a thin dark line in midline.

ANAL VALVES. Each with a long, dorsal spine and a well-developed, but small, triangular ventral one; marginal rim raised, setiferous tubercles well developed, on ‘ravelins’.

LIMBUS ( Fig. 4B ). With long, slender triangular lobes, separated by rounded sinuses; lobes striate on external surface.

TARSAL SETATION. Normal.

GONOPOD COXA ( Figs 9 , 30 ). About 3½ × as long as wide. Lateral margin almost straight, towards apex gently curving mesad and continuous with apical margin; cucullus (cu) an almost perfect hollow hemisphere. Metaplical flange (mf) ending in blunt, equilateral triangular process; metaplical mesal margin with large rounded process (mp) delimiting semicircular sinus together with base of metaplical shelf. Metaplical shelf (ms) simple, regularly rounded, mostly projecting laterad. Metaplical shelf-spine (mss) of medium length, originating from anterior-mesal part of ms, projecting disto-mesad, then basad, reaching beyond telopodital basomere.

GONOPOD TELOPODITE ( Fig. 30 ). Solenomere with a very long, straight, meso-basad, proximal spine (ps). Main stem of telomere with a small spine (sts) ca. in middle of basal surface. Telomere distally with two branches:

• a rounded anterior lamella (al) ending in a long, gently sinuous mesad spine (als),

• a large, irregular posterior lamella (pl).

Distribution and habitat

Known only from Udzungwa Mts, Kigogo FR. Altitudinal range: 1700–1900 m. Habitat: montane rain forest.

Coexisting species

All four species known from Kigogo FR, i.e., C. quasimodo sp. nov., C. scopus sp. nov., C. howelli sp. nov. and C. mwabvui sp. nov., were found in the same samples.

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. 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. 30. Chaleponcus howelli sp. nov., left gonopod. A. Mesal-ventral (-anterior) view. B. Posterior view. C. Anterior view. D. Ventral (-anterior) view. al = anterior telomeral lamella, als = spine on al, cu = cucullus, mf = metaplical flange, mp = mesal metaplical process, ms = metaplical shelf, mss = metaplical shelf-spine, pl = posterior telomeral lamella, ps = proximal spine on solenomere, sts = spine on telomeral main stem. Scales 0.1 mm.