Eviulisoma coxale, Enghoff, 2018

Enghoff, Henrik, 2018, A mountain of millipedes VII: The genus Eviulisoma Silvestri, 1910, in the Udzungwa Mountains, Tanzania, and related species from other Eastern Arc Mountains. With notes on Eoseviulisoma Brolemann, 1920, and Suohelisoma Hoffman, 1963 (Diplopoda, Polydesmida, Paradoxosomatidae), European Journal of Taxonomy 445, pp. 1-90 : 50-52

E viulisoma coxale sp. nov.

urn:lsid:zoobank.org:act:10D5E316-6E8F-4 A 38-8D58-197DDA963339

Figs 3B , 6F , 7E–F , 23

Diagnosis

Differs from other species of the E. dabagaense group, except E. culter sp. nov., by having a distolateral process on the gonopod coxa. Differs from E. culter sp. nov. by having map with two strong apical denticles and several small denticles along the dorsal margin.

Etymology

The name, an adjective, refers to the peculiar modification of the gonopod coxa.

Material studied (total: 7 ♂♂)

Holotype TANZANIA: ♂, Iringa Region, Mahenge District, West Kilombero Scarp FR, Nyambanitu Mts, S of Udekwa Village , 07°48′ S, 36°21′ E, 1500 m a.s.l., Dec. 1993, J.O. Svendsen leg. ( ZMUC) .

Referred non-type material

TANZANIA: 2 ♀♀, tentatively referred to this species, same collection data as for holotype ( ZMUC); 1 ♂, Morogoro Region, Mwanihana FR , 1800–1850 m a.s.l., 28–29 Sep. 1984, litter in montane forest, N. Scharff leg. ( ZMUC); 1 ♂, same collection data as preceding, but 1650 m a.s.l., 25–29 Sep. 1984, pitfall trap in montane rain forest ( ZMUC); 1 ♂, same collection data as preceding, but 1400–1650 m a.s.l., montane rain forest ( ZMUC); 1 ♂, Mwanihana Forest above Sanje , 1650 m a.s.l., 18 Aug. 1982, litter, M. Stoltze and N. Scharff leg. ( ZMUC) ; 1 ♀ (tentatively assigned), 2 ♂♂, Morogoro Region, Udzungwa Mts National Park, Mito Mitatu , Plot 15, 07°49′39.8″ S, 36°50′26.0″ E, 1552 m a.s.l., 27 Nov. 2014, pitfall trapping, J. Malumbres-Olarte leg., sample codes 15 PT6 and 15 PT8 ( ZMUC).

Description (holotype, male)

SIZE. Length 22 mm, max. width 2.0 – 2.5 mm.

COLOUR ( Fig. 3B ). Specimen from Nyambanitu Mts after 24 years in alcohol pallid, except collum and large lateral spots on body rings brownish, on poriferous rings the spots cover the ozopore. Specimens from Mito Mitatu and Mwanihana FR almost all pallid.

ANTENNAE. Reaching back to middle of ring 4.

BODY RINGS. Paranota absent, except for barely discernible keels on ring 2 (as in Fig. 4C ). Stricture between pro- and metazonite indistinctly striolate. A transverse row of setae on most body rings (probably abraded where absent).

HYPOPROCT. Rounded-trapezoidal, without distinct tubercles.

LEGS. Length 1.3× body width. Relative lengths of podomeres: femur> prefemur = tarsus> tibia> postfemur. Scopulae ( Fig. 7E–F ) on anterior legs on femur, postfemur, tibia and tarsus, diminishing and eventually disappearing on more posterior legs, especially on femur.

STERNUM 5. A rounded-trapezoidal process between legs 4 ( Fig. 6F ).

STERNUM 6. Deeply excavated, rim simple.

GONOPODS ( Fig. 23 ). Coxa with a long, digitiform distolateral process (cxp). Other gonopodal characters as in E. dabagaense : coxal lobe (cxl) moderate; prefemoral part (prf) ca 0.25 × as long as acropodite; mesal acropodital process (map) lamelloid, straight, with parallel margins, tip of process with two strong denticles, a row of smaller denticles along apical part of dorsal margin; solenophore (sph) a rolled sheet, separated from map by a distinct gap, less than ⅔ × as long as map, forming a tube with two small apical denticles and a slender process ca at mid-length.

Specimens from Udzungwa Mts National Park

Similar to type specimens, except as follows:

SIZE. Length 25 mm, max. width 2.5 mm.

COLOUR. Overall pallid after 3 years in alcohol; only head and collum slightly ochre-yellow; a small brown patch between antennae.

ANTENNAE. Reaching back to middle of ring 4. Antennomeres 2–6 subequal.

Distribution and habitat

Known from two sites in the Udzungwa Mts National Park. Altitudinal range 1400–1850 m a.s.l. Habitat: montane rain forest. Collected in litter and pitfall traps, together with E. breviscutum sp. nov. in Mwanihana Forest.

Remarks

This species is very similar to E. dabagaense , but differs in the presence of a distolateral finger-formed process on the gonopod coxa, the latter character being shared with E. culter sp. nov. There are several females and juveniles in the same sample as the holotype, in addition to the listed females. They agree with the holotype in all non-sexual characters except that they are uniformly pale. Whether this is due to fading of the large lateral spots seen in the holotype, or to the possibility that they represent a different species, is difficult to say. Several specimens from Udzungwa Mountains National Park carry large lumps of an amorphous mass (see Discussion) on the tip of process map ( Fig. 23E ). These specimens are slightly larger than the holotype and they do not have large lateral spots on the body rings, but these differences hardly warrant the recognition of a separate species.

Figures

Fig. 3. Eviulisoma spp., examples of colour patterns. A. E. akkariae sp. nov., paratype, showing a banded pattern (pale prozonites, dark metazonites) similar to that shown in Fig. 1. B. E. coxale sp. nov., tentatively referred female from type locality, showing dark lateral spots on a pale background. C. E. biquintum sp. nov., paratype from Mito Mitatu, showing a black body contrasting with white legs. Not to scale. Photographs by F. Vad and A. Illum.

Fig. 4. Eviulisoma spp. A–B. E. paradisiacum sp. nov., ♂. A. Head and rings 1–8, lateral view. B. Head and collum, frontal view. C. E. Zebra sp. nov., ♂, head and rings 1–3, lateral view. Abbreviation: pn = paranotum. Scale bars: 0.2 mm.

Fig. 6. Eviulisoma spp., male sternum 5 with lobe between 4th legs and sternum 6 with excavation. A–B. E. ejti sp. nov., paratype, sternum 5 and 6. A. Ventral view. B. Sub-posterior view. C. E. acaciae sp. nov., paratype, sternum 6, ventral view. D–F. Sternum 5 lobe, posterior view. D. E. chitense sp. nov., paratype. E. E. dabagaense Kraus, 1958, specimen from Udzungwa Scarp FR, above Chita Village. F. E. coxale sp. nov., specimen from Mito Mitatu. Abbreviation: am = amorphous mass. Scale bars: A–C = 0.2 mm; D = 0.05 mm; E–F = 0.1 mm.

Fig. 7. Eviulisoma spp., scopulae on postfemur (pof), femur (fe), tibia (ti) and tarsus (ta) of male legs. A. E. paradisiacum sp. nov., paratype. B, D. E. cetafi sp. nov., paratype. C. E. ejti sp. nov., paratype. E–F. E. coxale sp. nov., paratype from Mito Mitatu. Scale bars: A, C, E = 0.05 mm; B, F = 0.01 mm; D = 0.1 mm.

Fig. 23. Eviulisoma coxale sp. nov. A–D. Holotype, right gonopod. A. Mesal view. B. Ventral view. C. Dorsal view. D. Lateral view. E. Paratype from Mito Mitatu, right gonopod, showing lump of amorphous mass on tip of process map. Abbreviations: am = amorphous mass; cxl = coxal lobe; cxp = coxal process; map = mesal acropodital process; prf = prefemur; sph = solenophore. Scale bars: 0.1 mm.