Eviulisoma biquintum, 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 : 72-74

Eviulisoma biquintum sp. nov.

urn:lsid:zoobank.org:act:0B213B4D-8455-4489-B253-13B7769E1611

Figs 3C , 35 , 39C

Diagnosis

Differs from all other species of Eviulisoma by having two knobs on sternum 5, one between coxae 4

and one between coxae 6. Differs from most species of Eviulisoma by lacking an excavation of sternum 6.

Etymology

The name is composed of the Latin bi, meaning ʻtwoʼ, and quintum, meaning ʻfifthʼ, and refers to the two knobs on sternum 5.

Material studied (total: 3 ♂♂)

Holotype

TANZANIA: ♂, Iringa Region, Iringa District, Nyambanike Mts, Udekwa Village , Ukami Forest , 7°42′49″ S, 36°25′15″ E, Jul.–Nov. 1994, David Moyer leg. ( ZMUC).

Paratypes

TANZANIA: 1 ♂, Iringa District, Mwanihana FR, Uzungwa Mts, Sanje River valley near Sanje Falls , 3000 ft a.s.l., 23 Nov. 1979, W.A. Rodgers and K.H. Bulstrode leg. (VMNH); 1 ♂, Morogoro Region, Udzungwa Mts National Park , Mito Mitatu , Plot MM 1, 07°50′16.3″ S, 36°50′44.6″ E, 800 m a.s.l., 22 Mar. 2013, hand collected, T. Pape and N. Scharff leg. (ZMUC).

Description (male)

SIZE. Length 19–24 mm, max. width 2.0– 2.4 mm.

COLOUR. Specimen from Mito Mitatu after 4 years in alcohol with entire body deep black, except for amber-coloured sternal regions and contrastingly white legs ( Fig. 3C ). Specimen from Udekwa Village (holotype): after 23 years in alcohol head reddish brown; antennae, collum, metazonites and telson dark brown; prozonites and legs yellowish. Specimen from Mwanihana FR overall pallid after 38 years in alcohol, only metazonites dorsally very light brownish.

ANTENNAE. Reaching back to ring 4 or 5.

BODY RINGS. Paranota represented by very indistinct keels on body ring 2 (as Fig. 4C ), otherwise completely absent. Stricture between pro- and metazonite smooth. No setae seen on post-collar metazonites (abraded?).

HYPOPROCT. Semicircular, no marginal tubercles.

LEGS. Length 1.5 × body width. Relative lengths of podomeres: tarsus (>) femur> tibia (>) prefemur (>) postfemur. Scopulae poorly developed, only on tibia and tarsus, absent from posteriormost leg pairs.

STERNUM 5. With two small median knobs, one between legs 4, one between legs 5.

STERNUM 6. Not excavated, coxae more separated than on normal body rings.

GONOPODS ( Fig. 35 ). Coxal lobe (cxl) moderate, irregular, not evenly rounded. Prefemoral part (prf) ca 0.4× as long as acropodite. Mesal acropodital process (map) long, narrow, straight sides tapering

towards tip, apically regularly rounded, dorsally concave, forming gutter for solenophore. Solenophore (sph) slender, simple, a little longer than map, apically with two slender processes.

Distribution and habitat

Known from two parts of the Udzungwa Mts: Udzungwa Mountains National Park (incl. Mwanihana FR) and Nyambanike Mts in West Kilombero Scarp FR.

Remarks

The newly collected specimen from the Udzungwa National Park is strikingly coloured – black body and white legs ( Fig. 3C ) – whereas the one from Nyambenike seems to be less remarkable in this respect. Fading with age of the specimen may explain the difference, but more specimens from each of these sites would be highly desirable in order to ascertain whether we are really dealing with only one species.

The gonopods resemble those of E. taitaorum VandenSpiegel & Golovatch, 2014 , and E. taita VandenSpiegel & Golovatch, 2014 . These two species, however, have an excavated sternum 6, and E. taitaorum lacks a lobe on sternum 5. No other species has two processes behind each other on sternum 5, according to available descriptions.

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. 35. Eviulisoma biquintum sp. nov., holotype. A–D. Right gonopod. A. Mesal view. B. Ventral view. C. Lateral view. D. Acropodite, subapical view. E. Sternum 5. Abbreviations: cxl = coxal lobe; map = mesal acropodital process; prf = prefemoral part; slm = solenomere; sph = solenophore. Scale bars: A–C, E = 0.1 mm; D = 0.05 mm.

Fig. 39. Suohelisoma ulugurense Hoffman, 1964, specimen from Uluguru Mts, Lupanga, M. Stoltze and N. Scharff leg. A–C. Right gonopod. A. Mesal view. B. Ventral view. C. Lateral view. D. Body ring 6 showing excavated sternum, ventral view. E. Anterior leg, showing scopulae. Abbreviations: cxl = coxallobe; map/ fet = mesal acropodital process / ʻfemoriteʼ; prf =prefemoral part; slm =solenomere; sph = solenophore. Scale bars: 0.1 mm.