Xystopyge bentemarieae, 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 : 103-104

Xystopyge bentemarieae sp. nov.

urn:lsid:zoobank.org:act:0968ADE8-6469-44B3-AE8D-D427EED0A597

Figs 4B , 62–64

Diagnosis

Differs from other species of Xystopyge by the combination of a hammerlike profile of the distal part of the gonopod coxa in certain views ( Fig. 63C ) (shared only with X. martella VandenSpiegel & Pierrard, 2004 , and X. doggartae sp. nov.), an only moderately long, tongue-shaped gonopod sternum (very long, slender-triangular in X. martella and X. doggartae sp. nov.), a very stout, moderately curved hook (th) at midlength of the gonopod telomere (very strongly curved in X. doggartae sp. nov.), lack of a basal solenomeral spine (BSS) (a small tubercle in X. martella , a long basal spine in in X. doggartae sp. nov.) and a distal division of the solenomere into two branches (undivided in X. martella ).

Etymology

After my granddaughter Bente Marie Enghoff Mogensen.

Material examined (total 7 ♂♂)

Holotype TANZANIA • ♂; Morogoro Region, Kanga Mts , Kanga FR ; 400–500 m a.s.l.; 22–25 Nov. 1984; lowland rain forest; N. Scharff leg.; NHMD 621766 .

Paratypes TANZANIA • 6 ♂♂; same collection data as for holotype; NHMD 621767 .

Description

SIZE. Length 57–73 mm. Diameter 3.5–4.0 mm. 61–62 podous rings; no podous rings in fornt of telson.

COLOUR. After 36 years in alcohol faded to light (greyish) brown; however, a broad mid-dorsal pale stripe still evident.

SUPRALABRAL SETAE. 5–6.

MANDIBULAR STIPES. Distal margin slightly concave, posterior-distal corner almost right-angled.

ANAL VALVES ( Fig. 4B ). Each with a distinct dorsal spine and 2 setae on raised margin; no ventral spine.

LIMBUS ( Fig. 62C ). Margin with short, smooth rounded lobes.

LEGS. With postfemoral and tibial pads from leg-pair 5, except for last few leg-pairs; size of pads decreasing towards posterior.

FIRST PAIR OF LEGS ( Fig. 62D–F ). Prefemoral lobes short, triangular in ventral view. Six to eight long coxosternal setae (CXS) adjacent to lateral side of prefemoral process; prefemur with a few peglike mesapical sensilla (APS) and ca 12 peglike lateral sensilla (LPS).

GONOPOD STERNUM (STERNUM 8) ( Fig. 62A ). Tongue-shaped, ca twice as long as broad.

STERNUM 9. Pentagonal with parallel lateral margins (‘house-shaped’).

GONOPOD COXA ( Fig. 63 ). Proplica (PP) simple, proplical lobe (PPL) relatively slender, clearly visible in anterior view. Metaplica (MP) at level of proplical lobe produced mesad into triangular ridged process (mpo), at lateral end of mpo a large vertical lobe (mpv), distally produced into complex structure with four subhorizontal processes: 1. A large, subrectangular meso-posteriad process (mpp), 2. A long, triangular mesad process (mtp), 3. A very slender process (sx) process originating next to mtp 4. A subrectangular anteriad process (rx) (sx and rx corresponding to the similarly labelled processes in X. doggartae sp. nov.).

GONOPOD TELOPODITE ( Fig. 64 ). Arculus 135°. Torsotope not very well delimited. Solenomere (SLM) at rest concealed within gutter formed by telomere; ca as long as telomere, simple, without a basal spine, towards end divided into a long, striate branch (sdl) with the opening of the efferent canal, and a longer, slender, smooth, curved spinelike branch (sdp), the latter with a short basal accessory spinelike branch. Telomere (TM) overall consisting of a ribbon describing a full circle and at the same time folded lengthwise forming a concavity along the inner side of the circle, with a very stout, smooth hook (th) ca at mid-length; at the end with a transverse spinelike process (ttp).

Distribution and habitat

Only known from lowland rain forest at 400–500 m a.s.l. at the type locality, Kanga FR in the Kanga Mts (part of Nguru Mts).

Remarks

Although X. bentemariae sp. nov. is here diagnosed vis-à-vis X. martella and X. doggartae sp. nov., it also shows some striking similarities with X. robusta Attems, 1910 . This species has been illustrated by Attems (1910) and VandenSpiegel & Pierrard (2004), but the opportunity is here taken to show some SEM images ( Fig. 65 ) of the gonopods of a male of X. robusta collected close to the Uluguru Mts, viz:

TANZANIA • ♂; Morogoro Region, Morogoro, foot of Uluguru Mts , above the university campus; 17 Mar. 1989; hand collecting from ground and from plants; Mahunka and Zicsi leg.; HNHM diplo-03051 (Compared side by side with a syntype of X. robusta (NHMW 9114, Insel Pemba, Chake Chake, Voeltkow leg. and don.) – the gonopods are completely identical.)

Specific similarities between X. robusta and X. bentemarieae sp. nov. include:

- the very complicated distal part of the metaplica, especially the slender process sx

- the simple telomere (TM)

- the hooklike moderately curved telomeral process (th)

Differences include:

- details of the apical metaplical processes other than sx

- the solenomere (slm) which in X. robusta ends in a striate lamella with a terminal hook, vs divided into a striate branch (sdl) and a spinelike process (sdp) in X. bentemarieae sp. nov.

Figures

Fig. 4. Telsons of odontopygids. A. Spinotarsus axeli sp. nov., holotype, ♂ (NHMD 621761), telson and last six body rings, lateral view. B. Xystopyge bentemarieae sp. nov., paratype, ♂ (NHMD 621767), telson, lateral view, showing two setae per anal valve as characteristic of the genus Xystopyge. C–D. Aquattuor udzungwensis Enghoff, 2015, telson and last body ring (from Enghoff & Frederiksen 2015), showing three setae per anal valve as characteristic of most odontopygids; setae in this species placed on ravelins on raised valve margins. C. Lateral view, also showing the rectangular limbus flaps characteristic of the genus Aquattuor. D. Posterior view. Stars indicate the dorsal anal valve spines characteristic of family Odontopygidae; white arrows indicate anal valve setae. Scale bars: A=1 mm; B–D=0.1 mm. A–B: Photo S.G. Selvantharan.

Fig. 62. Xystopyge bentemarieae sp. nov., holotype, ♂ (NHMD 621766). A. Gonopod sternum (sternum 8). B. Sternum 9. C. Midbody dorsal limbus. D–F. First pair of legs. D. Anterior view. E. Lateral view. F. Ventral view. Abbreviations: APS=mesapical prefemoral sensilla; CXS =coxosternal setae; LPS =lateral prefemoral sensilla. Scale bars: A= 0.05 mm; B, E=0.1 mm; C=0.01 mm; D, F =0.2 mm.

Fig. 63. Xystopyge bentemarieae sp. nov., holotype, ♂ (NHMD 621766), left gonopod coxa. A. Anterior view. B. Posterior view. C. Mesal view. D. Apical view. Abbreviations: MP=metaplica; mpo =metaplical ridged process; mpp =metaplical posterior process; mpv =metaplical vertical lobe; mtp =metaplical triangular process; PP =proplica; PPL = proplical lobe; rx =metaplical subrectangular process; sx =slender metaplical process. Scale bars: A–C=0.2 mm; D =0.1 mm.

Fig. 64. Xystopyge bentemarieae sp. nov. A–D. Holotype, ♂ (NHMD 621766), left gonopod telopodite. A. Anterior view. B. Posterior view. C. Dorsal view. D. Ventral view. E–H. Paratype, ♂ (NHMD 621767), isolated solenomere. Abbreviations: sdl =solenomeral distal microstriate branch; sdp =solenomeral distal spinelike branch; SLM =solenomere; th =telomeral hook; TM =telomere. Scale bars: A –E= 0.1 mm; F–H =0.05 mm.

Fig. 65. Xystopyge robusta Attems, 1910, ♂, from Morogoro (HU-HR-124), right gonopod. A–D. Coxa. A. Anterior view. B. Posterior view. C. Mesal view. D. Lateral view. E–J. Telopodite. E. Anterior view. F. Posterior view. G. Mesal view. H. Ventral view. I. Lateral view. J. Tip of solenomere. Abbreviations: sx =slender metaplical process;th = telomeral hook;TM =telomere. Scale bars:A–I =0.2 mm; J =0.1 mm.