Hyperbolus apicomplexus, Enghoff, Henrik, 2011

Enghoff, Henrik, 2011, East African giant millipedes of the tribe Pachybolini (Diplopoda, Spirobolida, Pachybolidae), Zootaxa 2753, pp. 1-41 : 16-21

Hyperbolus apicomplexus n. sp.

Figs 28–37 , 84

Pachybolus n. sp. 1 (prope morogoroensis Kraus, 1958 ): Enghoff & Enghoff 1976 PACHYBOLIDAE Gen. & sp. nov.: Doggart et al. 1999: 75

Pachybolus aff. morogoroensis: Wesener et al. 2008

HOLOTYPE: 3 TANZANIA, Tanga Region, East Usambara Mts., Amani 5°06’S 38°38’E, at Sigi River, 500m, under fallen leaves of Dillenia indica , 5.ii.1977, H. Enghoff, O. Lomholdt, O. Martin leg. ( ZMUC 00101067).

PARATYPES from TANZANIA: 2 3, 4 ƤƤ, 1 subadult Ƥ, data as holotype ( ZMUC 00101068-00101074). – 2 3, 1 subadult 3, same data but 30.vii. –9.viii.1977, I.B. &H. Enghoff leg. ( ZMUC 00101077-001010078). – 1 3, 2 ƤƤ Tanga Region, Muheza district, East Usambara Mts., Kwamgumi Forest Reserve, 4°57’S 38°44’E, 170– 220 m, 15.vii.1995, L. Sørensen leg. ( ZMUC 00101079). – 1 3, 1 subadult Ƥ Tanga region, Muheza district, Handeni Hill Forest Reserve, 5°27’S 38°03’E, 790– 1040 m, i–iii.1993, Frontier Tanzania leg. ( VMNH). – 1 3, 1 Ƥ Tanga Region, Muheza district, East Usambara Mts., Manga Forest Reserve, 5°01’S 38°46’E, 120–360m, viii.1997, Frontier Tanzania leg. ( VMNH). – 3 3 Lindi Region, Rufiji District, Mchungo Forest Reserve, 7°42’S 39°16’E, viii.1990, Frontier Tanzania leg. ( VMNH). – 1 3 Tanga Region, Muheza District, Tongwe Forest Reserve, Mount Tongwe, 5°18’S 38°44’E, 300–600 m ASL, i–ii.1992, Frontier Tanzani leg. ( VMNH).

ADDITIONAL MATERIAL FROM TANZANIA: 3 juveniles Tanga Region, East Usambara Mts., Amani 5°06’S 38°38’E, at Sigi River, 500m, under fallen leaves on rock, 7.ii.1977, H. Enghoff, O. Lomholdt, O. Martin leg. (ZMUC 00101075). – 1 Ƥ Tanga Region, East Usambara Mts., Amani 5°06’S 38°38’E, 900 m, 1.ix.1981, M. Stoltze & N. Scharff leg. (ZMUC). – 1 Ƥ Usambara Mts., Amani, 1935, L.S. Venables leg. (NMHL). – 2 3, 1 (subadult) Ƥ Rubeho Mts., forest 5 km SW of Madizini, 7°12’S 36°47’E, 900 masl, 10–24.ix.1993, M. Andersen leg. (ZMUC 0 0 101088, 0 0 101089, 00101089). – 1 Ƥ Morogoro Region, Morogoro District, Nguru Mts., Divue River gorge, 6°9’S 37°33’E, 1200m, date? D. Emmrich leg. (VMNH).

ADDITIONAL MATERIAL FROM UGANDA: 1 3, 1 subadult 3 Mt. Elgon 1°11’N 34°25’E, 1998, E. Fischer leg. (MND)

Etymology. The specific epithet is a Latin noun referring to the complex posterior gonopod apex.

Diagnosis. A species of Hyperbolus in which the anterior gonopod coxite has two mesal processes, the anterior gonopod telopodite has a long, finger-shaped mesal process directed straight mesad, the posterior gonopod solenomerite is smooth, and the apical, multi-ridged structure of the posterior gonopod telopodite is mushroom-like and covered with parallel, strongly sclerotized ridges almost to the tip.

Description. Adults usually with 56 (19 out of 24 entire specimens), rarely with 55 (4 specimens) or 57 (1 specimen) podous rings, no apodous rings. Length 12–14 cm. Width 11.0–2.9 mm (3) / 13.1–14.5 mm (ƤƤ).

Colour: overall impression blackish brown, slightly lighter in ƤƤ. Pro- and mesozona light brown, preserved specimens hence appearing annulated. Head, antennae, collum and legs reddish brown in 3, yellowish brown in ƤƤ; telson light brown.

Head capsule smooth, except above eyes, where it is punctate: occipital furrow reaching down between eyes; clypeal furrow at most reaching level of antennal sockets. Clypeal and labral setae missing but some specimens with 1+0 or 1+1 pits which are probably setal sockets; 2+2 partly abraded labral teeth. Eyes small, largest diameter 51–52% (3) / 38–46% (Ƥ) of interocular space in frontal view; adults with 10(–11) RO, 5 horizontal series, 33– 39 ocelli per eye. Antennae at most reaching hind margin of collum when stretched back; antennomeres and antennal furrow as in Crurifarcimen vagans . Mandibles with 4–6 pectinate lamellae plus a variable number of teeth in a jumbled group basally; a sclerotized smooth-edged ridge between pectinate lamellae and mola, ridge dorsally with a row of small spines; 5 molar ridges; mandibles otherwise as in Crurifarcimen vagans . Gnathochilarium as in Crurifarcimen vagans , each stipes with 3 distal setae, each lamella lingualis with 4–7 distal setae.

Collum as in Crurifarcimen vagans . Body rings as in Crurifarcimen vagans , but ozopores no more than 1 diameter in front of meso-metazonal suture. No appreciable difference in surface fine sculpture between male and female. Telson as in Crurifarcimen vagans .

Legs as in Crurifarcimen vagans ; length of midbody legs 53–61% of body diameter in 3, 40% of body width in ƤƤ.

Male sexual characters. Ring VII and leg modifications as in Crurifarcimen vagans . Gonopods ( Figs 28–35 ) entirely concealed within ring VII at rest.

Anterior gonopods ( Figs 28–31 ) concave on oral face: sternum with high, broad, rounded-triangular mesal process reaching just beyond midheight of coxae; right and left halves of process meeting under blunt angle in midline; sternum laterally continuing as narrow band around side of gonopod, reaching well along base of coxa on aboral side, articulating with a narrow sclerite ("bride trachéenne") at base of telopodite (as in Crurifarcimen vagans ). Coxa in oral view with convex, lateral margin, overreached by tip of telopodite and by the visible tip of posterior gonopod; opposing coxae almost meeting in midline distal to sternum; here with two finger-shaped processes, one projecting distadmesad, the other projecting straight distad ( Fig. 30 ); apical margin of coxa sloping, with concavity for accommodation of posterior gonopod tip; oral surface of coxa shallowly concave; aboral surface (hidden from view in undissected specimens) broadly swollen mesally, swelling laterally delimited by sharp ridge, apically connecting with distadmesad process on oral surface; coxae extending to aboral side of gonopod where they appear as crescent-shaped lateral structures. Telopodite ( Figs 29, 31 ) consisting of a broad basal part abrubtly set off against much narrower, clubshaped apical part; basal part of mesal margin with very large, rounded, irregularly lobed, somewhat thumb-like process overlapping with opposite lobe under strong asymmetry (left lobe visible from aboral side); right lobe same shape and size as left.

Posterior gonopods ( Figs 32–35 ) with tips partly visible in situ (not obvious in Fig. 28 , however), connected by median sternal remnant similar to that seen in Crurifarcimen vagans . Orientation and divisions of gonopods following same scheme as in Crurifarcimen vagans . Each posterior gonopod consisting of:

1. a long, slender, almost straight tracheal apodeme, flattened towards its end

2. a basal, aboral sclerite which articulates with the tracheal apodeme, is roughly pentagonal in outline and has a distinct notch on its distal margin, next to articulation with median sternal sclerite

3. a slender intermediate segment (much longer in relation to terminal segment than in C. vagans ), delimited visa-vis basal sclerite across lateral half-width by shallow groove (no proper suture), across mesal half the limit appears as a limit between the sclerotized basal sclerite and a large membraneous area on the intermediate segment. Intermediate segment broadly sclerotized laterally, membranous orally and aborally, and again narrowly sclerotized along mesal margin; limit against terminal segment a very distinct, deep groove laterally.

4. a complicated terminal segment roughly with the profile of a twisted mushroom, i.e. with a basal "bulb", a "stalk" and a distal "hat" with basal and distal, rounded lobes; a small triangular tooth at base of "stalk"; "hat" on oral side with a field of densely set, strongly sclerotized ridges; towards both ends this field detaches itself from the surface, producing strongly striate lobes. Efferent groove running along mesal margin of intermediate segment, along narrow sclerotized strip, at base of mushroom stalk of terminal segment running onto slender, sigmoid solenomerite; solenomerite mostly without denticles (denticles present in 3 from Rubeho Mts.), ending near serrate edge of basal striate lobe.

Female sexual characters. Distal margin of lateral coxosternal extensions projecting as right-angled lobe. Vulva ( Figs 36–37 ) less elongated than in Crurifarcimen vagans , valves highly irregular in shape, with large interlocking lobes along free margins, including a large, subrectangular lobe on aboral valve just distal to operculum, distal margin of this lobe fitting against large, subtriangular lobe of oral valve; oral valve much longer than aboral valve, with large, rounded-subpyramidal apical appendix in situ lying close to lateral coxosternal extension. Crest not protruding.

Postembryonic development. Only five immature individuals were seen. One 6RO specimen has 43 podous and 6 apodous rings, i.e., one podous ring more than the studied 6RO specimens of C. vagans . Two 8RO specimens with 53 podous and 3 apodous rings agree with stadium 8RO in Crurifarcimen vagans . Two subadults, one ɗ and one Ψ, had 10RO, 56 podous and no apodous rings.

All mature specimens have 10RO, except one questionable 11RO (this is the single known specimen with 57 podous rings). The existence of 10RO subadults, cf. above, however requires that some mature specimens are at least 11RO. In a few of the 10RO specimens, the tenth row consists on only 1–2 ocelli, cf. discussion under Crurifarcimen vagans .

Habitat. Montane forest, collected under leaf litter.

Distribution. Quite widespread in NE Tanzania ( Fig. 84 ). Most finds are from the East Usambara Mountains, but H. apicomplexus has also been collected on Mt. Tongwe, a southern outlier of the East Usambara mountains, on Handeni Hill slightly more to the SW, in the Rubeho and Nguru mountains. Surprisingly, it has also been found in coastal forest at sea level in Mchungo Forest Reserve more than 250 km S and on Mt. Elgon in Uganda some 750 km NW of the Usambaras. Altogether, the known distribution area spans more than 1000 km in a SE-NW direction. Most records are from 500 masl or below, but the one from Handeni Hill is from 790–1040 masl, the one from Rubeho Mts is from 900 masl, and the one from Nguru Mts from 1200 masl.

Figures

FIGURE 84. Known distribution of East African Pachybolini, except Hadrobolus crassicollis and Epibolus pulchripes. dots (●): Crurifarcimen vagans, filled diamonds (♦): Hyperbolus apicomplexus, open diamonds (♢): Hyperbolus morogoroensis, filled triangle (˔): Parabolus dimorphus, inverted open triangle (): Parabolus calceus, inverted filled triangle (ˑ): Pachybolus tectus,, filled square (․): Pachybolini indet. Based on Yahoo maps.

FIGURES 28 – 31. Hyperbolus apicomplexus, paratype, gonopods. 28: gonopod block, anterior view, G. Brovad phot., 29: do., posterior view, G. Brovad phot., 30: right anterior gonopod coxa, anterior view, SEM, 31: right anterior gonopod telopodite, anterior view (i. e., from inside of anterior gonopod cavity), SEM. Scales 1 mm. cx: coxa, fp: finger-shaped processes, mp: mesal, thumb-like process of telopodite, st: sternum, tlp: telopodite.

FIGURES 32 – 35. Hyperbolus apicomplexus, paratype. 32: right posterior gonopod, aboral view, G. Brovad phot., 33: left posterior gonopod, oral view, SEM, 34: do., detail, showing mushroom-shaped terminal segment and solenomerite, SEM, 35: left posterior gonopod, oral view, tip of solenomerite, SEM. Scales 1 cm (32 – 33), 0.1 mm (34), 0.01 mm (35). bs: basal sclerite. is: intermediate segment, slm: solenomerite, tr. a.: tracheal apodeme (hidden in muscle).

FIGURES 36 – 37. Hyperbolus apicomplexus, paratype, right vulva, SEM. 36: posterio-lateral view, 37: lateral view. Scales 0.1 mm. ap: apical appendix, lav: subrectangular lobe of aboral valve, lov: subtriangular lobe of oral valve, op: operculum. SEM.