Lipseuma bernardi, Golovatch & Geoffroy & Mauriès, 2006

Golovatch, Sergei I., Geoffroy, Jean-Jacques & Mauriès, Jean-Paul, 2006, Four new Chordeumatida (Diplopoda) from caves in China, Zoosystema 28 (1), pp. 75-92 : 90-91

Lipseuma bernardi n. sp.

( Figs 7 ; 8 )

TYPE MATERIAL. — Holotype: China, Sichuan Prov., Xin Long County, Three Eyes Cave , No. 438, 7.VIII.1999, leg. B. & J. Lips, ♂ ( MNHN DA156 ). Paratypes: same locality, 1 ♂, incomplete ( MNHN DA156 ) ; 1 ♂, subadult ( MNHN DA156 ) .

ETYMOLOGY. — To honour Bernard Lips.

DIAGNOSIS. — Differs from the only congener ( L. josianae n. gen., n. sp.) by the slightly smaller size, as well as minor details of leg and gonopod structure.

DESCRIPTION

Length 7.2 (holotype) or 6.8 mm (subadult ♀); width of body segment 6, 0.72 mm, of midbody segments, 0.78 mm, maximum breadth of head, 0.9 mm (holotype).

Antennae ( Fig. 7A ) with even more exposed, highly elongate, pointed apical cones on stalks.

All peripheral characters like in L. josianae n. gen., n. sp. except as follows: exterior macrochaetae on midbody segments 0.6 mm long, i.e. nearly as wide as segment itself ( Fig. 7B ).

Male legs 6 ( Fig. 7C, D ), 10 ( Fig. 8A ) and 11 virtually the same as in L. josianae n. gen., n. sp., but male legs 7 ( Fig. 7E ) with a characteristic protuberance on tarsus ventrally at about midway.

Anterior gonopods ( Fig. 7F, G ) also virtually the same as in L. josianae n. gen., n. sp., but posterior gonopods ( Fig. 8B ) with traces of a second telopoditomere distally on caudal face.

Subadult male (26 body segments) with small but evident gonopod promordia, legs 7 almost as strongly incrassate as in adult male, legs 7 also slightly enlarged.

REMARKS

Both Lipseuma n. gen. species are remarkable in being completely unpigmented and eyeless, as well as in bearing strongly elongated antennae, legs (especially tarsi) and exterior macrochaetae. All these features leave no doubt that we are dealing with troglobites.

It is noteworthy that interspecific variation in Lipseuma n. gen. is very modest, in contrast to that observed in the other two kashmireumatid genera. In fact, L. josianae n. gen., n. sp. and L. bernardi n. gen., n. sp. are barely distinguishable. The very small differences noted between them suggest either a quite recent colonization of caves by their common ancestor or a fairly recent vicariance event with speciation within their respective cave systems. The latter scenario seems more plausible, given the profound troglomorphism of both species, which would require a geological time-scale to develop, along with the geographical proximity of Chuan Dong Zi and Three Eyes caves (both situated in the Xin Long geographical zone just at the border between Hubei and Sichuan provinces [ Degouve et al. 1997]). In other words, the old geological age of the genus Lipseuma n. gen. seems unquestionable, whereas the isolation of both hitherto known congeners probably occurred only relatively recently.

Figures

FIG. 7. — Lipseuma bernardi n. gen., n. sp., paratype ♂: A, antenna; B, left half of body segment 7, front view; C, D, leg 6, front and caudal views, respectively; E, leg 7, front view; F-H, anterior gonopods (leg-pair 8), front and caudal views, respectively. Scale bars: A-E, 0.2 mm; F, G, 0.1 mm.

FIG. 8. — Lipseuma bernardi n. gen., n. sp., paratype ♂: A, leg 10, front view; B, posterior gonopods, caudal view. Scale bar: A, 0.2 mm; B, 0.1 mm.