Cleidogona huebnerae, Shear, William A., 2013

Shear, William A., 2013, A new miniature species of the milliped genus Cleidogona from Costa Rica (Diplopoda, Chordeumatida, Cleidogonidae), with a review of Central American Cleidogonidae, Zootaxa 3635 (1), pp. 87-93 : 87-88

Cleidogona huebnerae , n. sp.

Figs. 1 –4

Types: Male holotype and two male and female paratypes, with other, juvenile specimens from Tropenstation La Gamba, Costa Rica, collected in 2008 by Barbara Hübner. Types deposited in Naturhistorisches Museum Wien, Austria.

Diagnosis: Distinct from all other known Central American cleidogonid millipeds in the small size of mature specimens, being about 50% smaller than the next smallest congeneric species, and in the details of the gonopods ( Figs. 1, 2 )

Description: Male: Length, 7 mm, greatest width 0.62 mm. Ocelli 18, in five rows. Color light chestnut brown, dorsally mottled with darker purplish brown. Diplosegments with moderately developed lateral tubercles bearing lateralmost segmental setae; segmental setae about one-third width of body. Legpairs 1–7 only slightly more crassate than postgonopodal legs. Gonopods: in anterior view ( Fig. 2 ) with broad sternum (s) not extending between angiocoxites, with paired, squarish median swellings; coxal knobs prominent. Coxae (c) with two setae. Angiocoxites (ac) short, broad, thin, with short, rounded apical process. In posterior view ( Fig. 1 ) angiocoxite tips extend prominently posteriorly, with fine cuticular spinules. Colpocoxites (cc) very low, semirectangular, separated from angiocoxites by poorly sclerotized membrane. Ninth legpair ( Fig. 3 ) reduced as usual for genus, but each with coxa, trochanter, prefemur (cpf) fused; coxal portion with small, perhaps vestigial gland openings surrounded by markedly thicker cuticle; femora (f) distally thickened. Legpairs 10, 11 typical, coxae elongate, with extruded glands. Legpair 12 with forward-projecting sternal peg fitting in situ between coxae 11.

Female: Length, 7.3 mm, greatest width 0.66 mm. Nonsexual characters as in male.

Distribution: Known only from the type locality.

Etymology: Named for the collector, Barbara Hübner.

Notes: One of the juvenile specimens collected with the types is a penultimate male, of interest because the ninth legpair, reduced in adult males, is of normal size in this instar. The gonopods appear as small primordia in place of the eighth legpair. While previously described Central American cleidogonids were primarily from higher elevations, this species comes from a lowland locality, suggesting that there may be additional species of Cleidogona to be discovered in such places.

The gonopods recall species of Dybasia (see below) in the short but obvious bifid sternal process and reduced colpocoxites, but are more complex at the angiocoxite tips. The ninth leg femora are distally enlarged, as in Cleidogona , and the coxoprefemora do not have processes. All in all, I think the species belongs in Cleidogona .

Tropenstation La Gamba is a field station in southern Costa Rica (8°42’03.67”N, 83°12’ 06.20W, elev. 75m) operated by Universität Wien and founded by Regenwald der Österreicher (Rainforest of the Austrians). Specimens of C. huebnerae were collected from leaf litter at two study sites, one a narrow ridge, and the other a steep slope down to a brook. Both were heavily vegetated with rainforest trees and understory plants but the canopy was less dense at the slope site. At both sites, the litter consisted mainly of fresh and undecomposed leaves, twigs, and fruits. The study focused on litter-trapping plants, but no specimens of C. huebnerae were taken in this microhabitat (B. Hübner, pers. comm. 2013).

Figures

FIGURES 1 – 3. Cleidogona huebnerae, n. sp., male. 1. Gonopods, posterior view. 2. Gonopods, anterior view. 3. Legpair 9, anterior view.