Pratherodesmus despaini Shear

Shear, William A., Taylor, Steven J., Wynne, Judson & Krejca, Jean K., 2009, Cave millipeds of the United States. VIII. New genera and species of polydesmidan millipeds from caves in the southwestern United States (Diplopoda, Polydesmida, Macrosternodesmidae), Zootaxa 2151, pp. 47-65 : 56-58

Pratherodesmus despaini Shear , new species

Figs. 1 , 5 , 8 , 20–24, 32, 35, 36, 39

Types: Male holotype, two male and one female paratype from Kaweah Cave, Tulare Co., California, collected 28 April 2004 by J. Krejca, P. Sprouse, S. Fryer, D. Ubick, P. Paquin and W. Savary; one male and two female paratypes from the same locality, collected 10 August 2006 by J. Krejca and J. Despain, deposited in FMNH.

Description: Male. Length 9.0 mm, width 0.6 mm ( Fig. 39 ). Head about 50% wider than collum ( Fig. 1 ). Antennae long, extending back to posterior border of fifth segment. Collum with anterior margin arcuate, with 12 marginal setae, posterior margin straight to slightly sinuate, with eight setae, middle row with six setae; posteriolateral angles slightly produced ( Fig. 1 ). Typical midbody segment ( Fig. 5 , segment 10) with three lateral marginal teeth, each subtended by a seta; anterior row of six setae very strongly procurved, lateralmost seta of row widely separated, not appearing to be part of row; middle row of six setae slightly recurved; posterior marginal row with six setae. Posteriolateral metazonital corners strongly produced beyond ozopores, ozopores subtended by usual three setae. Pygidium as described for P. voylesi , but with 12 long setae ( Fig. 8 ).

Pregonopodal legs markedly encrassate ( Fig. 1 ). Gonopods (Figs. 20–24, 32, 35) with gonocoxae and gonostome as described for P. voylesi . Prefemora strongly transverse, articulating process narrow, pointed; prefemoral stem not marked. Exomere present, small, slightly curved, acute. Endomerite large, trullate, apically with two small lobes set with prominent, regular, small warts. Solenomere longer than in other species, with fewer cuticular scales; subtending process short, acute. tibiotarsus not flattened, as acute process similar in length to solenomere.

Female: Length, 9.0 mm, width 0.70 mm. Nonsexual characters similar to male. Cyphopods not observed, not extruded in available female specimens.

Distribution and habitat: Known only from the type locality. Kaweah Cave is located close to the western boundary of Sequoia Kings Canyon National Park, and is unique among the caves in the park because it occurs at low elevation and has greater biodiversity than is found among the higher altitude caves (for locations of caves in the park, see the map in Shear & Shelley 2008). Four troglobitic species, including P. despaini , and two other endemic troglophiles are to be found there. The other troglobites are an unidentified trichoniscid isopod, a cambalid millipede, and a pseudoscorpion, probably a species of Tuberochernes . The endemic troglophiles include a harvestmen in the genus Calicina and a spider in the genus Usofila . These may all represent new unnamed species. The cave’s accessible portion is a sinuous crawl less than 100 m long, ending in a large room where the animals were collected. One male was collected from a root, and the other specimens were associated with unidentified guano (probably rodent or bat) on the floor. The temperature was not measured on the day of collections, but during an earlier visit to the same room of the cave the temperature was recorded at 11 degrees Celsius. The surrounding vegetation is California lower montane blue oak-foothill pine woodland and savanna (SWReGAP land cover type; Lowery et al. 2006).

Etymology: Named for Joel Despain, Cave Management Specialist at Sequoia and Kings Canyon National Parks, who organized and performed much of the sampling that resulted in the discovery of many new cave species.

Notes: This species is more distant from the closely related P. ecclesia and P. voylesi . While the gonopods are built along the same basic plan, the presence of a small exomere in P. despaini suggests, in comparison with Nevadesmus and Tidesmus , that it would occupy a more basal phylogenetic position within Pratherodesmus .

Figures

FIGURE 39. Living example of Pratherodesmus despaini, photographed in Kaweah Cave (photo by J. Krejca).

FIGURES 1, 2. Heads, collums and first two segments of males, dorsal view. Fig. 1. Pratherodesmus despaini. Fig. 2. P. voylesi.

FIGURES 3 – 6. Segments 10, dorsal view. Fig. 3. Nevadesmus ophimontis. Fig. 2. Pratherodesmus ecclesia. Fig. 3. P. despaini. Fig. 6. P. voylesi.

FIGURES 7 – 10. Figs. 7 – 9. Pygidia, dorsal view. Fig. 7. Nevadesmus ophimontis. Fig. 8. Pratherodesmus despaini. Fig. 9. P. voylesi. Fig. 10. Metazonital setae anterior to ozopore of segment 10, Nevadesmus ophimontis.