Canthyporus aenigmaticus Biström & Nilsson

Bilton, David T., 2015, A review of the Canthyporus exilis group, with the description of two new species (Coleoptera: Dytiscidae), Zootaxa 3957 (4), pp. 441-454 : 451

Canthyporus aenigmaticus Biström & Nilsson

Described on the basis of a single male, collected in the Cederberg by Sebastian Endrödy-Younga ( Biström & Nilsson 2006). My collections of this species include the first known females. These differ from males in the slightly more strongly impressed microreticulation, particularly on the elytra, the narrower pro- and mesotarsi and the shorter apical segment of the mesotarsi. The spermatheca is relatively small, short and stout, with a relatively narrow fertilization duct ( Fig. 3 A). The spermathecal duct (not shown due to damage during extraction) is coiled, and closely resembles that of other species of the group. I can add the following records, extending the species’ distribution north to the Gifberg-Matsikamaberg massif, which represent the northernmost extension of the Cape Fold Mountains, and the adjacent Bokkeveld Escarpment: 27/ix/2010 Northern Cape, temporary pond beside R27 ca. 1 km E of Vanrhyns Pass (1 ♀, teneral); 20/ix/2014 Western Cape, Gifberg, stream over sandstone rock in Gifberg pass (1♂, 1♀); 21/ix/2014 Western Cape, Matsikammaberg, temporary rockpools on NE edge of summit plateau ( Fig. 4 A) (2♂, 4♀, some teneral).

Figures

FIGURE 3. Canthyporus exilis group, female spermathecal tracts. A) C. aenigmaticus (coils of spermathecal duct not shown); B) C. exilis; C) C. namaqualacrimus sp. nov.; D) C. nebulosus; E) C. pallidus sp. nov. Scale bar = 0.25 mm. Spermathecal ducts of C. nebulosus and C. pallidus sp. nov. snapped on extraction, but shown in entirety.

FIGURE 4. Canthyporus exilis group habitats. A) Western Cape Province. Matsikammaberg, rockpool on summit close to northeast face— C. aenigmaticus and C. pallidus sp. nov.; B) Northern Cape Province, Kamiesberg, Johannes se Berg, seepages over sloping rockface below summit, 1,470 m— C. pallidus sp. nov. Photos A. Foggo.