Two new species of Neotropical land flatworms (Platyhelminthes: Continenticola) occurring in ferruginous and limestone caves

Abstract

Compared to epigean domains, subterranean natural cavities are relatively stable environments. Among other invertebrates, land planarians have been sampled from caves in the Neotropical region, where their diversity seems to be high, but almost unknown. Besides being photophobic, land flatworms depend on the moisture of their microhabitats, since they do not have water-saving adaptations and, thus, caves seem to be an appropriate refuge for them. In the present study we describe two new species of Geoplaninae sampled from two types of cave lithologies: Pasipha carajaensis sp. nov. was sampled in ferruginous caves from the Amazonian biome and Pasipha tutameia sp. nov., in a limestone cave from the Cerrado biome. The new species differ from their congeners and from each other by the color pattern and characteristics of the copulatory apparatus. P. tutameia sp. nov. shows an inverted penis, a type of copulatory apparatus that is also known from another genus of Geoplaninae, among other triclads, but it is described for Pasipha for the first time. Considering that only a single specimen was collected in each cave and that both species are devoid of troglomorphic traits, we consider that their occurrence in caves might be occasional.