No abstract

One of the main challenges in ecology, biogeography and evolution is to understand and predict how species may respond to environmental changes. Here we focus on the deep subterranean environment, a system that minimizes most of the typical uncertainties of studies on epigean (surface) environments. Caves are relatively homogeneous habitats with nearly constant environmental conditions and simplified biological communities, allowing to control for biotic interactions. Thus, this particular system could be considered a natural habitat whose environmental conditions are similar to what can be reproduced in a laboratory, being an ideal model system for ecological, biogeographical and evolutionary studies. Subterranean species may potentially be used to assess the capability to persist in situ in a global change scenario, as they cannot accommodate to drastic changing conditions by behavioural plasticity, microhabitat use or by migrating to distant, more suitable areas, something frequent in epigean environments. In order to provide accurate predictions of the response of the subterranean biodiversity to climate change, we encourage evolutionary biologist, biogeographers and conservation biologist to work in this interesting ecosystem.

No abstract

A molecular phylogeny of the species from the Trechus brucki clade (previously Trechus uhagoni group)based on fragments of four mitochondrial genes and one nuclear gene is given. We describe Trechus (Trechus) bouilloni sp. n. from the western pre–Pyrenees: Sierras de Urbasa–Andía, Navarra, Spain. The species was collected in mesovoid shallow substratum (mss), a subterranean environment. Molecular as well as morphological evidences demonstrate that the new species belongs to the Trechus brucki clade. A narrow endemic species of high altitude in western French Pyrenees merged with Trechus brucki Fairmaire, 1862a, Trechus bruckoides sp. n., is described. A lectotype is designated for Trechus brucki and Trechus planiusculus Fairmaire, 1862b (junior synonym of Trechus brucki). The species group is redefined based on molecular and morphological characters, and renamed as the brucki group, as Trechus brucki was the first described species of the clade. A unique synapomorphy of the male genitalia, a characteristic secondary sclerotization of the sperm duct, which is shared by all the species of the brucki group sensu novo, is described and illustrated. The Trechus brucki group sensu novo is composed of Trechus beusti (Schaufuss, 1863), Trechus bouilloni sp. n., Trechus brucki, Trechus bruckoides sp. n., Trechus grenieri Pandellé, 1867, T. uhagoni uhagoni Crotch, 1869, T. uhagoni ruteri Colas, 1935 and Trechus pieltaini Jeannel, 1920. We discuss the taxonomy of the group and provide illustrations of structures showing the differences between the species, along with distribution data and biogeographical comments.