Phylogenetic analysis of oligochaete Tubificinae (Annelida:Clitellata) based on mitochondrial sequence data

[ES]Se utilizaron secuencias parciales de los genes mitocondriales 16S rRNA y citocromo c oxidasa subunidad I (COI) (1) para resolver las relaciones internas de la subfamilia Tubificinae (Annelida: Clitellata) y (2) para analizar la existencia de especies crípticas dentro del oligoqueto estigobionte Troglodrilus galarzai (Giani & Rodríguez, 1988). Las filogenias se estimaron utilizando los métodos de máxima verosimilitud, inferencia bayesiana y parsimonia. Aunque los árboles no se resolvieron completamente a nivel intergenérico, se reveló una estrecha relación entre Heterochaeta Claparède, 1863 y Troglodrilus Juget, des Châtelliers & Rodriguez, y se corroboró la separación de Lophochaeta ignota Štolc, 1886 y Heterochaeta costata Claparède, 1863 de Tubifex Lamarck, 1816 por datos moleculares mitocondriales. La divergencia genética máxima entre poblaciones alopátricas de T. galarzai fue del 18% para COI (distancia por pares sin corregir), lo que sugiere una especiación críptica dentro de esta especie nominal.[EN]Partial sequences of the mitochondrial genes 16S rRNA and cytochrome c oxidase subunit I (COI) were used (1) to resolve the internal relationships of the subfamily Tubificinae (Annelida : Clitellata) and (2) to test the existence of cryptic species within the stygobiont oligochaete Troglodrilus galarzai (Giani & Rodriguez, 1988). Phylogenies were estimated using maximum likelihood, Bayesian inference and parsimony. Although trees were incompletely resolved at intergeneric level, a close relationship between Heterochaeta Claparède, 1863 and Troglodrilus Juget, des Châtelliers & Rodriguez was revealed, and the separation of Lophochaeta ignota Štolc, 1886 and Heterochaeta costata Claparède, 1863 from Tubifex Lamarck, 1816 was corroborated by mitochondrial molecular data. Maximum genetic divergence between allopatric populations of T. galarzai was 18% for COI (uncorrected pairwise distance), suggesting cryptic speciation within this nominal species.The first author had a PhD grant by the UPV/EHU (Euskarazko tesia egiteko ikerketa pertsonala prestatzeko laguntzen deialdia 2007-2011). The molecular analyses have been financed by the Catedra UNESCO (project UNESCO 04/04) and the GIU09/31 project (UPV/EHU

Is the Australian subterranean fauna uniquely diverse?

Australia was historically considered a poor prospect for subterranean fauna but, in reality, the continent holds a great variety of subterranean habitats, with associated faunas, found both in karst and non-karst environments. This paper critically examines the diversity of subterranean fauna in several key regions for the mostly arid western half of Australia. We aimed to document levels of species richness for major taxon groups and examine the degree of uniqueness of the fauna. We also wanted to compare the composition of these ecosystems, and their origins, with other regions of subterranean diversity world-wide. Using information on the number of ‘described’ and ‘known’ invertebrate species (recognised based on morphological and/or molecular data),we predict that the total subterranean fauna for the western half of the continent is 4140 species, of which ~10% is described and 9% is ‘known’ but not yet described. The stygofauna, water beetles, ostracods and copepods have the largest number of described species, while arachnids dominate the described troglofauna. Conversely, copepods, water beetles and isopods are the poorest known groups with less than 20% described species, while hexapods (comprising mostly Collembola, Coleoptera, Blattodea and Hemiptera) are the least known of the troglofauna. Compared with other regions of the world, we consider the Australian subterranean fauna to be unique in its diversity compared with the northern hemisphere for three key reasons: the range and diversity of subterranean habitats is both extensive and novel; direct faunal links to ancient Pangaea and Gondwana are evident, emphasising their early biogeographic history; and Miocene aridification, rather than Pleistocene post-ice age driven diversification events (as is predicted in the northern hemisphere), are likely to have dominated Australia’s subterranean speciation explosion. Finally, we predict that the geologically younger, although more poorly studied, eastern half of the Australian continent is unlikely to be as diverse as the western half, except for stygofauna in porous media. Furthermore, based on similar geology, palaeogeography and tectonic history to that seen in the western parts of Australia, southern Africa, parts of South America and India may also yield similar subterranean biodiversity to that described here.Michelle T. Guzik, Andrew D. Austin, Steven J. B. Cooper, Mark S. Harvey, William F. Humphreys, Tessa Bradford, Stefan M. Eberhard, Rachael A. King, Remko Leys, Kate A. Muirhead and Moya Tomlinso