title: Conquest of the deep, old and cold: an exceptional limpet radiation in Lake Baikal.
abstract: Lake Baikal is the deepest, oldest and most speciose ancient lake in the world. The lake is characterized by high levels of molluscan species richness and endemicity, including the limpet family Acroloxidae with 25 endemic species. Members of this group generally inhabit the littoral zone, but have been recently found in the abyssal zone at hydrothermal vents and oil-seeps. Here, we use mitochondrial and nuclear data to provide a first molecular phylogeny of the Lake Baikal limpet radiation, and to date the beginning of intra-lacustrine diversification. Divergence time estimates suggest a considerably younger age for the species flock compared with lake age estimates, and the beginning of extensive diversification is possibly related to rapid deepening and cooling during rifting. Phylogenetic relationships and divergence time estimates do not clearly indicate when exactly the abyssal was colonized but suggest a timeframe coincident with the formation of the abyssal in the northern basin (Middle to Late Pleistocene).
authors.affiliation: Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany Bjoern.Stelbrink@allzool.bio.uni-giessen.de.
authors.forename: Björn
authors.initials: B
authors.lastname: Stelbrink
authors.affiliation: Limnological Institute, Siberian Branch Russian Academy of Sciences, Ulan-Batorskaya Strasse, 3, PO Box 4199, 664033 Irkutsk, Russia.
authors.forename: Alena A
authors.initials: AA
authors.lastname: Shirokaya
authors.affiliation: Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
authors.forename: Catharina
authors.initials: C
authors.lastname: Clewing
authors.affiliation: Limnological Institute, Siberian Branch Russian Academy of Sciences, Ulan-Batorskaya Strasse, 3, PO Box 4199, 664033 Irkutsk, Russia.
authors.forename: Tatiana Y
authors.initials: TY
authors.lastname: Sitnikova
authors.affiliation: Institute of Biology and Soil Science, Far Eastern Branch Russian Academy of Sciences, 159 Pr. 100 let Vladivostoku, 690022 Vladivostok, Russia.
authors.forename: Larisa A
authors.initials: LA
authors.lastname: Prozorova
authors.affiliation: Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Albrecht
mesh_terms: D000818:Animals; D005075:Biological Evolution; D005580:Fossils; D049851:Gastropoda / Q000145:classification / Q000235:genetics*; D060086:Hydrothermal Vents; D060106:Lakes; D010802:Phylogeny; D017423:Sequence Analysis, RNA; D012800:Siberia
keywords: abyssal; molecular clock; phylogenetic analysis; pulmonate snails; species flock