Pallas’ spadefoot <i>Pelobates vespertinus</i> (Pelobatidae, Amphibia) tolerates extreme hypoxia

Amphibians are believed to be sensitive hypoxia, and in terms of this ability, they between mammals with poor toleranсе hypoxia some turtles fish good tolerance variable oxygen availability. However, we found that the Pallas’ spadefoot, Pelobates vespertinus (Pallas, 1771), a Eurasian anuran burrowing amphibian species, is capable surviving harsh during wintering. This species can tolerate over long-term vital concentration almost 10 times lower than normal atmospheric air (about 2%). The lethal was about 1% (from 0.6 1.8% for different individuals), i.e. 20 concentration. spadefoots overwinters soils more half year, having small sizes storage organs (fat bodies liver) low content lipids glycogen them, which consumed at rate normoxia 3°С. Under hypoxic conditions, lipid consumption stops, increases, indicating shift from aerobic anaerobic metabolism. cumulative effect reduced metabolic due wintering temperatures activation glycolysis allows Pallas’s spadefoot considered as one most hypoxia-resistant studied.