For the first time, radio‐tracking observations were made over 24 h cycles during the growing season to quantify the habitat use and home range of Zingel asper , a critically endangered fish species, endemic to the Rhône River with a high risk of extinction (IUCN). New advances in radio telemetry with regard to the size of tags provided an opportunity to collect behavioural and habitat use information while remaining non‐letha...

Annual monitoring of the apron Zingel asper in the Durance River, a tributary of the Rhône in which the fish is endemic, indicated its narrow diet range. Three types of prey made up the basic diet: Diptera (Simulidae and Chironomidae), mainly in winter, and Ephemeroptera (Baetidae) and Trichoptera (Hydropsychidae), during the rest of the year. Although some potential prey (Coleoptera and Gammaridae) were present in the substra...

The growth of Arctic charr Sahelinus alpinus in five high altitude lakes differed between lakes during the first 2 years but was similar thereafter. The average temperature during the summer had a direct effect on growth and an indirect effect on the productivity level of the lakes, particularly on the abundance of planktonic crustaceans. The results highlight the importance of planktonic crustacea in the growth of Arctic char...

Plan Vianney lake, situated in the Oisans massif (French Alps) at an altitude of 2250 m, has a fish fauna composed of brook trout, Salvelinus fontinalis (Mitchell), and Artic charr, Salvelinus alpinus (L.). The present study examines the feeding behaviour of S. fontinalis in 1993–94 but also gives some data on S. alpinus . The brook trout represented 80% of the fish fauna of the lake. Dietary analysis showed that this species...