Spawning migrations of the chub in the River Spree, Germany

Out of 52 chub Leuciscus cephalus tagged with internal radio-transmitters, 46 migrated to spawning grounds in the River Spree, Germany. All chub started their first spawning migration on 21-22 May in both years of study, 1995 and 1996. They arrived at three different spawning grounds within a day and left after 1 to 6 days to return to their original sites. On 17 and 18 June 1995 and 1996 chub started their second spawning migration with the same pattern as the first. About 60% of all migrating chub moved between 1 and 13 km upstream to the nearest spawning ground. Some exceptions were observed: a few chub did not use the nearest spawning ground, some chub used different spawning grounds at first and second spawning or moved downstream to a spawning ground. Spawning grounds were characterized by 0.4 m s(-1) current velocity, shallow depth (0.1-0.8 m) and a stony bottom, where most eggs adhered. (C) 2003 The Fisheries Society of the British Isles.