Annual movement and migration of adult pikeperch in a lowland river

The downstream migration of 46-66 cm radio-tagged adult pikeperch Stizostedion lucioperca in the River Gudenaa, Denmark, from late September to late December, coincided with a reduction in the frequent occurrence of prey fish in the tagging area, and hence was interpreted as a feeding migration. The upstream migration from March to mid-April in spring took place prior to spawning which occurred from late April to June. (C) 2000 The Fisheries Society of the British Isles.