Eco-ethological aspects of two natural hybrids involving Abramis brama (L.), of the River Meuse basin (Belgium) and implications in ecosystem management.

Eco-ethology as expressed in migration patterns, hybridisation level, growth rates in river conditions, and reproductive behaviour in a controlled environment were investigated in natural common bream Abramis brama × roach Rutilus rutilus and common bream × silver bream Blicca bjoerkna hybrids. From 2001 to 2003, hybrids and parental species were captured in a fish pass trap at the Lixhe dam on the Belgian Meuse River during their reproductive migration. The fish pass was checked 3 days a week and the water temperature was recorded hourly. The results showed that these hybrids were less freque... Mehr ...