The Spawning of Roach Rutilus rutilus (L.) in a Chalk Stream

Roach spawned on two sites where Fontinalis antipyretica (Hedw.) grew thickly on vertical pilings. The eggs were distributed throughout the fronds of Fontinalis but were concentrated near the water surface. The fish spawned on those parts of the sites where the current adjacent to the weed was relatively fast. The sudden drop in water levels caused by weed cutting presents a potential threat to spawning success.