Some observations of spawning by roach,Rutilus rutilusL., and bream,Abramis bramaL., and their implications for management

摘要

Abstract.The spawning behaviour of roach,Rutilus rutilusL., and the spawning of roach with bream,Abramis brama L., is described with details of the nature of the spawning ground used at two sites in mid‐west Britain. Roach appear to use traditional spawning grounds annually. Some female roach probably die as a result of damage inflicted by males during spawning. A simple exponential model is used to describe the relationship between temperature and the incubation period of roach egg