PREDATOR-INDUCED RESPIRATORY RESPONSES IN JUVENILES OF VENDACE COREGONUS-ALBULA, WHITEFISH C-LAVERTUS, PERCH PERCA-FLUVIATILIS AND ROACH RUTILUS-RUTILUS

Predator-induced respiratory responses of juvenile vendace, whitefish, perch and roach were studied in an intermittent-flow respirometer by creating visual contact between test fishes and predators (juvenile no rthern pike). Vendace and whitefish always responded to the presence o f pike with increased oxygen consumption. The response of perch was th e opposite: oxygen consumption decreased to near the standard respirat ory level. Roach responded more variably: some individuals increased t heir oxygen uptake while others decreased it. Changes in the rate of r espiration during exposure to predation are supposed to be caused by t he differences in locomotory activity due to induced antipredator beha viour. According to their responses, these species could be grouped in to escapers (coregonids), hiders (perch) or indeterminates (roach). Th e species-specific differences in the antipredator behaviour originate in morphological and physiological characteristics which together det ermine the effectiveness of a particular antipredator style (i.e. eith er hiding or escaping).