Predator avoidance strategies in early life stages of percid fishes

Project No. 206/09/P266

Applicant: RNDr. Martin Čech, PhD.

Financial support: Czech Science Foundation

Duration: 2009-2011

The project is focused on predator avoidance strategies of early life stages of percid fishes – European perch Perca fluviatilis L., zander Sander lucioperca (L.), ruffe Gymnocephalus cernuus (L.) - in stratified canyon-shaped reservoir, non-stratified shallow reservoir and opencast mine lake. It follows up the recent finding that percid fry are able to create sympatric ecological groups with different behaviour (Čech et al. 2005). This is supposed to be an excellent strategy of the species to avoid predation pressure, which would be of different level in different main habitats and in different water bodies. A special attention will be paid to the newly discovered community of bathypelagic percid fry in stratified canyon-shaped reservoir (Čech et al. 2005, Čech & Kubečka 2006, Čech et al. 2007a, b, Kratochvíl et al. 2008), which most probably changes to bottom-dwelling community in case of non-stratified shallow reservoir and to dense deep water vegetation-dwelling community in opencast mine lake. The effectiveness of individual strategies will be evaluated using various new approaches including scientific sonars (SIMRAD), acoustic (DIDSON) and underwater camera for monitoring of behaviour of both prey and predator and SCUBA divers for quantitative fry sampling in dense vegetation.