Polychlorinated biphenyls (PCBs) have been monitored in perch (Perca fluviatilis), pike (Esox lucius), and Arctic char (Salvelinus alpinus) in reference lakes since the late 1960s. Temporal trends and spatial patterns are currently monitored in nine and 32 lakes, respectively. Overall, PCB concentrations are decreasing. However, this is not consistent for all congeners across all lakes and spec...

Piscivory in cyprinids (Cyprinidae) is extremely rare. Specifically, common bream (Abramis brama) and common carp (Cyprinus carpio) are zooplanktivorous fish in deep lentic waters. Nevertheless, we observed predation by these two cyprinids under natural conditions in the Vír Reservoir, Czech Republic. We conducted diet analysis for cyprinids caught by trawling and gillnets and the large amount ...

During high summer seasons in 1994-1999 84 big (20-42 cm total length) female perch (Perca fluviatilis L) were sampled from the waters around Tvärminne Zoological Station on the Hanko-Hangö peninsula on the SW coast of Finland for mercury analysis. Additional sampling of 13 big female perch during the same season were carried out from the waters of Nåtö Biological Station on the Aland Islands i...

The selection of spawning depth by Eurasian perch Perca fluviatilis was investigated in an experiment using artificial substrata in Lake Constance during the spawning season of 2007. The experiment compared spawning behaviour at substrata between 0.5 and 15 m depth at two sites exposed to different regimes of ship-generated wave action. The total abundance of egg ribbons did not differ signific...

Rapporttyp Report category Licentiatavhandling x Examensarbete C-uppsats D-uppsats Övrig rapport _______________ Språk Language Svenska/Swedish x Engelska/English ________________ Titel Title Selective predation by perch (Perca fluviatilis) on a freshwater isopod, in two macrophyte substrates Författare Author Magnus Andersson Sammanfattning Abstract Recent studies show that populations of the ...

In freshwater environments, chemosensory cues play an important role in predator-prey interactions. Prey use a variety of chemosensory cues to detect and avoid predators. However, whether predators use the chemical cues released by disturbed or stressed prey has received less attention. Here we tested the hypothesis that the disturbance cue cortisol, in conjunction with visual cues of prey, ele...

The negative impact of anthropogenic noise on marine animals is receiving increasing attention. In order to study the effect of motorboat noise on foraging behaviour in fish, we chose 2 species with different hearing abilities. The roach Rutilus rutilus has a better developed sense of hearing than the Eurasian perch Perca fluviatilis. The study took place in an inlet of the Bothnian Sea where b...