Feeding trialsFor each fish species, 10 replicate tanks were used for the exper-iments and each tank housed 10 individuals. Seeds embedded indough pellets were fed to the fish. The number of seeds used pertrial depended on seed dimensions and ranged from 50 to 100.Within 1 h after feeding, non-ingested seeds were removed fromthe tanks. After a period of 26 h, egested seeds were retrieved,counted and stored in vials filled with tap water in darkness at5◦C until the beginning of the germination experiment. Thus, afterfish gut passage, retrieved seeds of aquatic and riparian speciesreceived the same treatment. In addition, three batches of controlseeds (n = 3 × 50 = 150) of each plant species were treated in thesame way as those used in the 10 replicate feeding trials, exceptthat they were put into a tank without fish for 24 h.