“…The period when juvenile crayfish begin an independent existence after leaving their mothers is the most dangerous in their life. Their relatively small size causes them to be exposed to many different potential predators, such as fish, insects and their larvae, bugs and amphibians (Gydemo, Westin & Nissling, ; Hager, ; Jonsson, ; Munkhammar, Gydemo, Westin & Ackefors, ; Ulikowski, Piotrowska, Chybowski & Traczuk, ). One of the most common and aggressive predators are insects of the genus Notonecta, and they are also very prone to cannibalism (Papáček, ).…”