Attack preferences of the red-bellied piranha (Serrasalmus nattereri)

Single small piranha (Serrasalmus nattereri) were exposed once per day for 30 consecutive days to a single comet goldfish (Carassius auratus) as large or larger than the piranha. The area of the goldfish's body first attacked and time to first attack were recorded. In 87·9 per cent of the trials, first attack was in the tail area. Pre-experimental observations were reported of attacks upon the eyes of goldfish. Attacks upon the tail and eyes of living goldfish are viewed as general mechanisms of survival and adaptation of piranha in increasing the vulnerability and reducing the mobility of its prey.