Effect of temperature on the predation rate of the pearl cichlid (Geophagus brasiliensis) on the channeled applesnail (Pomacea canaliculata)

Abstract

An experiment was conducted to evaluate the effect of temperature on the intensity of predation upon snails. The experiment was run for 60 days using 15 cement tanks with water temperatures of 18, 22, 26, 30 and 34°C in a completely randomized design with three replications. The pearl cichlids (n = 4 per tank) were distributed in tanks with heaters, which increased the water temperature by 1°C h -1 , in a room held at 17°C. The snails were selected (up to 3 mm) and distributed among the tanks (n = 32 per tank). The period of exposure to predation was 18 h, and the index of predation was significantly lower at 18°C. Temperatures between 26 and 34 did not result in significant differences in predation. It was conclude that the pearl cichlids prey efficiently on snails at temperatures of 26°C and above.