Behavioural syndromes, inducible defences and metabolic rate in snails
Such individual differences in personality should affect predator encounter rate with bold individuals being more vulnerable to predation. However, bold animals may compensate for the increased predation risk by showing a higher expression of inducible defence traits. Further, it is predicted that there are strong linkages between personality and metabolism, as the larger machinery required to support a bold, fast lifestyle should generate a higher metabolic rate.
In laboratory experiments we are studying how exposure to predator threat (chemical cues from predatory fish) affect the expression of morphological (shell shape) and behavioural (movement rates, habitat choice) anti-predator traits among individuals of the freshwater snail Radix balthica that differ in personality along the bold/shy continuum. In addition, we relate personality type and activity pattern to metabolic rate.
In earlier work we have shown that the snail (Radix balthica) show phenotypic plasticity in both morphology (shell shape) and avoidance behaviour in response to predator cues. Snails exposed to predator cues are less active and have a more rotund shell shape, which increase resistance to shell-crushing predators.
Heart rate monitoring
We study how personality traits in freshwater snails are related to metabolic rate. Here, we use changes in heart rate as a measure of metabolism using a non-invasive technique where an infrared light emitter and detector is fixed onto the snail shell.
The heartbeat causes a change the reflection of the IR light and the detected signals can be recorded after amplification.