UC San Diego

The study of predator effects is typically focused on the finalistic aspect of such interactions. Although direct predation is undoubtedly important, there is a far less studied realm that is equally, if not, more important than the direct effects of predation. Here we examine the indirect growth effects of predator and prey interactions by using predator stimuli experimentation. Juvenile rockfishes of the genus Sebastes were introduced to predation stimuli and within generation effects on growth were measured. Multiple experiments were run while manipulating visual chemical stimuli. It was discovered that the existence of predation stimuli resulted in a consistent negative growth effect on both body length and height in juvenile rockfish. Although sub-lethal predator effects significantly stunted growth in both mean body length and height, weight was not affected. It has been seen that juvenile survivorship can differentiate based on size relationships, and therefore stunted growth of juvenile fish by predation presence may lead to changes in survivorship. This study also reinforces the theory that energy allocation and metabolism may play a key role in the way that fish are affected by predation