SCIENCE IN THE NEWS DAILY
Do Fish Have Personalities?
from the Scientist (Registration Required)
... Though it sounds like an almost heretical term to use for fish, "personality," [researchers say] is nothing more than consistent, individual differences in behavior. And in any species--even surprising ones such as squid, birds, and insects--one can find such variability in spades. Meaning that, even if their environment is the same, one individual will consistently act differently from another.
Classic traits include shyness or boldness in response to threats such as the presence of a predator, and aggression to conspecifics, but there's also how actively an individual explores a new environment--curiosity, one might say--or how sociable it is, or its general level of activity. While these are the traits most widely studied so far, [researchers] say they're probably just a start.
In some cases, personality traits might be heritable, while in others they might develop as a learned response to differences in conditions of an organism's life--the kind of parental care it receives, for example, ... or an influx of predators into its habitat.