Abstract:
This thesis examines how dominance status of crayfish alters responses to their own
reflection. Crayfish are social animals that fight to develop a dominance hierarchy
consisting of dominant and subordinate members. After socialization, crayfish were
videotaped in an aquarium with mirrors on one half of the tank and a non-reflective
plastic on the other half. Dominants paired for 14 days perform more cornering, turning,
crossing and spent more time in a reflective environment versus a non-reflective
environment. Subordinate crayfish exhibit more reverse walking in a mirrored
environment while isolated crayfish show no preference for reflection. This change in
behaviour occurs immediately for dominants paired for 30 min while subordinates require
3 days of pairing to exhibit the same behaviour as subordinate crayfish paired for 14 days.
Thus, 30 min of pairing is required to enhance responses to a reflection observed in
dominant crayfish while 3 days is required to decrease subordinate responses to a
reflection. These findings propose that male socialized crayfish respond to their mirror
image as they do a male conspecific. Their responses depend on both their dominance
status and the length of socialization which suggests that crayfish are learning to behave
in a characteristic manner as a result of their social experience.
