Hvs. Peeke et al., PRIOR RESIDENCE EFFECTS IN SHELTER DEFENSE IN ADULT SIGNAL CRAYFISH (PACIFASTACUS-LENIUSCULUS (DANA)) - RESULTS IN SAME-SEX AND MIXED-SEX DYADS, Crustaceana, 68, 1995, pp. 873-881
In a variety of taxa, the initial resident in a spatial area enjoys a
dominance advantage over a subsequent intruder. In decapod crustaceans
this ''prior residence effect'' has been demonstrated in lobsters, pr
awns, and crabs. However, there is scant evidence for the effect in cr
ayfish. In the present series of experiments, individual signal crayfi
sh (Pacifastacus leniusculus) were introduced into one side of divided
aquaria, which contained a shelter. Another crayfish was put into the
opposite side. Twenty-four hours later the divider was removed. In sa
me-sex encounters 76% of female residents retained shelter possession,
as did approximately 70% of male residents, both sexes demonstrating
a significant territorial prior residence effect. In mixed-sex encount
ers, female residents retained shelter possession against male intrude
rs in 80% of them. However, male residents retained shelter occupancy
in only 33% of the encounters with female intruders. These findings de
monstrate the existence of a prior resident effect in P. leniusculus.
The contest advantage of females over males is consistent with previou
s research showing female dominance over males in social dominance hie
rarchies in this species.