Response of captive seabass and seabream as behavioural indicator in aquaculture

Welfare of cultivate fish at high-density represents an important concern for modern aquaculture.
The behaviour of European seabass (Dicentrarchus labrax) and seabream (Sparus aurata) reared in cages was studied
in a fish farm of northern Sardinia (Italy) in autumn 2006 to test whether captive condition had an effect on
the movement patterns of these two species.Video images recorded before, during and after the manual feeding distribution
allowed us to collect data on different behaviours of captive fish. Thus, behaviours indicating the position
of fish in the water column, swimming direction and possible aggressive behaviours (aggression, direction change
and collision) showed juveniles and adults of seabass and seabream were overall affected by feeding rhythms and
captive overcrowding. Seabream had a major tendency to swim towards the bottom and higher frequency of horizontal
swimming and collisions than seabass. The overall behavioural difference between two species was explained
in terms of their differences in ecological features in the wild.