The bacterial bath challenge was carried out after the sampling
and the biometric measurements. Twenty fish from each tank of the
RAS-C and RAS-O3 (i.e., 60 fish from each RAS) were lightly anes-
thetized after 24 h of starvation. Each of the four baths received 30
tagged fish for 1 h. After the challenge, the fish (both ozone-treated
and control) were placed in their respective RAS, as shown in Fig. 1.
Mortalities in the fish tanks were recorded over the following week.