EXPERIMENTAL TREATMENT WITH INCREASED TEM PERATURE OF JUVENILE COHO SALMON WITH EIBS

Experimental treatment by increasing temperature from 10-degrees-C to 16-degrees-C was carried out on juvenile coho salmon (Oncorhynchus kis utch) naturally infected with erythrocytic inclusion body syndrome (EI BS). Cumulative mortality of control fish kept at 10-degrees-C through out the experimental period of 40 days was 57%. In contrast, that of e xperimental fish kept at 16-degrees-C for the first 23 days and then a t 10-degrees-C for 17 days was 10%. The longer the period at which the fish were kept at the higher temperature (16-degrees-C), the lower th e mortality. Experimental challenge with EIBS to the survivors of the temperature-increasing treatment revealed an increase in the resistanc e to reinfection of EIBS.