Influence of dissolved oxygen concentration on the mortality of yellowtail experimentally infected with Enterococcus seriolicida

Abstract

Prior to the challenge with Enterococcus seriolicida, 50 yellowtail Seriola quinqueradiata were reared with the high dissolved oxygen (HDO), and another fifty with the low dissolved oxygen (LDO), for 10 days. After the fish were exposed to the pathogen, each group was separated into 2 subgroups and each subgroup was kept either in LDO or in HDO water. Low DO level during the pre-infection period shortened the length of the incubation period, and the low DO level during post-infection period increased the cumulative mortality of the disease.