Embryonic development of mulloway, Argyrosomus japonicus, and egg surface disinfection using ozone

The embryonic development of mulloway, Argyrosomus japonicus, was described. Ozone disinfection procedures were investigated using the combined effects of ozone CT (concentration of ozone [mg l−1] multiplied by contact time [min]; 0, 0.1, 0.5, 1 or 5) and treatment temperature (19, 22 or 25 °C), as well as the effect of ozone exposure (CT = 1) when applied at four different stages of embryonic development (3, 8, 20 or 27 h post fertilisation; HPF) on the hatching success of mulloway larvae. Significantly fewer eggs hatched when treated with a CT of 5 compared with those treated with a CT of 0, 0.1, 0.5 or 1, particularly when eggs were maintained in water of 19 °C. There were no apparent negative impacts of treating eggs at 22 or 25 °C and the highest CT value that did not negatively affect hatching was a CT of 1; therefore, it is recommended that eggs should be ozone treated with a CT of 1 at 22 °C. There were no significant effects of ozone treatment (CT = 1) on hatchability of eggs when applied at any of the development stages examined.