Salinity and oxygen tolerances of eggs and larvae of Hawaiian striped mullet (Mugilcephalus L.) were studied. Optimal salinities for eggs incubated at 19.5-20.5" C were 30-32%,.Maximum larval survival occurred within the salinity range of 26-28%,. Significant decreases in egg survival occurred with eggs incubated in mean oxygen concentrations below 5.0 p.p.m. and for larvae held in mean oxygen concentrations below 5.4 p . p n The results are discussed in terms of spawning sites and the effects of oxygen saturation values on fish eggs and larvae.