Sublethal and antioxidant effects of six ichthyotoxic algae on early-life stages of the Japanese pearl oyster

•The effects of exposure to six icthyotoxic algae on pearl oyster early-life stages were assessed.•Eggs, fertilization, embryos and larvae were differentially affected by the HAB.•H. circularisquama, H. akashiwo, Karenia spp., and M. polykrikoides affected eggs, fertilization and embryos.•Larval growth-specific effects of all HAB are reported, with increased GST activity but not SOD.•Cytotoxicty and detoxification could be associated with the effects.