Chemical cues in the interaction of herbivory-prey induce consumer-specific morphological and chemical defenses in Phaeocystis globosa

•Rotifer kairomones inhibited the colony development of P. globosa.•Rotifer kairomones increased hemolytic toxin synthesis in the P. globosa, which is detrimental to the development of fish embryos.•The conspecific-grazed cues (alarm cues) stimulated the P. globosa to produce rotifer-specific toxins.•Toxicity differences may be related to the upregulation of lipid metabolism pathways and the increased content of lipid metabolites.