This chapter presents a variety of field observations and ecophysiological laboratory studies that show how invertebrates and fishes deal with cyanobacteria as a potential food source. It demonstrates the importance of gut microbiota and epigenetic pathways in dealing with cyanotoxin exposure. However, our understanding of the latter pathways is still in its infancy. The chapter concludes with a consideration of whether cyanobacteria can be used as aquafeed in the longer term, mediated by epigenetic techniques and artificial intelligence. Mechanisms of toxicity and, in particular, tolerance are discussed in detail elsewhere (Steinberg CEW, Lieke T, Ecology of phycotoxins. Springer Nature, Cham, forthcoming). Aquaculture can benefit from detailed knowledge of tolerance mechanisms. In this chapter, an alternative hypothesis is discussed.