Utilization of zebrafish for intravital study of eukaryotic pathogen–host interactions

•Eukaryotic pathogens are of global importance and we need better treatment options.•Transparency and molecular tools highlight unique value of larval zebrafish model.•Comparative immunology may reveal conserved mechanisms of host–pathogen dynamics.•New zebrafish models of fungal infection have been recently developed and exploited.•Yet-unrealized potential in study of eukaryotic human and fish pathogens in zebrafish. Unique imaging tools and practical advantages have made zebrafish a popular model to investigate in vivo host–pathogen interactions. These studies have uncovered details of the mechanisms involved in several human infections. Until recently, studies using this versatile host were limited to viral and prokaryotic pathogens. Eukaryotic pathogens are a diverse group with a major impact on the human and fish populations. The relationships of eukaryote pathogens with their hosts are complex and many aspects remain obscure. The small and transparent zebrafish, with its conserved immune system and amenability to genetic manipulation, make it an exciting model for quantitative study of the core strategies of eukaryotic pathogens and their hosts. The only thing to do now is realize its potential for advancement of biomedical and aquaculture research.