Invertebrates, including shrimps, rely on their innate immunity to fight against pathogens. Innate immunity lacks the ability to show high degree of specificity and long-lasting memory. However, few reports claimed that invertebrates show some form of immunological specificity and memory similar to that of adaptive immunity in vertebrates. Using the gnotobiotic brine shrimp Artemia as model organism, this project aims to unambiguously prove the possibility or impossibility of immune priming, examining the presence or absence of specific and enduring memory against homologous and heterologous antigens.