The idea that phenotypic traits are heritable remains under debate. On exposed (a daily non-lethal heat shock) parental populations and three subsequent unexposed generations using parthenogenetic Artemia (originating from one single female), increased tolerance towards lethal heat stress, was observed (including common garden experiments where the animals from F1, F2 and F3 generations were tested at the same time). This transgenerational inheritance of the acquired traits was associated with altered levels of global DNA methylation and acetylated histones (H3, H4) and increased level of HSP70 production in the heat-shocked group compared to the control group. Upon immune challenge of the same population of Artemia by exposing the population at early life stages to Vibrio campbellii, it was demonstrated that immune-challenged Artemia by this specific bacterium bestow their next unexposed generation progenies with increased resistance against a challenge with the same Vibrio. Finally, we verified the possibility or impossibility of trained immunity using a wild population of bisexual A. franciscana, examining the presence or absence of enduring memory against homologous and heterologous antigens (Vibrio spp.). Our results showed the occurrence of memory and partial discrimination in Artemia's immune system, as manifested by increased resistance, for three successive generations, of the progenies of Vibrio-exposed ancestors towards a homologous bacterial strain, rather than to a heterologous strain. Our results also showed stochastic pattern in the acetylation levels of H4 and trimethylation levels of H3K4 histones in the progenies whose ancestors were challenged. A transgenerational increase in the mRNA levels of hsp70, hmgb1 and pxn was also observed. Additionally, immune challenge of the parental generation resulted in a shift from ovoviviparous to oviparous mode of reproduction. From these results it can be suggested that immune responses in invertebrates can be trained, and epigenetic reprogramming of (selected) immune effectors is likely to have a central place in the mechanisms leading to trained immunity.