Although zearalenone (ZEN, a mycotoxin known for endocrine-disrupting action) has been found in different fish feeds, there has been no systematic research to conclusively demonstrate what concentration of ZEN may be considered safe for the welfare and reproductive outcome of economically relevant fish species. The virtual lack of data, especially on the long-term effects of low dose exposure of fish to mycotoxins, leaves a serious gap in our knowledge concerning possible threats to aquaculture. In order to gain insight into the molecular mechanisms underlying the physiological consequences of challenging economically important fish with this mycotoxin, the project aims at high-throughput sequencing of the whole maternal and embryonic transcriptome of rainbow trout eggs after life-cycle parental exposure to ZEN. This knowledge could benefit not only aquaculture, but also provide further information of fundamental biological importance, such as clues to embryo development in fish.