The TREPAQUAMED project is focused on the study of the trasnsmission and life cycles of those trematodes (Platyhelminthes) related with pathologies in Mediterranean fish cultures. We also will study how their life cycles are modified by the seasonality and environmental changes. The cycle of these parasites is very sensitive to external variables, which, joined to the high Mediterranean environmental variability, makes them ideal models for studying the possible impact of global change on the transmission of parasites.