Environmental drivers of

Background: Methods: Ninety-six polyps were cultured for 71 days in well plates at four temperature treatments (14, 17, 20, 23 °C) and four salinity levels (10, 17.5, 25, 35). Survival, asexual reproduction, and strobilation were monitored. Seven years of citizen science data were analysed with environmental parameters to assess estuarine distribution. Results: Polyp survival was high, except at salinity 35, where mortality increased regardless of temperature. Podocyst production was enhanced at higher temperatures (20-23 °C) and intermediate salinities (17.5-25), although podocyst development into new polyps occurred at lower salinities (10-17.5). Strobilation occurred predominantly at intermediate temperatures (17-20 °C) and salinities (17.5-25). Medusae are most frequently found in the lower Tagus estuary and coastal adjacent areas, exhibiting a peak between July and January. Results showed that wind intensity was negatively correlated with medusa stranding abundances on the shores, possibly displacing individuals away from coastal areas during periods of strong winds. Sea surface temperature (SST), measured two to four months prior to medusae occurrence, was positively correlated with Discussion: Optimal polyp performance occurred at 17-20 °C and 17.5-25 salinity. When considered alongside citizen science observations, these findings suggest that polyps may occur in estuarine areas where such conditions prevail, such as upper estuary inlets and marinas. It is further hypothesized that ephyrae could disperse to downstream and adjacent coastal zones