Long before humans developed sailing boats, a kind of smaller, colonial organisms had already evolved their own biological version of ocean sailing. Instead of canvas sails, the Portuguese Man ‘o’ War (PMW) Physalia physalis use a gas-filled vesicle (the pneumatophore) to propel their colonies across the tropical and subtropical oceans of the world. In contrast to human sailors, the PMW drift passively, steered by the prevailing weather in an apparently unplanned trajectory. They may end up on the beaches of subtropical and temperate coasts, where their mere presence triggers closures due to their powerful sting, negatively impacting beach tourism economies. A combination of climatic drivers has been invoked to explain episodes of massive PMW arrivals on the coast, such as the unprecedented, summer 2023 episode in the northern coasts of Spain. However, the mechanisms that determine the seasonality, spatial distribution, and magnitude of coastal arrivals remain largely unknown both for PMW and other neustonic species.
Un proyecto para entender el origen evolutivo de la navegación en las Carabelas Portuguesas
