The Mediterranean Sea, although a biodiversity hotspot, is one of the most affected seas by non-indigenous species (NIS). This problem is worsened by rising sea temperatures due to climate change, which promotes the spread of thermophilic species. Among the NIS scyphozoan jellyfish species recorded in the Mediterranean, Cassiopea andromeda – commonly known as the “upside-down jellyfish”– is a notable example. Observadores del...