After the appearance of several specimens of Portuguese man o' war on some beaches of Formentera as well as in coves in the west of Ibiza, another type of jellyfish has invaded some beaches and coastal areas of the Bay of Sant Antoni. Hundreds of sailboat jellyfish, scientifically known as Velella velella, have dyed this Sunday of blue the beach of s'Arenal and other rocky areas of the Bay after strong gusts of wind and waves marked Saturday. As National Geographic explains, these hydrozoans (organisms that share some characteristics with jellyfish but belong to a different group) are part of the pleuston community, which means they live at the interface of water and air. This implies that Velella velella are particularly vulnerable to changes in wind and currents, often resulting in their mass stranding on beaches. Despite their appearance and stinging ability, velero are completely harmless to humans. However, it is recommended to avoid direct contact if you have open wounds, as this may cause a mild allergic reaction. These hydrozoans are known to be invasive in algae-rich areas, where they can feed on available plankton.