Overview

• Local authorities briefly banned swimming at several spots after Glaucus atlanticus was reported along coasts including Alicante and Valencia.
• Sightings included four specimens in Guardamar del Segura, five or six at a La Línea de la Concepción beach, one in Valencia, and additional reports from Lanzarote and Mallorca, where none had been recorded since 1916.
• Municipal advisories urge beachgoers not to touch the animal, to notify lifeguards if one is seen, and to rinse stings with salt water before seeking medical care if needed.
• The nudibranch, which floats belly-up and reaches about 4 centimeters, feeds on Portuguese man o’ war and retains its stinging cells, and warmer seas are linked to its growing Mediterranean presence.
• University of Cádiz biologist Juan Lucas Cervera says the irritation is generally mild and calls some beach closures an excessive response.