Spain holiday warning: Brit holidaymakers warned as beaches close in holiday hotspot over poisonous blue dragon sea slugs

Several blue dragon sea slugs, known as Glaucus Atlanticus, have been found along the Costa Blanca. The tiny blue creatures can deliver a potentially-fatal sting.

It feeds on the venomous cells of other creatures and stores the venom which it releases when it attacks its prey. The sting can cause sickness, pain and for those with several allergies, potentially fatal reactions.

They are usually found in the Atlantic Ocean and have previously been spotted at beaches in the Canary Islands, but now these dangerous creatures have been sighted more frequently in the Mediterranean. The most recent sighting was in Guardamar del Segura, a province of Alicante.

Last week the mayor reported sightings of the slugs, resulting in a red flag being raised at beaches in the area. This warning was later downgraded to yellow, but has since been raised to red after more of the creatures were spotted.

He said: “We continue to receive Blue Dragons on the Beaches of Guardamar, with increasing frequency and number. RED FLAG and take great care when walking along the shore BATHING PROHIBITED follow the instructions of local police.”

The creatures have now spread to Lanzarote, having been spotted on La Cantería beach in Órzola. As a result, the beach on the north coast of the island has been temporarily closed.

Authorities warn that if the public spot any of the molluscs they should notify lifeguards or emergency services on 112 (the emergency number in Spain and the Canary Islands). Tourists should not to touch these creatures under any circumstances, whether in the water or stranded on the shore.

If stung, those affected should carefully remove tentacle fragments with a stick or gloves before rinsing the affected area with seawater, as fresh water, vinegar, or alcohol, can worsen the sting. They should then apply a cold pack to reduce pain and swelling and seek medical attention immediately.