‘Blue dragons’ with painful, venomous sting continue to wash up on Cape beaches

Blue dragons (glaucus atlanticus) are still being spotted on Cape beaches, including recent sightings at Pringle Bay in the Overstrand.

The striking little creatures, also known as blue sea slugs, usually occur alongside washed-up bluebottles, and also pack a painful sting.

Beachgoers have been urged to keep their distance from the blue dragons, and not to handle or harm them.

A series of sightings

Several blue dragons were reported washed up on Muizenberg beach in January this year, prompting warnings from ocean scientists.

At the time, Heather Wares, communications manager at the Two Oceans Aquarium, described the sightings as rare, but not unprecedented.

“The blue dragon slugs seen washed up on Cape Town’s beaches are an unusual sight,” Wares said.

“This stranding event is an uncommon occurrence but is known to happen globally from time to time, often together with bluebottles.”

After the Muizenberg sightings, Cape Town deputy mayor Eddie Andrews warned that shores to the east of Cape Town could experience similar strandings.

“Given the current oceanographic and climatic conditions, it’s highly likely,” Andrews noted.

Andrews confirmed that City teams had also identified several blue dragons and numerous bluebottles during an inspection at Muizenberg in late January.

He also explained that the occurrence of blue dragons can be driven by warmer summer water temperatures and prevailing south-easterly winds.

More recently (7 November 2026), the dazzling little creatures were photographed by a beachgoer in Pringle Bay, on a beach roughly 80kms east of Muizenberg.

This adds another location to a series of blue dragon sightings reported along the Western Cape coastline this year.

How venomous are blue dragons?

Despite rarely exceeding 3cm in length, glaucus atlanticus delivers a surprisingly powerful sting.

These colourful nudibranchs usually live in the pelagic zone (open ocean). They float upside down at the sea’s surface, drifting wherever winds and currents take them.

They feed on venomous creatures, including the Portuguese man-o’-war, known in South Africa as bluebottles.

Blue dragons then ‘steal’ and store the stinging cells of their prey in specialised structures on their bodies. This allows them to deliver a painful sting, even after they have died.

Because it concentrates these stinging cells, a sting from a blue sea slug can be more potent and painful than a sting from a bluebottle.

This remarkable adaptation makes blue dragons deceptively dangerous, despite their tiny size and stunning blue-and-white appearance.

“While beachgoers should be aware of the risks associated with being stung by one of these highly venomous nudibranchs, this is also an opportunity to learn about these extraordinary marine animals,” Wares added.

What should you do if you are stung by a blue dragon?

With the festive season approaching, thousands of visitors are expected to flock to Cape beaches. Blue dragons could easily attract the attention of curious holidaymakers, particularly children.

Beachgoers are advised not to touch blue dragons or bluebottles, even if they appear dead.

If stung, rinse the affected area with seawater to remove any remaining stinging cells. Do not use fresh water.

Apply heat by immersing the affected area in hot water – about 45°C, or as warm as tolerable – for 20 to 90 minutes to help reduce pain.

Seek medical help if symptoms worsen, become severe, or if there are signs of an allergic reaction.