Blue dragons

Dec. 20, 2023

Recently, blue dragons (Glaucus atlanticus) have been spotted on the beach and in waters near the shore in Besant Nagar in Chennai.

About the Blue dragons:

  • The blue dragon (Glaucus atlanticus) is a type of mollusc known as a nudibranch.
  • They also are known as blue sea slugs, blue angels, and sea swallows.
  • It rarely grows larger than three centimetres long.
  • An air bubble stored in its stomach keeps the blue dragon afloat.
  • Distribution: It can be found drifting on the surface of the Atlantic, Pacific and Indian oceans in temperate and tropical waters.
  • Diet:
    • They feed on venomous siphonophores such as the Portuguese man-o-war and bluebottle, which also occur in ocean surface waters.
    • The dragons appear immune to the nematocystsstinging cells – of these jellyfish-like creatures.
    • They incorporate these cells into multiple finger-like structures protruding from their body which provides them with a potent form of protection from predators.
  • The slug isn't venomous all on its own, however, it stores the stinging nematocysts created by the creatures on which it feeds.
  • Its sting can cause problems, especially to children and elderly.  
  • One sting from this little creature can lead to nausea, pain, vomiting, acute allergic contact dermatitis, and post-inflammatory hyperpigmentation.
  • They are hermaphrodites, meaning they have both male and female reproductive organs.