Two venomous marine organisms usually found in deep sea were spotted at Chennai’s shoreline by beachgoers. Blue sea dragon (Glaucus atlanticus) – a nudibranch (also called sea slugs), and polyp colonies commonly referred to as Blue Button (Porpita porpita) were found at Besant Nagar beach. Hundreds of them washed ashore recently. Although both the marine organisms can inject venom into any foreign body that comes in contact with them, including humans, the venom is not lethal, according to experts.
Both Blue sea dragon (Glaucus atlanticus), and Blue Button (Porpita porpita) were spotted on December 17 by Srivatsan Ramkumar, a resident of Chennai who works with the Environmentalist Foundation of India. “Hundreds of them had washed ashore between the broken bridge and the Ashtalakshmi temple stretch of the beach. While a large number of them were dead, I spotted some Blue Sea Dragons and Blue Button which were alive,” he told TNM.
Blue buttons get their name from their button-like shape, but are not a single organism even if they appear so. They are a colony of small predators called hydroids that are often confused with jellyfish, to which they are closely related. As the Wildlife Conservation Trust highlights, these colonies float “passively” along the ocean “performing specialised roles – stinging and preying, defending the colony from predators, and producing more of their kind.” Chennaites may often spot the remains of these colonies washed up along the shoreline. The even more bizarre-looking blue sea dragon on the other hand, is a rarer sight as they inhabit the deep oceans.
Sea slugs, very simply, are shell-less molluscs that come in a near-unimaginable variety of colours and shapes. Interestingly, the Blue sea dragon spotted at Chennai’s beach uses its blue coloured side to camouflage against the ocean’s blue and its silver side to camouflage against the water’s bright coloured surface in the deep oceans. They are often spotted in groups, creating formations which are known as ‘blue fleets’.
Speaking to TNM, Prashanth E, Tamil Nadu Forest Department, Wildlife Warden linked their arrival on the shores of Chennai to Cyclone Michaung. “After cyclonic disturbances, flushing of the sea bed is a common occurrence. On Chennai’s shore, spotting Blue Sea Dragons is not a regular occurrence but they do show up once in a while. It is best not to touch them,” he advised.
But, the venom of both the organisms spotted isn’t lethal, said VS Chandrasekaran, retired Principal Scientist of the Central Institute of Brackishwater Aquaculture (CIBA).
“Blue Button have a ‘man of war’ mechanism – which means that they use the tentacles like body parts to sting any foreign body that comes in contact to defend themselves,” he said.
According to Chandrasekaran, Blue Sea Dragon stores venom that it consumes from other creatures, including the Portuguese man’o war, a separate jellyfish species, to sting foreign bodies that make contact. “Local fishers refer to these jellyfish kinds of organisms as Sori because they cause skin irritation, rashes and pain. It is best to not touch them even though their venom isn’t lethal,” he said.
He further explained that both the organisms will die if they continue to stay on the coast. “They will die once they dehydrate. They cannot withstand the daytime temperatures on the shore,” he added.
With Inputs from Bharathy Singaravel