Rare ancient arthropod becomes toxic to repel hungry predators

London, December 25 (ANI): Scientists have discovered that one species of a rare, ancient barnacle has extraordinarily high levels of a toxic chemical in its body, in order to repel hungry predators.

A barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters.

According to a report by BBC News, up to 7 percent of certain parts of the barnacle's body is bromine, with the chemical concentrated into the animal's most vulnerable parts.

The sessile crustacean likely hoards the chemical as a defence mechanism to repel predators.

Because barnacles cannot move, they are vulnerable to drying out, and to predators from which they cannot flee.

In response, most barnacles have evolved strong protective shells.

However, Chaetolepas calcitergum has only a weakly mineralised outer coating, and is therefore vulnerable.

So, it appears to have become toxic instead, in a bid to repel predatory gastropods that like to feed on barnacles.

Professor John Buckeridge and Dr Jessica Reeves of the Royal Melbourne Institute of Technology (RMIT) in Melbourne, Australia made the discovery while conducting a routine chemical analysis of a specimen of Chaetolepas calcitergum.

"The elevated levels of bromine were a surprise, I wasn't expecting this at all," said Professor Buckeridge.

The surface of the whole barnacle comprised about 1.5 percent bromine by dry mass.

But some regions contained up to 7 percent bromine by dry mass.

Because the toxic chemical is concentrated in the most vulnerable parts of the crustacean, the researchers strongly suspect it is used by the animal to defend itself against being eaten by predators.

"Bromine and bromine compounds are rather toxic. Their presence would deter predators or grazers from eating the host," said Professor Buckeridge.

The researchers now hope to investigate whether many other barnacle species also compensate for being sessile by having toxic bodies. (ANI)