Underwatertimes.com News Service - September 27, 2006 23:05 EST

The ability of barnacles to form clusters on ships' hulls and rocks has long been a puzzle to marine scientists. Barnacles need to be close to each other to mate - but how do barnacle larvae, in the form of plankton, know where to settle?

An Anglo-Japanese team of researchers, led by Newcastle University, has now identified a chemical signal released by adult barnacles which is recognised by the larvae. The discovery could suggest new, environmentally sensitive ways of protecting surfaces from unwanted growth of barnacles.

The principal investigators on the grant are Professor Anthony Clare, of Newcastle University and Dr Richard Kirby of the University of Plymouth.

Professor Clare, of the School of Marine Science and Technology at Newcastle University, explained:

'We have determined the nature of a chemical signal that allows barnacles to recognise their own kind at settlement. As adults, barnacles stick firmly to rocks, ships and other submerged objects in the sea. As planktonic larvae, barnacles disperse widely to colonise new habitats and surfaces.

'Proximity is achieved at settlement by the larvae recognising a protein associated with the adult exoskeleton. The settlement-stage larva is exquisitely adapted to search surfaces and to detect this chemical signal. 'Having identified the type of protein involved, the team now hope to determine how the signal is recognised. Ultimately, understanding the process of barnacle settlement may highlight new, environmentally sensitive ways to protect marine surfaces from unwanted growth of barnacles.'