Pleurobrachia

At first sight pleurobrachia may look like a Chinese lantern, a christmas decoration or a flashing sign. A strange animal, commonly called ‘sea gooseberry’ or cat’s eye Pleurobrachia, which means arm at the side, is about the size of a marble. Pleurobrachia belongs to the family of ctenophores, from the Greek word ‘ktenos’, a comb. Their iridescent combs are made up of thousands of cilia which are used for propulsion.

Pleurobrachia are carnivorous. They capture zooplankton using long tentacles armed with sticky cells – called colloblasts – and then pull them towards their mouth.

Ctenophores are amongst the most ancient animals known to have developed a neuro-sensorial system. By studying them, biologists hope to learn how the first neurons appeared, information vital to an understanding of our own brain cells.