DON’TTANGLEWITHSEAURCHIN
Collector sea urchins have an ingeniously gruesome way of defending themselves with tiny mobile “jaws”, a SCU researcher has found
WHEN under attack, the collector sea urchin can release hundreds of miniature “jaws with teeth” that can latch on to predators and release venom.
The discovery from Southern Cross University marine biologist and PhD candidate Hannah Sheppard-Brennand and her research team, shows sea urchins defend themselves with the pedicellariae, which is like an army of venomous jaws.
Her study was recently published in The American Naturalist.
Ms Sheppard-Brennand said the pedicellariae act as an unpalatable defence against being eaten but also as a deterrent. These semiautonomous structures detach from the urchin into the surrounding water.
“They resemble something out of a miniature horror movie,” she said.
The collector sea urchin, tripneustes gratilla, live in tropical reefs of the IndoPacific, eating algae and seaweed but have been documented moving into cooler subtropical waters.
Supervisor and coresearcher Associate Professor Symon Dworjanyn, from the university’s National Marine Science Centre in Coffs Harbour, said this discovery might explain why this urchin was often seen in the open while other species tended to hide in crevices.
“For other sea urchin species where regeneration has been studied it can take between 40 and 50 days to regrow these biting appendages on their shells,” he said.
“These urchins are capable of releasing hundreds of pedicellariae in seconds.”