VITERBO, Italy, Sept. 2 (UPI) -- Two marine species that dine on sea urchins but struggle to catch them sometimes seem to work together to tackle their common prey, an Italian researcher says.
A fish called the ornate wrasse likes to eat the tube feet of sea urchins but finds that difficult as the urchins routinely keep their feet anchored in the sea bed.
A starfish known as Marthasterias glacialis also likes urchins but is often too slow to catch them.
Nicola Galasso of Tuscia University in Viterbo, Italy, says the two species have been observed helping each other out, NewScientist.com reported.
When a starfish attacks a sea urchin, the urchin uproots itself to escape, which exposes its tube foot to the wrasse, which dashed in to make a meal of the foot. Without a foot the urchin is disabled and becomes immobile, allowing the starfish to capture it for a meal of its own.
While the two predators don't seem to be truly cooperating as neither makes a sacrifice for the other, Galasso said, their actions nevertheless benefit each other.
