EYE PUNCTURE AS A ROUTE OF ENTRY FOR SALIVA DURING PREDATION ON CRABSBY THE OCTOPUS ELEDONE-CIRRHOSA (LAMARCK)

In 45% of crab carapaces examined after octopus feeding, the surface o f an eye was found to have been punctured. Experiments in which green crabs (Carcinus maenas L.) were retrieved from feeding octopuses (Eled one cirrhosa Lamarck) showed that this penetration of the eye occurred less than ten min after capture. These findings are consistent with d irect observations and visualization by ultrasound showing that initia lly after capture the anterior of the crab is often held to the mouth of the octopus. In vitro injection of octopus saliva into crabs demons trated that eye puncture is the most rapid and completely effective ro ute of entry for cephalopod toxins. Comparative feeding experiments us ing swimming crabs (Liocarcinus depurator L. and Necora puber L.) show ed incidences of eye puncture of up to 75%. These observations provide a new explanation for the means by which the crabs are immobilized so rapidly during octopus predation.