Sunday, August 13, 2006

Melibe viridis

We found two distinct species of Melibe this morning at Tasi Tolu, including three individuals that I believe to be Melibe viridis. Although we have seen relatively small species of Melibe in the past (perhaps juvenile viridis), this is our first encounter with the larger Melibes. While we observed, one of the individuals caught and ate a small crab. It seemed to take about 10 seconds for the Melibe to work the live crab into its 'mouth' before continuing its hunt.

According to the Sea Slug Forum:
Species of Melibe feed on shrimps, crabs and other small crustacea which they catch by waving the inflated oral hood over the substrate like a metal detector. When the sensory papillae touch a crustacean the hood rapidly closes, trapping the prey inside where it is gradually manipulated back to the 'mouth'. Species of Melibe lack a radula, prey remaining alive in the gut until killed by digestive juices.
Just a few weeks ago I commented somewhat sympathetically on sea slugs' incredible ability to endure the stinging, biting, and otherwise annoying microscopic 'wildlife' they encounter. But these Melibe seem more like formidable predators, unlikely to be deterred by a pesky syllid.

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