Sunday, May 24, 2009


Diane spotted this Melibe sp., possibly viridis or mirifica, (10cm) at Tasi Tolu. It's an unusually clear photo of a Melibe...they usually look like blobs of algae and are difficult to wrap your head around.

Unlike any other genus of sea slug, Melibe have a unique "oral hood" A used to catch small crustaceans. The hood, which is cast out like a fishing net, has rows of 'hairs' along the rim that filter the sand and detritus from the catch. The oral hood, as well as the rest of the Melibe, is quite transparent and it's possible to actually watch small crabs struggle as they are pushed back to the Melibe's mouth. B are, of course the rhinophones and C are cerata. These cerata can be 'sacrificed' and break off, giving the Melibe opportunity to escape when threatened. And finally, D is the fin-shaped posterior. Only a few sea slugs, including Melibe, have the ability to "swim". Swim might be an overstatement, but they do have the ability to jerk their bodies side-to-side and, with the help of this fin-shaped 'tail', move from place to place.

Laying Around

This is a sea snail (1cm), perhaps Cancilla interlirata (or some other Mitridae), laying eggs on the underside of a Udotea sp. algae. These algae are prolific at Tasi Tolu and play host to a variety of organisms. It might help to enlarge this photo to see the processes of the snail involved in laying.

Sunday, May 10, 2009


Three Mimic Octopuses

There is absolutely no doubt: Tasi Tolu is the world's greatest dive site. Today we saw three mimic octopuses at about 20 meters.