Under my umbrella

The umbrella snail is still a little confusion for the scientific research. There are probably two common species worldwide the Umbraculum umbraculum (Indo-Pacific region) and the Umbraculum mediterraneum (east Atlantic-Mediterranean region). A lot of researchers confuse this two species. More species of the family Umbraculidae have been found as fossils or just once. As we know most of the species of the (Subclass) Opisthobranchia have no shell. U.mediterraneum and Tylodina pervesa are the strangest species of the subclass as they have a small shell that looks like an umbrella over their body. U.mediterraneum is feeding on sponges and for that reason has a broad radula with rasping teethes. It can also bury in the sand near the sponges that it prefers for feeding. If you find it on the rocks it maybe impossible to spot as it can hide all his body between the umbrella shell and the rock. The animal in the photo was met at Paros at the depth of 1 meter and it is the shallower I have ever met.