Cabo San Lucas nudibranch...? This brilliantly colored nudibranch known as Tambja eliora was found under a ledge during our snorkeling excursion on a beach near Cabo San Lucas. Nudibranchs belong to the Gastropod class in the Mollusca phylum. Over 3,000 known species exist, most of which have a reduced shell or have lost their shell completely, hence the name nudibranch meaning "naked snails". The bright coloration (known as Aposematic) of this beautiful sea slug acts as a warning sign to potential predators that they have a foul taste. This specific species is found in the Gulf of California, Mexico to Magdalena Bay.