Amphiprion oscellaris, the Oscellaris Clownfish or False Percula Clownfish. Amphiprion oscellaris is closely related to Amphiprion percula, the Percula Clown or Orange Clown and, for most of us, is nearly indistinguishable. How do the ichthyoligists ("fish" scientists) tell them apart? The eyes on the percula clown are bright orange with a dark, clearly demarcated center, making their eyes look smaller. The eyes of the oscellaris clown are orange with a black pupil and shades into grey on parts of th iris (i.e., looks a little smudgy), giving the appearance of a larger eye. Oscellaris also have 11 dorsal spines while percula clowns have 10 dorsal spines. The eyes, however, are easier to spot, especially on a moving fish. So which one was Nemo? Well, Nemo was a cartoon so he can be anyone you wish. However, he had brighter colors and clearly demarcated eyes (I dare you to count dorsal spines and get back to us gentle readers...), so I'm guessing Nemo was a percula clown.
Note, if you're thinking of buying one, oscellaris clowns look plenty close enough for most kids to call them Nemo and are a little hardier. They are both from the Indo-Pacific, particularly near Fiji and Tongo, where they live in large sea anemones which serve as home and protection for their little clownfish friends. Note that the clownfish are also known to feed their anemone hosts in a somewhat symbiotic relationship, pushing food into the anemone's mouth.
