Fishes of the genus Amphiprion and Premnas comprise a group commonly referred to as anemonefishes because of their symbiotic relationship with several genus of anemones and their bright colors and bobbing swim. This group is commonly referred to as clownfish in the aquarium trade, although most technical works refer to the two genus as anemonefishes.
Whether you call them anemonefish or clownfish, they enjoy a universal popularity among marine aquarist. They represent an excellent first choice for spawning and rearing efforts before the aquarist graduates to other more difficult species.
The genus Amphiprion presently has 27 identified species with several species in question that may represent hybrids (A. leuckocranos and A. theilli). The genus Premnas has but a single recognized species P. biaculeatus, more commonly known as the spine cheeked or maroon anemonefish. All species regardless of genus are found in Indo-Pacific waters. There are no known Atlantic/Caribbean species.
Genus - species, common (vernacular) name
Amphiprion akallopisos, Skunk anemonefish
Amphiprion akyndynos, Barrier Reef anemonefish
Amphiprion allardi, Allard’s anemonefish
Amphiprion bicinctus, Two-banded anemonefish
Amphiprion chagosensis, Chagos anemonefish
Amphiprion chryogaster, Mauritian anemonefish
Amphiprion chrysopterus, Orange-fin anemonefish
Amphiprion clarkii, Clark’s anemonefish
Amphiprion ephippium, Red Saddleback anemonefish
Amphiprion frenatus, Tomato anemonefish
Amphiprion fuscocaudatus, Sechelees anemonefish
Amphiprion atezonatus, Wide-band anemonefish, Lord Howe anemonefish
Amphiprion latifasciatus, Madagascar anemonefish
Amphiprion leuckocranos*, White-bonnet anemonefish
Amphiprion mccullochi, McCulloch’s anemonefish
Amphiprion melanopus, Red and Black anemonefish
Amphiprion negripes, Maldive anemonefish
Amphiprion ocellaris, Common anemonefish, False clown anemonefish
Amphiprion omanensis, Oman anemonefish
Amphiprion perculae, Clown anemonefish
Amphiprion perideraion, Pink anemonefish
Amphiprion polymnus, Saddleback anemonefish
Amphiprion rubrocinctus, Australian anemonefish
Amphiprion sandaracinos, Orange anemonefish
Amphiprionsebae, Seabae anemonefish
Amphiprion theillei*, Theille’s anemonefish
Amphiprion tricinctus, Three-banded anemonefish
Premnas biaculeatus, Spine-cheeked anemone fish, Maroon anemonefish
For photos see:
http://www.aquarium-design.com/fish/clownfishid.html
As you can see there are far more types of clownfish than just nemo. They are found among coral reefs thoughout the world.