clown·fish or clown fish 
(klounfĭsh′)
(klounfĭsh′)n. pl. clownfish or clown·fish·es or clown fish or clown fish·es
Any of various small, brightly colored marine fishes chiefly of the genus Amphiprion, having a symbiotic relationship with sea anemones. Also called anemonefish, clown anemone.