Porcupine Pufferfish or Puffer are two of the fishy names for this guy. Puffers have great eyesight and are prone to gazing. Caught this one gazing at me, so I took his photo and pixelated him.

Pirahna are quite pretty swimming behind glass and beneath aquarium lighting. Saw this one at Johnny Morris's Wonders of Wildlife Aquarium and Museum in Springfield, MO.

Clownfish, anemonefish, named not for the visual clown appearance with ruffled bands of bright color but for their swim pattern. They dart up and down, in and out of anemones, their symbiotic friends. Fish swim swiftly with a purpose. Clownfish hang around anemones, and appear to be "clowning around."