The domestic Goldfish is one of the most popular fish kept today, and also one of the very first to be kept indoors. Contrary to dated belief, goldfish cannot be kept in tiny, unfiltered bowls. They should get quite large (about the size of a sweet potato) and live for decades. These are intelligent fish that will come to recognize their owners; the idea that their memory span is only 3 minutes has been disproven by multiple scientific studies. An ideal environment for goldfish is a 30-40 gallon tank with at least 2-3 goldfish, and nice strong filtration.

Ryukin are a Japanese breed, similar to the American Fantail. Like the fantail, they are short-bodied, have a double tail fin, lack a hood or Wen, and are high-backed. Compared to Fantails, they are shorter in length, taller in the back, and tend to have a more defined head. Show quality Ryukin are known to sometimes be taller than they are long! These calico specimens are around 2long.