Acquired: Fish / pet store
Posted Jul 03, 2013
Goldfish are awesome! But they require a lot more to them than just a little fish bowl.
Appearance: The common goldfish has the basic fish shape - no bulbous body or huge eyes like fancy goldfish - and can have colors from brown to speckled to, well, the orangey gold that they are named for!
Compatibility with own species: Goldfish get along great with their own species! I don't think I've ever seen a goldfish of any kind get territorial.
Compatibility with other species: There are few aquarium fish that go well with goldfish. It's not that they are in any way agressive! Rather, it's because they are cold water fish! Sure, people put goldfish in tropical tanks, but it's not optimal for the gold fish, and can be horrible for their health. Also, goldfish produce a lot of waste, and can challenge the filter on a tank! This is something to keep in mind for any sensitive species. I kept my goldfish with minnows.
Easy to keep: With all technicality, the goldfish is a hearty species and will probably do well in any bowl you put him in. That's where the concept of a fish bowl came into play. But in reality, a single goldfish needs at least 20 gallons to itself. They grow large and produce a lot of waste! So in that sense, they are not as easy to keep as owners are led to believe.
Activity level/ Visibility: Goldfish are constantly on the move, and don't usually go hiding. They move all over the tank, which is great for visuals as they don't stay in the middle, top, or bottom.
Health/Vigor: Goldfish are overbred, so they often do not have the best genetic health. I've had a goldfish that, during a growth spurt, became deformed. I've had a goldfish that developed a large tumor on his side. Most goldfish are pretty hearty, but seeing the genetic casualties of these fish made me stop wanting to keep them, even if it was a small percentage of fish that suffered from this.
Interaction with owner: Goldfish will come and check you out when you come up to the tank. Some will follow your finger. I've heard of people training fish to do things like ring a bell in order to get food. And I've seen the goldfish come to the side of the tank from the side of the room I enter from. They are very cute this way!
Easy to acquire: Goldfish are so easy to acquire, they practically GIVE them away at carnivals!
Low cost to own: If you have a large tank and a filter, you're pretty set. Ideally, goldfish should get fresh food along with the flakes or pellets they get. But they don't need a heater unless the ambient temperature drops too low.
Overall, just make sure you get a big enough tank for them! I go by 20 gallons for the first one, and 10 for each additional. They can be fun to watch grow, and beautiful.