try paradise fish they are also cold water fish youre welcome or if she is lonely play with her more you can pet her with your fingernail and do peek a boo

Other similar bodied goldfish.

Goldfish have diffrent tank needs than other tropical fish and really dont make good tankmates as a result. They like their water colder and dont need a heater while all tropical fish do. Besides with comet goldfish, they do get rather large and I have heard of the bigger ones sucking up smaller tropical fish tankmates.

Best option, other comet, shubunkin or common goldfish.

Dont mix them with the round bodied fancy goldfish, the faster swimming slim bodied fish will win the race for food every time.

You are going to need a big tank or a pond for multiple comet type goldies though.

Ian

Each comet goldfish needs at least 5 gallons of water a piece. They have a VERY high ammonia output that no other fish can tolerate. If you put any other fish in with that goldfish, other than a similar type goldfish, they will most likely die because of the Ph level in your water. Most fish prefer a neutral PH of around 7, but the amount of ammonia put out by goldfish will put your PH levels around 9 or more.

Plan and simple, fish from the goldfish species are dirty fish, and really should only be put together.