Here is a list of goldfish species that can be kept together:
* Common goldfish: These are the most common type of goldfish, and they are generally peaceful and easy to care for.
* Fancy goldfish: Fancy goldfish come in a variety of shapes and colors, and they are often more expensive than common goldfish. Some fancy goldfish species, such as the lionhead and the oranda, can be more aggressive than common goldfish, so it is important to do your research before choosing a fancy goldfish.
* Pond goldfish: Pond goldfish are larger than common and fancy goldfish, and they are typically kept in outdoor ponds. Pond goldfish are generally hardy and easy to care for, but they can be aggressive towards other fish.
It is important to note that even compatible goldfish species can become aggressive if they are overcrowded or if they do not have enough food or space. Make sure to provide your goldfish with a spacious aquarium or pond, and feed them a high-quality diet.
Here are some additional tips for keeping goldfish together:
* Avoid keeping aggressive goldfish species with peaceful goldfish species.
* Keep your goldfish in an aquarium or pond that is large enough for all of them to swim comfortably.
* Provide your goldfish with plenty of hiding places, such as plants and rocks.
* Feed your goldfish a high-quality diet that is appropriate for their size and species.
* Monitor your goldfish for signs of aggression or illness.
By following these tips, you can help your goldfish live long, healthy, and happy lives.