Goldfish (Carassius auratus) are social animals and when kept in groups can be seen regularly interacting with other goldfish. Keeping at least two goldfish in an aquarium is recommended to provide companionship and promote activity. Solitary fish can exhibit depression and lethargy. 

Goldfish are generally not aggressive so they can be kept with most community fish provided the other fish are larger than the size of the goldfish's mouth.

Suitable goldfish tank mates for smaller aquariums may include white cloud mountain minnows, danios, and gold medaka (check these are larger than the goldfish's mouth). For variety in larger aquariums suitable tank mates for goldfish may include Murray river rainbow fish.

Goldfish with extended fins should not be kept with fish that tend to nip fins e.g. tiger barbs. The more unusual goldfish varieties such as the Celestial should be kept with their own variety as they may find locating and competing for food difficult when housed with other types of fish with superior swimming abilities.

Generally it is best to keep goldfish with tank mates that have similar swimming abilities to ensure all fish can obtain enough food and swimming space. You will also need to consider how large your goldfish and the other fish are likely to grow to ensure adequate space is provided.

Prior to housing goldfish with other fish species we recommend that you check with an experienced aquarist or a fish veterinarian for advice about species compatibility.