Do Goldfish get lonely and sad?
It's normal to wonder whether your goldfish will get lonely if kept in a tank on their own. Goldfish are just not the same as humans, the longest-living goldfish have been kept alone, with no obvious harm to their well-being.
Yes, Goldfish can feel lonely, you certainly don't have to get more fish just to keep your goldfish company. Consider the needs of each fish when choosing suitable tank mates.
Several factors can affect the well-being of your goldfish, as we know goldfish are active fish that need plenty of room to move around, so if your goldfish are kept in a tank that is too small and less decorative, it may become boring for your fish, somehow they feel lonely and sadness if they are alone or they have nothing to do.
Goldfish are social. Species, living in shoals in the wild. In captivity, it's strongly recommended that they should be kept at least in pairs, to provide companionship. If refusing food, sitting at the tank's bottom are some signs of sadness.