Goldfish are a type of carp from China. They’ve been bred to obtain many colors (brown, red, orange, black, white, yellow), sizes, fin shapes, and body shapes. Scientifically called Carassius auratus, they are among the most popular freshwater pet fish.
In aquariums, they grow to between 1 and 2 inches. They can grow larger but rarely longer than 6 inches in larger ponds. They can grow as long as 14 inches in ponds and the wild! The largest goldfish was 19 inches long and over 2 pounds heavy.
Although primarily freshwater fish, they are tough fish and can survive in saline water, with some having been found in water with a salinity of 17. Temperature changes, such as during spring, prompt their breeding and egg-laying.
Goldfish are a schooling breed of carp with gentle behavior. They rarely fight one another unless it’s over limited food or against aggressive fish breeds. Even during mating, they rarely fight over mates.
They have very interesting behavior; most of them have good enough memories to distinguish between owners and even respond accordingly to each one. They can recall things for at least 3 months and can tell colors, shapes, and sounds apart. They even perform tricks! No wonder they are favorites for many aquarists.