According to Encyclopaedia Britannica, the goldfish, a member of the carp family that originated from ponds in East Asia, is an egg-laying fish. A fish that lays eggs cannot be pregnant, and therefore no special designation exists for a pregnant goldfish.
Goldfish spawn in spring or summer. Colors become brighter and more vivid as breeding season approaches. The eggs of the goldfish are deposited on water plants and hatch in approximately one week.
Naturally sporting a greenish-brown or gray coloration, the goldfish has developed shades of black, white and gold due to selective breeding. Since its domestication during the Sung dynasty, it has become a cosmopolitan species.