![]() Within a week or so, the fry begin to look more like a goldfish in shape, although it can take as much as a year before they develop a mature goldfish color until then they are a metallic brown like their wild ancestors. The eggs hatch within 48 to 72 hours, releasing fry large enough to be described as appearing like "an eyelash with two eyeballs." They produce adhesive eggs that attach to aquatic vegetation. So if a goldfish is kept in the dark it will appear lighter in the morning, and over a long period of time will lose its color.Ī group of goldfish is known as a troubling (Owens 2009). The color of a goldfish is determined by which pigments are in the cells, how many pigments molecules there are, and whether the pigment is grouped inside the cell or is spaced throughout the cytoplasm. Cells called chromatophores produce pigments that reflect light, and gives coloration. Goldfish have pigment production in response to light. ![]() If left in the dark for a period of time, a goldfish will turn lighter in color. In optimal conditions, goldfish may live more than 20 years, but most household goldfish generally live only six to eight years, due to being kept in bowls. The longest goldfish was measured at 47.4 cm (18.7 in) from snout to tail-fin end on Main Hapert, The Netherlands (Guinness 2003). Goldfish, Carassius auratus, may grow to a maximum length of 23 inches (59 cm) and a maximum weight of 9.9 pounds (4.5 kg), although this is rare few goldfish reach even half this size. Members of the Cyprinidae are characterized by pharyngeal teeth in one or two rows, with no more than eight teeth per row usually thin lips, an upper jaw usually protrusible and an upper jaw bordered only by premaxilla (Nelson 1994). Particularly well-known species include the common carp and koi (Cyprinus carpio), goldfish (Carassius auratus), and zebra danio or zebrafish (Brachydanio rerio), the latter used extensively in genetic research (Nelson 1994). Nelson (1994) recognizes 210 genera and over 2,000 species in Cyprinidae, with about 1,270 species native in Eurasia, about 475 species in 23 genera in Africa, and about 270 species in 50 genera in North America. Common names associated with various members of this family include minnow, carp, chub, and shiner. The Cyprinidae family is the largest family of freshwater fishes in the world, and may be the largest family of vertebrates (with the possible exception of Gobiidae) (Nelson 1994). Beyond the aesthetic pleasure from such varieties, goldfish have also offered practical value in control of mosquitoes.Ī relatively small member of the Cyprinidae family, the goldfish is a domesticated version of a dark-gray/brown carp native to East Asia. Over the centuries, through human creativity acting on the foundation of an original carp species, many color variations have been produced, some far different form the original "golden" color of the first domesticated fish. One of the earliest fish to be domesticated-in China over 1,000 years ago (BAS 2007)-the goldfish remains one of the most popular aquarium fish.
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