Hobbies And Interests
Definition
Goldfish are a species of freshwater fish that are members of the carp family. They are indigenous to Asia.
Discovery
The first written record of a goldfish --- a gold-colored gibel carp -- dates back to the Chun dynasty, which existed during 265-419 A.D. The red-and-white variety of goldfish was reported approximately 800 years later.
Classification
Despite the wide array of colors, shapes and sizes, there is only one species of goldfish: Carassius auratus. The various appearances of goldfish are attributed to their numerous "breeds" as opposed to species. The biological classification of goldfish consists of the species Carassius auratus, family Cyprinidae, order Cypriniformes, class Osteichthyes, subphylum Vertebrata and phylum Chordata. Some groups cite Actinopterygii as the class category for goldfish. However, Actinopterygii (ray-finned fish) is actually one of the two major divisions within the large class Osteichthyes (bony fish). The other division within Osteichthyes is Sarcopterygii (lobe-finned fish).
Native Environment
Goldfish are native to China. In China, they live in rivers, lakes, streams, ponds and ditches. Unlike most commercial goldfish that grow up to 4 inches long, goldfish in their native environment grow to an average of 12 inches in length and weigh 5 ½ pounds. In the wild, goldfish feed on insects, crustaceans and plants.
Exportation
Goldfish were first exported to Japan in 1603, to Europe in 1611 and to America in 1874.
Life Span
Under optimal conditions, common goldfish can live up to 40 years. More specialized breeds (for example, short-bodied twintails) generally live up to 10 years.
Types of Pigments
Goldfish have three kinds of pigments: black or melanophores, red or erythrophores and yellow or xanthophores. The varying amounts of these pigments, coupled with the influence of external factors, attribute to the wide range of goldfish colors.
External Factors That Determine Color
The most pertinent external factor that determines the color of goldfish is the quantity of light in their environment. Goldfish that grow in a more dimly lit setting (such as deep rivers, etc.) are pale in color, whereas more brightly lit environments produce goldfish that have saturated colors. Diet is a secondary factor that influences the color of goldfish.
Sensitivities
Goldfish are naturally opportunistic eaters, continuously eating without stopping on their own accord. To avoid bloating, soak dry food pellets in tank water prior to feeding them to fish. Presoaking dry food prevents it from expanding in the goldfish's stomach, causing constipation and also swimbladder duct obstruction --- both of which they are vulnerable to.
Goldfish Bowls
Even though traditional "goldfish bowls" are cosmetically attractive and popularly synonymous with goldfish, they are actually detrimental to the fish's longevity. This is because conventional goldfish bowls do not have enough surface area to facilitate the oxygen needed for a goldfish to survive any substantial period of time. Goldfish are able to thrive in standard fish tanks.