Tuesday, January 13, 2009

Gold fish

About Gold fish

The Goldfish, Carassius auratus, is one of the earliest fish to be domesticated, and is still one of the most commonly kept aquarium fish and water garden fish. A relatively small member of the carp family, the goldfish is a domesticated version of a dark-gray/brown carp native to East Asia. It was first domesticated in China and introduced to Europe in the late 17th century.


Goldfish can grow to a maximum length of 23 inches (58.42 cm) and a maximum weight of 9.9 pounds (4.5 kg), although this is rare; few goldfish reach even half this size. The oldest recorded goldfish lived to 49 years, but most household goldfish generally live only six to eight years, due to being kept in bowls. The collective noun for a group of goldfish is a "troubling".

Scale groups
There are three scale groups in goldfish. They are: 1. Metallic 2. Nacreous (calico) 3. Matt
Metallic is the normal goldfish where the scale have a silvery shine due to the presence of guanine in the scale.
Nacreous scales is represented by the shubunkins, where the goldfish have both metallic and transparent scales (where the guanine is absent). Shubunkins was first bred in Japan in 1900 when mutations from telescope-eye (Demekin) goldfish first arose.
Matt denotes where the goldfish has 100% of transparent scales. They have pink gills as the gill plates do not have guanines, so they are transparent and the gills appears through (blushing). They generally have pink bodies. Some have orange or red colours. A recent gorgeous goldfish breed is the lemon yellow "sunburst" variety of common goldfish. It is a matt with intense lemon to deep yellow colours.
Crossing the scale types reveal simple Mendelian genetics:
If both parents are Metallics (AAAA) or Matts (aaaa), they will breed true, ie, 100% metallics (AAAA) or matt (aaaa) frys.
On the other hand, if both parents are nacreous (AAaa), the frys will be 50% nacreous (AAaa), 25% metallics (AAAA) and 25% matts (aaaa).
If Metallic (AAAA) or matt (aaaa) parent is crossed with Nacresous (AAaa): the frys will be 50% metallics (AAAA)/matt (aaaa) and 50% nacreous (AAaa).
If Metallic (AAAA) is crossed with matt (aaaa), the frys will be 100% nacreous (AAaa)(shubunkins).
Of the 3 scale groups, metallics are physically the strongest breed, with matts the weakest. In general, matts do not live long and are weaker.
Metallics should be raised in clear water and high temperature to promote them changing colour from their bronze phase to the gold/white/red colour. Nacreous and matts should be raised in green water instead to avoid them getting sunburnt in outdoor pools, as they lack the reflective scales.

Goldfish Family Tree

This chart displays the link of the various goldfish varieties and their lineage to their common goldfish ancestor. See: http://www.geocities.jp/dneumaier90/gtree.html

Feeding Gold fish

Like most fish, goldfish are opportunistic feeders. When an excess of food is offered, they will produce more waste and feces, partly due to incomplete digestion of protein. Overfed fish can sometimes be recognized by feces trailing from their cloaca. Goldfish need only be fed as much food as they can consume in one to two minutes, and no more than three times a day. Extreme overfeeding can be fatal, typically by bursting of the intestines. This happens most often with selectively bred goldfish, which have a convoluted intestinal tract as opposed to a straight one in common goldfish. Novice fishkeepers who have newly purchased ryukin, fantail, oranda, lionhead or other fancy goldfish will need to watch their fish carefully for a few days, as it is important to know how much the goldfish will eat in a couple minutes of time. They also die without eating in 4–8 days.
Special goldfish food has a lower protein and higher carbohydrate content. It is sold in two consistencies - flakes that float at the top of the aquarium, and pellets that sink slowly to the bottom.
Goldfish enthusiasts will supplement this diet with shelled peas (with outer skins removed), blanched green leafy vegetables, and bloodworms. Young goldfish also benefit from the addition of brine shrimp to their diet. As with all animals, individual goldfish will display varied food preferences. In any case, it is better to feed them a variety of foods listed above.

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