Koi Fish or Japanese Carp or Fancy Carp 3

Koi Fish or Japanese Carp or Fancy Carp 3

Health, maintenance and longevity[edit]

Traditional Japanese garden with koi

The common carp is a hardy fish, and koi retain that durability. Koi are cold-water fish, but benefit from being kept in the 15-25 °C (59-77°F) range, and do not react well to long, cold, winter temperatures; their immune systems are very weak below 10°C. Koi ponds usually have a metre or more of depth in areas of the world that become warm during the summer, whereas in areas that have harsher winters, ponds generally have a minimum of 1.5 metres (4½ feet). Specific pond construction has been evolved by koi keepers intent on raising show-quality koi.
Koi's bright colours put them at a severe disadvantage against predators; a white-skinned Kohaku is a visual dinner bell against the dark green of a pond. Herons, kingfishers, otters, raccoons, cats, foxes, badgers and hedgehogs are all capable of emptying a pond of its fish. A well-designed outdoor pond will have areas too deep for herons to stand, overhangs high enough above the water that mammals cannot reach in, and shade trees overhead to block the view of aerial passers-by. It may prove necessary to string nets or wires above the surface. A pond usually includes a pump and filtration system to keep the water clear.
Koi are an omnivorous fish, and will eat a wide variety of foods, including peas, lettuce, and watermelon.^[12] Koi food is designed not only to be nutritionally balanced, but also to float so as to encourage them to come to the surface. When they are eating, it is possible to check koi for parasites and ulcers. Koi will recognize the persons feeding them and gather around them at feeding times. They can be trained to take food from one's hand. In the winter, their digestive systems slow nearly to a halt, and they eat very little, perhaps no more than nibbles of algae from the bottom. Feeding is not recommended when the water temperature drops below 10°C (50°F).^[13] Care should be taken by hobbyists that proper oxygenation and off-gassing occurs over the winter months in small water ponds, so they do not perish. Their appetites will not come back until the water becomes warm in the spring.
One famous scarlet koi, named "Hanako", was owned by several individuals, the last of whom was Dr. Komei Koshihara. In July 1974, a study of the growth rings of one of the koi's scales reported that Hanako was 228 years old. The greatest authoritatively accepted age for the species is little more than 50 years.^[14][15]

Disease[edit]

Koi are very hardy. With proper care, they resist many of the parasites that affect more sensitive tropical fish species, such as Trichodina, Epistylis, Ich and other ciliated protozoans. Two of the biggest health concerns among koi breeders are the koi herpes virus (KHV) and Rhabdovirus carpio, which causes spring viraemia of carp (SVC). No treatment exists for either disease. Only biosecurity measures such as prompt detection, isolation and disinfection of tanks and equipment can prevent the spread of the disease and limit the loss of fish stock. In 2002, spring viraemia struck an ornamental koi farm in Kernersville, North Carolina, and required complete depopulation of the ponds and a lengthy quarantine period. For a while after this, some koi farmers in neighbouring states stopped importing fish for fear of infecting their own stocks.
^{[16] [17]}

Breeding[edit]

This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (May 2012)

Koi in an outdoor koi pond

Like most fish, koi reproduce through spawning in which a female lays a vast number of eggs and one or more males fertilize them. Nurturing the resulting offspring (referred to as "fry") is a tricky and tedious job, usually done only by professionals. Although a koi breeder may carefully select the parents they wish based on their desired characteristics, the resulting fry will nonetheless exhibit a wide range of color and quality.
Koi will produce thousands of offspring from a single spawning. However, unlike cattle, purebred dogs, or more relevantly, goldfish, the large majority of these offspring, even from the best champion-grade koi, will not be acceptable as nishikigoi (they have no interesting colors) or may even be genetically defective. These unacceptable offspring are culled at various stages of development based on the breeder's expert eye and closely guarded trade techniques. Culled fry are usually destroyed or used as feeder fish (mostly used for feeding arowana due to the belief it will enhance its color), while older culls, within their first year between 3" to 6" long (also called "Tosai"), are often sold as lower-grade, pond-quality koi.
The semirandomized result of the koi's reproductive process has both advantages and disadvantages for the breeder. While it requires diligent oversight to narrow down the favorable result the breeder wants, it also makes possible the development of new varieties of koi within relatively few generations.

In the wild[edit]

See also: Common carp

Koi have been accidentally or deliberately released into the wild in every continent except Antarctica. They quickly revert to the natural coloration of common carp within a few generations. In many areas, they are considered an invasive species and pests. They greatly increase the turbidity of the water because they are constantly stirring up the substrate. This makes waterways unattractive, reduces the abundance of aquatic plants, and can render the water unsuitable for swimming or drinking, even by livestock. In some countries, koi have caused so much damage to waterways that vast amounts of money and effort have been spent trying to eradicate them, largely unsuccessfully.^[18]

See also[edit]

• Aquaculture
• Carp
• Cyprinid
• Goldfish
• Koi pond
• Culture of Japan
• Japanese aesthetics

Notes[edit]

1. Jump up ^ "Pictures available for Cyprinus carpio haematopterus.". www.fishbase.org. Retrieved 2010-10-31. 
2. Jump up ^ "About Koi Fish". www.olympickoiclub.org. Retrieved 2009-05-01. 
3. ^ Jump up to: ^{a b} "Background information about goldfish". Retrieved 2006-07-28. 
4. Jump up ^ "History of common carp aquaculturing". Retrieved 2010-07-29. 
5. Jump up ^ "MPKS Ray Jordan Koi History". Ray Jordan. Retrieved 2009-04-26. 
6. Jump up ^ "Early Records". Netpets.org. Retrieved 2009-04-11. 
7. ^ Jump up to: ^{a b} Grossa, Riho; Klaus Kohlmannb and Petra Kerstenb (February 2002). "PCR–RFLP analysis of the mitochondrial ND-3/4 and ND-5/6 gene polymorphisms in the European and East Asian subspecies of common carp (Cyprinus carpio L.)". Aquaculture (Elsevier) 204 (3–4): 507–516. doi:10.1016/S0044-8486(01)00836-5. 
8. Jump up ^ "Discovery of an ancient lineage of Cyprinus carpio from Lake Biwa, central Japan, based on mtDNA sequence data, with reference to possible multiple origins of koi
9. Jump up ^ Pawlak, Joe. "Owner". Retrieved 2013-09-14. 
10. Jump up ^ Tamadachi M (1990). "Koi varieties". The Cult of the Koi. Neptune City, New Jersey: TFH Publications. p. 191. ISBN 0-86622-085-2. 
11. Jump up ^ "Aquatic-oasis articles". Aquatic-oasis. Retrieved 2012-02-02. 
12. Jump up ^ Olympic Koi, Goldfish & Water Garden Club, "About Koi Fish", 2004 outlines of koi diet and other information
13. Jump up ^ "Koi Feeding Guide". Retrieved 2 October 2013. 
14. Jump up ^ Carwardine, Mark (2008). Animal Records. Sterling Publishing Company. p. 201. ISBN 9781402756238. 
15. Jump up ^ "AnAge entry for Cyprinus carpio". 
16. Jump up ^ http://www.sfbakc.org/Articles/SVC_Impact.htm
17. Jump up ^ http://koisale.com/inprogress2/ourkoi.php
18. Jump up ^ USGS Non-indigenous Aquatic Species Program

References[edit]

• Froese, Rainer and Pauly, Daniel, eds. (2005). "Cyprinus carpio" in FishBase. 10 2005 version.
• George C. Blasiola (1995). Koi: everything about selection, care, nutrition, diseases, breeding, pond design and maintenance, and popular aquatic plants. Hauppauge, New York: Barron's Educational Series. ISBN 0-8120-3568-2. 
• David Twigg (2001). How to Keep Koi. New York: Howell Book House. ISBN 0-7645-6242-8. 

http://www.sfbakc.org/Articles/SVC_Impact.htm impacts of SVC Spring Viremia of Carp

External links and further readings[edit]