The Koi, goldfish and pond fish is a durable teleost physostome fish of the Cyprinid class. The Koi, goldfish and pond fish is scientifically referred to as Carrassius auratus. Koi, goldfish and pond fish occur in numerous varieties, which are described in detail in other sections of this book. As pet fish go, the Koi, goldfish and pond fish may be one of the most hardy fishes kept as an ornamental species because it can withstand temperatures as low as 33 degrees Fo and as high as the low 100’s in the peak of summer. Koi, goldfish and pond fish can withstand very poor water quality for long periods of time if they are spared any additional stress. It is clinically relevant that they are fundamentally a river fish, but can adapt to almost any body of water as long as some nominal water movement oxygenates it. As river fish, the hobbyist will find the Koi, goldfish and pond fish more energetic and active with dynamic water current and plenty of aeration. Stale still water tends to flatten their usually lusty activity level.

As an ornament, the fish is unparalleled. There are more colors and body morphs of this species than any other ornamental fish. The Koi, goldfish and pond fish in it’s many forms may range in size from a diminutive Natkin which may be only 2 inches at breeding size, up to a twenty to twenty two inch Pond Comet. Larger still, the Koi  x Comet hybrid can lumber in just under two feet and weigh six pounds.

Finally, Koi, goldfish and pond fish can represent a human achievement on several levels. The proud owner of a beautiful Ranchu or Lionhead who wins a ribbon in a Koi, goldfish and pond fish Exhibition will cherish such a pet and derive great pleasure from the possession of such a living jewel. <graphic>The breeders in Hamamatsu City in Japan take their Ranchu so seriously, that they trace their pedigrees back many generations and provide certificates with each fish sold. They have every reason to be proud. And finally, a hobbyist may be proud of a collection of valuable and attractive fish for many years.

Help With Koi Problems
Koi Community rates a variety of forums and message boards on ease of use, friendliness and quality of help. Not all boards are created equal. Not mincing words here.

Books on Koi Diseases
You will be introduced to Dr Johnson's Koi Health book but also to other books he's reviewed.

Finding Reputable Dealers
The fish are only as good as the dealer holding them. Quarantines, guarantees and fish quality all factor in. What to ask, what to see and how to handle your new fish.

Koi Filtration - Natural
Requiring no weekly management but one big yearly overhaul, natural filtration is the easiest there is. Relying on live plants and organic processes, water quality is usually superb. Described and common mistakes illustrated, visit this site!

Koi Food & Feeding
What should you feed your koi? How many times per day? Is Corn really that bad in a Koi diet? What are the most common feeding mistakes people make? What's the best food?

Koi Filtration - Natural
Requiring no weekly management but one big yearly overhaul, natural filtration is the easiest there is. Relying on live plants and organic processes, water quality is usually superb. Described and common mistakes illustrated, visit this site!

Buying Domestic Koi
What does "Domestic" koi mean? Why would you buy that kind? How do you pick good and healthy ones? Who sells them and where do you find the best ones?

 KoiCrisis.com
Koi Crisis has a symptoms chart by system you can choose the symptom by fish part, and resolve a lot of Koi pond fish problems or at least, learn about them understand how to remedy them.

Fish Medicines
Learn about fish medicines, what they do, and where to get them.

Fishdoc.co.uk
By Frank Prince-Iles. A UK authority who put this site together some time ago and which is still relied upon as a major source of good Koi and pond fish information
DrJohnson.com
More than koi health, this site spans all things animal, by a real veterinarian who shoots you straight.
Koivet.com
Koivet is a venerable, long lived koi and pond fish health site started by Dr Erik Johnson in 1994 as an off shoot of his first few websites at Mindspring.com. Now Koivet is full of information and movies and more.

Koi Beginner
Once you've leapfrogged through this tutorial you will have a solid, working concept of the Koi hobby and what it's all about. This is done just about exclusively with video and very little written material.