Koi (Cyprinus carpio carpio) Care

Basics

Koi (Cyprinus carpio carpio) are a common sight in ornamental ponds around the world. They represent good fortune and luck in many cultures and are sometimes referred to as living jewels. Koi are the domesticated form of wild Asian carps. The processed was begun in the 1800’s when fish that showed more gold coloring than others were pulled from fisherman’s net and put into ornamental ponds. By the 20^th century many of the recognizable color patterns were firmly established.

Koi come in combinations of yellow, orange, red, black and white. One of the most common color patterns is a simple white and red koi. This is called kohaku. A kohaku koi with a single red patch on its head is called a tancho and is highly prized because they resemble the Japanese flag as well as the sacred tancho crane. Some tancho koi sell for over a thousand dollars.

Tancho koi (KoiQuestion @ Flickr)

Minimum tank size

As beautiful as they are, koi are not for the everyday hobbyist. They are large fish that require large tanks or ponds. The average size of a properly cared for adult koi is over a foot (30 cm) long. When given enough room and good food, champion koi will reach almost three feet (91 cm) long. Like goldfish, they are also copious producers of ammonia. A fish of this size and dirtiness cannot be housed in a normal sized tank. I don’t recommend anything smaller than 500 gallons (1,892 L) for a single koi. I know other people would choose to keep them in smaller tanks, but I feel it would not give the fish enough room to reach its full potential.

There are a few different ways to stock a pond. Some koi hobbyists have heavily stocked ponds with professional-grade filtration systems and do large weekly water changes. Some, like myself, chose a more relaxed approach. I only have one fish per 550 gal (2,082 L) of water. This lower stocking level means I don’t have to spend as much on equipment and maintenance. As with a lot of fish, there are a few right ways to stock a pond and most of it depends on how much money and time you want to put into it. But there is one certainty with koi: they need large ponds.

Temperature range

Koi are a hardy pond fish with a wide temperature range. They can survive in water that is almost below freezing or up to tropical temperatures. The important thing is that they experience these transitions gradually. In a large enough pond there is little worry of temperatures changing drastically overnight; this is another reason to keep koi in large volumes of water. The generally accepted range of temperature tolerance for koi is 35F (2C) to 85F (30C). I highly recommend putting a thermometer into the pond because air temperature and water temperatures can differ greatly.

Keeping the water moving helps prevent freezing over (Aquascape Inc)

The depth of a pond plays a large role in temperature control. The deeper the pond is, the cooler it will be in the summer and the warmer it will be in the winter. This may seem counter-intuitive, but the ground acts as insulator against both the cold and the warm. It is this same principle of insulation that keeps caverns the same temperature year-round. The farther north you live, the deeper you will need to dig your pond in order to prevent it from freezing solid in the winter. In the southern US you may only need to go down 2.5 feet (76 cm), but in Ontario, Canada you may have to dig down 5 feet (1.5 m) deep.

Water quality

Just because koi are hardy doesn’t mean that water quality isn’t important. If you want to grow large and beautiful koi, clean water is a must. Just like with tanks, koi need filters and water changes. The filters on ponds are large and scaled to the pond, but just like tanks they will need some kind of regular maintenance, whether it is professionally done or your own labor. I clean the debris out of my filter about three times a year: once when I take the leaf net off in the spring; once in the summer; and once in the fall before I put the leaf net on the pond for the winter.

Because ponds are located outside we get assistance from Mother Nature with water changes. Unless you live in a desert climate, water changes are taken care of for you. When it rains, the fresh water enters the pond and causes it to overflow (most ponds have directed overflow drainage that also protects the fish from getting swept out). When the pond overflows, the older dirty water flows out and is replaced with the incoming fresh water. These pond overflows can also provide a nice area to plant a bog garden.

Bog garden with pitcher plants adjascent to koi pond (mmwm @ Flickr)

Food

Koi, like goldfish, are omnivorous fish. Because they are subject to large temperature changes throughout the year, their diet has to change with the seasons. Fish are cold-blooded which means their ability to digest food is dependent on the outside temperature. In cool weather they cannot handle protein-rich foods; if fed too much it can rot in their digestive tract and kill them. For this reason there are two general types of koi food sold: warm water food and cool water food.

At temperatures above 65F (18C) koi should be fed a staple food, sometimes called summer feed. This is food with a higher protein content, usually above 35%. Koi metabolisms work fast enough at these temperatures to digest proteins. This is when most growth occurs. As the temperature increase, you increase both the volume of food and the frequencies of feeding.

Koi eating floating pellets (Kristen Shoemaker @ Flickr)

Below 65F (18C) koi should be fed a wheat germ-based food. Below 65F (18C) the koi metabolism slows and cannot handle high proteins, but until the water reaches 50F (10C) koi still need to be fed. This high-carb food is easy to digest and helps them gather enough energy for winter hibernation. As the temperature decreases you lower the amount and frequency of feedings until you are only feeding once every couple of days. Below 50F (10C) your koi should not be fed. They are in hibernation. If the temperature warms slightly in the winter, they will graze on algae and detritus in the pond. 

I have included below the temperature feeding schedule I use for my koi. There is some debate about the exact temperatures among koi hobbyists but this is what has worked for me.

TEMP (°F)	FEEDING REGIMINE
Above 86	Feed cautiously as adult koi metabolism can shut down in temperatures approaching 90F
70 – 86	Every day. As much as they can eat in about 10 minutes. Feed 3 – 4 times a day.
69 – 65	Every day, twice a day with a staple food.
64 – 61	Every day, once a day (mix of wheat germ and staple). Midday feedings are best.
60 – 55	Every 3 to 4 days (Wheat germ base)
54 – 50	Feed once a week with presoaked if koi are moving around (Wheat germ base)
Below 50	Do not feed!

 

Substrate

This is more of personal preference than koi preference. Koi thrive in bare-bottomed ponds, gravel-bottomed ponds, and mud-bottomed ponds. Bare-bottom ponds are easier to keep clean. Most serious koi hobbyists use these types of ponds because it enables them to keep the water crystal clear to grow massive koi. Some Japanese water gardens use mud bottom ponds because that is traditionally how koi were kept. Koi breeders who breed the traditional way use mud bottom ponds as spawning sites. The downside to mud-bottom ponds is that koi like to root around in the substrate, and the stirred-up mud obscures your view of these gorgeous fish. I prefer a light layer of large gravel over the pond liner as it produces a natural look without the cloudiness of mud.

Tank mates

Koi, like most carps and minnows, are social fish. They prefer the company of their own kind but also do well with goldfish (Carassius auratus auratus), golden tench (Tinca tinca), channel catfish (Ictalurus punctatus), and golden orfe (Leuciscus idus). Sturgeon (Acipenseridae) do not make good pond-mates for koi because they are shy and require a carnivore-based diet. Koi should not be housed with fish that will fit in their mouth because they can and will eat the smaller fish. While guppies (Poecilia reticulata) would look pretty in with your koi, they will likely become snacks.

Juvenile blue and golden orfe (Pete Turnbull @ Flickr)

Plants

Koi, like goldfish, are notorious for eating plants in ponds. Most people don’t keep floating or submerged plants in koi ponds for this reason. However, marginal plants, bog filters, and waterfall filters are very popular. Not only do they add an aesthetic beauty but they also help keep the water clean.

Marginal plants are placed on the edge of the pond so that just the roots are in the water. There are two types of marginal plants: hardy and tropical. Hardy marginals can survive through the winter in most places but tropical marginals cannot (unless you live in a semi-tropical climate). Most of these plants need a decent amount of sun, so in my mostly shaded pond I can only grow a few marginals. I maintain a number of yellow flag iris (Iris pseudacorus). Tall marginals like cattails (Typha spp) and arrowheads (Sagittaria spp) should be placed on the far side of the pond so as not to obstruct your view. Low-growing marginals like marsh marigolds (Caltha palustris) should be planted on the side of the pond where you will be viewing the pond most times.

Marginal plants can also be put into a bog filter. This is a separate area of the pond that the koi cannot reach. It will only have about 6 inches of water which enables the roots to stay wet. This water comes from the koi pond filled with nutrients for the plants. The plants remove the nutrients generated by the fish and the cleaned water is returned to the pond. Some people who have koi that even eat the roots find this a wonderful way to introduce plants into the system without having to worry about them becoming a koi snack.

Water hyacinth in waterfall return (source unknown)

Another way koi-keepers can sneak plants into a koi pond is with a waterfall filter. The water return at the top of the waterfall of a koi pond is often an open-top barrel. Some people (including myself) use this space to grow plants. You can use floating plants like water hyacinth or marginal plants, and I’ve even seen people grow veggies hydroponically there.

Interesting facts

Koi are renowned for their longevity. The average lifespan of a properly cared for koi is between 20 and 35 years, but there have been some special cases that long surpassed that average. In a small, creek-fed pond in Gifu, Japan there were six fish that far surpassed that average. Hanako, a scarlet koi, was the oldest of the lot. She was hatched in 1751. To put that in historical perspective she hatched 25 years before the Declaration of Independence was signed. This was verified by Prof. Masayoshi Hiro, D.Sc., Laboratory of Domestic Science, Nagoya Women's College. She removed a scale from Hanako’s body and counted the growth rings under a microscope, much as you would count the growth rings of a tree. In 1966 when the interview with Hanako’s owner was aired on radio, the other koi in the pond were 170, 155, 151, and 141. Unfortunately Hanako is no longer alive today. She died July 17, 1977 and was 226 when she died.

Hanako and her keeper (Northernkoi.org)

All over the world, koi symbolize luck and fortune, but most people don’t know the reason why. An old Chinese legends hold that long ago the supreme god of the heavens called the Yellow Emperor became displease with the humans for their evil ways. He ordered the rain god to flood the earth to destroy the humans. Kun, the Yellow Emperor’s grandson was distraught by the destruction and pleaded with his grandfather to spare the humans. The Yellow Emperor did not relent, so Kun stole some “magic mud” from his grandfather’s treasure. Kun sprinkled this mud and as it hit the water turned into land where the humans could take refuge. Furious at his grandson, the Yellow Emperor sent the fire god to kill Kun who tried to disguise himself as a white horse, but the fire god saw through it and struck Kun down.

After many years of continued flooding a golden dragon named Yu emerged from the white horse that was once Kun. He flew to the heavens to plead with his great-grandfather to stop the flood. This time his perseverance paid off, and the Yellow Emperor told Yu to take the magic mud and make land again. Yu easily carved a river through the soft mud, but when he came to rocky cliffs he had to greatly increase his effort to dig out a gorge. In doing so he created huge waterfalls hundreds of feet high. He declared the waterfalls sacred to dragons. The river eventually became known as the Yellow River and those 12-mile long gorges located in China’s Shanxi province became known as Dragon’s Gate. Every spring thousands of koi swim up the Yellow River and if they have the skill and perseverance of a dragon to climb the falls they become dragons themselves. Because of this legend, koi are symbols of hard work, patience, and skill which are all things needed to have good fortune in life.

Taking care of koi isn’t always an easy task, but just like Yu and the Dragon’s Gate waterfalls persevering through the hardships can make the final outcome that much more beautiful.

Works referenced

"Frequently asked water gardening questions." Crystal Creek Pond Supply LLC. www.pondkoi.com. Updated: 8 May 2013. Retrieved: 8 June 2013. 

"Koi Encyclopedia." Pan Intercorp. www.koi.com. Updated: 8 June 2013. Retrieved: 8 June 2013.

"Legend of Dragon's Gate." www.foolonthenet.blogspot.com. Updated: 8 November 2010. Retrieved: 7 June 2013.

"The Story of Hanako." Koi.net. www.playkoi.com. Updated: 29 January 2013. Retrieved: 8 June 2013. 

"Temperature." Koi Club of San Diego. www.koiclubsandiego.org. Updated: 7 June 2013. Retrieved: 8 June 2013.

**Disclaimer** Since there is little to no scientific research about fishkeeping published, much of the hobby today is opinion, but they are opinions given by keepers and breeders who have been doing this longer than some of us have been alive. Temperature ranges and adult sizes are not opinion. They have been scientifically documented.

Summer Tub Update: May

It has been almost a month since I began my summer tub experiment. It's in full swing now. I added the mosquitofish (Gambusia holbrooki) roughly two weeks after I started it. I put in roughly 15 fish, most of them females. They aren’t very visible, but I have seen them a couple of times when I checked on the pond. Unless I see some overcrowding, I’ll wait until the end of the summer to remove some and really take a count of how many I have in there.

Two females and a male mosquitofish

The plants took off after I added the fish. The frogbit has taken over, and I recently removed a couple of handfuls. The water lettuce hasn’t done as well, but that could be because the frogbit is chocking it out. Earlier in May my iris flowered, and the potted grasses are also doing well. 

The iris that flowered on 10 May 2013

Since my koi pond is simply too shaded for most plants, I have never been able to have lilies. This tub with its 5 hours of sun is my best chance to grow them. A week ago I bought a lily plant from Lowes and decided to give it a try in the tub. It has been doing great! No flowers yet, but it sprouted and has broken the surface. I’m really hoping to get a flower or two from it later this summer.

The lily in the middle with dwarf water lettuce in the foreground.

Thus far I feel this is going very well. Because of the cool spring we had I don't feel I could have added tropicals until at least May 15. It's a good thing I wasn't planning on them this year. Although I can't see the mosquitofish that well, I want something that I know will survive on my first try rather than something I will have to worry about while I get the basics down.

Full tub shot!

Summer Tubbin'

It's getting warmer around the US and Europe which means pond season for the lucky few of us, but it's also something special for the serious hobbyist: a chance to expand your fishroom. I'm not talking about an extension on the house; I'm talking about your back porch. In most of the US and Europe, there are at least a couple of months of weather warm enough to house most of our aquarium fish outside.

Hobbyists take advantage of this warm summer weather to spawn and grow fish outside. Some accidentally discover that fish spawn like this while others, often going on the words of those with the happy accident, purposefully put fish outside to spawn. Most people believe the trick to getting the fish to spawn is how closely this replicates their natural environment. The floating plants, the live food, the cooling rain are all things the fish would naturally experience and have evolved to live with. People have had success spawning all kinds of fish from livebearers to egg-scatteres like barbs and tetra. Gourami are another favorite fish to spawn in these tubs.

Tubs used for breeding by renowned hobbyist Rachel O'Leary (msjinxkd.com)

Placement of the tub does matter. You can't put them in full sun all day long as this will heat up the water too much. Ideally you want about 4-5 hours of morning sun. This means  placing them on the eastern side of your house or yard. The tub (or tubs) should not be under cover or eaves of your house because the rain is important to them. Rain cools the water in the heat of summer and provides mother nature's water changes.

Most any tub that holds more than 20 gallons of water will due. Animal watering troughs are a favorite because they are large, built to hold water, and the plastic won't degrade under the UV rays of the sun. You might have to modify the tub a bit. If you don't like the idea of tubs overflowing when you get a lot of rain in a short time, then think about drilling overflow holes. These drain the tub when it reaches a certain water level and prevent the tub from overflowing and sending your plants and fish overboard.

Water trough made into a pond (azcopperpenny @ Photobucket)

An optional piece of equipment is a pump.  Some people like the calming noise of water moving, and some people just like to have some water movement in the tub to keep it a uniform temperature. Something like this would be less important if you were raising gourami or betta spawns.

When setting up these summer tub ponds, you are really at the mercy of mother nature. This often means being familiar with the weather patterns in your area: what time of year it really begins to warm; what time of year you see cooling off; just how much rain you get in the summer. When you see daytime temperatures steadily in the 70's (~ 21C) is when you should begin setup. Just as with a tank, start with the plants first. Fill the tub with a mixture of dechlorinated tap water and water from the tank that you will be bringing the fish. This gives the plants some nutrients to consume before you add the fish. Let the plants get settled for about a week. Then you add the fish. Don't just dump them in; acclimate them like you would any fish. You may also want to place some mesh netting over your tub pond because fish have a tendency to jump in the first few days.

Frogs in the pond are cute, but can eat fry (tomylees @Flickr)

Plants are a big aspect of these summer tub ponds. They are part filtration system, part cooling system, and part fry nursery. The best kind to have are floating plants like water lettuce, frogbit, water hyacinth, and duckweed. These all have roots that hang down and allow fry a good place to hide. Egg-scatterers can attach their eggs to these roots; bubble nesters can attach their nests to the undersides of leaves. If you are looking for some lovely blossoms, lotus plants do well in these setups, too. Marginal plants like iris, cattails, and rushes can be used to add some aesthetic appeal and make the tub really look like a pond. Just like with fish tanks, patience is key!

This summer, I've decided to try out these summer tubs. I have a lot of floating pond plants because they grow so well in the pond, and I have an old plastic tub that I used to haul around pond plants in. The only thing I would need is the fish. As much as I'd love to try breeding my gourami in a tub this summer, I don't want something to go wrong on my first try and accidentally kill them. So I'm going to use the livebearers from my pond, mosquitofish Gambusia holbrooki. When the summer is up I will just put the remaining mosquitofish back into my pond. Next summer I will be spawning my gourami. Wish me luck!!

My tub pond! Grow, baby, grow!!!

Works Referenced

Colleti, Tim, Dr. 2011. "Summer Tubbin': Breeding you Fish Outdoors."  Tropical Fish Hobbyist (June) 86 - 89.

Sipes, John. 2003. "Summer Tubbin'." www.aquarticles.com. Retrieved: 28 April 2013.

Marchio, Liz. 2008. "Urban Pond Tubbin' Water Gardens". AquaScaping World  (June): 8 - 11. 

My tanks: 6 April Update

With spring comes a lot of new things including lots of updates! The weather is finally warming up here, and I'm gearing up for some outdoor summer projects that I will fill you in on later.

First off, the pond is open for 2013! Earlier this week we took the net off the pond. I spent a few hours cleaning out a lot of the algae that built up over the winter and clearing out any debris that made it through the net. The koi were out to greet me and the water is almost warm enough to start feeding them. I start them out with Cheerios at 55F (13C) and move them to wheat germ when the temp hits 65F (18C).

Freshly uncovered and cleaned of most algae

The koi just hanging out in the sunshine.

The next major change is a new tank! I removed the red cherry shrimp from my community and set up a tank dedicated to breeding them. My gourami were making it next to impossible to breed them, so I just removed the shrimp. I moved over the remaining adults and later that week found four juveniles hiding in the moss. Thus far the female has released one clutch of eggs and is holding a second. Because the founding population is so small, I'm going to order more red cherries. Too much inbreeding produces shrimp that are far to weak. The plants are mostly stems with some anubias. The plant list: Bacopa carolinia, dwarf sagittaria (Sagittaria subulata), Myriophyllum mattogrossense, Rotala rotundifolia, Anubias spp, riccia, Subwassertang, and java moss.

Full tank shot

Two males and juvvie eating sinking wafers.

There have also been large changed in my community tank. I've finally added the cardinal tetra. I bought 12 from msjinxkd.com. They came in excellent condition and have been flourishing ever since. They are as gorgeous as they are in pictures, and I'm completely in love. The shoal has been dubbed "The Shinies" and my family remarked that they almost look like they are glowing.

My new cardinal tetra; I apologize for the dark picture.

The other major change in my community has been an addition of more crypts. The dwarf sagittaria (Sagittaria subulata) and dwarf chain sword (Echinodorus tenellus) I had in there was just languishing. I don't know if it was the light or the tannins or just what, but they never grew for me. So I removed what was still alive and placed it in the shrimp tank. I replanted that side of the tank with green wendtii (Cryptocoryne wendtii var green) and red wendtii crypts (Cryptocoryne wendtii var red) and C. spiralis from AquariumPlants.com. I've had minimal melt with them and even see new growth. I'm very pleased with them. You can see them on the right side of the tank.

Full tank shot; the bettas are still in the breeder boxes.

The first of my summer projects I have begun are my snail bowls. Since my goldfish are growing larger and more apt to eat the smaller snails, I need to grow out my snails before I introduce them into that tank. I have set up two old betta bowls as snail bowls. One has hornwort and the other has anarcharis clippings from my betta tank, and both have a layer of duckweed. Because my water is so soft I have crushed coral substrate to maintain a steady pH and enough water hardness for the plants and snail shells. They get weekly water changes with the waste water being used to water the terrestrial plants in the terrarium window.

Right bowl - hornwort; left bowl - anarcharis

Ramshorn snails in the anarcharis bowl

....

Goldfish Breeds

Goldfish are some of the longest domesticated fish. Today there are something like 20 different breeds recognized around the world. Many of these breeds originated in China and Japan, but the US and some Europeans have gotten into the game in the last century. Of all the breeds of goldfish only a handful would actually be recognizable to most people as a goldfish breed. I’ll recount most of the common ones (and some uncommon ones) here.

Single-tail goldfish

Common (also called hibuna)

This is your basic pet store goldfish. These are often the fish you see in the horrible “feeder goldfish” tanks. They are the stereotypical goldfish and resemble the first ones ever domesticated. They can come in any color from white to black to yellow. Their fins are short and their bodies are stocky.  

Common goldfish (Left: Bristol Aquarists Society | Right:raingarden.us)

Common goldfish, like all single-tail goldfish, are not suited for the typical home aquarium. Reports of these guys reaching 14 inches in a pond isn’t uncommon. They make good buddies with other single-tail goldfish as well as koi in a pond. They can be temporarily housed in large indoor tanks, but they are best kept in ponds away from fancy goldfish as commons will out-compete them.

Comet

These guys are one step up from the common goldfish. Their bodies are a bit slimmer, and they gain long, flowing fins. Comets come in solid or bi-color. Commonly found in pet stores, these are all too often stuffed into horrible fish bowls. But they really do best in pond with other single-tail goldfish and koi.

Comet goldfish (raingarden.us)

Shubunkin

Sometimes called the poor man’s koi, these are the goldfish that most resemble the typical koi colors. They have the same body shape and fins as the comet goldfish but are all tri-colored. A well-bred shubunkin will also have rounded ends to their caudal fins. Like koi, shubunkins don’t have a place in the home aquarium. They are best viewed in ponds with comets and common goldfish.

Shubunkin goldfish (raingarden.us)

Double-tail goldfish (fancy goldfish)

Fantail

This was the first fancy goldfish, and today remains the most common fancy goldfish. Their bodies have the typical rounded shape, and their dorsal fin is split into four segments. They come in all colors from black to yellow to tri-color and can have a variety of tail sizes from short to the elongated veiltail. These are generally hardy fish, and depending on how severe the winters are they can be kept in ponds year-round. For a fancy goldfish they are boisterous and fast and shouldn’t be combined with some of the fancier varieties I’ll cover later.

In terms of tank space, fancies are much less demanding than single-tail goldfish. A 30 gal (110 L) tank is just large enough to house two fancies, but really a 40 gal (150 L) or larger tank is best as goldfish like company.

Fantail goldfish (raingarden.us)

Wakin

Another uncommon goldfish breed that is best kept in ponds. These fish are like common goldfish in body shape and growth, but they have a short double-tail. The long-tailed version is called a wantonai. Due to their large size, these fish are best left in ponds as in fact they were bred to be viewed as such. They aren’t found in many pet stores around the country, but many goldfish breeders will have them or be able to acquire them.

Left: Wakin goldfish | Right: Wantonai goldfish (raingarden.us)

A variation of the wakin is the jikin. Jikin have the same body shape, but have all white bodies and orange fins. Since these fish are hard to breed, they are even more uncommon than the wakin.

Jikin goldfish Left: (exoticgoldfish.net) | Right: (Practical Fishkeeping)

Oranda

Similar to the fantail goldfish, but oranda have a fleshy growth on their heads and operculum called a wen. Often times the wen isn’t fully developed until three or four years of age. Oranda can be fast and feisty when they are young, but the large wen will slow them down as they age. Sometimes it will obscure the eyes and cause the fish sight problems. The fins can be long or short, and they come in a wide variety of colors. This is another variety of fancy goldfish that is hardy enough to survive in some ponds year-round provided the temperature doesn’t go below 55F (13C).

The redcap oranda is a specific variation of the oranda where the wen only develops on the top of the head. The wen is red, and the rest of the body completely white. This gives the fish an appearance like the tancho koi or the Japanese flag.

Left: calico oranda (cngoldfish.net) | Right: redcap oranda (lilopet.com)

Ryukin

My personal favorite, the ryukin, is another common variety of fancy goldfish. They have shorter bodies than fantails, but their bodies are thicker. The back should slope up sharply from the head and give a humped appearance. Their fins can be long or short, and they come in all colors from solids to calico. Because ryukin are so short, they often have digestion problems.

Ryukin goldfish (cngoldfish.net)

Telescope

Sometimes called “dragon goldfish” the telescope is another popular and widely recognizable fancy goldfish. They are defined by their bulbous, bulging eyes which give the fish a unique profile when viewed from above. This also gives them a sight disadvantage against other varieties of goldfish; for this reason they should be target-fed if kept with goldfish like fantails or orandas. They come in a wide variety of fin lengths and colors including solid, bi-color, and calico. When they are all black, telescopes are called black moors. The panda coloration (black and white) is another popular coloring.

Telescope goldfish | Center - black moor | Left - panda moor
Left: (exoticgoldfish.net) | Center (kokosgoldfish.com) | Right: (cngoldfish.net)

Tosakin

These little beauties resemble ryukin from the side, but show their true colors when viewed from above. Their fused caudal fins splay out to form a wide veil. They aren’t a very hardy breed, but are best kept in ponds as their tales are breed to be viewed from above. For this reason, they aren’t commonly seen in pet stores as few people can devote the energy to either heating a pond in the winter or constructing an indoor pond. They are most often seen in red and white, but some calico specimens are available. The breed was almost wiped out following the heavy bombing of Japan during WWII, but one breeder managed to find six fish still living in a restaurant. Today all tosakin goldfish are descended from those six fish.

Tosakin goldfish; Left (exoticgoldfish.net) |
Center (rafflesgold.com) | Right (Practical Fishkeeping)

Pearlscale

Still not common by any means, but gaining popularity is the chubby little pearlscale. These fish are even wider in body than ryukin. Their scales also have a pearlescences to them which gives them their name. Since their bodies are so bulbous, they usually have short fins to facilitate movement. They aren’t as hardy as the varieties I’ve previously listed, so they should be kept with other more fancy varieties. They are also prone to digestive problems due to their extremely rounded body.

A pearlscale with a wen is called a crowned pearlscale. Usually the wens don’t develop as fully as they do in oranda, but they do further hamper the swimming ability of these fish.

Right & Center: Pearlscale goldfish | Left: crowned pearlscale
Right (exoticgoldfish.net) | Center (Bristol Aquarists Society) | Left (petgoldfish.net)

Ranchu (sometimes called lion head)

These fish are distinguished by their lack of a dorsal fin and the presence of a wen that extends down the cheek. You may think this renders them rather useless at swimming, but they are adept enough to compete with oranda and ryukin. They come in all colors and typically have short fins. While not seen in all pet stores, they are found in some throughout the country and can be ordered online from breeders. 

Ranchu goldfish; Right: (Petgoldfish.net) | Center & Right: (raingarden.us)

Celestial

This is one of the most modified and fancy goldfish commonly seen. These goldfish have no dorsals, and their eyes bulge and face skyward, hence the name. This gives them a severe sight and swimming impediment. This is one of the breeds that does best in a single-breed aquarium with low water flow and no sharp decorations.

Celestial goldfish; Right: (Bristol Aquarist Society) | Left: (exoticgoldfish.net)

Bubble eye

Another highly modified breed of goldfish. These fish are defined by the large fluid-filled sacks that extend from under their eyes. They lack a dorsal fin and their eyes bulge upwards, too. Those fluid filled sacks are rather delicate and can be burst by objects in the aquarium. They will grow back and repair itself but the two sacks will not be equal in size anymore. Due to their delicate nature, they are best kept in single-breed aquariums. These goldfish are too delicate to combine with most other fancy goldfish.

Bubble eyes;  Right & Left (Bristol Aquarist Society) | Center (cngoldfish.net)

The images of fish and breed descriptions I have given you are from goldfish clubs and breeders. Often times pet store goldfish won’t quite fit into these categories nicely because they haven’t been bred for show. Sometimes you just have to take your best guess at what your pet goldfish is. If you have any questions, feel free to post a picture!