Goldfish, Koi and Other Goldfish Varieties

by JOSEPH J SIEGEL ~ June 17, 2001

Flat-Bodied Goldfish
This is a hardy strain that can be kept in aquariums or outdoor pond settings. In body shape it is nearly identical to the common goldfish. Its fins, however, are much longer, especially the caudal fin. In a good specimen the caudal fin is almost as long as the fish's body, but it can still be held erect. The caudal fin is deeply forked, and the lobes are sharply pointed. The fish is usually a deep reddish orange metallic color but sometimes can be more yellowish.

The comet is occasionally found with pearly scales, giving it a variegated color. It is known for its swiftness as a swimmer and a good feeder. A comet only reaches a length of 7 to 10 inches. Even the young fish at 2 inches their caudal fin begins to elongate. It is easy to tell that this is a comet and not a common goldfish and is an excellent variety choice for a beginner.

Shunbunkins
This fish was developed in Japan around the 1900s and in China is known as Chuwen-chin. This species is known most commonly as calico goldfish due to its arrays of color such as yellow, orange, red, brown, black, blue, purple, gray and white. The more blue the more they are worth.

There are two types: one is the London Shunbunkin, which is almost identical to the common goldfish and reaches a size of 6 inches (15cm). The second one is the Bristol Shubunkin which is the same as the common except in the tail area. Its tail has an enormous tail fin that is very wide but not as long as the caudal fin of a comet. The second one is not seen as much but both are very hardy strains to own and they are strong swimmers and competitive feeders. Great for beginners.

Egg-Shaped Goldfish
This group of fish have very short, stubby bodies. It is hard to tell where the head starts and the body begins. There are many varieties of this egg-shaped goldfish but they can be basically be grouped into two groups: one group has a dorsal fin and the other lacks a dorsal fin.

In those that do have a dorsal fin you will see they are very high and often convex along the top edge, rather than concave as in the flat-bodied goldfish. Of course a great specimen of a non-dorsal fin. They will have a well-rounded, smooth back with no bumps or notches.

If yours are not of good quality, they will have irregularities to their bodies which normally are the vestigial dorsal fin bones that are only partially developed. These fish need to be kept together by themselves. Why you may ask? It is simple they are not too competitive in community tanks of other fish or even other goldfish.

As far as health goes they are not the hardest goldfish to keep for reason of a very low tolerance for pollution than that of others. They will not tolerate water temperatures much below 60 degrees (F) or 16 degrees (C).

Breeding Goldfish

There is no reliable way to tell males from females except during spawning season. This is when females become swollen with ripe eggs. The best way to tell females is to look at them from above - from that angle, egg-laden females look much broader than males.

An easier way to tell their sex is look for fish that have white pimple-like bumps on heads and gill covers. If you buy them in a group of six of the larger fish, you will most likely end up with a pair out of the six. These are the males. The bumps are called "breeding tubercles," and they develop just prior to the breeding season. After spawning they will disappear. Occasionally males fail to develop tubercles, but they are still "ripe" for spawning. A less reliable way is by color, as the males are more intense in color than the females.

Pre-Spawning Preparations
A fairly long cooling period, down to 60 degrees F or 11 degrees C or lower, followed by a gradual warming period of the water will trigger the spawning season. Feeding live food such as brine shrimp and worms will condition them quickly. Thick clumps of bushy plants, such as Myriophylium, serve as a spawning site.

Courtship & Spawning
Goldfish do not form pair-bonds. They are promiscuous breeders. Any male will breed with any female. When the temperature of the water rises to 65-68 degrees F or 18-20 C and the fish are "ripe," courtship will begin. At first, and for a few days, males randomly chase females all over the ponds or aquariums, while the colors of both sexes are intensified . . . then heavy pursuit begins!!

The male will relentlessly chase the female into the plant thickets. After a few hours of intense pursuit, spawning begins. This happens by the male pushing the female against the live plants while both fish gyrate from side to side. During the gyrations eggs and sperm are ejected in the water they stick to the plants by sticky threads. After a few minutes the fish separate and the whole process begins again with strong chasing. Spawning is completed in two or three hours. A large females can lay as many as 10,000 eggs. After the spawning is completed the fish should be removed from the tank because they will consume as many eggs as they can be greedy during spawning and after.

Embryo Development
Goldfish eggs look like tiny, transparent bubbles. The incubation time is 5 to 7 days, depending on water temperature - 70 degrees F or 21 C is best.

During this time some eggs will develop a fungus turn white looking like a very tiny cotton balls. Adding some disinfectants such as methylene blue to the water inhibits the spread of the fungus on the eggs.

On the fourth day eyes and a beating heart is visible on the embryos and begins to wiggle in the eggs.

On the 5th to the 7th day the embryos and yolk sac are more pigmented and the larval burst out of the eggs tail first. For the next 48 hours the 1/5 inch or 5 cm long larvae hangs all over the plants and the sides of the aquarium or pond by sticky head glands, eventually becoming free and swimming off in search of food.

Raising The Small Fry
This becomes the most critical period. The fry must be fed well with powder food or live baby brine, micro worms or frozen baby brine shrimp. Most quality local fish stores will carry them if not you can raise your own brine shrimp. This is usually where you begin to lose your fry. This should be left to more experienced hobbyist usually, but even as a beginner, if you're interested, give it a try - it's lots of fun and work.

Egg-Bound Goldfish
Add one handful of Epsom salts (found in the spice or baking sections of most grocery stores or sometimes in health and beauty care) per 20 gallons of water in the tank.

If this does not help you may remove your fish and try milking the fish VERY CAREFULLY THIS IS VERY DANGEROUS FOR YOUR GOLDFISH. It will work ONLY THE LAST RESORT to SAVE your FISH.