How to breed goldfish, Carassius auratus, with pictures

Crowded. Most feeders are kept in very crowded conditions. Crowding can stress comet goldfish and enable nasty germs to get a foothold. It usually won’t hurt a predator fish to eat a sick fish. Their stomach juices eat up the germs. However, it could hurt that predator if you dump in several sick fishes that don’t get eaten right away. Examine your feeders before you feed them out.

Quarantine. Keep a close eye on your comet goldfish no matter who sells them to you. Fishes sold by the thousands per week don’t get as well inspected as fishes sold one or two at a time. Keep them in a separate tank -- not with your oscar you’ve been babying for three years.

Prophylaxis. Put comet goldfish in two-day old water with one teaspoon of salt per gallon. Add a water conditioner (We like NovAqua) and a standard ich remedy at half strength for three days. This adds about 20 cents per tank to their cost. This is the cheapest fish life insurance you will ever buy.

Add Salt. Why salt? Salt decreases the harmful effects of nitrites in the water. Nitrites are always a problem in new tanks. Salt also helps comet goldfish build their slime layer (their first defense against diseases) and decreases osmotic pressures. They need salt -- especially in new tanks.

Ammonia Remover. New tanks with inadequate filter systems also generate enough ammonia to stress and even kill comet goldfish. Ammonia comes from the digested food the fishes process and from any uneaten food that spoils on the bottom. If your feeders look a little wilty, use an ammonia remover before their gills burn out.

Clean Water. Frequent water changes prevent most comet goldfish problems. Water changes dilute any toxins or parasites in the water.

Cool Water. Goldfishes do not need a heater. We call them “cold water fishes” because they can live under the ice. You can crowd the heck out of comet goldfish if you keep them in cool water. It holds more oxygen. Tropical fish cannot stand these temperature extremes.

Test Fish. People think of small goldfishes as tough as nails. Not so. These young comet goldfish are fairly fragile. So why are they nearly always used as test fish when checking whether a tank will support aquatic life? Because of their price. Anyone would rather lose a few econo goldfishes than a dozen African cichlids. We test our new tanks with larger feeder goldfishes.

Small Bowls. Goldfishes are tough enough to survive in “goldfish bowls.” The advantage of bowls over the so-called “executive (with the emphasis on execute) aquariums” is that no one thinks the bowls are aquariums. Most people realize the limitations of goldfish bowls -- they get dirty fast. Ditto for those executive aquariums, except that executives don’t realize they are still fish bowls.

Fun Night. We give hundreds of comet goldfishes away on school fun nights. Actually, we’ve started giving out “Winner Certificates,” because by the time a nine-year-old kid carries the free goldfish he won around for two hours, the poor fishes lifetime warranty is usually expired. Certificates give Moms a chance to say “No” and give us a chance to put the winner’s new pet in enough good water to assure its survival.

Size. Those little two-inch feeder comets could live for up to 10 years and attain a foot in length (plus fins). When you see huge goldfishes cruising the local golf course, you know where they came from. They outgrew someone’s fish bowl or aquarium. They rarely attain their full size potential when kept in tanks.

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Sarasa comets look pretty good. For some reason, most goldfish with a red and
white pattern show much brighter reds.

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Goldfish kept outside develop deep, rich colors.

Color. Indoor goldfishes seldom show the bright reds we see on outdoor specimens. Why? They need special foods to bring out their red color -- foods high in carotene. When kept out in full sunshine, comet goldfish find and eat sufficient algae to color them to the max. Indoors, they need foods high in spirulina and crustacea or “color foods” to bring out their color potential.

More on Color. The advantage to feeding your feeder goldfish color foods is the way they let you feed the color foods to your predator fish. When your predator eats the goldfish, he also gets a fair helping of color foods. This can really brighten up your predators.

Overfeeding. If you overfeed your feeders, you cause problems. Solution? Add some mystery or trapdoor snails. Snails eat whatever’s on the bottom, no matter how stale. This means fewer water changes and healthier fish for you.

Plants. If your tank has access to light, add some plants. Plants “eat” a good deal of the pollutants your comet goldfish give off -- carbon dioxide and ammonia for starters. Some people also like to add plants because their goldfish snack on the leaves.

Livebearers. Moons and guppies make poor tank mates with comet goldfish. Ditto mollies and swordtails. They continually pick, pick, pick on their slime layer. This won’t kill the goldfish but it has to be an irritant to have something chewing on you all day long. If you work in a big office, you know what we mean. Livebearers really stress goldfishes.

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Every fall we get buckets of comets from pond keepers closing down for the winter.

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When you get right down to it, goldfish really catch your eye.

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Here's one of the feeder goldfish that was born without a tail. Tough little devils.

Last Words. We’ve mentioned slime more than once. Comet goldfish crank out much more slime than other fishes. You need to wipe your tank front more often with comet goldfish. Add a Plecostomus to help keep your glass clean. LA.

Tommie Eakins, Knoxville, TN, August 31, 2007
Hi, First off, kudos on having such a WONDERFUL website! I stumbled
across it while googling possibilities for new fish. Your attention to detail and incredible amounts of knowledge are a great resource. The creative writing keeps things entertaining and enjoyable. Excellent job!
I just wanted to point out an observation regarding the sentences "You need to wipe your tank front more often with comet goldfish. Add a Plecostomus to help keep your glass clean." on the page http://
www.aqualandpetsplus.com/Live%20Food,%20Goldfish.htm

It is well documented (google will reveal many instances) that COMMON
plecos tend to really enjoy sucking the slime coating off of common goldfish and comets. I don't know about Koi, though. I personally had to remove a 10 inch Pleco from a pair of foot long Comets (indoor) due to this problem. I kept noticing a scale missing from the comets here and there... could not for the life of me figure out what was going on, but one night as I happened to be passing by the tank a few minutes after lights out, I saw the pleco dart full speed at a comet and drill it in the side, followed by the unmistakable glimmer of two shiny scales floating free. I got on the magic internet, and sure enough, plenty of people have had the same
problem. Apparently, it is the same problem as you described with
livebearers -- the Pleco really likes the taste of the slime coating on the goldfish. I don't think they mean any harm, and I never experienced any long-term problems in the comets as a result (the scales grow back in a few weeks to a couple of months), but without action, I'm sure that the goldies would be much more susceptible to illness due to the raw spots on their sides.
In fairness, there are some goldfish/pleco keepers who swear that they've never had a problem, and I don't doubt that, but there certainly are a number of us who have experienced this behavior.
Interestingly, many goldfish owners report that bristlenose plecos and other similar (mainly smaller) species have not shown the same behavior. Beats me as to why, though.
Just wanted to bring this to your attention! Hope all is well,

A: Right you are. And hungry plecos are even more likely to nail koi. I'm adding your comments to my comet page. LA