Not only do guppies reproduce easily in the fish aquarium, but they come in a cavalcade of tropical colors.

Guppies come in a variety of types. Via Melanochromis/Wikipedia

If you have been keeping aquarium fish for more than the past two days or so, chances are good that you have kept guppies. One of my first encounters with tropical fish was a container of guppies that my friend’s mother – we knew her as Mrs. O – kept on the sun porch of their house down the street from me in Cincinnati, Ohio. I was about 8 or 9 years old. Mrs. O had one main aquarium, I think it was a 15 or 20 gallon. The water was pea soup green, and the fish aquarium was filled – really packed – with guppies and some floating aquarium plants.

There were all sizes of guppy fish, from big, fat pregnant females to tiny newborns hiding in the aquatic plants. When Ms. O dropped some fish flake food on the surface of the fish aquarium, the water boiled with hungry, feeding guppies. On both sides of the fish aquarium were all kinds of glass bowls (pickle and mayonnaise jars and other containers), each filled with more guppies.

Apparently, Mrs. O didn’t know what to do with her rapidly expanding population of guppies, so she put them into whatever containers she could and gave them away. Unfortunately for young friends of her daughter, she adopted a policy of checking with parents first before sending a kid (including me) home with a bowl or jar of guppies. My parents declined on the dubious excuse that I wasn’t ready to take care of fish. However, I so often and so unmercifully pestered my parents that on my 12th birthday, I got my first freshwater fish aquarium, all because of what Mrs. O and her guppies had started.

Why the Guppy?

The guppy has a lot to offer as an aquarium fish. It’s very hardy and easy to keep, as long as you give it decent water conditions, a stable environment and decent fish food. It comes in what seems an infinite number of colors and varieties. The list of guppies available from Singapore – the largest producer of guppies for the aquarium trade – fills two to three pages. Guppies are prone to producing mutations and variants – “sports” as they are called in the hobby. Because they can produce each generation in a matter of months, breeding and hybridization programs for guppies are fairly easy to put together.

Guppies can be purchased for 10 cents each for “common” or “feeder” guppies all the way up to $25 to $50 or more for a trio (one male and two females) of top-quality fish. Most stores sell guppies by the pair, but many are now offering males and females separately at different prices because male guppies are by far more colorful and showier.

A Short History of the Guppy

There is perhaps no freshwater fish in the aquarium hobby that has had a more convoluted and confusing history than the guppy fish. The best source for a detailed history of the guppy can be found in the newly revised edition of The Toy Fish –   A History of the Aquarium Hobby in America – The First 100 Years by Albert J. Klee (published by Finley Aquatic Books, Pascoag, Rhode Island). I’ll give a brief summary here.

The guppy was first described by Peters in Berlin in 1859 as Poecilia reticulata from Venezuela. In the same year, Robert John Lechmere Guppy sent some guppies from Trinidad to Guenther at the British Museum, who promptly decided that they were a different species and described them as Girardinus guppii. As proof that the “my name is better than your name” game is not something that contemporary ichthyologists invented recently, during the next 40 years or so, a number of scientists described guppies they “discovered” as new species. Klee gives more than 20 names (including misspellings) that have been hung on this little fish over the years.

In terms of the hobby, in the early 1900s, guppies were being raised in Germany and England, and by the 1910s, the fish had reached the United States. Shortly after WWII, the first guppy societies were holding shows and developing many new, different strains. Now guppies are bred by the millions all over the world. They can also be found all over the world in many bodies of freshwater (or even a little brackish) as they have been purposefully – and perhaps foolishly – introduced to control mosquitoes and other insects that have a water life stage. (This practice is considered unwise because guppies are so prolific, and will usually out-compete any other native fish in their niche/feeding guild.) They also have appeared in many places as the result of accidental (one would hope) releases from the aquarium hobby and commercial breeders.

One final brief note on guppy species: There is a fish in the hobby known as Endler’s livebearer. It was introduced from the wild in 1937 and is currently still in the hobby. Males are very similar to male guppies, although with somewhat brighter colors and green metallic spots not normally seen on male guppies. The jury is still out on whether Endler’s is a separate species or a different type of guppy. Endler’s livebearers are sufficiently different to be accorded the status of “rare” fish, and while kept by many hobbyists, they are infrequently seen in stores. If you do obtain some Endler’s, please be very careful not to allow them to mate with regular guppies – just to keep them “pure,” in case they are finally and definitely judged to be a species of their own.

Keeping Guppies

One of the reasons guppies are so popular and there are so many of them in the hobby is that they are so hardy and adaptable. The “secret” of keeping guppies is to start with healthy stock (more about this later). Assuming the fish you start off with are healthy, guppies are basically undemanding. They prefer a pH of around neutral (7.0), but can adapt down to 6.0 and all the way up to the high 7s (approaching 8.0). Hardness should be moderate, although they can handle hard water fairly well. They do not respond well to very low hardness. Temperature should be in the low 70s (Fahrenheit), but they tolerate down to the low 60s and into the high 80s.

As with most fish, the values for pH, hardness and temperature are not as important as the conditions being consistent and not subject to wide swings over a brief period of time. The better the water quality, the healthier your guppies will be, although they can exist in less-than-pristine water, as long as the conditions deteriorate slowly over time. As with all fish, guppies do best with a regimen of frequent water changes – 10 to 15 percent every week or 20 to 25 percent every other week.

When it comes to fish food, guppies are not picky eaters. Their natural food is small insects and crustaceans, which is why they have been used so extensively for mosquito control. In the aquarium, they will eat just about anything presented to them, and very rarely will they refuse any kind of food. They should have some live plants they can nibble on (hornwort, Egeria or water sprite) and should be fed prepared foods that have a high vegetable content, such as Spirulina. Frozen or live fish foods of approprite size are, of course, taken with great gusto.

Breeding Guppies

Guppies are livebearers, which means that every 30 days or so, the female will drop a litter of babies that are fully formed miniatures of their parents. In a community aquarium with other types of fish or in an aquarium with many adult guppies, the babies stand an excellent chance of becoming a snack for the adult fish. If you have a lot of floating plants in the aquarium, some of the babies will probably survive, but if you want to maximize the number of offspring that make it, it’s best to give the pregnant female her own small aquarium in which to give birth. A 5- or 10-gallon fish aquarium is fine.

This fish aquarium should be set up with floating spawning mops and more mops on the bottom of the aquarium, and/or some dense aquarium aquatic plants like Java moss, hornwort or water sprite. Use a sponge filter and heater (if needed). The female should be added to the aquarium when she just begins to really show her pregnancy because moving her too close to her due date runs the risk of her dropping her babies before they are fully formed. I prefer not to place guppies (or any livebearers) into those small plastic breeding traps because I believe they can stress out the fish. I think that the “net” breeder setups with aquatic plants or spawning mops are better, and if you cannot set up a dedicated aquarium, net mesh will do in a pinch.

Once they get pregnant, female guppies are almost always pregnant. Even without the presence of males, a female guppy can get pregnant with future litters by storing sperm from a single previous mating to produce a few more batches of babies. This is an attribute known as super-foetation. The “millions fish” (an old common name for guppies) can have huge numbers of offspring in a very short period of time. Consider that a female guppy can get pregnant at 2 to 3 months of age. Each pregnancy can lead to 20 to 50 babies. These babies can themselves throw 20 to 50 more babies within two to three months, and on and on. If you do the math, you can see that pretty soon you get a lot of guppies.

Here’s a word of caution about local fish store guppies: It is virtually impossible to guarantee that you will get a pure strain of guppy (ones in which the babies will all look like the parents). The females are usually young breeders that are sold after they’ve dropped a few batches of young. The males come from everywhere in a hatchery or wholesaler. The fish in your local fish store have all been commingled, and to a guppy it matters not what strain or color they are – any male will mate with any female. After a few generations of random mating, guppies will begin very quickly to revert to the wild-looking fish, and lose much of their beautiful but artificially bred tail size and color. If you want to be sure of a true strain of guppy, you will likely have to get them from breeders who advertise in fish magazines and on the Internet.

Obtaining Healthy Guppy Stock

I believe that local fish stores are the backbone of our hobby, and should be supported and patronized as much as possible. Unfortunately, it’s tough to get good guppies from them. This is because most of the guppies sold wholesale to stores come from the Far East, primarily Singapore. These fish have been forced to grow as large as possible within the shortest time. This is done by keeping the fish at high temperatures, feeding them all the time and changing the water constantly.

These fish look spectacular when they first come in from overseas and should be hardy. They fail easily, however, because they are suddenly subjected to the normal conditions of a wholesaler’s aquarium, then they’re sent to the retail store and eventually to you. They have been subjected to all kinds of water, put into small bags and shipped halfway around the world, and go from being fed all the time to being fed sparingly, if at all. Stress is the biggest problem for all fish, and believe me, imported guppies have been stressed.

In addition to all the above, they are now subjected to forms of bacteria and parasites they never were exposed to before, and they do not have much resistance left. The poor fish are susceptible to a variety of problems, and they simply die “without any reason” you can put your finger on. In order to obtain as healthy fish as possible from your local fish store, make sure the fish you’re buying have been in the store’s aquariums for a week or so, and have adapted to aquarium (as opposed to hatchery) life.

If possible, you are best off buying guppies from a local fish store that gets them from a local breeder – or possibly try to find a local breeder yourself. Your local aquarium society is the best way to find breeders, or you can find them in the classified ads in the back of this magazine. There’s also the Internet. Buying from breeders will usually assure you of healthy stock, although some breeders keep their fish in such sterile conditions that the fish have very little resistance and will fare no better in your aquarium than imports. You should be prepared to spend a lot more on fish from a local breeder or over the Internet than from your local fish store.

“Guppy Disease”

It seems that some types of popular fish are developing their very own diseases. Koi are the most recent example, with a very serious viral infection decimating many of the fish in Japan and other places. Discus and angelfish both have their disease syndromes known as the “plague.” Guppies also have one for themselves; there is definitely a constellation of symptoms confined to guppies that pretty much don’t affect other types of fish in an aquarium.

This guppy disease usually starts with whitish patches on the body of the fish, primarily on the mouth, and around the dorsal fin and the base of the tail fin. Shortly after the white patches appear, the fish becomes sort of rigid, seems to have trouble swimming normally, and the fins clamp up. Guppies that reach this stage usually perish within a day or so.

I have seen many published accounts of guppy disease and how to treat it, and I’ve spoken with a number of folks about it. In addition, because I wholesale fish to local fish stores, I have also had this problem with the guppies I bring in from the Far East.

I think that this malady is a combination of a protozoan and a bacterial/fungal infection. I have had excellent results in preventing this disease in guppies I handle by using Quick Cure and triple sulfa. I treat the fish when they first arrive, and then two days later I do a 25-percent water change. I treat with triple sulfa only every other day for three additional times. I would appreciate hearing from any of you who have tried this treatment, or who have any other ideas/experience with the cause and cure of this problem.

Types of Guppies

Many strains or types of guppy fish have been developed over the years. I suggest you obtain the Klee book I cited earlier for a thorough discussion of the history and development of what we now call “fancy” guppies. Most of the fish you will find in your local fish stores are “fantail” or “deltatail” strains of guppies. All have very wide, flowing tails and dorsal fins, usually of the same color or pattern. Among the real guppy specialists – the folks who enter and win shows and who sell their fish through this magazine and on the Internet – you will also find swordtail and lyretail guppies of many variations. These are not usually seen in local fish stores because they are not as flashy and colorful as the guppies with fantails or deltatails.

Fancy guppies come in virtually any color you can think of and in a few albino strains. Blues, greens, reds and yellows are probably the most common colors available, with many variations on each color strain. Males show the most color and have the largest fins, but in the better strains of fish, females also show a fair amount of color in their tails and dorsals. Females of all strains usually have very little color on the body.

In uni-color strains of guppies, the body, tail and dorsal fins are the same color. Tuxedo guppies have a black rear half of the body, and then another color on the tail. Some also have a golden sheen to the front of the body. Snakeskin is a strain of guppy that has wiggly lines all through the body into the tail.

In addition to these sort of “standard” fancy guppies that combine body and tail coloration, there are all kinds of different-looking progeny from crosses of guppies that are never fixed. My favorite one is called “tequila sunrise,” in which the males have a yellow body with a red tail edged in yellow (sort of like the cocktail of the same name). These fish come from the Far East, and as with many unique and attractive fish in the hobby, only males are available. This is an attempt by the breeders to ensure the market for this fish is all theirs, and they have succeeded so far.

On the private breeder/club level of guppy breeding, there are strains called Moscows that come in solid colors such as “Moscow greens” or “Moscow purples.” These are huge fish, very sturdy, with large flowing fins, and the entire fish is one color. These guppies have yet to make it to the mass market of local fish stores, but they will likely eventually get there.

The guppy is all over the world both in the wild and in the tropical fish hobby. They are easy to keep, beautiful and inexpensive, and they breed – well, like guppies.

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Fish · Freshwater Fish