Name: Poecilia reticulata
Origin: Tropical Americas
The captive-bred fancy guppy is arguably the most popular aquarium species in the world. Derived from the wild species Poecilia reticulata (originally from Central/South America) it is small, beautiful, peaceful, lively and generally hardy. Better yet, there's a myriad of colorful variants that can be collected and easily bred, so the guppy is one of the best choices for beginners in the hobby, especially children. I'm sure almost everyone has this figured out already, but just in case: the fancy guppy males are the ones with more slender bodies and large tails, while the females are bulkier (especially when pregnant, which is almost always) and are generally less colorful. If you look carefully at the anal fin (the fin just in front of where the poop comes out) you'll also see the difference between the female's normal fan shaped fin and the male's modified tube-like fin (gonopodium).
Guppies are reasonably tolerant of water parameters and many beginners can keep them alive for a year or two without even doing any type of monitoring, but if you try to keep stable pH from neutral to slightly alkaline (7.0-7.5), stable temperature around 26-28°C, and a good maintenance rountine you'll have more colorful, healthier and longer lived guppies (3-5 years). Feeding guppies is straightforward, they're always hungry and will accept all types of food, but there are specialized commercial foods meant to enhance fin growth and coloration.
Breeding guppies is essentially automatic, just add water. Many times you don't even need a male since the females can store sperm and already come pregnant from the shop. As everybody knows, they're livebearers so the babies develop inside the mother and she expels them already fully formed, as miniature versions of their parents. Guppies are NOT good parents, they'll readily eat their own young if they can, so special breeding nets/tanks are needed if you want to raise the young. In a well planted tank, many babies do survive unattended by hiding in between the vegetation, and as soon as they pick up a reasonable size they're safe from the adults.
As already mentioned there are many varieties (strains) of guppies, and guppy breeders in many countries are very dedicated and organized, forming clubs, holding events, competitions and auctions. While "mutt" guppies are so cheap they're often used as feeder fish, well-developed strains can reach some pretty impressive price tags.
The guppy is the ideal beginners fish, although in my experience it does not seem to be quite as hardy as it used to be, possibly through excessive inbreeding. An easy livebearer to breed, it is a good idea to obtain male and female from different sources to prevent the problem of inbreeding since fish from the same source are probably related.
Along with the fact that most fancy guppies that are available are inbred, most adult males appear to be completely un-interested in breeding, possibly because of the size of their tails. If you are interested in breeding them, try getting immature males, or if you're just interested in keeping guppies (as opposed to breeding for a physical type), then try crossing the fancy females with healthy feeder males to get a much hardier crossbreed.
Guppies are spectacularly beautiful and usually do well in a guppy tank, but from my experience, they do not do as well in community tank as many people suppose. They [the fancy varieties] are often the first to catch disease and are also very succeptable to harrassment, being one of the most peaceful fish around. Beginners should use caution in keeping them with a large variety of species.
Guppies are beautiful, hardy and tolerant, as well as very peaceful. An excellent community fish. One of the most important things to remember is to get the male female ratio right. I found that the following ratio works quite well: 1 male for every 3 females. A smaller ratio usually results in the males nipping each otherīs fins. Otherwise I found them not too easily harassed by other fish. WARNING! not a fish to have if you do not know what to do with all the fry!!!
Guppies a community fish? Well, due to their peaceful nature they won't harm any other fish in your tank. Unfortunately, I have recently witnessed other fish and shrimps harrassing my prized fish. In my tank I had two blue Gouramis, two beautiful white satin Angel fish, several colorful tetras, a dozen ghost shrimp and one shrimp that grew ten times it size in three months and became a threat. Despite their mean appearance, when the tetras were introduced to the tank I didn't see them attack the guppies. They were too busy playing amongst themselves. It wasn't until they were settled that they began taking interest in the Angel fish and guppies. First I noticed the Angel fishes fins getting shorter and shorter (the two long one's that sweep downwards). Then I noticed that a few of my guppies had chunks of their tail missing. After careful observation I found it to be the tetras fault so I removed them. I was fond of the Gouramis. They were the blue tigers of my tank and though they did appear a little aggressive at times I hoped I wouldn't have to remove them.
Alas, they pecked at my guppies one too many times for my liking so I removed the Gouramis. I had always thought that ghost shrimp were passive, gentle creatures. However, I noticed that if a fish was sick in the tank the ghost shrimp turned into vultures and would attack it! I removed the ghost shrimp. While the big shrimp in my tank was too slow to catch anything I was concerned that at night when the fish were resting at the bottom of the tank it could get up to some mischief. Indeed, it wasn't until I had removed all of these other fish (excluding angels) and shrimp that signs of harrassment stopped completely.
Now I have a beautiful tank of several different strains of guppies and about 20 fry. I have many times in the past tried to mix fish and have a community tank. Unfortunately, I have also made a lot of fish suffer as a result! Not only are my guppies now swimming in a bastion of peace unharrassed by any fish but I feel a lot better and happier. Not only can mixing fish be a strain on certain fish in the tank but also on you. It disturbs me seeing my fish physically harmed and suffering.