Guppy (Poecilia reticulata)

Group of Guppies, Timothy Jabez, March 10, 2019. Canon EOS 60D. Flickr.

Guppies are one of the most common fishes in the aquarium hobby. In fact, they have been around for a long time, and the aquarium hobby as it is known today probably would not have existed without this fish. While it can sometimes be viewed as a beginner fish, it is so much more than that, and here is everything there is to know about these amazing freshwater fishes.


During the initial days of the aquarium hobby, when it was still in the process of going mainstream, there weren’t a lot of options when it came to the fish. Transportation by air was too expensive, and no other viable way existed to transport most of the tropical fishes available. Only those fish that were small, abundant, and very hardy were capable of being exported, which is how the guppy became so popular in the aquarium trade. 


Almost every guppy sold in the hobby today is captive-bred. However, they originally came from the many different freshwater bodies in South America. They also naturally occur in parts of the Caribbean. It is also worth noting that guppies have found their way back into lakes and rivers in countries they did not occur naturally as a result of being artificially introduced in many places.

Discovery & Etymology

As alluded to earlier, these fish naturally occur in two places, and thus, they were discovered two separate times. This was first done by German naturalist and explorer Wilhelm Peters in Venezuela in 1859. Two years later, Italian zoologist Filippo De Filippi independently discovered the same fish in Barbados.

As this fish was discovered twice, it was known by two names initially – Poecilia reticulata and Lebistes poecilioides. Later, it was named the Girardinus guppii after Robert John Lechmere Guppy, who was responsible for sending specimens of this fish to the western world, and that is how it came to be known as the Guppy. This name has stuck even though its scientific name has changed multiple times after that.


Yellow Cobra Guppy

The Guppy has been subjected to more than a century of selective breeding, creating many varieties. An example is the Cobra Guppy, as seen above. Generally, guppies are small and elongated with a tail that can be everything from short and round to fan-like and elaborate. The colors can also vary widely. The markings on the tails can also differ a lot from one guppy to another and include stripes, spots, and blotches.

One trait that all guppies share is sexual dimorphism. This is when the male and female differ physically. In the case of guppies, the males are smaller, slenderer, and more colorful, while the females are larger, rounder, and not as brilliantly colored. The anal fin in females is triangular, while those in males are narrow and pointed.

Aquarium setup

Owing to their hardiness, there is a common misconception that these fish can be kept in very small setups and feature minimal to no equipment. This is not quite right. Guppies can survive longer than most fishes in unfavorable conditions, but that does not mean they should be subjected to such conditions. 

Guppies need a proper tank instead of being kept in vases, bowls, or bottles. The tank should be at least 10 gallons in size, even though a 20-gallon tank or more is preferable. The tank must have a good filtration system and a heater. The filtration system should be rated at least 1.5 times the total volume of water in the aquarium.

The tank should also be properly cycled before introducing this fish, or any fish for that matter. Regarding the type of filter used, no particular type is preferred as long as it is dependable. The same applies to the heater. It should be rated for the volume of water in the tank and from a reputable brand.

Guppies aren’t very picky when it comes to the tank setup. They can even be kept in bare-bottom tanks, but it is advisable to have some substrate as it makes maintaining the tank a lot easier. Guppies make a great addition to planted tanks, but they will do just as fine in a tank with artificial or no plants. The ideal setup would include a nice mix of open spaces and hiding spots for the fish. As these are active fish, sharp decor should be avoided.

Water conditions

The guppy is renowned for its hardiness and will forgive many beginner mistakes regarding water conditions. However, sticking to the following parameters is recommended. The temperature should be kept between 20°C to 26°C or 68°F to 78°F. The pH can be between 6.5 and 8.0, and the hardness should ideally be between 50 mg/L and 150 mg/L. Even though these fish can tolerate some fluctuations in these parameters, stability is key to their long-term good health, which should be assured as much as possible.


Guppies are very docile and make a great addition to a community tank. However, tankmates for these fish should be chosen with care. The first factor to consider is their temperament. Any fish chosen as coinhabitants for the guppy should be equally docile and of a similar size. The size criterion is important as even gentle fish can either willingly or unwillingly eat the diminutive guppy if their mouths are large enough. Some great tankmates for the guppy are:

  • Mollies
  • Platies
  • Gouramis
  • Cory Catfish
  • Neon Tetras and other peaceful Tetras
  • Swordtails
  • Ender’s Livebearers 

SPECIES-ONLY GUPPY TANK: Given the variety in the shape and colors among guppies, keeping just a species-only tank is a viable option, even for those looking for a good amount of variability in their tank. A few things need to be kept in mind when going for this approach. Guppies are livebearers, meaning they give birth to their young instead of laying eggs. They are also pretty prolific at this, and the females can store sperm for a long period and across multiple spawnings. 

As such, the right ratio of males and females must be maintained to avoid an explosion in the guppy population unless that is the goal. The ideal male-to-female ratio is 2:1.   


Almost all the guppies found in the aquarium trade are captive bred and this, along with their naturally easy-going approach, makes them quite easy to feed. They are omnivores and will readily accept almost anything. For their best health, it is advisable to give them high-quality fish food from micro-pellets or flakes that float. There should also be a nice mix of plant and meat-based food. They should be fed at least once a day with just enough food to consume in about five minutes. Along with this, their diet can be supplemented by giving them live or frozen foods once a week. 


Few fishes are as prolific breeding as guppies are. They can give birth to hundreds of young even in a female-only tank, thanks to the female’s aforementioned ability to store sperm. If breeding is the objective, then there should be two males for every female. They don’t need any special conditions to induce spawning either. They will mate independently, and the female will eventually become gravid and give birth to about 50-100 young.

As the fry is incredibly tiny, it should be kept away from other fish as they will get gobbled up. The males should be switched out after a couple of births to avoid congenital abnormalities and shortened lifespans.

Frequently Asked Questions

How many guppies can live in a fish bowl?

The general rule of thumb is 2 gallons per fish.

Can a male betta fish live with female guppies?

Your betta fish is likely to cause harm to your female guppies. It is, therefore, not recommended.

Which insects can I safely feed to my guppies?

Mosquito larvae.

What is the best water temperature for my male guppies?

The optimal water temperature for guppies (male or female) is between 70–77°F.

Do guppies eat insect larvae?

Yes. Guppies have been used to control mosquito populations.

What are some characteristics of a guppy’s gestation period?

The gestation period in a guppy is approximately 30 days and it produces between 2 to 100 offspring per brood. Younger and smaller females tend to produce fewer offspring.

Can goldfish and guppies be kept in the same tank?

No. Goldfish are a cold water species, while guppies are tropical. The common goldfish can survive in temperatures ranging between 50 F and 77 F. Guppies, on the other hand, do well between 70–77°F. Goldfish do not do well in temperatures over 70 F in the long run. The pairing of goldfish and guppy is not ideal and likely unsustainable. Guppies’ most common companions include (but are not limited to) mollies, platies, and swordtails.

Are guppies schooling fish?

Guppies are a schooling and shoaling species. Schooling is more common in guppies found in habitats under high predatory pressure.

What kind of fish food do guppies eat?

The diet of guppies in an aquarium will consist of prepared foods like flakes, and small live food like

Where are guppies from?

Guppies originated in South America.

Interesting Reads:

Guppies Have Personalities Too “Guppies Have Personalities Too”. Web.Psych.Ualberta.Ca, 2022,

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