Guppy Fish Species Profile

Guppy male and female

 slowmotiongli/Getty Images

Guppies have been a staple of the aquarium hobby for generations. Originating in tropical pools in South America and the Caribbean, these fish are now available in a wide variety of breeds and all captive-bred. Many guppy keepers may start out with only one fish, but being live-bearers with long-term sperm storage, you may be in for a full tank before long.

Species Overview

Common Name: Guppy 

Scientific Name: Poecilia reticulata

Adult Size: 2 inches

Life Expectancy: 2 to 3 years

Family Poeciliidae
Origin South America, Captive-bred
Social Peaceful
Tank Level Top, mid-dweller
Minimum Tank Size 20 gallon
Diet Omnivore
Breeding Live-bearer
Care Beginner
pH 6.5 to 8.0
Hardness 100 to 150 mg/L
Temperature 68 to 78 F (20 to 26 C)

Origins and Distribution

The guppy has been captive bred for countless generations, but originally came from South America. They are named for Reverend Thomas Guppy who originally identified these fish on Trinidad. There are hundreds of various guppies found throughout freshwater in South America, including Brazil and Venezuela, and the Caribbean, including Barbados, Trinidad and Tobago.

Colors and Markings

There are countless color varieties of guppies. Males tend to have more vibrant colors than females. Depending on the variety, some guppies have short, rounded tails, some "V"-shaped and others can have an elongated tail half the length of their body. Tail fins may have a marbled or striped appearance or the fish may be all one or two colors. Whatever color combination you can dream, there is probably a perfect guppy for you.

Many websites and some pet stores will offer "select" or "unique" breeds found no where else. Many times, these strains are the result of serious inbreeding and result in fish with compromised immune function and shorter life spans. Try to stick to the mainstream varieties with well-established lineages. If you end up breeding two different strains, you may be surprised how the variations mix.


Guppies are peaceful, easy-going community fish and play well with a mix of fish species. You may want to keep them with similar, live-bearing fish, such as platys or mollies. Other good tankmates include small fish such as neon tetras or zebra fish. Keep in mind that any fry spawned from an active guppy female may be dinner for other fish in the tank, so smaller tankmates will ensure more fry survive.

Many guppy keepers often opt for a guppy-only tank. You are welcome to mix different varieties of guppy in the same tank.

Guppy Habitat and Care

Guppies are great beginner fish. They are low maintenance and can tolerate some beginner mistakes. A bigger tank size is recommended since guppies are very active fish. They thrive in a tank with plants and soft decor items.

In order to keep your population from exploding, it is strongly recommended that you separate males and females in separate tanks. Guppy females can store sperm for multiple spawnings, even after separation. Tank dividers are okay as a temporary solution, but many of these flimsy, plastic dividers are usually not enough to keep fish separated. Two separate tanks will keep unwanted spawning to zero.

Guppy Diet and Feeding

Guppies are omnivores and do well on a variety of commercially available feeds. Even though guppies are small in size, pelleted diets, called micropellets, are the best choice since they hold onto their nutrition longer than flakes. You are welcome to add supplements, such as frozen diets and veggies, but no more than once or twice a week. The complete pelleted diet is best for most pet fish species.

Depending on your tank's temperature, and other tank inhabitants, you may feed your fish once or twice a day. Always start with a little bit of food, and when it has all been consumed, add a little more. Repeat for a few minutes and use this time to check out all of your fish. Feeding time is a great time to see if any of your fish are acting odd or sick.

Gender Differences

There are a few gender differences you will need to master in order to keep your male and female populations separate. Males tend to be smaller and more vibrantly colored. Females tend to have a brown coloration and are larger and rounder.

Three guppy females and one male
Three large female guppies and one male (bottom right)  underworld/Getty Images

On the underside of the fish, the anal fin of the male is usually longer and tapers to a point. The anal fin on the female guppy is triangular in shape.

Breeding the Guppy

Many beginner hobbyists will start with only one female guppy and suddenly have a swarm. Since female guppies can store sperm, it only takes one spawning for a few generations to be born. In order to prevent your system from maxing out its stocking capacity, it is always best to divide up male and female guppies.

Guppies are live-bearers, so the female will give birth to 50-100 wiggling fry per birth. Many times, the newly born fry will be eaten by other fish in the tank, so if you want to save any fish, keep them in a separate tank or breeding box.

After breeding together many generations of the same population, you may notice an increased number of fish with congenital abnormalities, such as crooked spines or shortened lifespans. Inbreeding is a common occurrence in isolated fish systems with a simple solution: add more diversity! Many hobbyists will elect to trade fish with a fellow guppy keeper or you can purchase new fish to add once they have cleared quarantine.

More Pet Fish Species and Further Research

If you like guppies, and you are interested in suitable tankmates, check out these other species:

Here are more suggestions for low-maintenance freshwater fish for beginners.