Guppies – A Complete Guide – Care, Diet, Facts

The guppy is a fish common to household aquariums.

It’s important that you gain the proper knowledge, tools, and time required to take care of guppies. They are a great fish for beginners and experienced home aquarists alike. With their colorful appearance and energetic nature, guppies are sure to be a great addition to your tank.

Before purchasing this popular fish, there are a few things that you should know about them. To be a good guppy owner, you should be well versed in their environment, diet, social structure, and more.


About Guppies

Guppies are a South American fish that live in the warm, fresh waters of areas like Trinidad, Venezuela, and Brazil[1]. Their home aquariums should mimic these environments.

They are members of the Poeciliidae family of fish[2]. This family includes many popular aquarium fish including guppies and mollies.

Guppies were discovered by Naturalist Robert John Lechmere Guppy, an Ichthyologist, or fish scientist. Guppy discovered the animals in Trinidad. He named the fish after himself.

Since they were founded in 1866, guppies have been called many things. Today, they still go by several monikers including “The Rainbow Fish” and “The Millions Fish”.


Oftentimes, the attraction of guppies is in their beauty. With supply for these bright, active animals, also comes demand. The practice of breeding guppies for aquariums has improved their appearance. Through specific breeding practices, guppies’ looks are even more varied.

With almost 300 kinds of guppies, they come in many colors, sizes, and even shapes. This notable range of appearances is one of the reasons guppies are so popular among fish keepers.

Their looks have become more diverse with specialized reproduction. By breeding guppies with specific physical traits, new guppy varieties are very common[3].


There is a guppy to match every color of the rainbow and more. Their appearance has dubbed them, “The Rainbow Fish”.

Many might note that guppies have a shiny appearance. This iridescent or metallic look is due to colorless cells. These cells, called iridophores, refract light, giving them a natural shine to their scales.


While they’re famous for coming in a variety of colors, guppies also come in different patterns. Some guppies even have spots, stripes, or other noticeable pattern types.

Many guppies are a lighter color on the top and darker color on the bottom. Scientists are unsure why they have this particular coloration, as it makes it difficult for them to hide from predators.[4] This might be why they are often seen hiding in vegetation. Keep this in mind when designing their tanks, as they will require plants due to this nature.

There are noticeable patterns on both the bodies and tails of guppies. This trait is believed to be due to a mix of natural and sexual selection. This nature is why the scientific community considers them “evolution in action”. Their patterns give knowledge to new necessities in their environment.

Common body patterns include snakeskin, cobra, and tuxedo. Common tail patterns include leopard, lace, and mosaic.

Tail Shape

Despite their small size, guppies can have long, attractive tails. Guppy enthusiasts and breeders have noticed a variety of tail shapes including fan shaped, sword shaped, and spade shaped. Their tails often vary in color and pattern, as well.


The guppy is a dimorphic species, meaning that the two sexes look different. This dimorphism makes it easy to distinguish the males and females apart by looking at them.

In their natural habitat, females tend to be larger and less colorful. Females average size is two inches; double the size of the male. In the wild, females tend to be dull or grey in coloration. However, selective breeding has assisted in allowing females to be more brilliant in color.

Males are more colorful than their female counterparts. Males average size is one inch; half the size of the female.

Males also have a longer anal fin, or the middle find on the fish’s underside. Females have a gravid spot, or a dark spot behind their anal fin.

Tank Requirements

Before choosing to buy a guppy, you must ensure that they have a suitable aquarium. The first step is setting your tank up.

When choosing the size of your tank, five gallons is the smallest appropriate size. Many guppy owners choose to house their fish in ten gallon or larger tanks.

Prior to introducing your fish, the tank’s water must cycle through to allow good bacteria. This bacteria helps to regulate harmful compounds.

Being from South America, guppies do well in warm water. It’s important to match these conditions in as close of manner as possible. You’ll need a heater for your aquarium to match these natural conditions. Their water should always be between 75 and 82 degrees.

It’s good practice to keep a thermometer in your tank, too. Place the thermometer on the opposite side of the tank as the heater. By doing this, you’ll ensure that the entire tank meets the temperature standards.

Monitoring pH balance is important. PH, or potential of hydrogen, is the measure of acidity in the water. Guppies do best in pH levels between 7.0 and 7.2.

You should clean your tank weekly and perform partial water change of around 25%.

Your guppies’ tank will need a filter to assist with daily maintenance. When choosing your filter, it’s important to make note of your tank’s size. Tanks larger than 50 gallons may need an external canister filter. For small tanks, a filter that sits on the back of the tank should work.

Furthermore, you’ll need to consider what you’ll use your tank for. Most people use their tanks for either show or breeding. Which one you choose will decide how to set up your tank.

For show tanks, you need to ensure that your tank has a lot of scenery. Start with a substrate, or the base material. Guppies tend to stay in the middle and top part of their tank. They don’t seem to show a preference in a substrate, so the materials used are up to you. Many aquarium owners use gravel or rocks. Next, a show aquarium requires plants. Guppies tend to do well with thick vegetation.

Contrary to the show tank, breeding tanks should not have a substrate. Having a bare tank will provide an easier setting to pick up leftover food. Plants are important for the filtration of your aquarium. While breeding tanks should have plants, these plants should float. This allows a place for fry, or the young that the guppies produce, to have a place to hide.

Social Behavior

Guppies are generally social animals and do well with other guppies and fish. While easygoing fish by nature, guppies are very active; another trait that makes them popular in show aquariums.

If your tank has males and females, you might see more high energy behavior. Males will often try to impress females by moving their tails.[5]

If you see a guppy showing introverted behavior, they might be ill or stressed.

Guppies do well in larger groups. Keep in mind that the size of your tank matters. Every one guppy should have two gallons. For example, if you want five guppies, you should have a ten-gallon tank.

If you have a show tank, you should have only males. Males tend to be more colorful and lowers the risk of becoming a breeding tank.

If you have a breeding tank, you should have two males for every one female.

When looking to add other fish species to your tank, you should avoid housing them with larger fish. Do not integrate guppies with a species that is large or aggressive enough to eat or attack your guppy.

Guppies also do well with small, peaceful fish, like Mollies and Platies. They can live with Ghost Shrimp and African Dwarf Frogs, as well.


If you have a breeding tank, you should expect for guppies to reproduce a lot. Guppies are ovoviviparous, meaning the females grow eggs inside their bodies. Guppies hatch inside the female, who then gives live birth.

Guppies reach sexual maturity between three and five months. It is easy to identify the males and females. To reiterate, males have a more vivid coloration and are smaller than the females.

The breeding process occurs when the male passes a package of sperm, or spermatophores, inside the female. This causes fertilization. The package is then split, creating broods through thousands of sperm.

When breeding, it is believed that males know when a female has been fertilized. One fertilization can lead to a series of pregnancies over the course of time.[6]

The guppies’ gestation period is between 21 and 30 days. The embryo takes four to five days to form. The fish develops organs throughout the rest of the gestation period.

Due to their iridescent skin, you may see the babies’ eyes through the female’s skin towards the end of the pregnancy.

After giving birth to live fry, the female will repeat the process.

Make note that the adults will likely try to eat the eggs. There are options to avoid this, such as removing them once the fish are born.

If you choose to use a breeding trap or tank, ensure that you’re monitoring the fish’s stress levels.


Guppies are omnivores, so they eat both plants and animals.

When choosing your guppies’ diet you should choose a high quality fish food. You should also ensure that the diet includes a lot of protein. To do so, check the ingredients. The first ingredients should include a protein like shrimp or other fish.

Avoid products whose first ingredients are soy or wheat. These flakes lack proper nutrients for a guppy.

You can also feed your guppies live or frozen meat products such as shrimp or bloodworms. They’ll eat vegetables, as well.

To avoid nutrient deficiencies, you should always feed your fish a variety of foods.

When feeding your guppies, they should only eat once or twice a day for no more than two minutes. Overfeeding fish can lead to health and water quality issues. Overconsumption has also been linked to death in guppies.

If you’re choosing to breed your guppies, you must also consider how to feed their young. Fry eat smaller amounts, but more often. They will need to eat crushed up or specific fry food four to five times a day.


While guppies can withstand a lot, they are prone to infections.

One common infection seen in guppies is called “ich”. This disease causes small, white dots to grow on the fish’s skin. You may also see your fish rubbing their body against objects in their tank. Pregnant females are more susceptible to ich and their health should be monitored appropriately.

Due to their long tails, guppies are also prone to “fin rot”. Fin rot causes guppies’ tails to look ripped.

Monitoring your fish’s behavior is an important step in noticing and handling disease. Medication is available to treat ich and fin rot, but certain measures can help avoid it. Keep in mind that many of these diseases are communicable. This means that the chances of being spread among the tank’s population is high.

Ways to avoid these fungal infections include:

  • Regular Cleaning & Maintenance
  • Good Water Quality
  • Varied Diet
  • Low Stress
  • Enough Space

Global Reputation

Guppies are beautiful and practical fish. They have been introduced to every continent except Antarctica[7]. In India, they help control pest populations. Guppies eat the mosquito larvae, helping to lessen their numbers. This practice has become more widespread in recent years.[8]

Unfortunately, introducing guppies to habitats can also cause overcompetition for food. This harms other fish populations with similar diets in areas of introduction.

Unique Traits

Guppies are a “model organism”[9]. Model organisms are animals that are studied to better understand biological phenomena. This concept is most widely used when studying diseases.

Are Guppies Right For Me?

Whether it’s your first fish, or one adding to a larger collection, guppies make a great fish for almost everyone.

While it’s important that you gain the proper knowledge, tools, and time required to take care of guppies, they are a great fish for beginning and experienced home aquarists. With their colorful appearance and energetic nature, they’re sure to be a great addition to your tank.

By following the instructions listed in this article, you’re on the way to being a great guppy owner!









[9] Magurran, Anne E. (2005). Evolutionary Ecology The Trinidadian Guppy. New York: Oxford University Press. ISBN: 978-0-19-852786-2.

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