How Big Do Guppies Get? (Growth Stages + Speedy Growth Factors)

Image of a fully grown guppy

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Guppies are small fish with low maintenance costs. Due to their vibrant colors, they are favorites among aquarists. However, looking at their small size, you may wonder if they will grow big. So, how big do guppies get?

Male guppies can grow up to 1.5 inches (3.8 cm) in size, while female guppies can grow up to 2 inches (5 cm). Under suitable living conditions, guppies with good genetic backgrounds can grow to full size in around 6 months. A nutritious diet and proper care are the keys to guppies’ optimal growth.

The average life span of guppies in captivity is 2 to 5 years. Hence, they grow fast compared to other fish. There are various stages that a newborn guppy fry passes through before reaching adulthood. In this article, we will cover how guppy fry grow in stages and what care you should take for their healthy growth.

Guppy Growth Stages

Guppies are livebearers, meaning they give birth to live fry. Male guppies mate with the female ones. Once the male guppy fertilizes the female, the baby guppies start developing within the female guppy’s body.

It takes around a month until the fry are born. After that, it takes around six months for guppy fry to develop and reach the adulthood stage.

Given below are the various growth stages that guppy fry pass through to become adults.

1. Fry Stage

Baby guppies are also known as guppy fry. They are tiny at birth, about 1/4 inch or 0.6 mm in length.

Guppy fry are in a deformed state when they are just born. However, after a couple of hours, their body straightens and becomes strong enough to start feeding. Once the fry are born, you need to provide ample hiding spots to avoid them being eaten by other fish.

A balanced nutritious diet is vital for fry to grow healthy. Hence, you need to ensure that guppy fry get adequate nutrition in their daily diet. You can feed them the same food that adult guppies eat. The difference is you need to grind the food as the mouths of guppy fry will be relatively small.

Baby brine shrimp and hard-boiled egg yolk are an excellent source of proteins for fry. Besides, exposure to light for 12 to 16 hours a day can also contribute to their growth.

2. Juvenile Stage

Just one month after their birth, guppy fry will enter the juvenile stage. Their average size will be 1/4 inches to 3/4 inches (1.2 cm to 2 cm) in length at this stage.

Female guppies will be larger than males. Their gravid spot will be visible, and you may notice your guppies gaining color using which you can distinguish their sex.

Male guppies will be brighter than their female counterparts. Another difference is that the female guppies’ tails will be bigger than the tails of males. At this stage, the gonopodium of the male guppies will also start to form.

During this stage, guppies need plenty of food to stay healthy. You can include brine shrimp, bloodworms, spirulina, and high-quality flakes in their diet for optimal growth.

At around two months, the juvenile guppies will enter the young adult stage.

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3. Young Adult Stage

At this stage, young guppies will become sexually active. They may start looking out for partners to mate with. You can separate the male guppies from the females if you don’t want more guppies in your aquarium.

Separating them will also ensure the proper growth of guppies as they will be more inclined to eat food rather than mating. At this stage, you need to alter their diet a bit. It would help if you lowered their fat intake to avoid ill-health. Instead, feed your guppies a diet rich in proteins and lots of greens.

Brine shrimp should continue to be their primary source of food. Besides, spirulina and plankton pellets will help to develop striking colors.

4. Adult Stage

Guppies reach their adult stage at around six months after birth. Depending on their genetics, nutrition intake, and other living conditions, guppies grow about 1.5 inches to 2 inches (4 cm to 6 cm) in size.

At this stage, the growth of your guppies will stop completely. However, the fins and tails of the male guppies may grow longer over time, depending on their genes.

Since your guppies are fully grown now, they need a varied diet to stay healthy. A flake-based diet that is high in proteins is ideal for adult guppies. Also, avoid feeding any fatty food as it is terrible for their health.

Adult guppies become infertile at around 1.5 to 2 years of age and are unable to reproduce. The average life span of guppies is 2 to 5 years with proper care.

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Factors That Hinder Guppy Growth

Guppies need favorable living conditions for optimum growth.

Given below are the various factors that can hinder the growth of guppies:

  • Lack of space in the aquarium can stunt guppy growth.
  • On the other hand, a big tank can also cause problems. Guppy fry may not be able to search food efficiently if the water volume is high.
  • If the tank is overcrowded, it results in high toxin levels and a lack of oxygen. This can result in health issues such as stress, which can hamper the growth of guppies.
  • Unsuitable water parameters that are not within the optimal range can cause problems in the development of guppies.
  • Fatty food impacts the immune system of guppies and can result in their ill-health. Also, an unsuitable diet can prevent guppies from growing healthy.
  • Starvation or less feeding can also impact the growth of guppies. Guppies will be malnourished if a diet rich in protein is not fed to them.
  • Lack of hiding space is yet another reason. Guppy fry need hiding spots to safeguard themselves. Else they may get eaten by the mother guppy or other big fish.
  • Aggressive tankmates can cause undue stress to timid guppies. Stress often results in the underdevelopment of guppies’ health.
  • Poor water quality in the tank can adversely affect the growth of guppies. Irregular water change can attract parasites that can harm guppy growth.

Alright! Now that you know the various factors that affect guppy growth, let’s discuss how to help your guppies grow healthy.

Factors That Speed Up Guppy Growth

The healthier your guppies are, the faster they will grow. Guppy fry can be a challenge to grow, especially when you don’t know how to take proper care of them. Guppies need specific conditions and a high-quality diet to remain healthy.

Given below are the various factors that can help speed up guppy growth:

  • Housing guppies in an appropriately sized aquarium is a prerequisite. If you have 3 to 5 guppies, the tank size should be at least 10 gallons.
  • Periodical water change is a must. Just like any other fish, guppies need clean water to thrive.
  • You can install a filter to maintain water quality. Also, a water conditioner can help remove any chlorine or chloramine present in the water.
  • Maintenance of tank is of utmost importance for a healthy fish. Gravel needs to be vacuumed and cleaned.
  • Water parameters such as water temperature and pH levels should be stable and suitable.
  • Installation of a heater is helpful as it will keep the water warm.
  • Adequate nutrition is the key to the optimum growth of guppies. They need a diverse diet rich in proteins, vitamins, and minerals to grow properly.
  • Separating the male guppies from female guppies also helps in their growth. Guppies can breed at around three months. If they attempt to breed, it will consume a lot of their energy.
  • Providing sufficient hiding spots is vital. Guppies resort to hiding places when sick, stressed, or in need of rest.
  • In a community tank, only fish that are compatible with guppies should be kept. Since guppies are peaceful fish, they grow well with compatible tankmates.

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Related Questions

How big do fancy guppies get? Fancy guppies grow up to 0.6 inches to 2.4 inches (1.5 cm to 6 cm). There’s not much of a difference in their size compared to other guppy species.

How big do male guppies get? Male guppies with good genetic backgrounds and residing in favorable tank conditions can grow up to 0.6 inches to 1.4 inches (1.5 cm to 3.5 cm).

How big do female guppies get? Female guppies grow bigger than male guppies. Female guppies grow up to 1.2 inches to 2.4 inches (3 cm to 6 cm).

How big do endler guppies get? Male endler guppies grow up to one inch long (2.5 cm). On the other hand, female endler guppies grow up to 1.8 inches (4.5 cm). Female endler guppies have plumper bodies compared to males.

How big do feeder guppies get? Feeder guppies reach a maximum length of 2.5 inches (6.4 cm). Male feeder guppies are slightly smaller than their female counterparts.

How big do cobra guppies get? The average size of yellow cobra guppies is 2.5 inches (6.3 cm). Female guppies are a bit larger than their fellow males.

How long do guppies take to grow to full size? Guppies take an average of six months to reach adulthood. Several factors, such as water temperature and other living conditions, influence the growth rate of guppies. On average, most male guppies grow up to 1.5 inches to 1.8 inches long (3.8 cm to 4.5 cm). In contrast, female guppies grow up to 2 inches to 2.5 inches long (5 cm to 6.4 cm). Jumbo guppies are an exception. They can grow up to 5 inches long (12.7 cm) and take a year to grow completely.

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