guppies are a very popular fish for many reasons, one of which is because they breed so fast, there like the rabbits of the fish world. The gestation period for guppies can vary dramatically and there are many things that can affect how long they carry their babies for.
Before we look at what can affect a guppies gestation period we should discuss what it normally is, on average they give birth to new babies every 25 – 35 days but things like age, water temperature, number of spawns and even stress levels can affect these numbers.
Age: A female’s age is one of the biggest things that can affect how long she’s pregnant for and how many babies she will have. A young female could be pregnant for as long as 40 days for the first few pregnancies and only have between 5 and 10 babies whereas a older female could be pregnant for as little as 20 days and have 40+ babies.
Water temperature: Unlike age this is something that you can control, the optimum water temperature for guppies is 75°F. If guppies are kept lower than this their growth rate including unborn babies is a lot slower, however if the water is slightly warmer the opposite comes happens and they grow quicker. Please keep in mind that you cannot go higher than 82°F as this could harm and even kill your guppies.
Number of spawns: This is similar to the age of the female, the more spawns she has had the short time it’s likely to take. This is still true if you take an older female guppy that is a virgin; her first spawn even though she is older will be considerably longer than an old female than has had multiple spawns.
Stress levels: This is a huge factor that needs to be taken very seriously, the higher your guppies stress levels the longer her pregnancy will be. In extreme cases excess stress can cause a female to abort the spawn and either have them early even though they are undeveloped or she will re-absorb the eggs.
There are a few things that you can do to help reduce your fish’s stress level; providing plenty of hiding places for her to hide such as rocks, caves and plenty of plants. Providing a variety of foods on a regular basis can also help to keep stress levels low, not just guppies but all fish.
As you can see there are many things that can affect the gestation period of guppies; keeping note of when and how often your females give birth will make things a lot easier in guessing when she is due to have her next spawn which will make it easier for you to make arrangements and catch the babies.