From speedy sharks to spawning salmon, many fish are known to leap out of the water. Impressive acrobatics aren’t limited to wild fish either — pet fish know how to ‘get air’ too! Understanding why fish choose to leave the water is both fascinating and useful, especially if you keep fish in an aquarium.
In this guide, I discuss why fish jump and provide some handy tips on how to keep your pets safely in the water. Let’s get started!
Fish Out of Water
If you’ve ever spent some time at a local lake or river, there’s a good chance you will have seen fish splashing or even jumping out of the water. There are many reasons for this interesting natural behavior, and the same triggers can cause pet fish to jump out of their tanks. Let’s take a closer look at four of these causes and learn how to avoid them in the home aquarium.
Fear
Many fish leap out of the water when startled, sometimes in huge numbers. Believe it or not, jumping fish can be pretty dangerous, especially when they collide with people on fast-moving boats!
Silver carp and bighead carp are Asian fish from the goldfish family that have been introduced into North American waterways. These invasive fish are well-known for their leaping abilities, and their large size makes them particularly dangerous to boaters and water skiers.
Frightened pet fish might also jump when you walk past their tank, make a sudden noise, or switch the lights on.
Clearing Barriers and Dangerous Conditions
Sometimes, fish need to jump to clear barriers in the water. Many fish species head upstream each year to lay their eggs, but reaching their spawning ground can take some acrobatic effort. Fish like salmon are well-known for leaping over obstacles like rapids and waterfalls.
Aquarium fish that feel trapped in their tank might also leap out of the water in the hope of finding more space or if they feel stressed. Poor water conditions from a lack of water changes or overfeeding can also create unhealthy conditions in a fish tank. This is a good reason to keep your aquarium clean and well-maintained.
Escaping Predators
Small fish often leap out of the water to escape other fish. This helps them confuse their predators and buys them some time to change their direction and swim to safety. Some fish are specially adapted for jumping out of the water, and one special fish has taken this skill to impressive levels.
Flying fish have huge pectoral fins that they use like wings to glide through the air. These speedy saltwater fish can ‘fly’ over a thousand feet through the air before diving back into the water. Pretty amazing!
You aren’t likely to find flying fish at your local pet store, but many tropical freshwater fish will also leap out of the water to escape larger fish and other predators. Some fish become highly aggressive when breeding, and a spawning pair might chase and attack their tank mates, causing the poor fish to leap out of the water for safety.
Hunting
Jumping out of the water can help fish escape their predators, but some species are just as happy to leave the water to catch a meal. Some fish are experts at catching insects and other small animals from low-hanging branches above the water and some species will leap right out of the water in pursuit of smaller fish.
Betta fish aren’t exactly apex predators, but these colorful fish can jump pretty well. In fact, some fish keepers even train their bettas to leap out of the water for a tasty treat! Jumping to catch food is one thing, but fish might also jump if you aren’t feeding them enough.
How to Prevent Jumping
Some fish species (like clown killifish and marbled hatchet fish) are more prone to jumping than others. Your task as a fish keeper is to create an environment that your fish don’t want to leave. Remember, most pet fish will only survive for a few minutes out of the water, and that’s if they survive the fall.
Maintaining a clean aquarium with the correct water chemistry and temperature is especially important for creating a suitable habitat. Cycling your aquarium is the first step toward managing your water parameters.
Decorating your aquarium with natural materials like rocks, driftwood, and live plants that create hiding spaces will help your pet feel secure in its home. You can also help to prevent jumping by choosing compatible fish species and avoiding sudden movements and noises near their tank. However, the most effective way to prevent your fish from jumping out of their tank is to fit some sort of cover.
There are many options for covering your aquarium, such as glass or acrylic lids that are great for fish keepers who want to view their tank from above. Alternatively, plastic or wooden canopies provide excellent attachment points for your lighting. Whatever type of cover you choose, ensure there are enough holes to allow some air movement (fish need oxygen, too) but no spaces large enough for them to leap through.
