Why Fish Jump (8 Common Reasons)


Fishing is a pretty popular sport because it can be fun and relaxing. It’s not so relaxing, however, if the fish you’re trying to catch is constantly jumping out of the water. Let’s find out why they jump.

Fish jump for a variety of reasons, but the most common reason is that the fish is being hunted or feels threatened in some other way. When a fish is being hunted, it will jump to lose the predator. Fish will do this whether they feel threatened by a natural predator or by a human.

Is this the only reason fish jump? Certainly not. Read on to learn more about why fish jump out of the water and to learn how to catch them when they do this!

Jumping Fish: In the Wild and in the Aquarium

1Avoiding predators. As mentioned before, the most common reason fish jump out of the water is to avoid predators, whether those predators are humans or other fish. The big fish prey upon the smaller fish; it is simply the natural order of things. Jumping out of the water allows the fish to temporarily escape whatever fish might be hunting them.

Species such as marlin and largemouth bass will also jump out of the water to loosen fishhooks that may have gotten caught to their lips. Additionally, species such as Asian carp are known to jump out of the water when a boat speeds by. The cause for this is unknown, but it is possible (and likely) that the sound startles them. Since fish are easily startled, boats probably trigger their survival instincts just like a predator would.

2- Finding Food. We have all seen dead bugs floating around on the surface of the water. If you see a lot of fish jumping in and out of the water at the same time, it is probably indicative of feeding time. Those bugs on the surface make ideal meals for most kinds of fish.

Some fish can jump remarkably high, so do not be surprised if one day you see one reach low hanging tree branches to catch dragonflies or other insects perched there. Feeding time usually happens around dawn and dusk, so if you are interested in watching fish jump in and out of the water, head to the lake around one of these times, and it’ll probably be a sight to see!

3- Debugging & Killing External Parasites. So what’s the deal if a fish is jumping out of the water for no apparent reason? Biologists have recently observed and theorized that some fish will jump out of the water to try to rid their bodies of parasites and bugs. While this is not a totally certain conclusion, it does make sense. Fish cannot use their mouths or their fins to rid their bodies of parasites, so jumping out of the water is the last, most desperate attempt to do so.

4- Decrease in Oxygen Supply. Animals (including fish) will use the first instinct they have, especially if it is a matter of survival. If a fish’s habitat has deteriorated, it cuts off the oxygen supply and makes it difficult for the fish to breathe. Sometimes the only way to get in a sufficient, healthy breath is to leap out of the water and take a gulp of air. Some fish are even smart enough to know that their environment is no longer healthy. In these cases (though they are not always successful) the fish may even migrate to look for a new place to live.

5- Spawning. Most people know that several species of fish will move upstream to reach spawning grounds. Salmon is one species that does this. Do not be surprised if you are moving past a stream or river and see huge amounts of fish jumping up and out of the water. Jumping in this way is a faster and more powerful way for the fish to reach where they need to go. Fish will jump to scale seemingly impossible waterfalls and rough rivers. Some fish can jump as high and as far as two meters.

6- Force of Habit. It is also possible that fish just do this for the heck of it. If these fish are young, full of life, and in good physical condition, they might just enjoy the exercise. However, a lot of the jumping fish do is likely to be instinct-related. Because fish are fairly easy to startle, sudden movements, sounds, or shadows might cause them to get jittery and jump out of the water since that’s what they would do when threatened.

7- Mating. Sometimes (especially on the Gulf of Mexico) fish will gather in large groups or “schools” to feed and mate together. Scientists have concluded that certain species of fish gather in these places to create nurseries. When both male and female fish jump together, it is to indicate that there are others of their species nearby.

8- Ill Fish or An Ill Environment. Now that we’ve talked about fish in the wild, let’s talk about fish in the aquarium. Fish who live in fishtanks or aquariums that like to jump out of the tank are usually either looking for another body of water or are feeling stressed/sick and therefore not behaving normally. If your fish tank is getting grimy and your fish has started jumping out of it, it is probably an attempt to find better living conditions.

Likewise, if something is wrong with your fish, they may start exhibiting abnormal behavior and that could include jumping out of the fish tank or bowl. If you suspect something is wrong, consider talking to a vet or specialist. However, this may not be the case if the fish in question is a betta fish.

Betta fish are native to Thailand and can commonly be found in still waters such as puddles, swamps, and rice paddies. During dry months, the water may evaporate or ammonia levels in the water will get too high to be healthy. If this is the case, betta fish will often hurl themselves out of their current body of water and into another one that might be healthier. If betta fish exhibit this kind of behavior, they are likely just following a natural instinct. Make sure you are keeping your fish tanks and bowls clean!

Aaron Warner

Aaron Warner is an avid angler with over 15 years of experience. He has participated and won fishing tournaments all over the country and enjoys fishing for bass, trout, walleye and other species.

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