When you look at your betta fish, you may notice it doesn’t have ears. At least, not like ears on you or your dog.
This may lead you to wonder: can betta fish hear?
The answer is actually yes, betta fish can hear! However, it is a little different than the way you or I hear sound.
After all, you can’t see their ears, can you?
If you’re interested in learning about how fish, including bettas, can hear, read on!
Do Betta Fish Have Ears?
When looking at betta fish, one thing you may notice is that they don’t have external ears. When you look at their heads, you’ll see nothing but smooth skin where their ears would be if they weren’t fish!
However, this doesn’t mean they don’t have ears at all. Bettas, like other fish, actually have internal ears that you can’t see! (*)
Who would’ve known?
Turns out, betta fish have tiny “ear stones” called otoliths. These otoliths are able to detect vibrations in the water and translate them into sound, the same way our earbones do with vibrations in the air!
Guess we aren’t so different after all!
Bettas have three pairs of otoliths, so six of these hard calcium stones in total! The three types of otoliths are:
- Sagitta
- Asteriscus
- Lapillus
Sagitta is the largest type of otolith and helps convert sound waves into electrical signals that are sent to the brain. Asteriscus helps detect sound and relay sound waves to the sagitta.
Finally, lapillus detects both sound and gravitational force, so it helps the fish stay balanced as it swims!
As betta fish grow and age, their otoliths grow as well. They do this by forming more material around the core of the otolith, so it becomes thicker over time.
Otoliths are made of calcium carbonate, so it’s easy for them to acquire more calcium buildup as the betta fish ages.
Because of this constant growth, scientists are sometimes able to determine the age of a fish based on the size and layers of its otoliths, like they would with a tree.
Cool, right?
Why Do Betta Fish Need To Hear?
Now that you know your betta fish can hear, you may be wondering why they need to hear. Well, the answer is that there are many reasons they need to hear!
Fish like bettas use their hearing to (*):
- Find mates
- Respond to fry
- Seek food
- Escape predators
- Maintain their balance
Though fish have sight and other pressure-related senses to help them do all of these things, hearing certainly helps with them. After all, hearing helps you interact with your world too!
Find Mates
Fish may use their sense of hearing to find single bettas in their area.
Basically, some fish may produce sounds, similar to singing, to attract female mates. These fish may then lay their eggs for that male.
While betta fish in particular don’t sing, they do make popping or clicking sounds. Hearing can help bettas figure out if there’s another betta fish nearby, which can lead to them becoming mates!
Love is in the… Water, I suppose.
Respond to Fry
No, we don’t mean the fast food kind. Fry, as in baby fish, can produce sound underwater as they swim and develop.
Just like adult bettas, babies can produce popping, clicking, or crunching sounds, which can be responded to by others in the tank.
In particular, male bettas are known to protect their fry for several weeks once they hatch in the wild, so this sound can help them find their fry faster.
Seek Food
Like with most other animals, being able to hear can help bettas find food! (*)
Bettas mostly eat insects in the wild. You may be wondering how hearing can help with this, since insects like worms don’t make noise.
The answer is that they don’t make noise to us. Underwater, fish have extremely sensitive hearing, and the movement of a worm can be heard by a hungry fish in quiet waters.
Other insects may be louder, which can make them even more susceptible to being eaten by betta fish. If you ever find yourself reincarnated as a water insect, try to stay as quiet as possible!
Escape Predators
One of the most important things hearing does for a betta fish is help them escape predators. Predator fish may produce specific sounds like grunts or clicks, which can spur a betta to escape.
Betta may also hear if a predator fish makes a sudden lunge for it in the water. This can cause the betta to startle and escape the jaws of the predator, rather than get eaten without warning!
Maintain Balance
Finally, betta fish are able to maintain their balance in the water thanks to their hearing ability. By knowing which direction sound is coming from, they can figure out where they are in the water compared to their surroundings.
Their otoliths also help them maintain their balance since one of them (the lapillus) can detect gravitational force. This means they can detect the pull of the earth and can determine the difference between up and down.
This is particularly helpful for bettas since they can swim to the top of the tank to get some oxygenated air into their labyrinth organ. Over time, that oxygen is then absorbed, keeping the fish alive. (*)
Without that special otolith, your betta may not know how to reach the top of the tank. Who knew such a tiny stone could be so important?
Conclusion
Now, you know how your betta is able to hear, as well as why they need to hear!
Hearing is essential to survival for fish like bettas, as it can help them find partners, escape predators, and swim properly!
The next time you go to tap the glass on your betta fish tank, think again. Remember that sound travels approximately 4.3 times faster in water than in air, so tapping sounds extremely loud to your fish’s internal ears and can frighten them. (*)
If you have other questions about your betta fish, feel free to ask them below and we may pick your question to answer next!
