Do Fish Cough?

You know it’s amazing having a fish tank. You know what’s even more amazing some of the questions people have when it comes to fish.

Moreover children and their fish questions now Children have the best questions. Think certain search engines are using these children.

A few questions my children have asked and I’ve already written about may interest you. Do Fish is the tag I’m gonna use.

# Do Fish 

Do Fish Poop

Do Fish Have Teeth

Do Fish Like Or Need Toys 

Do Fish Tanks Make Noise

Do Fish Tanks Need A Lid

As I’m seeing the same queries as questions that one of my inquisitive children asked the other day.

This particular child of mine has been asking a few interesting things about fish that ill share here throughout the post but the main question that came up was.

Do Fish Cough?

Yes, fish cough when particles get stuck or a change in water conditions happens a fish will rapidly move its buccal & opercular cavities forcing water over their gills sometimes in reverse allowing them to cough.

Now that was just a brief snippet let’s look into how and why this happens and a few extra questions that come up courtesy of said child.

How Can Fish Cough?

Buccal & Opercular Cavities

Right then let us start at the beginning and work our way through together. How do fish cough here’s how?

Either side of the fish’s pharyngeal cavity fancy way of saying throat. On either side of the throat are the gills inside the gills are tissues called filaments which are a structure of threads.

At the back of the mouth just before the throat and gills is what’s known as the buccal which is like a pump.

This buccal pump does just that pumps water over the gills. Now we have the opercular cavity which is the space where the water is pumped to and is directly outside the gills.

Gills Need Constant Water

As we know the gills themselves need constant water to flow over them. This is because fish breathe via water by exchanging gasses.

Water flows over their gills and the gills filter oxygen out from the water. Do fish drink water or get thirsty comes to mind check these two articles out Why Saltwater Fish Drink Water It’s A Thirsty Job & Why Freshwater Fish Don’t Get Thirsty

For the definitive answer check the above posts.

exchanging gasses, that’s what happens when the fish exchanges carbon dioxide ammonia acid and of course oxygen.

Taking oxygen out of the water via these gas exchanges. How does this help us understand coughing in fish?

Glad you asked 

Respiratory Rate & The Flow Of Water

When or if a fish gets something stuck in its gill a particle for instance the muscles in the buccal start to expand and contract.

This forces more water over the gills at a faster rate. In the same way as when we start to breathe faster. This reaction of forced water and muscle movement builds up pressure and pushes the stuck particle out in the form of a cough.

Negative Pressure & Reverse Water Flow

What is even more fantastic is that fish can also cough in a more forceful way. This process happens when negative pressure builds in the opercular cavity.

That space between the throat and mouth, When this happens water is forced via the buccal pump backwards yes backwards over the gills.

As the water is passed a slimy mucus is released into the mouth. Fish seem to have slime all over how slimy are fish check the link and find out.

This mucus helps trap the debris as it gets sucked in and then the fish spits it out via a cough. Or more accurately the mucus is ejected with great force.

How Do We know Fish Can Cough?

Well, it all started with a fella named Bert in 1870 and the techniques were upgraded by Francois Franck in 1906.

The first method was to put a small tube into the fish’s mouth towards the buccal and opercular to measure pressure build-up.

Also, a cannula can be inserted into the fish and pressure changes are recorded by a pressure transducer.

Electrodes To Detect Coughing

I Know crazy and a little bit geeky. I’m gonna try and keep this simple. Two electrodes of stainless steel are placed on either end with a fish freely swimming in between them.

The way I understand it is that electrically charged signals are picked up in the microvolt range. These are electrical signals from the fish.

Those signals that the fish send are picked up by the electrodes. A shielded cable picks the signals up and sends them to be recorded on a script chart recorder.

Changes In Water Condition

So it turns out that changes in the water condition will make a fish cough. This can be done with different metals like copper zinc etc.

Also changes in chemical balances like chloride ammonia etc. Lack of oxygen and changes in the ph of the water.

These were all tested and correlated and all proved to give different levels or strengths of cough.

Water Changes Chemical Inballances Can Cause Coughing

This is why it’s so important to check your water conditions as often as you can. Water changes are a perfect example after doing a change you turn the filter back on and bang debris.

Some debris can get stuck in a gill. The temperature change can affect oxygen levels hard water the list goes on.

Fish will usually exhibit signs of rocking their heads up and down gulping or just open-mouthed. Although there’s no real sound that we no off.

So no point putting your head in the water as you probably won’t hear anything.

Other Questions 

Back to those other questions my child has been asking and seems popular on the SERPs.

Do Fish Sneeze

No fish don’t sneeze they don’t have lungs and in essence, the process of sneezing is the forceful expelling of air from the lungs and out of the mouth and noses.

Do Fish Cry?

No fish don’t cry they don’t have tear ducts or the biochemistry needed. The cortex in the brain that allows crying isn’t present in fish.

Do Fish Burp

Yes fish indeed do burp they have gasses and sometimes gasses are exchanged in the stomach and these gasses return back up causing small burps.

Do Fish Cough Conclusion

Fish indeed cough and there are a few different types of cough similar to us. Whenever a chemical is present in the water that shouldn’t be it’s passed via the gills and picked up instantly and pumped back out or reversed and expelled by that mucus.

Clever stuff and it’s all controlled by the buccal & Opercular Cavities and the muscles that help pump water continually over the gills.

Hope you enjoyed the read and decide to hang around and read some more.