Fish might not attend meetings or binge-watch TV, but they do share some quirky biological habits with humans—like coughing, yawning, and even burping. These behaviors, however, aren’t about etiquette or fatigue. They’re survival tactics fine-tuned over millions of years of evolution.
Let’s start with the cough. Fish “cough” by rapidly expelling water through their gills to clear debris, parasites, or excess mucus. This isn’t a polite ahem but a violent gill flush, often triggered by polluted water or pesky hitchhikers like lice. Goldfish, for example, cough more in dirty tanks, their version of complaining about the housekeeping. Scientists call this a branchial purge, which sounds like a rejected Harry Potter spell but is just fish hygiene.
Yawning in fish is even weirder. Species like cichlids and bettas open their mouths wide in a yawn-like motion, but it’s not about tiredness. For some, it’s a threat display (imagine someone yawning to say, “I could eat you”). For others, like the Siamese fighting fish, it’s a way to stretch jaw muscles or adjust their gills after a meal. And no, they don’t catch flies mid-yawn—unless the flies are underwater, which would be impressive.
Then there’s burping. Fish that gulp air from the surface, like gouramis and catfish, often release bubbles to adjust their buoyancy. This isn’t a post-soda belch but a swim bladder recalibration. The swim bladder, an internal gas-filled organ, helps fish stay afloat. By “burping” excess air, they fine-tune their depth—like a submarine pilot with hiccups.
But why mimic human behaviors? Evolution loves efficiency. Coughing and yawning solve universal problems: keeping respiratory systems clear and maintaining muscle function. Even burping, in this case, is about physics, not indigestion. Fish just repurposed existing anatomy for survival, proving that nature’s playbook is full of cross-species plagiarism.
There’s a catch, though. These actions are purely mechanical, devoid of the social cues humans attach to them. A fish’s yawn won’t make its friends yawn (unless they’re all stressed about the same shark). And their burps don’t require awkward apologies—just a quick bubble release.
Researchers study these behaviors to monitor aquatic health. Frequent coughing can signal polluted water, while abnormal yawning might indicate parasites. Even burp patterns help aquarists assess swim bladder disorders. So next time your goldfish does a little gill-clearing dance, remember: it’s not judging your cooking. It’s just doing fish CPR.
In the end, fish remind us that biology is a universal language—one where a cough isn’t a cold, a yawn isn’t boredom, and a burp is just physics being polite. Now, if only they could teach us how to breathe underwater. We’d finally have an excuse to avoid small talk.
