Your Fish Have Superpowers (You Just Never Looked It Up)

Added: 2026-05-31

[00:00:00]You think your aquarium's glass box of pretty animals. It absolutely is not. On this list, there are fish that see with electricity, fish that breathe through their guts, and one fish that carries a poison with no antidote. By the end of this video, your tank will look different to you. Some of these you already own and you have no idea what hidden powers they have. But, before we dive in, yes, I am a real person. I'm Taylor, I'm the narrator for Aquarium Store Depot, and I have been for years.

[00:00:30]And And I want to say this, I know that the internet right now is chock-full of AI sloppiness. It's everywhere, but I assure you everything made right here at Aquarium Store Depot is made by living, breathing, actual fish nerds. Now, if you'll excuse me, I've got a clownfish persona to morph into. Ah, the quiet kid in class who turns out to be reading at a college level while everyone else is still learning sight words. That is the elephant nose. In the pet store tank, it looks soft, dopey, slightly sad, and I mean, just completely unremarkable.

[00:01:05]Then, you find out it has a sense that humans literally don't. This fish generates a weak electric field from a modified muscle organ near its tail, somewhere around three to eight pulses per second at rest, ramping up to roughly a hundred per second when it's on alert. Receptors all over the skin pick up how nearby objects warp that field, giving it a full three-dimensional map of everything within about one body length in total darkness. I mean, even in muddy water that you can't see your hand through, the picture on this fish's head is sharper than yours with the lights on.

[00:01:41]The trunk, that sad little chin appendage that makes everyone go aw, is the sensory fovea. It's packed with hundreds of electroreceptors. It's like using a flashlight that your species was never invited to. The wildest part is that it can recognize individuals, like, I mean, other elephant noses by their personal electric signature, like a a fingerprint made out of electricity.

[00:02:03]Scientists needed laboratory equipment just to confirm this thing was real, and it's sitting in your local fish store with absolutely no fanfare. The most dangerous animal you can legally keep in a glass box in your living room is not a stingray. No, no, not a lionfish, not a venomous octopus that pet stores won't even touch. It's the puffer everyone owns and treats like a goofy aquatic puppy. Saltwater puffers hold tetrodotoxin in their tissue, roughly 1,200 times more potent than cyanide by weight. No antidote, stays toxic even after the fish is dead. The most chilling documented case involves a public aquarium curator who happened to prick himself on the spines of a dead porcupine puffer during an autopsy, and through those tiny pricks alone, he caught dizziness, numbness, a headache, and partial paralysis. Yes, from a dead fish. Like, it's been dead for a while.

[00:02:57]This is the same animal that swims up to the front of the tank and follows your finger like a Labrador. The other piece of this, and it's genuinely equally insane in the or the more you sit with it here, is that the toxicity comes from bacteria in the food chain. Puffers raised in captivity on clean diets become essentially non-toxic over time.

[00:03:15]They're not born with the chemical weapon, they earn it from their lunch.

[00:03:19]They are a walking pharmacology lecture in cute little fins. Five years is the average lifespan of an aquarium fish if you actually take care of it, maybe 10 if you're like a saint. A koi named Hanako lived 226 years, not not days. That is not a dinner table folk tale, all right? Her age was scientifically verified by a professor at Nagoya Women's College who examined her scales under a light microscope. Because koi grow annual rings on their scales the same way you think of like trees in their trunks, they counted them. 226.

[00:03:57]The other five koi in her pond came in at 168, 153, 149, and 139 years old. The entire pond was full of fish that outlived empires. Her owner said he could call Hanako by name and she would even surface for him. That's right, a fish with a name, a fish that knew her own name. A fish, mind you, that was alive before for the light bulb, before the country some of you are watching this from, before almost everything you've ever learned about in history class. It is the only fish in the hobby with a documented case of being older than modern dentistry.

[00:04:31]That's right, 400 million years old.

[00:04:34]Watched the dinosaurs come, watched them go, and decided that none of that warranted a redesign. The pectoral fins on this fish are not regular fins, they're mounted on a lobed muscular structure that lets the animal prop itself up and walk across land. And that structure? Well, it's the same anatomical setup that eventually became your shoulders. Your arms are a remix of what this fish is doing in the substrate right now. It also breathes air, not like as a backup, its swim bladder is heavily modified into primitive lung-like organs. So, as it surfaces, it gulps atmospheric air and survives in oxygen-poor water that would kill almost anything else. Super cool. It can also hang out on land for like a surprising amount of time as long as it stays moist, which felt like a fun little party trick until you find yours behind the dresser at 3:00 in the morning cuz you forgot to put the weight on the lid.

[00:05:23]Genuine warning here, these guys are escape artists. Oh, and did I mention they also live to be like 30-plus years in captivity, so it's not a short-term commitment. It's a ghost from the Triassic that's also walking proof of how vertebrates left the water and most people just think it looks cool. Most Raphael owners have no idea what the chunky little armored loaf parked under their driftwood's actually doing in there. It talks audibly from outside the glass. Most fish that produce sound use one mechanism. The striped Raphael runs two simultaneously. Big big moves.

[00:05:58]First, it grinds its pectoral fin spines against their sockets producing this sharp buzzing click. And secondly, a muscle running down between the back of its skull and the front of its swim bladder contracts and relaxes fast enough to vibrate the bladder like a tiny fleshy subwoofer at a much deeper frequency, though. Both these noises happen at the same time in the audible range, which means if you've ever caught one of these to move tanks and you heard a weird croak coming from the net, it wasn't your imagination. That was a Raphael giving you a stern review. Most hobbyists hear it once assume something's wrong with the filter and move on. They never find out their pet is yelling at them in stereo. This is the most underrated noise maker in the hobby and nine out of 10 people who own one have zero clue. What are the odds that two completely unrelated fish on two different continents, you know, separated by a an entire ocean would independently evolve the exact same alien sensory system all the way down to the same neural circuit for not jamming each other's signals.

[00:06:57]Apparently, it's pretty good. The black ghost knife fish is a South American gymnotiform with no shared electric ancestor with the African elephant nose previously mentioned. None. Zero. Africa and South America split apart well over a hundred million years ago and somehow both lineages independently arrived at the same answer. Both grew electric organs. [music] Both developed electroreceptors. Both even evolved the same jamming avoidance response where they shift their own electrical frequency so they don't overlap with another individual nearby.

[00:07:31]Fish fish Wi-Fi etiquette, if you will.

[00:07:34]Convergent evolution this clean is one of the most cited examples in evolutionary biology and you can just go buy one at a fish store. The catch is that this is a sensitive, slow-growing fish that gets to be about a foot and a half and it's going to need a setup most beginners do not have the space or stability to provide. A lot of them are going to die quietly in community tanks within like a year. The black ghost knife fish is evolution writing the same script twice and your local pet shop is selling the second draft. Ah, the mud skipper. Fish that quit. Did not wait for evolution and just made the call.

[00:08:09]While the rest of the fish kingdom is committed to staying wet, this animal spends most of its day on land fighting other mud skippers, hunting bugs, defending territory, and flirting with prospective mates all on a stick mat of mud where technically none of that should be even possible. Cutaneous respiration through its moist skin lets it absorb oxygen directly from the air.

[00:08:29]Enlarged sealed gill chambers hold a bubble of water like a built-in scuba tank except the opposite. Like a like a anti-scuba tank. You get the point. Its pectoral fins act as these little crutches for crab walking across surfaces and when it wants to show off, it can flip its entire muscular body up to 2 ft straight into the air. A fish doing a backflip. That is a real thing this animal does both for threat displays and to impress potential mates.

[00:08:57]Because of the cosmic punchline of having gills and lungs and pectoral fin crutches is well, you still got to look good doing it. One genuine note for hobbyists here, do not impulse buy a mud skipper for your standard fresh water tank, please. They want brackish water in a paludarium with actual land area.

[00:09:15]Shoving one into a normal aquarium is one of the saddest deaths in the hobby.

[00:09:19]Of all the things a fish could evolve as a superpower, having an instrument feels weirdly understated until you actually hear one. The croaking gourami produces sound by plucking modified pectoral fin tendons.

[00:09:31]Plucking like guitar strings. This mechanism is not found anywhere else in the entire family, which includes every other gourami you've ever seen. Both sexes croak mostly during aggression and courtship, and the volume is loud enough to hear from the other side of the room without pressing your ear to the glass.

[00:09:49]But, it's the spawning behavior that gets me. The female purs to initiate.

[00:09:54]The female initiates with a purr. This is the only confirmed case of female-initiated acoustic courtship in fish, and yes, that's exactly as wholesome and unhinged and nerdy as you are imagining. Research also shows that males can assess the body weight of a rival just by listening to its croak, settling fights without ever even having to throw a fit. They're doing the bouncer-at-the-door thing through sound alone, which is more emotionally regulated than most people that I know.

[00:10:23]It's a fish that talks, sings, and negotiates its own peace treaties from inside a 10-gallon criminally slept-on superhero of a fish. Most aquarium fish, when their water dries up, do what you would expect a fish to do, you know, uh die. The African lungfish refuses.

[00:10:40]When the habitat happens to go dry, this animal digs a chamber down into the mud, curls up headfirst, and secretes mucus that hardens into its own personal sleeping bag. I wish I could do that.

[00:10:51]Then, it enters total metabolic shutdown. No food, no water, no movement. There is a documented captive case of a lungfish emerging from its cocoon after 7 years, and just swimming away like nothing ever happened.

[00:11:05]Individuals have gone 3-plus years in aquaria without a single bite of food.

[00:11:10]The other thing worth knowing here is that this is a lobe-finned fish, which means more closely related to you, the person watching this, than it is to most other fish in the hobby. The same evolutionary branch produced land vertebrates. When you're looking at a lungfish, you're not really looking at a fish, you're looking at a distant, soggy, aggressive cousin who took a different exit on the highway. I know we've all got a few of those. None of those things change the fact that it is a genuinely difficult fish to keep. It gets large, it gets nippy, and it bites with intent. Reaching in carelessly is a mistake you're going to only make once.

[00:11:44]I see a lot of new keepers display what I call common rationalization.

[00:11:49]This thing is just a fish. Fish do not need lids. What is the worst that can happen? Well, my friend the rope fish is the worst that can happen. The rope fish has a swim bladder split into two chambers with the right side functioning as a real auxiliary breathing organ, which means this animal is genuinely obligated to gulp atmospheric air to live. Like a labyrinth fish, it can actually drown if denied access to the surface. It's fossil relatives swim around in rocks from the Triassic. The lineage is older than every single tree species currently on Earth. And the species is infamous for one specific behavior, and that behavior is escape.

[00:12:27]Rope fish slip out of the pinhole gaps lid you swore were sealed, navigates across the floor, and turns up under the couch, behind the bookshelf, or in the bathroom doorway like a roommate you did not properly vent. The reason they survive long enough to be found is the same air-breathing trick that keeps them alive in stagnant water, and well, that also keeps them alive on hardwood for a while as long as they stay moist.

[00:12:48]Standing in your kitchen at 2:00 in the morning with a damp towel and a sense of betrayal is a rite of passage if you keep these guys. It's a snake-shaped time traveler with built-in lungs and a documented escape habit. How does an invasive fish species survive in polluted oxygen-starved canals that everyone keeps trying to poison out of existence? Well, the answer is that it breathes air through its gut, and it waits for you to leave. The common pleco, that algae eater that you bought when you were 14 cuz the pet store guy said, "It'll clean your tank, bro." has an absolutely wild adaptation hiding inside it. This fish gulps air at the surface, extracts oxygen directly through its intestinal wall, vents out the rest out the back here, and then goes on about its day. This is why invasive plecos in places like Florida and Texas are basically immune to chemical control. You cannot poison the water out of an animal that is breathing the room. The other thing your 14-year-old self was not told is that this fish does not stay tank cleaner sized. It hits roughly 18 in as an adult and stops eating algae years before that. Starts producing a bio load that looks more like a dirty puppy than small fish. Most of them end up re-homed, dumped, or quietly suffering in a tank built for a fraction of their adult size. One of the most common and most avoidable mistakes in the hobby. The most underestimated animal in fish keeping and also a low-key biology miracle that's breathing through its colon in your living room. Finding Nemo lied to your face and you sat there and thanked Pixar for the lesson. In the actual biology, when Nemo's mom got eaten in the opening scene, you remember? Well, good old Marlin or Martin or whatever his name is, Nemo's dad. Okay, Nemo's dad should have changed sex. He would now become Marlene. Anyways, a fully functional female. And then it would have mated with Nemo.

[00:14:40]>> [clears throat] >> That is That's how Hey, don't shoot the messenger. This is how clown fish work.

[00:14:44]They live in strict size-based social hierarchies. One dominant female on top, one breeding male below her, and a stack of smaller non-breeding males who actively suppress their own growth so they don't threaten the dominant pair.

[00:14:57]When the female dies, the breeding pair permanently changes sex into a female.

[00:15:01]Complete restructuring I'm talking about here of gonads, hormones, behavior. The largest non-breeding male is going to step up to become the new breeding male, and none of this is temporary. There is no going back. Every clown fish in every reef tank started life as a male. The females you're looking at are males who got promoted through the death of the previous boss, which is a corporate structure that is simultaneously kind of horrifying and the most stable society in the ocean. This is a clownfish, people, the most marketed saltwater fish in the world quietly running a sex-changing social hierarchy that Pixar absolutely could not touch with a 10-ft pole. A fish that hunts birds, not big insects, not little frogs, birds. The silver arawana is a surface ambush predator from the Amazon basin that launches its entire body clear out of the water to grab birds, bats, basically anything stupid enough to perch on a low branch over the river. Documented leaps go multiple feet straight into the air, which is why the family is sometimes called water monkeys. The lineage is ancient. Family Osteoglossidae goes back around 150 million years, which means this strategy of yeeting itself at flying animals predates flowers existing on Earth in any meaningful way. It's also got a swim bladder that functions as an accessory breathing organ, so it survives in oxygen-poor water that would kill almost anything else. But, my friends, none of that matters more than this one piece of advice. If you keep one, your lid needs to be heavy, and it needs to be actually secured. Arawana escapes are not like a meme, they're a real cause of death for adolescent and adult fish in private aquariums. It's the only animal on this list whose superpower is hunting things that are technically supposed to be safe from fish. Let me tell you, the archerfish should not, by physics, work the way it works. This fish compresses air through a groove on the top of its mouth and fires a high-pressured jet, sometimes up to about 10 ft in the air.

[00:17:06]They use this to knock insects off overhanging vegetation, mind you.

[00:17:10]Standard nature documentary stuff, until you read the University of Bristol research showing that the power of the jet actually exceeds what the fish's own muscles should be capable of producing.

[00:17:21]It's not just spitting hard, it's using fluid dynamics to externally amplify its own force, generating power outside its body. That is a big deal. And keep in mind, it it's also aiming through the water-air interface, correcting for light refraction every single time, compensating intuitively for the difference between where the bug appears to be and where it actually is. Your nephew ain't doing that with a Nerf gun.

[00:17:44]And he's got a frontal lobe. One care note worth saying out loud here, the archerfish is brackish, not freshwater.

[00:17:51]They get sold into regular community setups constantly by people who either don't know or don't care. And the long-term mortality on those purchases is brutal. They need a proper brackish tank with overhanging emergent plants for the spitting behavior to actually develop. Out physics its own body, people. It out-snipes most humans. And it performs applied optical engineering for breakfast. True superpowers. Now, this one's going to sound a little tinfoil hatty at first, but stay with me. The weather loach, sometimes called the Dojo or the weather fish, has been used by hobbyists and farmers for centuries as a barometric pressure detector. Why? Well, because its behavior reportedly changes before storms arrive. If the fish is going feral and zooming around the tank like it's got somewhere to be, well, it's time to check the radar. And this is not totally folklore. The animal extracts oxygen from gulped air through its modified intestinal tract. And it's genuinely sensitive to changes in dissolved gas and pressure. That exact mechanism behind the weather forecasting behavior is not fully understood, which makes it more interesting, not less. It also survives droughts by burrowing into the mud and using its own slime coat to stay moist until water returns. This is a real emergency life skill that no other community fish in the hobby is casually tucked away. All right, this is unique. They're peaceful, they're hardy, and almost completely inappropriate for the small heated tanks that people usually try to keep them in. This species in particular is going to want cooler water in a long horizontal footprint to wander. Most beginners get that wrong on day one. The Dojo loach is a living barometer with an undocumented superpower nobody can really fully explain. The most quiet mystical fish you can buy for $10. Anyways, like I said before, your tank it's not just a glass box of pretty animals. You just needed someone to tell you what's actually in it. Half these fish have been sitting in the hobby for decades doing things that nobody thought to mention at the point of sale. Drop the one you already own in the comments and subscribe if you want the next one.

[00:19:52]Catch you next time.