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While amphibious fishes face a multitude of new challenges upon leaving the water,they’ve evolved ingenious ways to overcome them.They’re resilient in the face of droughts and floods and have access to new prey as well as a plan B if they need to escape competitive, polluted, or unhealthy environments.While being a “fish out of water” is generally regarded as a bad thing,for these species, it offers an undisputed edge.

Our walking catfish, meanwhile,uses the taste buds that coat its body for navigation.These taste buds are concentrated in its whiskers,which whip through the air,sensing compounds that signal the proximity and quality of nearby water— and prey.The walking catfish will shimmy towards attractive volatile amino acids while steering clear of foul waters emanating hydrogen sulfide.

The Nopoli rock-climbing goby, no bigger than a few centimeters,scales hundred-meter-tall Hawaiian waterfalls,inching its way up by alternately attaching the suction cups on its mouth and pelvic fins.To find water while on land, the mummichog,like most amphibious fishes, is on the lookout for reflective surfaces.Other species, like mosquitofish,exercise their inner ear to determine where they’re oriented on a slope,relying on the probability that they’ll find water by moving downhill.

But the lungfish takes the cake:the rivers it inhabits disappear during dry seasons,so it buries itself in the eart hand coats its body in a mucus cocoon.It can survive like this for years until being resuscitated by the next big rainstorm.Amphibious fishes use powerful fins to move on land and clever tools to navigate as they go.

And lungfish, being related to the ancestors of all tetrapods,or four-limbed vertebrates, are equipped with true lungs.They’ll actually drown if they’re kept underwater too long.Fish have thin, permeable skin that allows for essential compounds to diffuse into and out of their bodies while they’re underwater.But this works against them on land as their bodily moisture diffuses into the air.To dodge dehydration, mudskippers roll in the mud like puppies.

Underwater, fish breathe with gills,which are feathery organs packed with blood vessels that absorb dissolved oxygen from the water.But in the open air, their gills collapse and are rendered useless,so amphibious fishes need other ways to breathe.The armored catfish’s stomach is packed with blood vessels,so it can gulp down air and breathe through its stomach lining.

the eel catfish makes its onshore voyage to satisfy its hearty craving for beetles.And for others, the terrestrial draw is more ritualistic.Every year under the cover of night,masses of California grunion flop their way onto sandy beaches,where females deposit thousands of eggs into the sand before re-entering the ocean.

And at the other end are species like mudskippers that nonchalantly hop around mudflats for days at a time.But why do fish make the exodus from water to land?And how do they cope with this drastic transition?If temperatures get too high for the mangrove rivulus in the shallow tropical pools it inhabits,it’ll flip itself onto a bank and cool off in the shade.During the dry period,it can survive for two months out of the water by staying in moist environments.

We think of fish as completely aquatic animals.But the walking catfish is just one of hundreds of fish species that are actually amphibious,meaning that they possess adaptations that enable them to survive on land.Fish amphibiousness is a spectrum.At one end are species like the mosquitofish that’ll only move on land when forced.

This pond is the only home this fish has ever known.But lately, it’s gotten crowded and food is scarce.Luckily, it has an option many don’t:as a walking catfish, it can dance its way out of the water and onto bigger and better things.However, it faces many challenges on its terrestrial journey:it’s now in danger of suffocating, drying up,suffering physical damage from rough terrain,and being hunted by land predators.

Even humans might benefit from the sting of a jellyfish one day. Scientists are working on manipulating cnidocytes to deliver medicine, with nematocysts rarely 3% of the size of a typical syringe needle. So, the next time you're out in the ocean, be careful. But also, take a second to marvel at its wonders.

and recurved teeth behind the sunfish's cheeks. Even tiny lobster slipper larvae can cling to the bell of a jellyfish and hitch a ride, snacking on the jelly while they preserve their own energy for growth. Small agile fish use the jellies as moving reefs for protection, darting between tentacles without ever touching them.Nudibranchs, which are sea slugs covered in protective slime, can actually steal the jelly's defenses by eating the cnidocytes and transferring them to specialized sacks for later use, as weapons against their own predators.

There's an anti-venom, but the venom is fast-acting, so you'd need immediate medical intervention. Despite the impressive power in their tentacles, jellies aren't invincible. Their stinging cells are no match for the armor of thick-skin predators, like the leatherback turtle and ocean sunfish. These predators both have adaptations that prevents slippery jellyfish from escaping after they are engulfed: backwards pointing spines in the turtle's mouth and esophagus

That's why urinating on the affected area,a common folk remedy, may do more harm that good, depending on the composition of the urine. Most jellyfish stings are a painful nuisance, but some can be deadly. An Indo-Pacific box jelly, also called a sea wasp, releases venom which can cause contraction of the heart muscles and rapid death in large doses.

Nematocysts can continue to fire even after a jellyfish has died, so it's important to remove lingering tentacles stuck to the skin. Rinsing with vinegar will usually render undischarged nematocysts inactive. Seawater can also help remove residual nematocysts. But don't use fresh water because any change in salt balance alters the osmotic pressure outside of the cnidocyte and will trigger the nematocyst to fire.

Venom is ejected via a nematocyst, a whip-like hollow tubule, which lies coiled under high osmotic pressure. When mechanical or chemical stimuli activate an external trigger, the lid of the cell pops open and sea water rushes in. This forces a microscopic barbed harpoon to shoot out, penetrate and inject venom into its victim. Nematocyst discharge can occur in less than a millionth of a second, making it one of nature's fastest biomechanical processes.

Even baby jellyfish, the size of a pencil eraser, have the ability to sting. Larval jellyfish, ephyrae, look like tiny flowers pulsating in the sea. As they grow, they become umbrella-shaped with a bell at the top and descending tentacles around the margin. The largest species of jellyfish, the lion's mane, has tentacles that can extend more than 100 feet, longer than a blue whale. These tentacles contain most of the stinging cells, although some species have them on their bells, too.

You're swimming in the ocean when something brushes your leg. When the tingling sets in, you realize you've been stung by a jellyfish.How do these beautiful, gelatinous creatures pack such a painful punch? Jellyfish are soft because they are 95% water and are mostly made of a translucent gel-like substance called mesoglea. With such delicate bodies, they rely on thousands of venom-containing stinging cells called cnidocytes for protection and prey capture.

A journey that ultimately drove our own evolution, survival and existence.Today the coelacanth remains the symbol of the wondrous mysteries that remain to be uncovered by science.With so much left to learn about this fish,the ocean depths and evolution itself,who knows what other well-kept secrets our future discoveries may bring to life!

Not only are those fins structured in pairs to move in a synchronized way,the coelacanth even shares the same genetic sequence that promotes limb development in land vertebrates.So although the coelacanth itself isn't a land-walker,its fins do resemble those of its close relatives who first hauled their bodies onto land with the help of these sturdy, flexible appendages,acting as an evolutionary bridge to the land lovers that followed.So that's how this prehistoric fish helps explain the evolutionary movement of vertebrates from water to land.

Not only are those fins structured in pairs to move in a synchronized way,the coelacanth even shares the same genetic sequence that promotes limb development in land vertebrates.So although the coelacanth itself isn't a land-walker,its fins do resemble those of its close relatives who first hauled their bodies onto land with the help of these sturdy, flexible appendages,acting as an evolutionary bridge to the land lovers that followed.So that's how this prehistoric fish helps explain the evolutionary movement of vertebrates from water to land.

But the fact that the coelacanth came back from the dead isn't all that makes this fish so astounding.Even more intriguing is the fact that genetically and morphologically,the coelacanth has more in common with four-limbed vertebrates than almost any other fish,and its smaller genome is ideal for study.This makes the coelacanth a powerful link between aquatic and land vertebrates,a living record of their transition from water to land millions of years ago.The secret to this transition is in the fins.

When she finally was able to reach J.L.B. Smith, a local fish expert,he was able to confirm, at first site,that the creature was indeed a coelacanth.But it was another 14 years before a live specimen was found in the Comoros Islands,allowing scientists to closely study a creature that had barely evolved in 300 million years.A living fossil.Decades later, a second species was found near Indonesia.The survival of creatures thought extinct for so long proved to be one of the biggest discoveries of the century.

To biologists and paleontologists,this creature was a very old and fascinating but entirely extinct fish,forever fossilized.That is, until 1938 when Marjorie Courtenay-Latimer,a curator at a South African museum,came across a prehistoric looking, gleaming blue fish hauled up at the nearby docks.She had a hunch that this strange,1.5 meter long specimen was important but couldn't preserve it in time to be studied and had it taxidermied.

The dead coming back to life sounds scary.But for scientists, it can be a wonderful opportunity.Of course, we're not talking about zombies.Rather, this particular opportunity came in the unlikely form of large, slow-moving fish called the coelacanth.This oddity dates back 360 million years,and was believed to have died out during the same mass extinction event that wiped out the dinosaurs 65 million years ago.