Fin Day For A Stroll: Seven Amazing Walking Fish
A fish out of water? In my environment? It’s more likely than you think, as these 7 amazing walking fish gladly step forward to show. Equipped with extra organs which enable them to draw oxygen from the air, these piscine perambulators provide a glimpse of what life must have been like for our “ground-breaking” early ancestors.
Originating in Thailand, the Walking Catfish (Clarias batrachus) is known in Thai as Pla Duk Dam, which means “dull colored wriggling fish”. Nice. What’s NOT so nice is that this pug-ugly, barbel-faced fish is a notorious invasive species that has established itself well beyond Thailand’s borders to Australia, India, the Middle East and (since the late 1960s) Florida. On the bright side, they make good eating for both predatory birds, alligators and the odd two-legged Floridian.
(image via: Ferrebeekeeper)
Walking Catfish often use their marginal air-breathing abilities to escape seasonal or temporary ponds that are in the process of drying up. They also take advantage of very rainy conditions to expand their range – sometimes using flooded streets or highways to do so, to both their own and drivers’ disadvantage.
Snakehead fish can grow up to 40 inches (1m) long and in one case, a 60-inch (1.5m) specimen was recorded. Their size, toothiness and of course their ability to walk on land where other fish would perish has contributed to their reputation as “Frankenfish”. Movies like 2004′s Snakehead Terror just add fuel to the fire, as has this year’s Animal Planet and Discovery Channel television hit River Monsters, which devotes one show to the “Killer Snakehead”.
Here’s River Monsters star and consummate angler Jeremy Wade reeling in a Giant Snakehead:
Snakehead fish, the Northern Snakehead (Channa argus) in particular, have been known to awkwardly crawl overland from one body of water to another in search of food and fresher water to swim – and breed – in. They’re able to survive for several days out of water thanks to something called a suprabranchial organ that allows the fish to draw oxygen from the air.
(image via: Eduplace)
Although the ability to “walk” from one pond to another has made Snakeheads a formidably invasive species in North America, this same characteristic aids fishermen in their native East Asia in keeping the tasty fish as fresh as possible before they’re sold in fish markets.
The Wooly Sculpin (Clinocottus analis) is native to the California coast where its ability to flop about from one tidal pool to another has long been noted. The fish can survive up to 24 hours out of water if need be. It may be that 400 million years ago (give or take a few million), certain species of fish in similar intertidal zones gradually expanded their air-breathing, fin-walking talents to the point where they were more comfortable on land than in water.
(image via: University of San Diego)
The otherwise unremarkable Wooly Sculpin, on the other hand, seems to be perfectly content with its lifestyle at the border of land and water, proving that once a species settles into a viable ecological niche, it tends to stay there as long as the niche remains available to it.
Though superficially similar in appearance to the Mudskipper (not to mention Admiral Akbar), Rockskippers are Blennies while Mudskippers are Gobies. The Leaping Rockskipper (Alticus arnoldorum) will crawl out onto land for up to 20 minutes, searching for food and if need be, escaping from predators. Rockskippers use their pectoral fins to crawl and will sometimes flex their muscular tails to “skip” quickly away if they feel threatened.
(image via: Alessio Di Leo)
Rockskippers deviate somewhat from the standard fish body plan and to some, look a lot like tiny marine iguanas. They use their bulging eyes to peer above the water’s surface, checking to see if – literally – the coast is clear before hauling their bellies onto the beach.
The Eel Catfish (Channallabes apus) hails from Africa, has a long and sinuous body, and grows up to 16 inches (40cm) long. Like the Snakehead, the Eel Catfish has a suprabranchial organ that takes over oxygen-absorbing duties from the gills when the fish decides to hunt for land-based prey.
(image via: Nature Photographic Society)
Having no pectoral fins, the Eel Catfish uses a unique strategy to track its prey – usually beetles or other small insects – on land. The creature’s spine is unusually flexible, especially in the neck area. Unable to suck food into its mouth as it does when underwater, the Eel Catfish bends its neck downward so that its jaws can clamp down on prey from above. These adaptations help the creatures move from pond to pond as required, and allow for snacking along the way!
(images via: Africa Geographic)
The Climbing Gourami, also known as the Spotted Climbing Perch, is native to Africa and Southeast Asia. This is one fish that takes walking very seriously: it uses its entire repertoire when taking to land. Inside, a labyrinth organ (sort of a turbocharged suprabranchial organ) grabs oxygen molecules out of the air while on the outside the fish uses a varied array of fins to “walk” short distances from pond to pond. Of course, even the fastest fish on land is still no match for predators more fully adapted to life both in the air and on the ground.
Even so, Climbing Gouramis don’t look at all awkward when taking the overland route… well, maybe a BIT awkward. Check it out for yourself:
(images via: FishIndex)
The Climbing Gourami has been known to travel overland by night and in groups. Imagine traveling on foot one night when a school of Climbing Gourami crosses your path… we’re not sure if that would be lucky or not.
We’ve saved the most ambulatory fish for last: behold, the Mudskipper! Like the Rockskipper, it doesn’t look all that fish-like. Think of what Sea Monkeys would look like if Sea Monkeys were real: subdued fins, a long, lizard-like body and bulging eyes last seen on the last bullfrog you saw make the Mudskipper (subfamily Oxudercinae) eminently suited for its unique lifestyle.
(image via: ScienceRay)
Mudskippers employ highly adapted pectoral fins that look and act like arms to enable a wide range of mobility on land. They also rely on cutaneous (through their skin) breathing to maintain blood oxygen levels, much like amphibians.
(image via: TWM1340)
Mudskippers are native to tropical climes in the eastern hemisphere, so most North Americans have never seen them in the flesh. There IS, however, one Mudskipper that we in the west are familiar with: the animated Muddy Mudskipper character from John Kricfalusi’s Ren & Stimpy cartoons.
Here’s a quick video mashup of actual mudskippers frolicking on the beach to the Muddy Mudskipper Show theme:
Everybody sing now, “Who’s the greatest mudskipper of them all? Who can skip thru the mud with the greatest of ease? What kind of wonderful guy? Who can crawl like a dog without scraping his knees? Who’s got seg-ment-ed eyes? It’s Muddy Mud-Skipper! It’s Muddy! Mud-Skipper! It’s the Muddy! Mu-ud Ski-pper show!!!” You gotta admit, walking fish – real or animated – are pretty darned awesome!