The Ellen Show, YouTube
The Ellen Show, YouTube

10 Huge Facts About Whale Sharks 

The Ellen Show, YouTube
The Ellen Show, YouTube

This fascinating, filter-feeding species will finally get its close-up in this summer's Finding Dory. Here are a few things you might not have known about the world's largest fish.


It’s often said that the whale shark’s maximum length from end to end is about 45 feet, but this is a fish story. The longest verified measurements of live (or recently dead) specimens are in the 40-foot range. 

How heavy can they get? That’s a difficult question to answer. Weighing such huge marine animals is no easy task; many scientists simply estimate instead. Still, researchers at the Okinawa Churaumi Aquarium have managed to weigh several individuals over the years. The heaviest they’ve encountered was a captured 30-footer that weighed just above 7 tons. In the wild, longer ones probably weigh a good deal more.


For years, there was much debate over how baby whale sharks come into the world. Then, in 1995, a pregnant female was fatally harpooned near Taiwan. An autopsy revealed that her uteri (all sharks have two) contained around 300 unborn embryos. This discovery confirmed that the species is ovoviviparous. In other words, whale sharks—like certain snakes—hatch from eggs that are stored inside their mother’s body. Afterward, the little fish exit her womb fully-formed.


Thirty or 40-foot adult whale sharks have few natural enemies. Juveniles, on the other hand, are easy pickings for predators like blue sharks and marlins. These youngsters have every incentive to get big quick—which is exactly what they do.

Consider this: In just three years and 68 days, one newborn whale shark at Japan’s Oita Ecological Aquarium went from weighing 1.7 to 333.4 pounds. Another infant showed the astonishing growth rate of 18 inches per year over 630 days.

But, like human babies, young whale sharks don’t keep growing at the same speed forever. Once the fish reach a certain size, scientists theorize that their growth rate slows down considerably. By then, the creatures have—again, in theory—become big enough to scare away would-be attackers. 


Most sharks have 20 to 30 rows of pearly whites, but whale sharks have more than 300 rows. That means a whale shark has 3000 individual teeth, each one about the size of a match head.


All those teeth don't do very much, though. Despite their enormous size, whale sharks exclusively dine on very small life forms like plankton, krill, fish eggs, and small fish. The sharks usually swallow their food whole. Attached to the gills is a mesh-like network of long, cartilaginous bars known as “gill rakers.” These allow water to escape, but prevent even millimeter-sized victims from doing so. Eventually, the meal is forced down our whale shark’s narrow throat and digested.

Sometimes, a whale shark will lazily swim with its mouth agape. This low-energy feeding technique allows the beast to passively swallow any food items that might be in its path. But when it sees a dense cluster of potential targets, the shark changes tactics: The animal creates suction by rapidly opening and closing its jaws, pulling dinner into its cavernous maw. Here’s a look at this second method in action:


Generally, whale sharks—which are tropical and sub-tropical fish—are encountered from latitudes 30° N to 35° S. Within this range, they move around a lot: In three years, a single whale shark can travel 8000 miles or more. Though scientists don’t fully understand their migration habits, we know that the fish tend to gather en masse in specific places at specific times. For example, huge schools visit exotic locales like the Galapagos Islands and Yucatan Peninsula every summer to gorge on plankton.


Covered in hard, tooth-like scales called denticles, the hide on a whale shark's back can be up to 4 inches thick. Whale sharks can toughen this skin still further by clenching the muscles that lie just beneath it. Conversely, their underbellies are relatively soft and vulnerable—so when approached by human divers, a whale shark will often turn its belly away from them.  


Most experts agree that whale sharks reach sexual maturity around age 30, but their total life expectancy is unknown—and estimates are all over the map. According to some ichthyologists, the big fish probably die in their sixties. Others speculate that whale sharks can live to be 100 or even 150 years old. For the record, scientists aren’t completely sure about the great white shark’s maximum lifespan either—though they’re now known to reach age 70 or more.


In 2003 and 2004, a team led by biologist S.G. Wilson studied the long-term movements of six different whale sharks near western Australia. According to their results, the sharks mostly avoid deep plunges—in fact, the surveyed animals spent over half of their time within 100 feet of the surface.

With that said, though, whale sharks occasionally travel much, much further down. One of the Wilson team’s specimens, for instance, spent at least 12 uninterrupted hours at a depth of 3215 feet. And this wasn’t an isolated incident—tagged whale sharks off the coasts of India have been recorded hitting 2200- to 3200-foot depths as well. Why do the fish embark on such extreme dives? Nobody knows, although the answer likely has something to do with either keeping cool or gathering food.


No two whale sharks share the exact same pattern. Just behind their gills, every single one has a totally unique arrangement of pale, white spots. Today, this fun fact is helping biologists keep tabs on individual sharks—with some help from a secret weapon inspired by NASA. 

Mapping out stars can be a daunting task. The Groth algorithm, created in 1986, is a pattern-recognition formula that enables NASA scientists to identify the countless star fields observed by instruments like the Hubble Telescope.

Decades later, one conservationist group is using a new version of this for a very different purpose. ECOCEAN is an Australian non-profit that runs the largest whale shark identification program on earth—and anybody with a camera can participate. The concept is simple. If you’ve ever filmed or photographed a wild whale shark, send ECOCEAN a copy of your footage—along with some basic details about when and where the encounter occurred.

Then, a modified Groth algorithm is used to figure out if your fish is one of the 13,000-plus individuals on their record. If a match is pinpointed, you’ll get an email with a summary of that particular shark’s migration history.

Jason Holmberg of Portland, Oregon is ECOCEAN’s information architect. During the early 2000s, he worked with NASA astrophysicist Zaven Arzoumanian to develop this new fish-centered Groth algorithm. As Holmberg explained, their final product closely resembles the original. “We just adapted that from [identifying] white spots on a black night sky to white spots on the flank of a whale shark,” he told National Geographic

Why Tiny 'Hedgehog Highways' Are Popping Up Around London

Hedgehogs as pets have gained popularity in recent years, but in many parts of the world, they're still wild animals. That includes London, where close to a million of the creatures roam streets, parks, and gardens, seeking out wood and vegetation to take refuge in. Now, Atlas Obscura reports that animal activists are transforming the city into a more hospitable environment for hedgehogs.

Barnes Hedgehogs, a group founded by Michel Birkenwald in the London neighborhood of Barnes four years ago, is responsible for drilling tiny "hedgehog highways" through walls around London. The passages are just wide enough for the animals to climb through, making it easier for them to travel from one green space to the next.

London's wild hedgehog population has seen a sharp decline in recent decades. Though it's hard to pin down accurate numbers for the elusive animals, surveys have shown that the British population has dwindled by tens of millions since the 1950s. This is due to factors like human development and habitat destruction by farmers who aren't fond of the unattractive shrubs, hedges, and dead wood that hedgehogs use as their homes.

When such environments are left to grow, they can still be hard for hedgehogs to access. Carving hedgehog highways through the stone partitions and wooden fences bordering parks and gardens is one way Barnes Hedgehogs is making life in the big city a little easier for its most prickly residents.

[h/t Atlas Obscura]

Penn Vet Working Dog Center
Stones, Bones, and Wrecks
New Program Trains Dogs to Sniff Out Art Smugglers
Penn Vet Working Dog Center
Penn Vet Working Dog Center

Soon, the dogs you see sniffing out contraband at airports may not be searching for drugs or smuggled Spanish ham. They might be looking for stolen treasures.

K-9 Artifact Finders, a new collaboration between New Hampshire-based cultural heritage law firm Red Arch and the University of Pennsylvania, is training dogs to root out stolen antiquities looted from archaeological sites and museums. The dogs would be stopping them at borders before the items can be sold elsewhere on the black market.

The illegal antiquities trade nets more than $3 billion per year around the world, and trafficking hits countries dealing with ongoing conflict, like Syria and Iraq today, particularly hard. By one estimate, around half a million artifacts were stolen from museums and archaeological sites throughout Iraq between 2003 and 2005 alone. (Famously, the craft-supply chain Hobby Lobby was fined $3 million in 2017 for buying thousands of ancient artifacts looted from Iraq.) In Syria, the Islamic State has been known to loot and sell ancient artifacts including statues, jewelry, and art to fund its operations.

But the problem spans across the world. Between 2007 and 2016, U.S. Customs and Border Control discovered more than 7800 cultural artifacts in the U.S. looted from 30 different countries.

A yellow Lab sniffs a metal cage designed to train dogs on scent detection.
Penn Vet Working Dog Center

K-9 Artifact Finders is the brainchild of Rick St. Hilaire, the executive director of Red Arch. His non-profit firm researches cultural heritage property law and preservation policy, including studying archaeological site looting and antiquities trafficking. Back in 2015, St. Hilaire was reading an article about a working dog trained to sniff out electronics that was able to find USB drives, SD cards, and other data storage devices. He wondered, if dogs could be trained to identify the scents of inorganic materials that make up electronics, could they be trained to sniff out ancient pottery?

To find out, St. Hilaire tells Mental Floss, he contacted the Penn Vet Working Dog Center, a research and training center for detection dogs. In December 2017, Red Arch, the Working Dog Center, and the Penn Museum (which is providing the artifacts to train the dogs) launched K-9 Artifact Finders, and in late January 2018, the five dogs selected for the project began their training, starting with learning the distinct smell of ancient pottery.

“Our theory is, it is a porous material that’s going to have a lot more odor than, say, a metal,” says Cindy Otto, the executive director of the Penn Vet Working Dog Center and the project’s principal investigator.

As you might imagine, museum curators may not be keen on exposing fragile ancient materials to four Labrador retrievers and a German shepherd, and the Working Dog Center didn’t want to take any risks with the Penn Museum’s priceless artifacts. So instead of letting the dogs have free rein to sniff the materials themselves, the project is using cotton balls. The researchers seal the artifacts (broken shards of Syrian pottery) in airtight bags with a cotton ball for 72 hours, then ask the dogs to find the cotton balls in the lab. They’re being trained to disregard the smell of the cotton ball itself, the smell of the bag it was stored in, and ideally, the smell of modern-day pottery, eventually being able to zero in on the smell that distinguishes ancient pottery specifically.

A dog looks out over the metal "pinhweel" training mechanism.
Penn Vet Working Dog Center

“The dogs are responding well,” Otto tells Mental Floss, explaining that the training program is at the stage of "exposing them to the odor and having them recognize it.”

The dogs involved in the project were chosen for their calm-but-curious demeanors and sensitive noses (one also works as a drug-detection dog when she’s not training on pottery). They had to be motivated enough to want to hunt down the cotton balls, but not aggressive or easily distracted.

Right now, the dogs train three days a week, and will continue to work on their pottery-detection skills for the first stage of the project, which the researchers expect will last for the next nine months. Depending on how the first phase of the training goes, the researchers hope to be able to then take the dogs out into the field to see if they can find the odor of ancient pottery in real-life situations, like in suitcases, rather than in a laboratory setting. Eventually, they also hope to train the dogs on other types of objects, and perhaps even pinpoint the chemical signatures that make artifacts smell distinct.

Pottery-sniffing dogs won’t be showing up at airport customs or on shipping docks soon, but one day, they could be as common as drug-sniffing canines. If dogs can detect low blood sugar or find a tiny USB drive hidden in a house, surely they can figure out if you’re smuggling a sculpture made thousands of years ago in your suitcase.


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