Saltwater SWAT team: Top 5 fascinating shark hunting techniques

I’ve been entranced by sharks since I was a little kid. From the first time I saw Jaws, I was hooked (pun intended). There are so many aspects of a shark’s physiology I admire, but my favorite point of fascination is probably the variety of hunting techniques they use to capture their prey. Though most of my friends are aware of my sharktastic obsession, others are surprised because I’m, well, a vegetarian. Yes, I’m a vegetarian with an intense interest and, dare I say, admiration for this aquatic carnivore’s feeding habits. This animal’s intelligence, grace, stealth, and prowess are unparalleled on land (except maybe when J.J. Watt is playing for the Texans). When people hear the word “shark,” they typically picture mindless killing machines, but they couldn’t be further from the truth. Sharks have highly adapted hunting strategies that have been honed over millions of years to make them one of the most efficient predators on the planet. Here is my own personal countdown of the most fascinating shark hunting methodologies.

mako shark

Mako shark, Isurus oxyrinchus.

Photo credit.

5. Mako shark (Isurus oxyrinchus): Mako sharks are one of only a few shark species that are technically endothermic meaning they are able to maintain a fairly high internal body temperature roughly seven to 10 degrees above that of the water around them. This high body temperature gives them the energy they need to maintain a constant swimming speed of up to 35 miles per hour and bursts of speed of up to 70 miles per hour. The symmetry of their caudal fin also helps them maintain these high speeds. Due to this unique adaptation, Mako sharks are the fastest shark species out there making them a lethal predator. Though they’ll eat a number of different oceanic species including cephalopods, dolphins, and sea turtles, they can also chase down some of the fastest schooling fish in the sea like tuna and swordfish.

whale shark

Whale shark, Rinchodon typus.

Photo credit.

4. Whale shark (Rinchodon typus): Whale sharks get bragging rights as the largest fish species in the world. And while they can grow more than 40 feet in length, their food of choice is plankton. That’s right, ladies and gentlemen, the largest fish species in the world feeds on tiny plankton. As a filter feeder, they swim through the ocean with their mouths wide open to filter out these delicious little morsels and any other small fish that make the mistake of getting in the way. Getting out of the way isn’t always the easiest feat though, since a whale shark’s mouth can open to almost five feet wide!

3. Bull shark (Carcharhinus leucas): The bull shark is definitely a contender when it comes to most fascinating hunting techniques. One of the main reasons for this is its increased territory and hunting ground; it’s one of the few shark species known to habitually hunt in freshwater. When it comes to hunting, bull sharks get their name from their use of a technique known as the bump and bite. Bull sharks will use their body weight to propel themselves into their prey to stun or even kill it. Then, before the prey has a chance to recover, the bull shark attacks. Their unique ability to adapt to freshwater environments means they also have a wide range of prey from sloths to cows to hippos! They are extremely territorial, so they are one of the most common offenders when it comes to shark attacks on humans. Rule of thumb: if you’re in a murky body of water and you feel a hard bump, maybe get out of the water for a bit.

Bull shark

Bull shark, Carcharhinus leucas.

Photo credit.

2. Great white shark (Carcharodon carcharias): Of course, I had to include the famous great white shark. Great whites are probably the most well-known shark, because they have the best agent. Or maybe it’s because almost any movie about a killer shark stars the great white. While many of these Hollywood depictions have led the general public to believe these animals kill without discrimination, they are actually exceptionally precise and calculating hunters. Great white sharks utilize two hunting practices that, when put together, make them an aquatic force to be reckoned with. The first, known as spyhopping, is predominantly seen in marine mammals like dolphins and whales.

Spyhopping is when an animal brings its head above the water’s surface to take a look at their prey. The great white shark is one of the only shark species that we know of that to utilize this technique. After their recon mission, great white sharks travel below the surface to wait for the opportune moment to seize their prey. To capture fast-moving marine mammals (their favorite blubbery snack), great white sharks travel at incredible speeds and explode through the surface of the water. This practice is called breaching, and it’s most impressive when you consider the size of these predators. Great white sharks can weigh up to 2,000 pounds and burst out of the water at speeds up to 40 miles per hour. Some can even reach heights of 10 feet above the water’s surface! It’s a fairly rare occurrence, because it takes considerable energy to propel these animalistic torpedoes out of the water.

 

1. Thresher shark (Alopias vulpinus): By far, my favorite hunting technique of any animal. For decades, fishermen claimed that these sharks used their caudal fin to hunt. They would consistently find thresher sharks caught in their hooks; however, the sharks weren’t hooked by the mouth, they were hooked by their tail fin. Their conclusion was that the unusual shape of this shark’s tail fin was a prominent and integral part of its hunting technique, though they weren’t sure how. Thresher sharks are easy to identify, since they have a highly elongated upper lobe on their caudal fin. This caudal fin can sometimes make up two thirds of the shark’s body length. It has only been throughout the last few decades that researchers have come to witness their amazing hunting technique in the wild. Thresher sharks can actually use their caudal fin like a whip to stun their prey before going in for the kill. It’s a truly remarkable hunting strategy that you have to see to believe!

Don’t forget to stop by the museum’s Shark! exhibition this summer to get a chance to learn even more about these amazing animals. You can track sharks, learn about how researchers tag and study great whites, and touch live epaulette carpet sharks and white-spotted bamboo sharks at our touch tanks, open through Sept. 7.

Still not enough saltwater for you? Drop by the brand-new Hamman Hall of Texas Coastal Ecology, opening this Friday, May 22.

Shark Week: Of Fins and Fiction

At the risk of sounding obvious — it’s Shark Week, the Discovery Channel’s annual plug for the much maligned (but secretly awesome) top predators of the deep!

Started in 1988, as a way for the station to capitalize on the lack of summer competition for programming while aiding conservation efforts for the infamously finned and fanged fellows, the sharks and Discovery Channel have had what you may call a symbiotic relationship. Sharks get the station viewers and the viewers provide better ratings for the station while becoming better educated about sharks and the need for strong conservation efforts. Win/win/win.

Well, at least that’s how Shark Week started…

Lately, Shark Week has, well, it’s been a little disappointing — at least from a scientific standpoint. 

Most of the programming is seemingly centered on making the public at large even more afraid of sharks than they already are (even while these fears are generally not grounded in fact). They’re hyping up fears of getting eaten by one while making the shark from Jaws look comparable to a goldfish you’d take home in a plastic bag.

Here I’m talking about the megalodon, or Carcharodon megalodon

While it’s incredible that this positively massive species of shark ever existed (let alone that we now have the capabilities to find and date their fossils to between 28 and 2 million years ago) the folks with Shark Week have decided that the species wasn’t interesting enough on its own merit. Instead, they’ve now made two completely un-scientific “documentaries” about “scientists” “searching” for it (Click here for an in depth review of actual scientific theories surrounding megalodon).

You may also have heard that some restaurants have tried to capitalize on Shark week this year by serving shark meat on their menus. Really.It’s getting pretty clear at this point that the programming is seriously diluting the conservation message that Shark Week was originally meant to convey.

In a conversation on all things Shark Week with the International Business Times, Sonja Fordham, a marine biologist and founder of Shark Advocates International was asked about the positive and negative effects of Shark Week on the public’s perception of sharks. On this point she said:

“Well, it’s really hard to tell. There’s good things and bad things,Talking about sharks, providing all types of people and interest groups to get out their messages tied to this global event — one time a year we’re all focused on sharks — so that can be very positive if we capitalize on that. But then of course the negative image, the perpetuation of the fear of sharks, does not help shark conservation. It’s a pretty outdated view to see sharks as killing machines or serious threats to beach goers. That negative imagery doesn’t help in help of advancing shark conservation policies.” 

So it’s a mixed bag. But we can use the hype of Shark Week to start conversations about conservation, the need to protect sharks and ways change our perceptions of them.

It might be an uphill battle, but we’re still making progress.

If you have the desire to learn more about sharks (including the extinct megalodon) make sure you come to HMNS for our SHARK! exhibit, opening August 29.

Why all the Shark Week mania over megalodon? Why two other sharks blow it out of the water

With all the fuss over megalodon lately (including the Discovery Channel’s doubled-down non-apology), we decided to give some attention to a couple of grossly unappreciated other prehistoric sharks. Great whites are great and all, and megalodon is a marvelous monstrosity, but there are two other prehistoric shark species that really blow everything else out of the water.

We get that megalodon is mega-huge, and it’s thrilling to ruminate over an extra-large, extra-hungry version of today’s Great White. But what about sharks with scissors for jaws? Or a buzz-saw mouth full of teeth?

It’s not science fiction. Here are two prehistoric sharks that we think should be in the running for their own Shark Week special:

Edestus

There were several species of this scissor-jawed prehistoric shark, the largest of which — Edestus giganteus — could rival the size of a modern Great White. But instead of regular shark teeth (which are pretty scary as is), Edestus had a mouth that cut like giant scissors.

“When you say ‘shark,’ the first thing that pops in your head is teeth,” says Associate Curator of Paleontology David Temple. “Sharks have had similar kinds of teeth, but there were some weird evolutionary offshoots where the teeth don’t look like we imagine them now. Instead of the rows and rows of teeth that we expect the mouth, Edestus’ mouth looked more like a modern dolphin’s, and its teeth were more like shearing scissors.”

Image courtesy wikimedia

Edestus wound up with its unusual, protruding shears (pictured above and reenacted here) because it did not shed its worn teeth like a modern shark would. Instead, new teeth continued to grow outward until its two rows of single-file teeth protruded out past its mouth.

Helicoprion

Also called the whorl shark, the Helicoprion is notable for its bizarre toothy set-up. Like Edestus, instead of shedding its old, worn teeth, Helicoprion retained them, adding new teeth in a single row in a spiral formation (imagine the growth pattern of the world’s longest fingernails, and you’ll get the idea.)

For years, Helicoprion’s remains confused scientists and an accurate body outline eluded researchers:

Photo courtesy Scientific American
The many faces of Helicoprion, courtesy of Ray Troll for Scientific American.

Recently, though, a report published in Biology Letters offered new insight into the shark’s unusual jaw. Instead of protruding past the lower jaw and coiling beneath the chin, as was once thought, or existing completely externally as some sort of defensive structure, scientists now believe that the shark — which had no teeth at all in its upper jaw — housed its “whorl” of teeth inside its lower jaw. To kill soft-bodied prey, it sliced upward like a buzz-saw, using this vertical spiral of teeth to push food back into its throat.

courtesy WikiMedia

A “whorl” of Helicoprion teeth

“Two of my fantasy acquisitions to the museum are paleozoic sharks,” Temple says of these often underappreciated freaks of the sea.

What say you: Should Discovery Channel devote a special to these super-special sharks?

On the Discovery Channel’s megalodon bungle: In defense of cryptozoology and critical thinking

For us, as for many science lovers, it’s currently our favorite season. Some might even call it the most wonderful time of the year: Shark Week.

The Discovery Channel’s annual full-channel takeover, devoted to all things predatory and sleek, is one of the single-most anticipated science events of the year. So we were a little disappointed — as, apparently, were many Discovery Channel viewers — when the network aired a film that implied that the extinct monstershark megalodon might not really be extinct.

We consider ourselves something of experts on the subject, because, well, this:

Megalodon Jaws
(That’s our Associate Curator of Paleontology, David Temple, with our Adult Education Director, Amy Potts, NOT being swallowed alive by an EXTINCT shark.)

We sat down with Associate Curator of Paleontology David Temple to dish over the epic bungle and set the record straight. Here’s his point-by-point breakdown of how wrong — WRONG WE TELL YOU! — it all is:

Point 1 (less a point than a fun fact):

The largest recorded (and verified) Great White Shark was caught off Prince Edward Island in 1988. It measured 20 feet long, meaning the 25-foot “Great White” featured in Jaws would have actually been more believable as a megalodon. The movie is, of course, fictional. Temple says there is a truism in diving that Discovery might have missed during its excitement over giant sharks: “Everything underwater looks a third bigger and a third closer than it really is, except for sharks. Then you can multiply that times 10.”

Point 2

For a threatened “living fossil” species to exist, they must retreat into the margins of their ecosystems. See: the Coelacanth. Megalodons required tropical, warm water to survive, and so for them, retreating into the depths of the ocean simply wouldn’t be a viable option.

Point 3

Megalodons were, as the Discovery Channel portrayed, extremely aggressive and proficient predators. As a result, their impact on their native ecosystems was great. If a population of megalodons yet existed, it’s impossible that we wouldn’t have noticed.

Point 4

If megalodons still existed, even in the cool depths where they couldn’t possibly survive, we would have seen a carcass by now. Even the Giant Squid, seen for the first time just last year, periodically washed up on shore to confirm its existence.

So in conclusion, while it’s fun to imagine a world in which megalodons still swam the seas (“Imagine Jaws on steroids,” says Temple); and while cryptozoologists chasing hidden and mythical creatures like the Loch Ness monster and Big Foot are occasionally right (see: the Okapi); you’d be far more likely to discover a small new species of frog than a 70-foot shark that could eat a fishing boat.

Point? Science.