Shark Week/Newsflash: A Real-Life Jaws?!

Sometimes, things just click into place. This is one of those times; the perfect, Jaws-related tidbit of news came to light during Shark Week. This was too good not to use:

"BOSTON (Reuters) - A 13-foot great white shark off the coast of Cape Cod prompted Massachusetts officials on Friday to warn beachgoers to be aware of their surroundings and to use common sense when swimming.

State biologists located the shark, which had been tagged with an acoustic transmitter, near Cape Cod island of Monomoy on May 28. White shark sightings have been on the rise off the Massachusetts coast, the setting for the 1970s shark movie, "Jaws".

The Department of Marine Fisheries advised people to avoid swimming at dawn and dusk, to stay close to the shore and to avoid areas where seals congregate.

Massachusetts has been compiling data on great white sharks since 1987. Experts have said the sharks are attracted to that coast by a growing population of gray seals.

There have been eight recorded shark attacks in Massachusetts, two of which were fatal, according to Shark Attack File, which compiles data on shark attacks worldwide." - Source and more. 

 For the record, great whites and other sharks usually do not see humans as dinner. If you happen to be stupid and punch the shark in the face or something, that gives the shark an excuse to eat you. Likewise, swimming with cuts is never a good idea. The ocean's full of sharks; not all of them are lethal.

Shark Week: Pet Sharks?

Some people like menageries. They love having exotic animals that nobody else on the street has, and they happen to show off a lot of them. 

So what if one of those animals happens to be a shark?

It's hard to find a shark that will not get at least ten feet long.  You're looking at a whole room's worth of an aquarium. Oh, and you should have handled saltwater tanks before; the best sharks are in the oceans, and for regular fish, saltwater tanks are hard enough to maintain. How about feeding a shark? They aren't going to take fish flakes. In other words, for pretty much any shark, you're looking at a millionaire's investment.

So, let's say you do have the insane funds to provide for a shark. What types of sharks are good for relative beginners, seeing as some undoubtedly make better pets than others?

Well, I have good news and bad news. The bad news is that there's no "ball python" to the nurse shark's "Burmese." In English: there is no pet shark that the average person can keep on a whim. There are freshwater fish called "sharks," but those are not true sharks. The good news is that there are some sharks that make better pets than others. Don't start with a great white, now.

This handy little site has some details on the best types of "starter" sharks. I'm going to save you all some research and post a little bit more on its recommendations...with pics.

Source. This image is amazing.

Wobbegongs: I want to say that this blog has already done an entry on wobbegong sharks. To my great surprise, these oddball sharks from the waters of the Pacific and Indonesia are some of the best pet sharks for the average, research-loving schmuck. Some wobbegong sharks get only 4.1 feet long, and they have slow metabolisms, needing only to be fed twice a week. Not a bad deal if you want to say you own a shark, but still requires some aquarium knowledge. The tasseled wobbegong (Eucrossorhinus dasypogon) above is one of the better wobbegongs, if a shark suits your fancy. Alas, it looks more like a bunch of seaweed than an actual shark.

Bamboo sharks: Again, these are bottom-dwelling sharks from the Indo-Pacific like wobbegongs, except they look a lot more like miniature sharks. They can "walk" on the bottom of the sea, or your tank, with their surprisingly dextrous fins. The largest species is roughly 4 feet in length. FYI, the shark the wobbegong is eating is a bamboo shark, but here's a better pic of the thing while it's alive.

 

  Epaulette sharks: THESE are so worth their own entry in the future! I'm just looking at a video and being totally charmed by it. The ocelli (big black "eye" spots) above the pectoral fins make these sharks very pleasing to the eye. These are, again, Indo-Pacific bottom-feeders. They can be fed raw shrimp, which is fairly easy to acquire and handle. They are not as small as wobbegongs and Bamboo sharks, however, so please make sure you can handle these slender sharks before taking one home!

Shark Week: Nurse Shark.

This is a weird shark week. That means we'll be going off the beaten path, looking at sharks you never knew existed. Not every shark can be Jaws, so how about we switch to something more docile, yes?

This is a nurse shark (Ginglymostoma cirratum). Nurse sharks are fond of shallow, warm waters in the Pacific and Atlantic Oceans. They aren't dangerous to humans unless you disturb them, in which case prepare for a nasty bite from thousands of needle teeth. Small stuff on the bottom, be it fish, crustacean, or mollusc, is not so lucky. Their barbs function much like the whiskers on a catfish, meaning that stuff beneath the sand is not safe.

Nobody really knows why these sharks are called nurse sharks. They don't take particularly good care of their (!live) babies. The name could come from the shark's docile nature or how it "nurses" the sea bottom with its mouth, but the most likely explanation is the Old English "hurse," meaning this particular type of bottom-dwelling sea shark. In other words, name change via spell check. We've all been there.

Now, here's a puzzle: How do bottom-dwelling sharks, well, stay on the bottom? Most sharks need to swim constantly to circulate water across their gills.Nurse sharks circulate water by pumping it through their mouths. These sharks do rest a lot, sometimes on top of each other. They can be seen sleeping in masses of up to 30-40 members in one spot, meaning that these are relatively social sharks. How far removed is that from a terrifying great white?

In many ways, nurse sharks are the "Burmese pythons" of the saltwater aquarium trade. People see a cute juvenile, don't think it'll get very big, then wind up with a 10+ foot shark that no tank will hold. Good luck finding a home for a shark; most aquariums will not take them. Please do your homework before taking home any animal, especially a shark!

Creature Feature: Basking Shark.

So, wait a tic. Is hakarl made of basking shark or Greenland shark? Actually, this is where the video got something wrong: basking sharks aren't poisonous. They can still be used for hakarl, but the curing does little more than make the meat extra-pungent. What is a basking shark, anyways, because the image of a shark basking sounds like something off of a cheap beach souvenir?

Source.

This is what a basking shark looks like. It is native to all the seven seas, presumably following the  plankton by smell. Being large, slow-moving, and calm, it has been a fishery staple for quite some time. It is the second largest fish in the world after the whale shark.

These sharks are big. You thought 23 feet was big? Nah, the basking shark can get up to 40 feet long. To reuse a bad joke, that's a lotta fish; it makes sense that some Vikings would want to preserve that. Numbers like that have not been seen for a while, but remember that the basking shark is kind of like a whale shark. Yes, it is similar to something with whale in is name for so many reasons.

Source: BBC, but sharks aren't mammals, silly network.

The basking shark, like the whale shark, is a filter-feeding shark. It eats whatever small things it swims through. That means it is only a threat to the tiny little creatures (zooplankton) that get caught in the basking shark's super-large mouth. Even though it may look a lot like a great white, it's not going to bite you. I would not, however, suggest going up to random large sharks and testing this.

Alas, this is another one of those creatures that is at risk of going extinct. Shark fin soup can come from these sharks, too. Shark liver oil was once popular, and Japan uses parts of this shark as an aphrodisiac. Basking sharks were once so common that they were thought pests. Now some areas ban catching them while others seem to have lost them entirely. If you see one of those sea monsters, look on at it in awe; unless you live at sea, they're an uncommon sight.

Maybe it's about time I did my own version of Shark Week...hmm...

"They Actually Eat That:" Hakarl.

I think some of my faith in humanity just died. Why? Because people actually eat toxic, 23-foot-long shark, and it's popular.

No, really. There are people who eat poisonous, polar bear-eating shark. In Iceland, there is a dish called hakarl frequently eaten in winter. It happens to be the national food of Iceland, and is made entirely of Greenland shark. There are different varieties depending on where it comes from. It still comes from the same shark that is about the size of Jaws and eats Christmas mascots as a snack.

How do they do it? By making the shark rot. They bury it in a pit for a month or five, using heavy rocks to add pressure onto the dead shark. Bacteria take out the toxins in the shark's flesh during that time, making it fit for human consumption. It is then hung up to dry. Note how "delicious" does not come up in that description. Just "fit for human consumption." It's edible, but by no means delicious.

Hakarl is definitely an acquired taste. Most first-timers are advised to hold their noses; like many fermented foods, hakarl tastes (slightly) better than it smells. But don't take my word for it; the video below has testimonials detailing exactly how bad hakarl is. Chef Ramsey himself could not stomach it. No wonder brennivin is consumed afterwards.



To be fair, we can see how someone would want to eat the shark. Traditional Icelandic stuff is made with shark teeth. Just about the only thing they weren't using was the meat. It's still a freaky way to use it; "hey, let's get this bad-tasting shark to decay, and hope the poison's out while the shark's still reeking from bacteria." Yep, great logic.

After Earth would never happen. Humans would decimate every habitat so much that nature would bounce back in strange, unpredictable ways, using exactly none of the cute, fuzzy animals in that movie. The future bat in Primeval is more realistic than that.

Creature Feature: Greenland Shark.

Want an animal that could still be around 10,000 years after humanity? Sharks. Sharks are badasses that ate dinosaurs.  If we haven't dehydrated the planet, sharks will live, and they will always be associated with Jaws music in the back of our minds.

Enter the Greenland shark (Somniosus microcephalus). True to the name, it is native to the area around Greenland and Iceland. They are the largest species of dogfish and northernmost species of shark. Unlike most sharks that the general populace is aware of, these guys are probably primarily scavengers, picking on whatever carrion they can get. They also have live babies, just like boas and several other species of shark.

First of all, these sharks are huge. Jaws huge. They can grow up to 23 feet from head to tail and live around 200 years. Luckily for us, they swim only 1.6 miles per hour; a human can easily outdo that. If they did not have such derpy little mouths, we might be inclined to take them more seriously. Huge? Yes. Threatening? Hardly.


From: Fishindex.blogspot.com.

These sharks will eat any meat that fits in their goofy-looking mouths. Along with things that one might assume like seals and fish, Greenland sharks can eat reindeer and polar bears. Read that again: Reindeer and polar bears are on this thing's menu. Dear Hallmark: start marketing this thing on Christmas cards, because it's eating your mascots.

Did we mention that its flesh was poisonous? No? It is. The Greenland shark has an extremely high trimethyline oxide content in its skin. Sled dogs who eat the flesh won't die, but are unable to stand from the poison. In humans, the meat causes symptoms akin to high drunkenness. It tastes so much like piss that the folklore around the shark usually involves urine.

Wait a minute...what? Did I just say they actually ate that?

Newsflash: Tapeworm Eggs Found In Prehistoric Sharks.

Although it's easy to focus on giant mammals for an entire week, here's a small reprieve: parasites have been around even longer. (Actually, I couldn't find too many newsworthy things related to ancient mammals.) Tapeworms have been found in the body of a shark from the Permian, a time when mammal-like reptiles were a thing. That was before the dinosaurs, in case you aren't up to snuff with your periods of Earth's history.

The tapeworm cysts were found in the gut of  a 270-million-year-old fossil shark. Given the presence of Brazilian journals, we can safely assume that it was found somewhere in South America.

"Remains of such parasites in vertebrates from this era are rare- of 500 samples examined, only one revealed the tapeworm eggs. This particular discovery helps establish a timeline for the evolution of present-day parasitic tapeworms that occur in foods like pork, fish and beef.

The fossilized eggs were found in a cluster very similar to those laid by modern tapeworms. Some of them are un-hatched and one contains what appears to be a developing larva. According to the study, "This discovery shows that the fossil record of vertebrate intestinal parasites is much older than was previously known and occurred at least 270-300 million years ago."

The fossil described in this study is from Middle-Late Permian times, a period followed by the largest mass extinction known, when nearly 90% of marine species and 70% of terrestrial species died out."- source.

It's kind of humbling to know that tapeworms have lived so long. If you know absolutely nothing about parasites, you know that some parasites have super-specific life cycles. Tapeworms have survived so long precisely because they are simple. Humans can get fish tapeworms, pork tapeworms, beef tapeworms...you name it. The tapeworm is not picky, which explains its amazing endurance over eons.Versatility tends to win out in the long run.

Parasite fanaticism over. Back to your regularly-scheduled mammals. Speaking of, happy Groundhog Day!

Creature Feature: Zebra Sharks.

Sharks don't get enough love. Along with snakes and wolves, they are among the moat falsely-demonized animals in the modern media. Nothing makes people scatter quite like a triangluar fin above the surface of the water.  Thanks, Jaws - thanks a lot.

Source.

Zebra sharks (Stegostoma fasciatum) are among the awesome sharks that do not deserve a Jaws reputation. They can be found in the Indo-Pacific, or "anywhere from South Africa to Australia."  They eat fish, molluscs, crustaceans, and maybe even sea snakes. These sharks are nocturnal, so unless you happen to enjoy diving at night, don't expect to see one moving around much. They can usually be found chilling on the bottom of the sand near some coral.

At first glance, the zebra shark has none of the "sleek predator" features that Great Whites or tiger sharks have. The zebra shark is a carpet shark; along with having a nice pattern, it spends most of its time on the bottom instead of swimming menacingly up top. The location of the mouth on the bottom of its body and its overall appearance almost make it look more like a catfish than a shark.  It doesn't even swim like Jaws -it swims like an eel.

Source.

By the way, wondering why a spotted shark is called a "zebra?" The shark pups are striped, that's why! The young zebra sharks look more like young whale sharks than anything. The white lines and black bars soon make way for an almost cheetah-like look as the shark grows older. The young sharks look so different from their parents, in fact, that science thought that mother and child were two different species.

Source.

Zebra sharks are 100% harmless to humans. In many areas of the shark's range, they are even marketed as scuba diving attractions. It is perfectly possible to touch a wild zebra shark, just because they're chill like that. Just don't do anything stupid; people who try to ride the sharks can still get bitten. Jumping the sharks doesn't sound like a wise move, either. You don't have to tell your friends that zebra sharks are harmless; just say "I touched a shark" and watch their eyes widen.

Remember when we had an entry on eating sharks? In part because of their docility, zebra sharks are the most eaten sharks on the planet. These are the sharks used in the infamous shark fin soup. The liver is also used medicinally. This over-hunting has nudged the zebra shark onto the "vulnerable" status, but worry not; these docile sharks have a super-strong presence in captivity. You've got plenty of time to pet a shark.

Creature Feature: Helicoprion.

As the Monty Python sketch above will tell you, paleontologists can get crazy when it comes to piecing together dead animals. The most notable case is Anomalocaris, in which several of its parts were confused for being parts of different organisms. Juvenile dinosaurs frequently lead to new species due to subtleties in the jaw and spine as well as size.

This is one time I really have to wonder: Are you sure this is right, science?

 

Helicoprion was a strange-looking shark that swam the pre-dinosaur seas (290 m.y.a.). It lived between the Late Carboniferous and Triassic - in land life terms, right after the cool synapsids died and right before the dinosaurs got started. It may have been anywhere from 10-15 feet long.

It also had a jaw that would make most modern horror monsters run screaming in sheer WTF. That jaw could presumably coil and uncoil, lashing rows of sharp teeth at anything it pleased. We aren't exactly sure where it was located, but it was definitely in the lower jaw. Do not let this uncertainty be any consolation- it's the difference between being lashed at by a giant toad or being licked by one of the Xenomorph's inner mouths, neither of which would be any more pleasant if sharp teeth were added.

Nobody really knows what Helicoprion used this weird jaw for. Our best guess is that it was used to pierce ammonites, squidlike molluscs with shells like snails, right in the shell's air chambers. It also could have used that coil to lash out at schools of fish. I will even go out on a limb and suggest 'mating display' if this thing was on the outside, even though sharks don't have visual mating displays today. Regardless of where it was placed, the coil had rows upon rows of sharp teeth, so whatever got in there was put through a meat grinder.

To make this even more disturbing, Helicoprion had relatives. That is how we know science might be right with this one: we have more complete shark skeletons with jaws like that. The whole ocean was filled with sharks that had jaws like buzzsaws. By comparison, our sharks are cute and cuddly.

Awww, look! It's only got ONE set of teeth! 

 

So, the next time one of those killer shark movies comes out, bear the following in mind: Just like you, that shark has teeth inside its mouth as opposed to stuck on a death coil. Science, if you were trying to create a nightmare machine, good work.If you were trying to revive one of Dagon's minions...good luck with that.

Bio-Art: Jaws...in Formaldehyde?!

Art is meant to spark controversy. Modern art in particular really plays with what it means to be art. "But is it art?" can be asked of almost any modern art piece, especially when it comes to mixing art with science.



Damien Hirst is a British artist famous for a number of biological art pieces. He is a 46-year-old man still living in Britain. Among other things, he pioneered the "Britart" trend of the 1990's. He even designed a piano for Lady Gaga. We'll be seeing this guy again.

For now, though...



Yes, that is a real shark. No, it is no longer alive.

Damien Hirst looooves doing things in formaldehyde. Besides this shark, he has done preserved art with cows on several occasions, sheep, and dogs. There will be more of him in future weeks, but for now, know that he wandered a tiny bit into hubris territory by plating a cow's horns and hooves in 18-karat gold. Of course he put it in formaldehyde. 

The Physical Impossibility of Death in the Mind of Someone Living is one of Hirst's many formaldehyde pieces. It was commissioned in 1991 by one Charles Saatchi, who apparently had nothing better to do than get his name attached to an undead shark. The tiger shark itself cost 6,000 British pounds. The whole display cost 50,000. Whatever floats your boat, Saatchi...whatever floats your boat.

I HUNGER.

As per the reeaaaalllyyy long title, the shark is supposed to be so lifelike that it can inspire fear even after death. Small wonder; if you saw a 14-foot shark up close and personal, you would probably flinch. The first shark decayed after a while in its original gallery, and, after being replaced in 2006, was temporarily moved to the New York Metropolitan Museum of Art. It left there in 2010, making one wonder where the giant shark is now.

You could almost say Hirst jumped the shark. Naaaah...let's not. He probably still has a few ideas left.

Creature Feature: Megalodon.

As I was saying yesterday, sharks are the most feared creatures in the sea. If people see a shark fin sticking up from the water, the whole beach gets evacuated. The sail of the deadly man-o'-war may be mistaken as an inflatable pool toy, but the fin of a shark looks sinister. Never mind the rows upon rows of teeth in its mouth, or that its torpedo-shaped body is much better adapted than yours for swimming.

Hell, sharks even made the mammoths piss themselves. Sharks have been around since before the dinosaurs, but did not reach the epitome of "death by teeth" until the Cenozoic. The monster of the seas back then was not the Great White, but a far more massive shark called megalodon. (Carcharodon megalodon? Nobody's really sure.)



C. megalodon was the terror of the ancient seas.  Fossils show that it ate dolphins and could easily have swallowed modern dolphins whole. A single tooth was 7 inches long. This thing made Jaws look like a cute, fluffy kitten.



What did it eat? Everything. Nothing was bigger than C. megalodon. It joins Andrewsarchus in the "We know this thing was huge, but we don't know how huge," category. All we can guess is that this was a gigantic shark from the teeth alone. What we have says that it should have been around 16 meters (52 feet) in length. That's larger than the whale shark, which is a giant plankton-eater.

The largest TWO are megalodon.

How the hell did this massive predator die out? Cooler waters and a shortage of food.  For once, humans are not to blame at all. Other predators, including orca relatives, simply gave C. megalodon trouble. Yes, it ate delphinids, but the dolphins and whales were eating its food right back. Flipper has once again saved us from shark attack.

Creature Feature: Whale Shark.

If we said that today's entry was a giant shark, many of you would flip your lid. After all, there is no "extinct" tag down at the bottom of this post. The idea of a shark over 12 meters (41 feet) in length sends most people screaming from the beaches.


Get outta the water! IT HAS SCIENCE IN IT!

Actually, today's shark is a perfectly docile creature, just like many, many other sharks in the sea.



Not all sharks are Jaws; the whale shark (Rhincodon typus) has diminished teeth in favor of filter feeding. The only thing these sharks attack are giant clouds of zooplankton (a fancy word for very, very small animals). It looks like a whale and eats like a whale, but that is definitely a shark. It is perfectly friendly towards humans; good thing, seeing as we all love to watch these leviathans swim! 

Reports of exactly how big the whale shark gets are often exaggerated. There have been reports of whale sharks up to 75 feet/23 meters. These are as valid as giant anaconda stories (i.e. "pics or it didn't happen").  The length stated earlier - approximately 41 feet or 12 meters - is as long as science has been able to confirm. If someone finds a bigger one, show us and we will gladly update our records; there's a good chance we might be wrong.

As menacing as whale sharks get.

We are still learning about whale sharks. Until 1996, it was thought that the whale sharks laid eggs. A catch revealed a female pregnant with 300 maturing shark pups - proof that whale sharks are ovoviviparous like boas and livebearing fish. Many more mysteries remain regarding their mating rights and exactly where they give birth. There is still a lot to discover about these massive, gentle sharks, and not all of it can be done by swimming up to them while scuba diving.

Whale sharks are native to warm waters around the world. With that distribution came an abundance of folklore and cute nicknames. The whale shark's distinct skin pattern has granted it the name "domino" in some Spanish-speaking regions. Stories about how coins (Kenya) or stars (Java and Madagascar) were planted on the shark's back are common.  The Vietnamese consider this giant fish a deity ("Sir Fish") and, umm, well...

 

...if you have been keeping up with this blog, you know what happens to Asian deities most of the time: They wind up on the menu. Shark fin soup can include whale shark meat as well. A single fin from a whale shark fetches a very pretty penny. There are bans fishing for whale sharks, but oil spills and unknown population numbers mean that this shark will be in the "vulnerable" category for a long time. Few aquariums can hold whale sharks; enjoy them while you can.

Tomorrow: Who's that red-eyed frog we keep seeing at the Rainforest Cafe, again?