Disclaimer: All scientific information presented was gained from my academic studies, free research, and avid watching of the Discovery Channel. I used Wikipedia to look up the spelling of the scientific names and structures.
Sharks. What do you think of them? Nightmare fuel? Mindless man-eaters? Apex predators? Something to stay away far from? Regardless of popular public opinion, I think they’re amazing and awe-inspiring. Perhaps only second to snakes, sharks are among the most misunderstood animals out there. They aren’t exactly cuddly, but I can’t get enough of ’em! Along with genetic pathology, becoming a marine biologist to specifically study these creatures is a prime goal of mine.
The inspiration for this uncalled, impromptu, off-topic, post? Discovery Channel’s annual “Shark Week” ends tonight. It was its 25th anniversary. I’ve personally been watching it since 2006. This post is in celebration of sharks, and regardless of your opinion, it certainly doesn’t hurt to gain a little extra knowledge.
To whet your palate, I present to my readers some basic info. First, sharks belong to a class of fish known as cartilaginous fish. Unlike bony fish and the alien-looking jawless fish (That’s a lamprey, by the way.), a shark’s body structure is composed entirely of cartilage, though they do possess a vertebral column. Humans have five senses. Sharks have six. Along the tip of the snout, you can see clusters of dots, the shark’s sixth sense organ. These structures are known as the ampullae of Lorenzini. They sense the electrical impulses that all living beings emit when their muscles contract. (The electrical charges come from the inflow and outflow of ions, charged atomic particles, that come during muscular contraction. Calcium, in particular, plays a crucial role in muscle contraction.) This is why any sort of struggle attracts them. We humans lose our baby teeth and gain our adult teeth, and we shouldn’t have any tooth loss from there. Sharks replace their teeth throughout their lifetime. When one falls off, a preset tooth comes in after it. Sharks are considered to be apex predators, individuals at the top of the food chain. Long ago, people slaughtered sharks out of fear. As each creature has its ecological role, this is not safe at all. *puts on large, tinted sunglasses* We’re all connected, man. *sunglasses off*
Main Course: South Africa’s Fabulous Five
For my still-hungry readers, I present to you five entrées. They can all be found in South African coast, the world’s hotbed for sharks. All are considered dangerous, but that’s what makes studying them oh, so delicious. Feel free to partake in more than one entrée, and do go back for seconds!
These guys may not colossal, but one look at those teeth show that this shark doesn’t mess around. Typically, “raggies” are found in the deeper depths of the ocean, unlike other sharks. Scuba gear, while recommended for each of our entrées, is absolutely necessary to see raggies.
Make no mistake. If you see one of these in the water, calmly make your way to the boat. The highest levels of testosterone in the animal kingdom have been recorded in the Bull Shark. This means that these sharks are very, very aggressive. Most attacks that I’ve seen on the Discovery Channel or read about where the victim has suffered life-altering injury has been at the teeth of a Bull shark. They are also known to ram their prey, hence, their name. But that’s not all. Bull Sharks are one of the few species that can thrive in both salt and freshwater. Bull Sharks have an excretion system in their body’s, like our kidneys, that can release or retain the salt as needed. Sensors all over their body relay such information to the shark. That’s why some attacks have occurred in freshwater lakes.
Your basic information about this shark is all in the name. What I find interesting is that they’re often seen with little silver fish swimming at their sides. These are cleaner fish. They eat any leftovers the Blacktip may have forgotten, and they also eat parasites that may be residing on the shark’s body. It’s a mutualistic relationship. They can also be found swimming alongside other shark species.
I’m not sure which shark is more dangerous. The Tiger Shark or Bull Shark. Like the Bull Shark, this shark is also highly aggressive. It, too, is also reported in many serious, non-lethal shark attacks. What’s more, this shark isn’t a fussy eater. Dissections have revealed pieces of metal, wallets, a wooden drum, and all other sorts of inedible materials.
Finally, I present my readers with our most infamous entrée. If you are to partake of it, scuba certification and a dive cage are required. When people think Jaws, they picture this shark. Sadly, this was also the very same shark that caught the brunt of the slaughter when the movie incited mass panic back in the seventies. They are now considered to be threatened. If not for their size and raw power, these sharks are also famous for flying. You heard me, flying. Off False Bay, South Africa, you’ll find the home of what Discovery fans know as “Air Jaws”. More specifically, this hunting technique is known as a Polaris Breach. Amazing, huh? This has been developed by the Whites of South Africa because they hunt seals. Seals are fast and intelligent, so the Whites had to learn how to ambush. Even with this amazing ambush, the seal gets away fifty percent of the time. Not bad odds considering the size difference. It’s been theorized that the waves of energy emitted as the shark surges vertically in addition to the shark’s white belly may give the seal just enough time to get away. These sharks are at the top of list when it comes to human endangerment. Truthfully, I really think it’s because of the shark’s size and capability that earns it such a reputation. Seventy-five percent of White shark attacks are nonlethal. That’s not to say they aren’t devastating, but at least the victim lived. They can be aggressive, yes, but studies have shown that individuals may also have a sort of personality to them. Some sharks are rather cautious and skittish. Others may be more bold and exploratory. Some final food for thought: Whites, along with other sharks, are highly curious. Unfortunately, they lack hands to investigate foreign objects in their habitat. What do you think they use?
Dessert: Mac Daddy Megalodon
If there was a shark of nightmares, this would be it. I don’t know much about Megalodon, but I do know two things. One, this creature is extinct (thankfully for us), and modern sharks are said to be descendants of this Colossus. Second, it could gulp down a Great White like it was a tortilla chip. You’d probably be a speck of dust in its environment should you have ever had the misfortune to share its water. Here’s a fossil of Megalodon, a tooth. Consequently, this is the only kind of fossil they’ve found of this creature.
If that’s the tooth, can you imagine what the creature itself must have been like? Now that’s scary! Even a tooth can provide scientists with enough evidence to speculate on the creature’s size, diet, even behavior. From the teeth, scientists have pieced together an educated guess of what the whole thing might have looked like: