Teaching with Stamps: Primary resources for teaching America’s history and heritage.
When it comes to the water, perhaps no beast invokes more fear than the almighty shark. Big, toothy, and terrifying, sharks have earned their menacing reputation not only through sensational movies like Jaws, but also through the very incidents they’ve caused at America’s beaches – this summer alone! Thus, sharks tend to be mysterious creatures whose reputation precedes them. But how much do you really know about this fascinating species? Fresh off of Shark Week, we take a dive into the treacherous waters.
Sharks constitute a large, magnificent breed of fish that can be classified by over 500 different species all over the world, and are closely related to their prehistoric ancestors. Most are saltwater animals, found in depths up to 6,000 feet, and most are carnivorous, reigning at the top of the underwater food chain. Sharks can be as small as the six-inch Dwarf Lantern Shark, but are primarily known for their walloping size. You may know sharks to be twice as large as humans, long and bull-like. The notorious Great White grows to be an average of 13 feet long, while the largest shark known to man – the Whale Shark – can be over 45 feet. Sharks come in all shapes and sizes, but they’re all typically distinguished by a sharp, pointed nose, unmistakable dorsal fin (you know what to do when you see one on the surface!), beady eyes, five to seven gill slits, and of course, THOSE TEETH!
Sharks have earned a reputation, of course, for being fantastic eaters. They have an incredible set of senses, including their electroreception. Sharks have the greatest sense of electromagnetic signals (which every living creature emits) of any animal on earth, and use it to sense their prey. Their jaws are like a snake’s, and can unhinge when biting (bringing down 660 pounds per square inch in doing so). Plus, most sharks will go through tens of thousands of teeth in one lifetime. To say that eating is a shark’s job is an understatement!
That said, it is our job to understand that sharks are obviously serious predators, and we must be cognizant of their environment. This summer, as with others, we’ve seen multiple reports of beach goers suffering serious injuries at the incredible capabilities of a shark. If you’re planning on swimming in any saltwater area this summer, check with the site’s lifeguard about safety precautions and conditions. Shark attacks are incredibly rare, but they are real. According to the Discovery Channel (our favorite Shark Authority!), sharks injure 70 and kill roughly six people per year.
That’s nothing, though, compared to the amount of sharks humans kill. It may seem odd to think of such a ubiquitous predator as an animal in need of protection, but with over 100,000 shark casualties per year, shark conservation is critical. Sharks are hunted by fishermen in other countries primarily for their meat and fins, which are considered a culinary delicacy in foreign markets. But the way in which they are hunted and farmed is often cruel and unnecessary, and shark meat is steadily (and rightly) becoming taboo in international markets. What’s more, sharks generally don’t become mature enough to breed until later in life, so many of them are killed before they’ve had the chance to provide the waters with future generations. And remember, sharks – like all plant and wildlife species in land, sea, or air – are part of an insurmountably delicate ecosystem. If they suffer, so does everything in their habitat.
To learn how you can help save the world’s sharks, check out www.Oceana.org.
In the Meantime, More Cool Shark Facts!
- Sharks are one of the oldest species on earth, predating the dinosaurs by at least 200 million years!
- Sharks have a tough, nearly impenetrable skin with an armor called dermal denticles, which are more like teeth than fish scales.
- Sharks literally will eat anything in the ocean! While many types of animals – both terrestrial and marine – have been found in sharks’ stomachs, seafarers have also found a lot of ocean junk, from tires to license plates to canon balls to full bottles of wine!
- Sharks’ skeletons are made out of cartilage, not bone.
- You may have heard that if sharks stop moving, they’ll die. Technically, that’s because sharks must have water move past their gills to breathe, as they don’t have lungs. But if a shark finds itself in a strong enough current, it can stop long enough to rest.