By Courtney Cooper
Truths about Sharks that Might Surprise you
Think you know all there is to know about sharks? With over 500 species, we are still learning more about these magnificent creatures of the ocean every day! In this blog, we’ll be exploring some more fascinating truths and myths about sharks that you may have heard before. From who’s the biggest and fastest, to who’s the slowest and smallest. We also discuss further shark facts that you might be interested in! Apex Predators provides the best kelp forest diving cape town and shark cage diving in Cape Town.
12 Interesting Truths About Sharks
Sharks are ancient
The existence of sharks can be traced to over 450 million years ago, before the existence of trees or dinosaurs! Their most famous ancestor, the megalodon was 40-60 feet long and weighed between 50 and 70 tons. The bite force of the megalodon was so strong, it could crush a car. We have the privilege of seeing the modern-day version of the megalodon, the great white shark.
Different shark species reproduce in different ways
All sharks reproduce via internal fertilization. There 3 main ways in which they reproduce, viviparity (fed via placenta and then live birth), oviparity (hatch inside of the female and then live birth), and ovoviviparity (eggs are laid on the ocean floor). Some sharks are also known to be asexual such as the hammerhead shark and the zebra shark.
Sharks skin feels like sandpaper
Dermal Denticles are the small scales that cover the sharks’ skin. They are made of the same material as human teeth and grow as the shark grows.
Their scales face towards the tail, which reduces friction when swimming. When rubbing a shark’s skin from back to front, their skin feels rough like sandpaper.
They never stop growing new teeth
Sharks go through approximately 30,000 razor sharp teeth in their lifetime. On average sharks have between 50 and 300 teeth at any one time that consist of multiple rows from the front to the back. When a tooth from the front row falls out, the tooth behind it simply replaces it.
Sharks aren’t only found in the ocean
If you thought that sharks were only found in the ocean, think again! The Ganges shark is known to live in freshwater only in India and Bangladesh. The Northen River Shark, Speartooth, Pondicherry and Greenland shark are known to live in both salt water and fresh water. Unlike the previous sharks mentioned, the Bull Shark is the only known shark capable of staying in fresh water for prolonged periods of time whilst also being able to return to salt water.
South Africa was the first country to declare the Great White Shark a protected species
In 1991, South Africa pioneered the conservation of the Great White by declaring them a protected species. The Australian government declared them a vulnerable species in 1999. Most recently in 2013, the great white was added to California’s Endangered Species Act.
The population of the great white is declining fast and increased conservation efforts such as protecting and declaring them endangered is vital to their survival. We hope you’ve brushed up on some of your shark facts and learnt something new.
Each whale shark’s spot pattern is unique identifier
Whale sharks have a white under belly and blue and grey colouration which forms white stripes and spots on their backs. Their spot patterns are like human fingerprints, unique to each whale shark. They use these patterns to camouflage and communicate with each other. For the most part, their spot and stripes remain the same as they age.
Sharks have a 6th sense
Ampullae of Lorenzini are the shark’s 6th sense, they are electroreceptors that are able to detect electric fields in the ocean. They are in the head and snout area and are highly sensitive jelly filled organs. Sharks use this 6th sense to track their prey, identify predators and find a mate. These electroreceptors are also thought to aid the shark in navigating the ocean and its currents.
Sharks can get cancer
Over the years, scientists have recorded cancer in over 40 species of sharks. Cancer can be observed on sharks that have tumours on their body, sometimes large tumours protruding from their mouth. Tumours have been recorded on Great Whites and Bronze whaler sharks. It’s still unclear what causes sharks to get cancer, however polluted oceans could be one reason.
They can vary significantly in size
Sharks come in all shapes and sizes. The smallest shark is the Dwarf Lantern shark reaching a maximum length of 20 cm. Although they are rarely seen, they have been sighted in Colombia and Venezuela. The Whale Shark is the largest shark (and fish), reaching a maximum length of 18 meters. They are migratory and are mostly found in tropical waters.
The short-fin mako shark is the fastest
The fastest shark being the short-fin mako can swim 45 miles per hour. They use their speed to hunt their prey (tuna, swordfish, and other sharks), catching them before they even know they are being hunted. The slowest shark is the Greenland shark, swimming 1 mile per hour. They slowly and quietly hunt seals while they sleep.
Sharks are part of Hawaiian mythology
There are many peons, artwork and legends containing sharks in Hawaii and they are believed to be guardians of the sea. Legends speak of a shark man able to change from man to shark, that would warn people of sharks nearby. There are the Shark God’s (Kamohoali’I is well known) and the Queen of the Sharks (Kaʻahupahau) in Hawaiian mythology. The Tiger Shark has long been considered a guardian by the Hawaiians.
There’s still so much more to learn about these magnificent animals of the sea from how they mate, communicate to how they know to migrate and how many species there are.
If you enjoyed this article, you may also be interested in our other article, where we discuss the agonistic behavior in sharks.
