It seems as though mankind has had a fascination with sharks for some time.

The movie “Jaws” was a massive blockbuster and shark documentaries are keenly watched by many fans.

There might be some of us who seek to find shark skulls, jaws, or real shark teeth for sale.

But there is more to these mammals than what meets the eye.

Here are some random facts about sharks that you might not have known.

1.              They are actually quite old.

It is thought that sharks made their initial debut approximately 455 million years ago.

This makes them older than dinosaurs!

2.              They have no bones whatsoever

There is a special kind of fish called “Elasmobranchii”, which means fish made of cartilage.

Their cartilage skeleton is much lighter than real bone, and the large liver is packed with low-density oil, both of which help increase buoyancy.

As most sharks grow older, they deposit and strengthen calcium salts in the skeletal cartilage.

The dry chin of the shark appears and feels heavy and firm.

These same minerals allow most shark skeletal systems to fossilize very well.

Since the teeth have enamel, they also appear in fossil records.

3.              Even before they’re born, they’re eating each other.

It’s a fight of survival of the fittest amongst sharks and there definitely seems to be no sibling love happening.

In what’s called intrauterine cannibalism, the biggest and strongest shark embryo will eat the other smaller weaker embryos.

4.              Female sharks are bigger than their male counterparts.

This is thought to be due to the fact that they need to carry all those wee carnivorous embryos.

5.              Speaking of carrying those embryos.

If 9 months seems as though it’s a long time to be pregnant being a human, spare a thought for sharks.

The dogfish breed of these ocean dwellers can be pregnant for up to 2 years!

6.              They can actually have a lot of pups at once.

Yes, a baby shark is called a pup!

Each litter size may vary, and if the sharks are lucky enough to survive the embryo-eating fiasco, they can a part of a very large family indeed.

Blue sharks can have up to 135 pups at once!

7.              But, they don’t all live in the ocean.

If you think rivers and lakes are safe from sharks, think again.

There are types of sharks that live in lakes and rivers too.

River sharks and bull sharks live in fresh water.

8.              They can see quite well.

The rear of these animals’ eyes has a reflective layer of tissue which is called a tapetum.

This enables them to see quite well in dark areas (like the ocean).

9.              They have a great sense of smell too.

Their nasal and nostril components are situated below their snouts.

Their noses are solely for smelling, not breathing.

(They breathe through their gills)

10.           You tell their age by their spine.

A shark’s vertebrae comprise concentric pairs of opaque and translucent bands. Band pairs are counted like rings on a tree and then scientists assign an age to the shark primarily based on the count.

If the vertebrae have 10 band pairs, it is assumed to be 10 years old.

Recent studies, however, have shown that this assumption is not usually correct.

Researchers must therefore study each species and size type to decide how frequently the band pairs are deposited because the deposition fee may additionally change over time.

Determining the proper charge that the bands are deposited is known as “validation”.

11.           They don’t sleep, and I mean never.

Sharks need to stay awake to float/swim.

So, instead of drifting off they just stay semi-conscious.

12.           They actually used to be A LOT bigger!

About 16 million years ago, there was a breed of shark known as the Carcharodon Megalodon.

This guy was monstrous!

Weighing approximately 4000 stone and growing to around 55 feet this was one big shark!

Records indicate this was the biggest predator in known existence until it became extinct 2.5 million years ago.

13.           They can still grow pretty big these days too.

The whale shark can grow up to 18 meters or 60 feet long!

14.           They have a serious amount of teeth!

Each species will vary in the number of teeth they have.

Some breeds can have up to 15 rows of teeth, going from largest to smallest (front to back)

The teeth towards the back of the sharks’ jaws also serve as replacements for the teeth up front for when they become damaged or fall out.

Shark teeth are not as deeply rooted as humans, so they lose teeth quite often.

Great White shark teeth are serrated as they are designed to cut prey.

15.           Sharks have electroreceptor organs that are unique to them.

Small black patches can be found near the snout, eyes, and mouth of sharks. These spots are Lorenzini ampullae, which are specific electroreceptor organs that allow sharks to detect electromagnetic fields and temperature changes in the ocean.

16.           Their skin isn’t smooth.

You might think that because sharks swim in the ocean, their skin would be smooth.

Shark skin is made up of small teeth-like structures called placoid scales, also known as dermal denticles, it feels like sandpaper. When the shark swims, these scales point towards the tail, reducing friction from the surrounding water.

17.           They give birth to their babies in different ways.

Sharks have a wide range of reproductive strategies.

There are two types of species: oviparous (egg-laying) and viviparous (live-bearing).

After the eggs are laid, oviparous animals lay eggs that grow and hatch outside the mother’s body with no parental care.

18.           They can’t talk.

Due to a lack of vocal cords, sharks actually can’t make a sound.

They express themselves physically instead.

19.           They can travel very long distances.

Sharks can swim for days on end without stopping.

Great whites have been noted to travel up to 2500 plus miles without eating or sleeping.