The more I learn about these majestic creatures, the more fascinated I become and the more I want to know! I think this is true of most of us. Let’s see how many of these facts you were familiar with.
What makes a shark a shark?
What is it, which characterizes sharks and differentiates them from the other sea creatures?
- Their teeth – did you know that sharks re-grow their teeth from the back to front, almost like a conveyer belt, and can “shed” as many as 6000 teeth per year
- Their sandpaper like skin – did you know that their skin is made up of thousands of “tooth-like” scales with sharp enameloid crowns that poke through their tough skin
- Their multiple gills – did you know that their gills can be found on the side of the head. Most shark types have five pairs of gill slits, but there are others that sport six and even seven pairs
- Their skeleton – did you know that sharks have a cartilaginous skeleton, which is strengthened at strategic points with unique hexagonal plates, these are found in such parts of the skeleton as the jaws and vertebral centra, because this is where they need the most strength
- Their jaws – the upper jaw is not attached to the head, so this allows the jaws to partially protrude from their heads.
- Their fins – Like most fishes, sharks have two sets of paired fins (pectoral and pelvic, like the arms and legs in humans) but what makes them different from other bony fish is that they are supported by a soft, un-segmented rays called “ceratotrichia”
- The way they breed – All existing sharks are fertilized internally.
- Their liver – Sharks don’t have a swim bladder; this is a gas-filled buoyancy-control organ that most other bony fish have, so rely instead on a large, oil-filled liver to reduce their over-all density and provide some measure of buoyancy and lift. This is an enormous liver which pretty much fills their body cavity, so as a result it leaves very little space for other organs.
- Their intestines – as a result of their massive livers, their intestine of sharks is short and partitioned. This partitioning slows the digestive process and aids in the more efficient absorption of nutrients.
- Their metabolism – Sharks retain high tissue concentrations of urea and trimethylamine oxide, unlike most vertebrates, they don’t simply “poop” out nitrogenous waste, which in turn plays an important role in
- regulating their internal salt-to-water ratio
These are pretty much the characteristic that in some degree are shared by most sharks, but wait, there’s more…
Did you know…
- Sting rays, manta rays, electric rays and skates, all form part of the 500+ species within the shark family – this is due to their skeletal structures and gills
I hope you have had as good a time with these fun facts as I had researching them!
Until I see you again, keep that toothy grin!
By Nadine Bentley