Sharks! A neatly wrapped overview.
- sharkscaped
- Jul 29
- 3 min read
Intro
I spent months (literal months) trying to work out What shark would be fitting for my first blog post. I first thought of a Shark everyone knows like a great white. Then, I thought about a shark that’s so interesting and biologically weird that I could talk about for hours (or write about I should say). Finally, I thought about my favourite shark... but let's be real, I love all sharks too much to have 1 favourite. Besides, none of them really seemed to fit and if they did, I didn’t have a high enough interest in that specific shark at that specific time. So, I finally settled on this. The general overview of sharks.
quick disclaimer- you’re going to have to bear with me here as I’ve never written a blog before so it might take me a while to get the tone right and everything. In the meantime, I hope this can be somewhat entertaining and if nothing else informative.
So, what is a shark?
Most people when thinking of a shark will think of a long stocky fish with rows of razor-sharp teeth and a large triangular dorsal fin. Which isn’t wrong exactly. However, Sharks are so much more than that. They are the small dogfish that no one notices half the time. They're the large deep-sea sharks that don’t hunt but filter feed. Back on point though, a Shark biologically speaking is a fish with a cartilaginous skeleton of the class Chondrichthyes. The class Chondrichthyes consists of chimaeras, skates and rays and of course sharks. And while they all have the overarching similarity of having a cartilage skeleton, there are some differences that set them apart. The most notable being:
Chimaeras have 1 gill slit on either side of their body leading to all 4 of their gills. Sharks (and skates and rays) on the other hand have 5-7 (usually 5) gill slits on either side each leading to 1 gill each.
Let's pause for a sec. Now I want this to be as accessible as possible. So, if you are unaware of how fish “breath” let's go into it. Fish have gills. Each gill is covered in many gill filaments. These gill filaments is where the blood flows through for gas exchange (oxygen in, carbon Dioxide out). Sharks have individual openings to each gill called gill slits. This compares to chimaeras as they have a singular opening that leads to ALL of their gills.
Oh, and yes chimaeras are named after the Greek mythological creature due to them looking like a mash of other marine animals like sharks, rays and other fish. But I won’t go into that now
Skates and rays also differ from sharks as their pectoral fins (the ones on the side) connect the top of their head compared to sharks that have their pectoral fins as separate appendages. Most people assume guitar fish are sharks. However, they are actually rays because their pectoral fins attach to their head.
The characteristics of a sharks
sharks are characterised by having, as previously mentioned, a cartilage skeleton with usually 2 (sometimes 1) dorsal fins and a large caudal fin (the tail). They also have a jaw that isn’t fully attached to their skull this allows their jaw to protrude when they bite down. If you have ever seen a picture of a goblin shark the picture that you have most likely seen is with the goblin shark having a protrude jaw. In general, they don’t look like that, and they only do when feeding or hunting. It is also one of the more extreme versions of this. Most sharks aren’t able to protrude their jaw to such a degree. Sharks also have replaceable teeth that once they fall out there is already a replacement tooth right behind that can quickly take its spot. I'm not scared to admit I’m so envious of that. Like imagine never needing to go to the dentists again. Anyway, they have a much wider range of senses that are much better than what us humans have. What I think is really cool though, is that one of these senses is electrosensing. Which means that they can pick up electrical signals from nearby animals. I can't overstate how cool I find this(I'm definitely doing a whole blog post on this).
As for their behaviour there isn’t too much to say. Their behaviours are for the most part innate meaning they are born with it. It’s like instinct. In general, they are predators either sitting at the top of the food chain as an apex predator or sat somewhere in the middle so while still hunting smaller fish they can also become prey to larger animals sometime even other sharks.
If I’m being honest there isn’t really much more I can say about the characteristics of sharks as a whole as the term ‘shark’ encapsulates over 500 knows species all with different evolved biology and behaviours that allow them to survive in their respective habitat. I know this is quite a quick overview that goes over the very basics of what a shark is without too much detail but as I am writing this, I want to get it out today. So, I think this is a nice start to the blog. I hope you enjoyed? Sorry I don't know how I'm meant to sign this off.
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