Heyyy, so I was watching a program on Sharks this morning on Nat Geo Wild, Starhub, which introduced some sharks with interesting features whether it is for hunting or self protection. Here is the list:
1. Wobbegong shark
This shark was introduced as one with a very huge gaping mouth which it uses to catch prey of course. It also has an outer covering of skin which is coloured just like the sea floor and with patterns and markings to help these fish better camouflage with the seafloor. As such, these sharks spend most of their time on the seafloor and are passive hunters, lying in wait and feeding on small fish which swim too close to their gaping mouths.
2. Thresher shark
Now, this is one interesting shark. It has a really long tail which can be as long as the body of the shark itself. Of course, that long tail helps in swimming but the shark uses that tail for hunting too. It "swipes" or "slaps" the water to stun prey such as small fish or even kill them. It was said that this "slapping" even splits the H and the O of the water. Haha, I dunno how true that is but it sure sounds cool.
3. Epaulette shark
Unlike most other sharks, this one is much smaller, growing up to about 1m at most. The only feature introduced about this shark was the black rings found behind each pectoral fin thus making it look cute. Hahaha... quite an innocent word to describe sharks but given it's size, I guess it might really look cute.
4. Sevengill shark
This shark, as the name suggests, has seven pairs of gill slits. I learnt that this differs from other sharks as most other sharks have only 5. This again is a relatively small shark, growing up to about 1.4m in length.
5. Nurse shark
Okay, here's a shark that actually sleeps. It was said that most sharks are active 24 hours of the day due to the need to be in constant motion to seek waters rich in oxygen. Otherwise, these sharks may die due to a lack of oxygen. Furthermore, sharks, as do most fish, need to be in constant motion to remain afloat and not sink to the bottom of the ocean. This would then be dangerous for the sharks as well.
So basically, the Nurse shark has the ability to respire by pumping water out of their gills even when sleeping thus having the ability to take a rest at the bottom of the ocean.
6. Horn shark
This shark has special features not to aid it in hunting but to protect it. There are large venomous spines behind its two high dorsal fins which predators will inevitably come into contact with should these predators attempt to devour the horn shark. Moreover, this shark also has a rather ugly look with a short and flat head.
More interestingly, the eggs of the horn shark are shaped like huge cork screws which the mother wedges into crevices or rocks to prevent them from being washed away by the ocean currents or to protect the eggs from predators. The female horn shark usually lays up to 24 eggs within 2 weeks.
Moreover, the horn shark prefers using its fins to push itself along the seafloor to move from place to place rather than swimming. Thus, it almost seems like the horn shark is walking. It is also able to store oxygenated water in its gills for up to three and a half hours.
7. Angel shark
Ooops... cannot remember what was special about this fish.
8. Goblin shark
This one looks real nasty, much like an ugly goblin and hence it's name. Much of the reason for its ugliness is a long flat snout protruding out of its head. It also has long teeth which extends out of its mouth giving it a menacing look. It can grow to 3-4m or even larger which makes this quite a huge fish.
One other interesting thing about this fish is that its scientific name, "Mitsukurina Owstoni" is derived from two people, Alan Owston and Kakichi Mitsukuri, both who helped in discovering this shark.
Its snout is also covered with "ampullae of Lorenzini" which help it to detect electric fields so that the shark is able to find its way around, much like us using compasses.
9. Frilled shark
The only thing I remembered about this shark is that the gills on both sides of its head extend out under its head and connect, looking sort of like frills hence its name.
10. Cookie cutter shark
This shark was introduced as one which has hardly been seen. This is likely due to its small size, growing up to around 50cm only. So little is known about this fish and much is merely deduction using scars on its victims. Haha, what is interesting about this shark is its feeding habit. Basically, it swims up to huge sea creatures, be it bluefin tuna, or larger sharks or whales and uses its razor sharp teeth to take a bite out of them. Just one crunch, and the round shape of a cookie is carved out of the flesh, just like a cookie cutter. It was not mentioned whether the bite was deadly so I guess it just goes around taking bites out of creatures and does not finish its prey whole. Oh, and they are definitely not at the top of the food chain, given their size.
So if ever you are out there swimming in the sea and happen to have a round shaped wound... you might just have been bitten by a cookie cutter shark. Yes, they do bite humans too!
11. Great white shark
Okay, so the next few sharks are the more common ones. This Great White Shark is quite well known to many right? It is probably the most feared shark of all. Well, the only new thing I learnt about this shark was that it has the ability to keep its body warm even in cooler waters. Thus, this is how it keeps its energy level up and is thus so powerful in hunting prey.
12. Hammerhead shark
The only thing I remember about this shark, besides how it looks, is that a huge school of this fish gather together at a certain time each year. However, it is not clear whether they do so to mate or for other purposes. Still, it is really a majestic sight!
13. Tiger shark
I learnt something new about this shark too. Apparently, they eat any rubbish they can find in the seas and have stomachs which have really strong acids to digest all that "rubbish" too. It was said that these sharks have been known to eat everything ranging from metal signs to sea creatures and other sharks. They can even turn their stomachs inside out to remove all the excess which they do not need.
Having watched this program and another one about polar bears and their Arctic habitat which I had watched previously, I was once again reminded of how human activities have very detrimental impacts on the fauna and flora of this Earth. More specifically, air and water pollution caused by our mining and burning of fossil fuels has resulted in very toxic habitats for these other occupants which share this Earth, ultimately leading to the deaths and even extinction of these creatures. I do feel more needs to be done to minimise such consequences and at a faster pace too.
Phew, what a long post...
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