The ocean covers an area of about 71% of the earth's surface, and there are tens of thousands of creatures living in it, some of which are extremely ugly, some of which are beautiful in color but highly poisonous, and some of which are like tools used by humans.
Sawfish, an ancient fish that alternately lived in seawater and freshwater, has a history of more than 56 million years. It looks strange, like a shark that has been flattened, and is a close relative of the shark, weighing more than 500 kilograms and generally between 5.4 and 7.6 meters in length. Its upper lip is flattened up to 2 meters long and about 30 centimeters wide, and it has 21 to 35 pairs of hard and sharp kissing teeth on both sides, which are very similar to chainsaws, and can launch several lateral attacks per second, and in an instant the prey will become a sieve or be cut in half.
This "big saw" is not only a powerful weapon of the sawfish, but also carries a detector on it, and the "electronic receiver" covered with it can detect the electric field generated by the prey, just like humans holding the detector to search for treasure, and with a drop, they know whether there is any goods underneath. Once the prey is found hidden in the sand, its "saw" will transform into a shovel to dig up the sand for food, after all, the flat and sluggish sawfish is also like the ray, it will also do "Voldemort", but if it encounters the fish, it will reveal the ferocity of the shark, then the saw will become a "chainsaw", it rushes into the fish and wields the saw, the fish have not reacted to the death of the whimper, after some operation, it will slowly enjoy this hard-won food, and when it encounters a slightly larger fish, the scene is even more spectacular.
Possessing huge weapons, coupled with ferocious adult sawfish, no fish can compete with them. In the sea, only bull sharks and hammerhead sharks have a way to do it, while in freshwater, crocodiles become their worst natural enemies. But it is this fish, which has few natural enemies, that is now facing extinction.
Sawfish have been widely distributed in tropical and subtropical shallow seas around the world, as well as in the estuaries of rivers, rivers and lakes, but because of the fragility and slow growth of sawfish larvae, it is easy to become food for other fish. Female sawfish can give birth to about 18 juveniles at a time, breeding once every other year, but the survival rate of larvae is very low, only about 35%, and it can only mature at the age of 10, coupled with environmental changes and pollution. In particular, sawfish have huge economic value hidden in them, which makes them face extinction.
In order to survive, in 2015, scientists found that wild sawfish can reproduce unisexually, which means that females do not need males to complete pregnancy and childbirth. It has been suggested that it may be that sawfish populations are too small for females to find mates to evolve.
In order to reproduce, the sawfish released a final move, hoping that this big fish would be valued and protected as soon as possible, without our descendants pointing to the pictures or specimens in the book and saying that this is a sawfish.