1, swim bladder: You can float and sink freely in the water by adjusting the air capacity in the swim bladder.

2, fishtail: you can control the direction of swimming.

3. Finn: It is the driving force for progress.

4, fish gills: can absorb dissolved oxygen in water, will not drown.

5, the shape of the fish: the body shape of the fish is more suitable for living in water, and the resistance to water is small.

Scientists have found that different fish twist in different amplitude and frequency, but the core lies in twisting. Of course, the swing of fins also plays a certain role in swimming, mainly to adjust the direction. The main driving force comes from the twisting of the body, especially when the fish moves quickly. Therefore, the fin is not the main power source of fish swimming, but the twisting of the trunk.

The fastest fish.

1, sailfish

The fastest fish in the upper reaches of the world is naturally swordfish. Because it can swim at a normal speed of 130 km, it is related to its body structure. First, its stomach is strong, equivalent to the diesel engine of a car, which can show its great driving force. Secondly, its spear is located at the front end of the car body. It can help him cut the river reasonably and improve the speed. In the case of its fast driving, he can even use his hair to push aside the 60 cm thick joinery board at will. That kind of impact is unimaginable.

2.swordfish

The structure of swordfish is actually similar to swordfish. Their front-end development is that they have spears to help them cut the river reasonably, but its structure is different from that of swordfish, that is, part of its dorsal fin looks like a flag, so it is also called swordfish, and its greater speed can reach 1 100 km per hour.

3. Tuna

The usual swimming speed can range from 60 km to 80 km, and the larger final sprint speed can reach 160 km. Actually, it's not because he wants to swim. This is because of his scheme problem, some of his cheeks have declined, and it is necessary to maintain co2 acquisition through continuous final sprint and swimming.