A child asked, "Will the fish drown?"Do you know the answer to this question?
Hello everyone, I'm Li Xu.
Fish are animals that live in water, and their streamlined body reduces the resistance of the water, allowing them to swim faster and with less effort.
The gills are specialized organs that help fish breathe freely in the water.
But the ancients said: "Those who are good at water drown", that is, as the old saying goes, "those who drown can swim".
According to this statement, fish, as the most swimming creature on the earth, eats and drinks in the water, so don't they drown in the water?
To answer this question, we must first know why animals on land are drowned, that is because animals that breathe by lungs, after falling into the water, the water makes the alveoli unable to contact the air, and as a result, oxygen cannot be inhaled, carbon dioxide cannot be excreted, and finally drowning and suffocating.
But we all know that fish breathe by gills, which are actually made up of a bunch of jagged gill filaments, which are filled with capillaries that allow for rapid gas exchange when in contact with water.
Therefore, unlike the alveoli, the gills themselves are not afraid of flooding, but if there is too little oxygen in the water or there is no oxygen at all, the fish will also be suffocated to death due to suffocation!
Under what circumstances does this suffocation that can drown a fish occur?
One is that in a short period of time, tiny organisms such as cyanobacteria and diatoms in the water grow wildly, that is, blooms in fresh water, or red tides in coastal areas, they will quickly use up the oxygen in the water and suffocate all the fish in that area.
On the other hand, some fish like the great white shark, in order to improve breathing efficiency and save energy, have long abandoned the ability to use their mouths to absorb water and breathe, and instead rely on the huge water pressure generated during swimming, so that the seawater is actively poured into the mouth, and then discharged through the gill slits, using this method to quickly obtain a large amount of oxygen.
However, the biggest problem with this kind of "impact breathing" is that it can never stop swimming, and once these fish stop moving, there will be no fresh water with oxygen flowing into their mouths, and after a long time, they will only end up drowning alive.
Of course, there are some sea creatures that have learned to poison, and the venom spewed out can make the gills lose the function of ventilation for a short time, and the octopus, squid and cuttlefish that we are familiar with, there are some types of ink sprayed with this effect!
I don't know my answer, did the child who asked the question understand?