Unique behavior of some common fish in winter: even fishermen may not know these things. The answer to this question - where do fish go in winter? - is not as straightforward as you might expect. Herrings at least have a fur coat, but ordinary crucian carp and perch freeze, it turns out?!
Stop catching herring for their fur coats!
Exactly. Fish feel the uncomfortable winter cold in the same way. Of course: the temperature drops from a comfortable +25 °C to +1-4 °C. A person at such degrees can spend no more than 15 minutes in the water. And the fish freeze until spring! In order not to kick the bucket before the warm weather arrives, the inhabitants of rivers and lakes have come up with various strategies to survive even the most severe cold.
When you go to school without a hat.
The most frostbitten inhabitants of reservoirs are crucian carp, dalliyas and rotans. They do not think about how to survive the frost, but simply freeze into the ice! Fish are able to survive deep freezing of liquids inside and around the body.
Today we catch fish with a pick and a crowbar...
All thanks to cryoprotectants. They begin to circulate in the blood of fish with the arrival of winter. Like antifreeze in windshield washer fluid, cryoprotectants prevent ice crystals from forming on the body's cells. Naturally, rotans, crucians and dallias will not be able to spend six months frozen. But surviving the complete icing of the lake is quite a feasible task for them!
If you don't understand what's going on here: in the photo, a pike caught a perch and somehow froze into an ice cube. That's what happens when you forget to put antifreeze in your blood!
Most water inhabitants don't joke about cryosleep. They are for classic hibernation. Herbivorous and omnivorous species of gill-breathing fish: bream, catfish, barbs, and others - arrange wintering pits when the temperature drops.
A cozy blanket of seaweed, a soft bed of mud. Beauty!
Fish of the same species choose a cozy place and cram themselves into it like herrings in a barrel. The deeper, the better. If the surface temperature is kept at +1 °C, then at the bottom it rises to +4-5 °C. The fish that have hibernated have a slow metabolism, lose their appetite, and their entire body is covered with thick mucus. For 3-4 months in a wintering pit, the tailed ones survive solely due to their accumulated reserves.
Many fishermen look for wintering holes specifically. The fish may be sedentary, but they certainly won't refuse a free lunch!
If you can't find a suitable place in your native waters, it's no big deal. Roach, roach, and pike perch migrate in search of warmer wintering holes. Thus, river fish swim into stagnant waters, and northern populations swim into the southern part of their range.
Well, let's go south with the fish?
There are those for whom winter does not interfere with life. Perch, pike, roach, bream - the majority of active predators almost do not change their behavior. And for some, bad weather even affects their fins. Burbot, for example, spend the entire summer in hibernation. Only with the onset of cold weather do they live a full life. All these fish continue to hunt, however, only those who remain active in winter. They do not react to fish in wintering pits or to their comrades in the lake frozen into the ice as prey.
— Well, Emelya, make a wish. — Wish number 1: don't eat me while I'm making other wishes! — I don't promise...
By the way, fishermen become salvation for such inhabitants. Ice, which binds the surface of rivers and lakes, does not allow oxygen to enter the water. In severe cold, this can lead to fish death - they will simply suffocate. The holes work like an open window in a stuffy room - they provide direct access to fresh air. So a good winter catch is the fishermen's payment for saving thousands of aquatic inhabitants!