What fish like to swim on the surface of the water, and what fish swim by in the water

Just go to the wet market.

See if there are any smaller fathead fish.

2. In summer, goldfish "like" to swim to the surface because they want to stay alive, because:

1 In summer, when the water temperature is high, the amount of dissolved oxygen in the water decreases.

2 In summer, the water temperature is high, the food residue is easy to spoil, the water body is polluted, the water quality deteriorates, and the oxygen consumption increases.

3 In summer, when the temperature is high, the metabolism of goldfish is vigorous and digests food.

4 Recently, the air pressure has been lower, and the amount of dissolved oxygen in the water has decreased.

5. The breeding density is too large, there are too many fish, and the oxygen content in the water is reduced.

For these reasons, goldfish have to float to the surface in order to obtain enough oxygen to sustain their lives, trying to get more oxygen from the surface of the water, which is higher than underwater. Once goldfish come to the surface, they think that their lives are threatened, and if they do not manage to change the water and increase oxygen, they will be in danger of death.

In addition, once the fish floats to the surface of the water to breathe, the physical exertion increases, the appetite decreases, and even if it does not die, it will become very emaciated, dull in color, and lose its vitality.

Fish swim in the water mainly through the oscillation of the tail and trunk, as well as the coordination of fins. Fish are ectothermic aquatic vertebrates that breathe by gills and inhabit almost all aquatic environments on Earth, including freshwater lakes and rivers, saltwater seas and oceans.

What do fish swim around in the water?

The tail fin of the fish determines the direction of movement and provides forward momentum, and if the tail fin is lost, the fish will not turn.

More than 32,000 species of fish have been discovered, two-thirds of which live in the ocean and one-third in freshwater.

The shape of fish is different, and the common ones are flat side, stick type, flat type, etc.

1. Pectoral fin: pectoral fin is a fin that grows on its chest and is close to the gills of fish, similar to the forelimbs of land animals. Without pectoral fins, the fish will sway from side to side.

Usually when swimming slowly, the pectoral fins can be paddled like a boat's oars, while when swimming at high speeds, the fish will hold their pectoral fins close to their bodies, and they can slow down and brake at critical moments.

2. Pelvic fin: If the pectoral fin is the forelimb of the fish, the pelvic fin is the hind limb, but unlike terrestrial animals that rely on the movement of the hind limbs, the pelvic fin of the fish does not play a role in providing power, but is responsible for assisting each fin to maintain balance, and at the same time allowing it to turn when it rises and falls in the water. Interestingly, different fish have different positions on their pelvic fins, not all of them on the abdomen, and some even in front of the pectoral fins or between the cheeks.

3. Dorsal fin: The dorsal fin can keep the fish standing sideways, without it, the fish will roll over on its side, which is especially important in swimming. There are also some fish with relatively long bodies, and the dorsal fin can play a role in providing power, such as hairtail, moray eel, seahorse, etc.

4. Tail fin: For fish, the most important thing is the tail fin, which can determine the direction of movement, and can also provide power, and fish without tail fin can only swim in one direction for a lifetime. Different fish have different shapes of tail fins, some have only one leaf, and some have two upper and lower leaves.