What do fish swim in the water, what do fish swim in the water, and what do fish swim by

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, the pelvic fins are born in different positions for different fish, not all of them are on the abdomen, and some are even in front of the pectoral fins or between the gills.

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.

Fish swim by swinging their tail fins.

The fish relies on the swing of the fins to generate forward momentum, and the fish floats and sinks by the swim bladder, and the air inside can increase or decrease, thus helping the fish to swim between different water layers. Thanks to the coordination of muscles, bones, fins and swim bladders, fish can move freely in the water.

Fish

Fish are body covered with bone scales, breathe with gills, swim through the swing of the tail and trunk and the coordination of fins, and feed on the upper and lower jaws, belonging to the vertebrate subphylum of chordates, and generally people divide vertebrates into five categories: fish (53%), birds (18%), reptiles (12%), mammals (9%), and amphibians (8%).

Distributed in the waters of the world, according to the statistics of the late Canadian scholar "Nelson" in 1994, there are 24,618 species of fish in the world, accounting for more than half of the named vertebrates, and new species of fish continue to be discovered, with an average of about 150 species per year, and more than 1,500 species should have increased in more than 10 years, and there are about 32,100 species of fish named in the world at present.

According to the species, fish are mainly divided into: tropical fish, temperate fish and cold ribbon fish; According to the living habits, it can be divided into: freshwater fish and saltwater fish.

Fishes are the oldest vertebrates. They inhabit almost all aquatic environments on earth, from freshwater lakes and rivers to saltwater seas and oceans, and about 32,000 species of fish have been found in the world.

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.

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.