Thrush
In the concept of physics, since the density of water is greater than that of air, it is relatively Since the resistance of fish in water is relatively reduced (the main reason is that humans walking in water are not as fast as on land, the resistance of water is less), so fish must adapt to different sizes of resistance (such as tides, eddies, coral reefs, rivers in the ocean) (the movement of torrents and lakes), thus deriving various different body shapes. In addition, fish can take advantage of the differences in their body shapes to use the lowest energy to achieve the fastest movement speed under different circumstances, or they can Rest in different places to achieve the effect of protecting yourself.
The body types of fish are densely classified, but generally speaking, the most important ones can be divided into five categories:
The first type of spindle type:
The most common body shape in aquariums. Most fish belong to this type. This body shape is well-proportioned, and the friction in the water is small, so the resistance is relatively small, allowing the fish to move freely in the water. They are mobile and rich in transportation energy, so most fast-moving fish belong to this type, and their resting water layers are mostly in the middle and surface layers. Such as red lotus lanterns and guppies (definitely introduced).
The second type of lateral flat type:
Derived from the spindle type, that is, the dorsoventral direction is increased and the tissues are thinned, resulting in a body shape. It is a coastal and grassroots fish in the sea. Its number is smaller in fresh water. It mostly rests in waters with relatively slow currents. Its movement is not very fast. It mostly moves forward by twisting the fish body. Most of the resting water layers belong to the middle layer. Such as the Egyptian giants and the colorful giants.
The third type of vertical flat type:
The dorsoventral direction is flat, and the organization direction gradually decreases, and the movement is slower, and most of them rest at the bottom. , the recreational water layer belongs to the base layer. Such as pearl rays and hanging rats.
The fourth type of tube type:
The fish body is about 10 inches wide from head to tail, like a stick, and is mostly submerged in the mud. Among the sand, there are some that live in crevices on the seabed, and most of them make a bottom-dwelling living, and there are only a few fish on the bottom. Such as snake fish and loach.
The fifth type of ball type:
The body shape is similar to a ball or oval. Some fish will swallow air or water to stretch their bodies. Most of them are Middle level. Little honey peak, eight-character doll.
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