Question

Как называется орган, помогащий рыбам перемещаться по вертикали? Почему у рыб нет шеи?

Answer 1

По вертикали рыбам позволяет перемещаться воздушный пузырь. Когда рыбе надо подняться к поверхности, то пузырь накапливает в себе воздух, когда опуститься - сдувается.
У рыб отсутствует шея, т.к. глаза у рыб(за исключением камбалы) расположены по обе стороны головы, что обеспечивает им большой угол обзора.

Answer 2

The Organ That Helps Fish Move Vertically

The organ that helps fish move vertically is called the swim bladder. The swim bladder is an internal gas-filled organ that helps fish control their buoyancy and move up or down in the water column. It acts like a float, allowing fish to adjust their position in the water without expending much energy.

The swim bladder is located in the abdominal cavity of most bony fish. It is filled with gas, usually oxygen or nitrogen, which is extracted from the bloodstream. By adjusting the amount of gas in the swim bladder, fish can increase or decrease their buoyancy and control their depth in the water.

The swim bladder works by regulating the amount of gas inside it. When a fish wants to ascend, it reduces the volume of gas in the swim bladder, making it less buoyant. This allows the fish to rise in the water column. Conversely, when a fish wants to descend, it increases the volume of gas in the swim bladder, making it more buoyant. This helps the fish sink to lower depths.

The swim bladder is an important adaptation that allows fish to move vertically in the water column without expending much energy. It helps them conserve energy and maintain their position in the water, whether they need to swim closer to the surface or dive to deeper depths.

Why Fish Don't Have Necks

Fish do not have necks because their bodies are adapted for life in water. The absence of a neck is a characteristic feature of fish anatomy, and it is related to their streamlined shape and swimming abilities.

Fish have evolved to have a streamlined body shape that allows them to move efficiently through water. Their bodies are elongated and tapered at both ends, which reduces drag and allows them to swim quickly and maneuver easily. This streamlined shape is achieved by having a continuous body structure without a distinct neck region.

The absence of a neck in fish is also related to their skeletal structure. Fish have a series of bony or cartilaginous vertebrae that make up their backbone. Unlike mammals, which have a flexible neck made up of multiple vertebrae, fish have a more rigid structure with fewer vertebrae. This rigidity helps support their bodies and maintain their streamlined shape.

Additionally, the absence of a neck in fish is also related to their feeding behavior. Fish typically capture their prey by opening their mouths wide and rapidly sucking in water along with their prey. Having a neck would limit their ability to create this suction force and capture their food effectively.

In summary, fish do not have necks because their bodies are adapted for life in water. Their streamlined shape, skeletal structure, and feeding behavior all contribute to the absence of a distinct neck region in fish.