Lateral line in fish and its role in fish behavior and life

The sense organs play a very important role in the vital activity and behavior of fish. Fish, like other vertebrates, have a complete set consisting of five senses. But they have a significant difference - the lateral line. In fish this sense organ is called the sixth. Ground animals in the process of evolution lost this sixth sense, but in waterfowl it remains and quite significantly facilitates their life, helps to survive and feed.

Anatomy of fish. Sense organs

One of the main sense organs in fish is the sense of smell and taste. With their help they are able to detect even minor changes in the environment. Fish pike, for example, with the mouth not only eats, but, sensing the touch to the ground, instantly reacts, changing direction. Sensitive cells in the mouth transmit nerve impulses, signaling danger, obstacles or food.

Fish have a fairly thinly developed temperature sensation. Such a high sensitivity to fluctuations in temperature and pressure is not relevant to terrestrial animals.

The organs of the olfactory fish are located on the side parts of the head and resemble small cones. With their help they can catch changes in the chemical composition of water. Especially sharply developed sense of smell in those animals that are nocturnal hunting. For example, pike fish can sniff the prey that swims a few meters from it.

Lateral line. Location:

Many scientists believe that the lateral line of the fish is the most important sense organ that helps animals to live more comfortably. The lateral line is a kind of single center that unites all the sensitive cells in the body that are in the head or body.

The organ is located throughout the body, beginning at the head and ending at the tail. Anatomy of fish, their variety and subspecies determine the location of the lateral line and its color. In one species it can look a bright white line, in others it is a dark, almost black stripe.

In more fish, the lateral line is represented in a single specimen. But there are some species that can boast of five or more. The lateral line of the fish can be very visible visually, and can be hidden in the scales and immediately invisible to the human eye. In some fish it is arched, while in others it is in the form of small, jerky strips on the head.

There are fish that are deprived of the sixth sense organ. These include mullet, dallium, some fish of the family of carpiformes.

The lateral line consists of ...

As we have already said, the lateral line in the fish is a kind of brain and nerve center, allowing to control what is happening around. What does this center consist of?

The lateral line is an accumulation of a number of receptors that are located between themselves at a certain interval. Receptors can be in channels on the head or indentations that are located on the sides of the body. Most receptors are hidden under the skin of a fish. Only some come to the surface and are hidden in the scales. Remind open pores on the skin.

Inside the channel of the lateral line is filled with liquid. Nerve receptors (their sensitive hairs), catching changes, give the signal of this liquid itself. Any stirring, changing pressure or water temperature can cause receptors and, consequently, water in the channel to move. The stronger the changes in the habitat of the fish, the more the hair-receptors will deflect, the faster the information will enter the central nervous system.

The significance of the lateral line in fish

The sixth sense, or lateral line, allows the fish to feel the approach of other animals dwelling in the water, much earlier than they are informed about by the organs of sight or smell. The lateral line is capable of detecting the smallest changes in pressure in the water. Scientists say that the distance at which it is able to determine the approaching danger is six times the size (length) of the fish itself.

The importance of the lateral line in fishes with poor eyesight is especially great. There are animals that are able to react solely to shade or light, while completely ignoring the movement in the water. The lateral line in this case makes it possible to compensate for the underdevelopment or lack of visual or olfactory skills.

The life of a fish often depends on the lateral line. If it is damaged, then the external impacts will not be perceived by the animal so brightly. It will cease to react to danger from the outside, can not fully hunt, procure food, hide from enemies. And soon he will die.

Lateral line and biting

For sure, all experienced fishermen know the importance of the lateral line in the fish. With its help, the fish is able to catch the slightest noise and water fluctuations. As experts say, a shot, an explosion, an ordinary conversation on high tones, a blow on the water, the side line will immediately "feel". And the fish, therefore, will react, get scared and hide. It is for this reason that fishermen try never to make noise in the pond, do not talk too loudly, do not throw something into the water.

Movement, small noise and vibrations should not be created by a fisherman, but by a bait in the water. Experienced fishermen say that the bait should not stand in a pond, it must necessarily move, making fluctuations in the fluid. Only in this case the fish with its lateral line will smell the food and will move in the direction of the hook.