Cuttlefish is a cephalopod: description, lifestyle and nutrition

Cuttlefish is a mollusk belonging to the class of cephalopods. In the concept of people, it is associated with something unimpressive and formless. In fact, cuttlefish are very beautiful.

Appearance of animals

Cuttlefish has an oval, slightly flattened body. The mantle (dermo-muscular sac) forms the main part of it. The inner shell plays the role of a skeleton, and this distinctive feature is characteristic only of cuttlefish. It consists of a plate with internal cavities that provide buoyancy to the buoyancy. The shell is located inside the trunk and protects the internal organs.

The head and body of the mollusc are fused. The cuttlefish's eyes are very large and can zoom in, while the pupil controls the intensity of the light. On the head of the cuttlefish there is something that looks like a beak, the shellfish extracts and shatters the food. And also, as with numerous cephalopod mollusks, cuttlefish have an ink bag. This is a special organ, which is a dense capsule, divided into two parts. In one part are already ready ink, and in the other - special cells, saturated with special grains with paint. When maturing, the cells are destroyed, and ink is formed. The ink bag produces a huge amount of ink. The devastated bag is restored in an average of half an hour.

The most famous species are:

• Common cuttlefish;
• Pharaoh's;
• Crucifying (the most beautiful and poisonous);
• Wide-witted (the largest);
• Striped (very poisonous).

The mollusc has eight tentacles and two front feelers. On each of them there are small suckers. The front tentacles are hidden in the pockets under the eyes and are used when attacking the victim. The elongated fins are located on the sides of the trunk and help the cuttlefish during the movement.

Description of cuttlefish, coloring

A characteristic feature of these mollusks is the ability to change the color of their body. The color of cuttlefish is extremely diverse. This is possible due to skin cells-chromatophores. Change in body color is conscious, chromatophores are subject to the brain. This process is instantaneous, and it seems that everything happens automatically. Cages of cuttlefish are filled with special pigments of different colors.

Due to the variety of colors, the complexity of the pattern and the speed of color change, the mollusc has no equal. Certain types of cuttlefish are capable of luminescence. Color changes are used when masking. Patterns of different forms carry certain information for the relatives. Cuttlefish is one of the most intelligent species of invertebrates.

The sizes of molluscs

Cuttlefish have relatively small sizes in comparison with other cephalopods. Wide-sepia sepia is the largest among cuttlefish. Together with the tentacles, the body length is 1.5 m, and the weight is about 10 kg. However, the majority of individuals are smaller, their length is not more than 20-30 cm. Also, there are several species of very small size - up to 2 cm, which are considered to be the smallest cephalopod mollusks in the world.

Areal

Where does the cuttlefish live? And it lives only in shallow waters, in tropical and subtropical seas, which wash the shores of Africa and Eurasia. Nevertheless, striped cuttlefish was also found off the coast of Australia. Molluscs prefer to live alone, occasionally in small groups, and only during the breeding period large gatherings of cuttlefish are formed. During the mating season, they can carry out movements, but, as a rule, lead a settled life. Mollusks are swimming shallowly, adhere to the coastline. After seeing the prey, the cuttlefish freeze for a second, and then quickly overtake the victim. When a hazard occurs, the mollusks lie on the bottom and try to fill themselves with fins with sand. Cuttlefish is a very careful and timid shellfish.

Nutrition Cuttlefish

From time to time large individuals are able to eat smaller brethren. This is not due to an aggressive nature, but more because of food illegibility.

Mollusks eat practically everything that moves and does not exceed their own sizes. They feed on fish, crab, shrimp, shellfish. Cuttlefish blows a stream of water into the sand from the siphon, thereby it rises, while the mollusk at this time swallows the small living creatures, and the larger cuts its beak. Cuttlefish will not be difficult to crack the shell of a crab or the skull of a small fish.

Reproduction

Cuttlefish is an animal that multiplies only once. Molluscs migrate to comfortable places for laying eggs, along the way forming flocks of several thousand individuals. Communication occurs by changing the color of the body. With mutual sympathy, both mollusks glow with bright colors. Eggs of cuttlefish are mostly black and resemble grapes. After laying eggs, adult cuttlefish die. Cephalopods are born already formed. Since birth, small cuttlefish can use ink. Cuttlefish live on average 1-2 years.

Nutritional value of shellfish meat

Cuttlefish is a source of excellent meat that contains valuable unsaturated acids - eicosapentaenoic and docosahexaenoic, protecting against many diseases of the cardiovascular system. And also these elements reduce the level of triglycerides in the blood, prevent the formation of thrombi and clogging of the arteries. In cuttlefish meat, vitamins B2, B12, A, nicotinic and folic acids are present. In addition, the meat of shellfish is rich in minerals. In addition to useful substances in meat, impurities such as cadmium and mercury are present. Nutritionists recommend eating no more than two servings per week.

Useful properties of ink

• Improve mood and struggle with emotional problems.
• They help in the treatment of reproductive diseases.
• Eliminate the symptoms of digestive disorders.
• Help with the treatment of skin diseases.

In ancient times, ink was used for writing. Ink of cuttlefish is a part of medicines. This substance has a calming effect.

Inks are used in the production of food colorings and seasonings. They give the dishes a special black color and an excellent salty taste. Ready-to-use ink is sold in stores. And also on the basis of ink, sauces are made, which differ in bright and unique taste. Ink of cuttlefish contains elements that help metabolism and have an anti-inflammatory effect.

Interesting facts about cephalopods

1. Cuttlefish has three hearts. Two hearts are used for pumping blood to the gills, and the third is used to circulate oxygenated blood to the rest of the body.
2. In the blood of cuttlefish there is a protein called hemocyanin, which is used to transfer oxygen. Therefore, her blood is blue-green.
3. Cuttlefish is a shellfish capable of mimicking the shape and texture of surrounding objects. The mollusk changes its color by expanding or pulling small bumps located throughout the body, thereby practically merging with sand, cobblestones and other surfaces.
4. Males, in order to care for the female and not attract the attention of others, are repainted in an interesting camouflage. One half of the body they paint with colorful paint, and the other is masked under the females, imitating muffled tones.
5. Cuttlefish can see well in low light conditions, as well as what is behind them.
6. Cuttlefish are able to simulate dynamic movements of algae on their bodies to become invisible. Or they arrange a color show for catching prey.
7. Mollusks skillfully defend themselves from enemies, but a relatively low rate of movement makes them vulnerable to pursuers: dolphins, sharks.

Cuttlefish is an entertaining object for aquarists. However, keeping them is not easy due to the fact that mollusks are very fearful, they often release ink into the water, and it becomes opaque. After a certain amount of time, cuttlefish gets used to the owner and stops fearing him.