Sepia, or cuttlefish ink, is a dark blackish liquid secreted by the cuttlefish cephalopod.

The tincture is made from sepia, which must be obtained in liquid form and dried naturally. Milk sugar rubs are made from the same product.

Pathogenesis Sepia is in " chronic diseases"Hahnemann.

PHYSIOLOGICAL ACTION

Action Sepia from the very beginning of the experience, it manifests itself in the sympathetic nervous system and mainly in the vasomotors. Indeed, after four hours, there is an increase in blood circulation, flushes to the head, which end in the release of sweat, fainting and loss of strength. At the same time, there is irritation of the nervous system with excitement and sadness.

This is followed by venous congestion. It is especially noticeable in the portal vein system, hence the congestion in the liver and uterus. The congestion of the veins in the extremities causes a painful feeling of weakness, twitching, heaviness, especially noticeable in the thighs, after sleep. There are fainting spells, prostration, general prostration; muscles that are flaccid in themselves relax even more, hence the prolapse of the rectum, the inactivity of the intestines.

This general violation body functions produces visible changes in the skin, which become yellow, earthy.

The mucous membranes are also affected: the discharge is always mucopurulent, greenish-yellow, not irritating; due to irritation of the mucous membrane of the urinary tract, there are diseases of the urethra with pain and Bladder; irritation of the mucous membrane of the respiratory tract causes a dry incessant cough, aggravated by cold. Later comes the discharge of greenish-yellow sputum, as in the early stages of consumption. There is also a flaccid chronic catarrh of the nose with profuse green and yellow discharge, as in Pulsatilla, but the action Sepia deeper - bones can often be affected, as in lakes.

TYPE

Type Sepia with sickly sallow complexion; on the face, mainly on the bridge of the nose, in the form of a saddle, there are yellow spots that are also found on the whole body. Blue under the eyes, black hair, slender figure. Such subjects, both men and women, are prone to sweating. They suffer from hot flashes, headache in the morning, wake up feeling tired. There is almost always some kind of disease in the genitals. Both sexes have congestive liver, atonic dyspepsia, constipation.

Physical type Sepia never has a strong, healthy appearance, good health, but on the contrary, impotence, general weakness, pale color of the connective membranes.

Mentally subject Sepia- and this is most often a woman - always sad for no reason; seeks solitude, avoids society, cries without any reason on the sly. Everything is boring for him, things are disgusting to him, and he is not at all interested in them; family and even children are completely indifferent to him.

Sadness is replaced by periods of excitement, during which the patient becomes irritable. Attacks of involuntary tears and laughter are often observed.

PECULIARITIES

Worse: morning and evening, new and full moon.

Improvement: after noon.

Dominant side: left.

CHARACTERISTIC

Feeling of heaviness and pressure on the bottom, as if all the contents of the abdominal cavity want to go out through the vagina, as a result of this, a characteristic posture: the patient crosses her legs with force or presses on the vagina with her hand.

Yellow patches, hepatic, particularly visible on the face, cheeks and nose, where they are butterfly or saddle shaped.

Abrasions and eczema on the folds of almost all joints.

Rigor and heaviness in the thighs, especially after sleep.

Weakness in the joints that disappears when walking; looks like they are about to pop out.

Sensation of a foreign body, bullets, in various parts of the body, especially in the rectum.

Every collar seems narrow; the patient stretches it ( Lachesis).

Foul-smelling perspiration, chiefly under the armpits and in the popliteal pits.

Mucopurulent discharge, yellowish green and non-irritating, similar to Pulsatilla.

Vomiting and nausea, easily coming on under the influence of the slightest physical or moral influence.

Food seems too salty Pulsatilla vice versa.

Pain. pain Sepia are often at rest, and movement never improves them. They are worst at night, accompanied by numbness of the affected part, they are worse from cold and better after dinner.

The chair is hard, knotty, balls, insufficient, difficult. Pain in rectum during and long after stool.

Menses are irregular, unlike one another, most often late and scanty. Colic before menses. During them, pressure on the bottom, the need to cross the legs.

MAIN INDICATIONS

Wherever there is a disease requiring a prescription Sepia, according to Testa, we can certainly say that it is always accompanied by known organic or functional disorders of the genital organs.

The consequences of venous stasis in the uterus can be:

LOSS AND DISPLACEMENT OF THE UTERUS.

BELI against whom Sepia often the best remedy; they are yellow, green, with severe itching.

STOPPING AND TOO HEAVY MENTIONS are indifferently cured Sepia, unless they depend on venous congestion in the uterus.

It is the best remedy for gonorrhea in women, after the acute symptoms have disappeared.

Venous stasis in the abdominal cavity causes from the intestines:

PROLONGATION OF THE RECTUM.

HEMORRHOIS: bleeding in the stool, with fullness in the rectum, as if distended by some foreign body, which causes urging.

DYSPEPSIA with empty and sinking feeling in stomach, weakness in pit of stomach and in abdomen, with normal or bitter taste in mouth; the need for sour and seasonings; bloating. The patient easily vomits (when brushing his teeth, from the smell of food, when receiving unpleasant news, etc.).

Sensitivity in the region of the liver.

Does not tolerate milk, it produces a sour eructation.

Dyspepsia of smokers.

MIGRAINE with throbbing pains over the eye (usually over the left).

Gouty headache, worse in the morning with nausea and vomiting (the liver is naturally affected and the urine is saturated with uric acid). Shooting pains over left eye, in vertex and occiput. Very intense pain, sometimes like a blow, when shaking the head.

ECZEMA on the head and on the face, on the folds of the joints, in the vagina and anus. Dry scaly crusts, firmly seated and separated with great difficulty in the presence of uterine disorders, indicate mainly Sepia. The rash periodically gets wet. It often takes on a round or annular shape, especially at the folds of the joints. Worse during and after menses, from warmth in bed. Skin diseases are often replaced by uterine disorders.

BRONCHITIS: expectoration of dirty, salty tasting sputum.

Lack of strength, worse in the evening, ptosis. Sudden loss of vision.

DOSES

Most often, medium and high dilutions are used. Low rubbing is useful in diseases of the throat, uterus and skin. With leucorrhea, a first decimal rub of five centigrams twice a day is often necessary, according to Piedvas.

SUMMARY

Wherever there is a disease, one can certainly say that it is always accompanied by known overt or latent organic or functional diseases in the genital area. Already Hippocrates used Sepia in women's diseases. Sepia called "washerwomen's medicine", many illnesses are caused or aggravated by work in the laundry. Venous congestion in the portal vein, with painful disorders of the liver and uterus.

Cuttlefish (Sepia) belong to the class of cephalopods. About 30 belong to this group. modern species. Cuttlefish are the smallest of all cephalopods. In most species, the body length reaches 20 cm, and in small species - 1.8-2 cm. Only one species, the broad-armed sepia, has a length of 150 cm along with the "arms". Cuttlefish live mainly near the coast in shallow water in tropical and subtropical seas. Atlantic Ocean and in the Mediterranean.

Structure

The structure of the cuttlefish is in many ways similar to the structure of other cephalopods. Its body is represented by a skin-muscle bag (the so-called mantle) and has an elongated oval shape, slightly flattened and does not change in size (octopuses, for example, easily squeeze into narrow crevices). In cuttlefish, the head is fused to the body. On the head are big eyes, having a complex structure and a slit-like pupil, and on its front part there is a kind of beak designed for crushing food. The beak is hidden between the tentacles.

Eight short tentacles-arms and two long grasping tentacles extend from the body of the mollusk, all of which are dotted with suckers. In a calm state, the "arms" of the cuttlefish are folded together and stretched forward, thus giving the body a streamlined appearance. Grasping tentacles are hidden in special pockets under the eyes and fly out from there only during the hunt. In males, one of the arms differs in its structure from the others and serves to fertilize females.

On the sides of the body of the cuttlefish are fins, elongated in the form of a border, which are a means of facilitating movement. The cuttlefish accelerates its movement in the water through several sharp movements. It draws water into a compression chamber, which compresses to expel water from a siphon under the head. The clam changes direction by turning the opening of this siphon. The cuttlefish differs from other cephalopods in the presence of an internal calcareous shell in the form of a wide plate that covers its entire back and protects the internal organs. The inner shell of a cuttlefish is built of aragonite. This substance forms the so-called "cuttlefish bone", which is responsible for the buoyancy of the mollusk. The cuttlefish regulates its buoyancy by the ratio of gas and liquid inside this bone, which is divided into small chambers.

The remaining internal organs in cuttlefish are arranged in the same way as in other representatives of cephalopods. This animal has three hearts: one heart for two gills and one heart for the rest of the body. Cuttlefish have blue-green blood, due to the pigment hemocyanin in it, saturated with copper-containing proteins, which are able to “preserve” oxygen for a long time, preventing the mollusk from suffocating at great depths. Also, cuttlefish have an ink sac that produces very a large number of ink compared to other cephalopods. The ink substance is brown and is called sepia. Having such a protective agent, the cuttlefish uses it directly for protection as a last resort.

The color of cuttlefish is very variable. In their structure skin there are three layers of chromatophores (coloring pigment cells): on the surface there is a light yellow layer, the middle one is an orange-yellow layer and a dark layer located under the two previous layers. The transition from one shade to another is regulated by the nervous system and occurs within a second. In terms of the variety of colors, the complexity of the pattern and the speed of its change, these animals are unmatched. Some types of cuttlefish can luminesce. Color change and luminescence are used by the mollusk for camouflage.

reproduction

Cuttlefish live alone, very rarely in small flocks, and lead a sedentary lifestyle. During the breeding season, they form large aggregations and may migrate. Usually cuttlefish swim at a short distance from the bottom, tracking down prey, when they see it, they freeze for a moment, and then overtake the victim with a swift movement. When cuttlefish are in danger, they lie down on the bottom, and with a wave of their fins they cover themselves with sand. By nature, these animals are very cautious and timid. Cuttlefish hunt during the daytime and feed on various fish, shrimps, crabs, mollusks, worms - almost all organisms that move and do not exceed their size. To increase the effectiveness of hunting, the mollusk blows a jet of water from the siphon into the sand and catches small living creatures washed by the jet. Cuttlefish swallow small animals whole, large ones are butchered with their beaks.

Cuttlefish have many enemies, as their low movement speed makes them vulnerable to predatory fish. These mollusks are eaten by dolphins, sharks and rays. Cuttlefish are sometimes referred to as "chameleons of the sea" for their good camouflage to match the color of their surroundings. When hunting or fleeing predators, they rely more on their ability to disguise themselves than on their protective ink.

Cuttlefish are dioecious animals. They breed once in a lifetime. The male treats the female with quivering tenderness, swimming nearby, he strokes her with his tentacles, while both of them flash with bright colors. The male brings sperm to the female with a modified tentacle, the eggs are fertilized already during laying. Eggs of cuttlefish are black in color and look like bunches of grapes; when laying, the females attach them to underwater vegetation. Some time after spawning, adults die. Juveniles are born fully formed, having an ink sac and an inner shell. Already from the first moments of life they can apply ink. Cuttlefish grow quickly, but do not live long - only 1-2 years.

Since ancient times, cuttlefish have been hunted by people because of their delicious meat, which is used in Mediterranean and Chinese cuisine. The crushed shell is part of a number of toothpastes. In the old days, cuttlefish ink was used for writing, and diluted to prepare a special paint for artists - sepia. Therefore, people owe countless masterpieces of painting and writing to cuttlefish.

  • Type: Mollusca Linnaeus, 1758 = Mollusca, soft-bodied
  • Class: Cephalopoda Cuvier, 1797 = Cephalopoda
  • Order: Sepiida Zittel, 1895 = Cuttlefish

    • Species: Sepia apama = Giant Australian cuttlefish

    The giant Australian cuttlefish can reach 50 centimeters in length and is considered the largest cuttlefish in the world. Its weight can reach from 3 to 10 kilograms. There is sexual dimorphism in size - males always outnumber females in size.

    The Giant Australian Cuttlefish is an endemic Australian species. It lives exclusively in coastal waters in the south, southwest and southeast coasts of Australia, from the coast of Queensland to Shark Bay in Western Australia. And there is a giant Australian cuttlefish at depths of up to about 100 meters, but even more often prefers shallow water.

    The giant Australian cuttlefish has a body slightly flattened in the dorsal-abdominal direction, which is decorated with a wide leathery fold on the sides. Here, on the sides of the body, there are also fins - the main organ of their movement in the water. The head end of the urvkatica is adorned with 10 tentacles. Of these, 2 tentacles are grasping, they are the longest, although they can be completely retracted into special sac-like pits under the eyes. The remaining 8 tentacles are short, and all are located around the mouth, framing it. All tentacles are equipped with suction cups that are very necessary for the animal. There is a difference in the structure of the tentacles of cuttlefish of both sexes. So in a male, unlike females, the 4th tentacle serves to fertilize females.

    The respiratory organ of cuttlefish is the gills. On the dorsal side of the body under the mantle, there is a porous calcareous shell, which looks like a plate, which gives the animal a fixed body shape. The eyes are similar in structure and visual acuity to human eyes. Cuttlefish, if necessary, are able to change the shape of the lens. Their mouth, like that of other cephalopods, consists of a strong beak, which is shaped like the beak of birds, especially a parrot, there are also jaws and a tongue.

    Speaking of Features internal structure cuttlefish, it remains unclear why nature endowed these creatures with 3 hearts. In this case, one is responsible for the blood supply to the nervous system, and the other two are responsible for the coordinated work of the gills. And the blood of cuttlefish is not red, but blue. Blue color blood is caused by the presence of a special pigment hemocyanin in it. Hemocyanin, like hemoglobin in vertebrates, is responsible for the transport of oxygen.

    The giant Australian cuttlefish is known for its unique ability to instantly change its color, which can depend both on the mood of the animal and the characteristics of the environment. The coloration of males changes greatly during the mating season. This becomes possible due to the presence of a special pigment in the cells of the body, which is responsible for their stretching or contraction, depending on the signals from the nervous system. During the mating season or during an attack on prey, their color acquires a metallic sheen and is covered with bright luminous dots.

    An interesting feature of this species is that during the mating season, males can sometimes pretend to be females in order to try to outwit a stronger rival and try to get closer to the female. If they succeed in this maneuver, they mate with her very quickly and retreat until the dominant male has figured out what's what ...

    As a defense against predators giant squid use their stock of ink. In case of danger, the squid releases an ink cloud either directly into the “face” of the enemy, after which, under its cover, they quickly hide away, or a little to the side. At the same time, the spot often takes on such a shape that it becomes in shape a little like the cuttlefish itself, and let this a short time, but diverts the predator's attention from the cuttlefish's own person.

    The giant Australian cuttlefish is predominantly nocturnal. They spend most of their time hiding among kelp beds, rocky reefs, or simply burrowing into the seabed. Cuttlefish are homebodies, they spend almost all their active time on a small territory, not exceeding 500 m2. Therefore, most of the absorbed by them food energy they spend not on physical activity, but on their own growth.

    The giant cuttlefish is very curious and is not averse to even playing, which is often used by divers. Despite their relatively peaceful nature and cute appearance, cuttlefish are dexterous predators, extracting various small mollusks and crustaceans, fish, sea ​​worms and even small cuttlefish. Cuttlefish go hunting at night, attacking prey from an ambush, grabbing it with two long tentacle arms.

    By their nature, cuttlefish are solitary, and only during the breeding season, which falls on June-August, they often gather large groups. One such favorite place for marriage dates is False Bay, located in the northern part of Spencer Bay. At this time, it is simply teeming with giant cuttlefish, and at this time there are almost 1 individual per 1 m2. This is where the fun begins. The largest and strongest males begin to care for the females. They "put on" a bright wedding dress and begin to wave their long "arms" in front of their chosen one. At the same time, they drive away smaller and younger males. Then they are forced to go for a deceptive maneuver, changing their bright cavalier outfit to "ladies" and under the guise of "females" they try to make their way through the "vigilant guard" to the females. And if the dominant male is distracted for a few moments, the werewolf immediately quickly acquires his bright male color in front of the female and mates with her, transferring his spermatophores to her with the help of the 4th “hand”, and quickly swims away from trouble.

    After some time, females lay eggs under stones or in other hard-to-reach places, enclosed in a thick shell. After that, they die. And the cubs are born, depending on the temperature of the water, after 3-5 months, having a body length of about 2.5 centimeters. Outwardly, they are very similar to adults, and at this age they feed only on plankton.

    The meat of the giant cuttlefish is edible and is widely used in cooking as food. Cuttlefish ink is still used in painting today. Therefore, large-scale capture of this species for export is currently underway, because of which the giant cuttlefish is already at risk of declining numbers. Now the capture of the giant Australian cuttlefish in False Bay in Australia is prohibited.

    Class Cephalopoda

    Cephalopods are the most highly organized molluscs. They are rightly called the "primates" of the sea among invertebrates for the perfection of their adaptations to life in the marine environment and the complexity of their behavior. These are mainly large predatory marine animals capable of actively swimming in the water column. These include squid, octopus, cuttlefish, nautilus (Fig. 234). Their body consists of a torso and head, and the leg is transformed into tentacles located on the head around the mouth, and a special motor funnel on the ventral side of the body (Fig. 234, A). Hence the name - cephalopods. It has been proved that part of the tentacles of cephalopods is formed due to the head appendages.

    In most modern cephalopods, the shell is absent or rudimentary. Only the genus Nautilus (Nautilus) has a spirally twisted shell, divided into chambers (Fig. 235).

    Only 650 species belong to modern cephalopods, and there are about 11 thousand fossil species. This is an ancient group of mollusks known from the Cambrian. Extinct species of cephalopods were predominantly testate and had an external or internal shell (Fig. 236).

    Cephalopods are characterized by many progressive features of organization in connection with actively life marine predators. At the same time, they retain some primitive features that testify to their ancient origin.

    External structure. Peculiarities external structure cephalopods are diverse due to different lifestyles. Their sizes range from a few centimeters to 18 m in some squids. Nektonic cephalopods are usually torpedo-shaped (most squids), benthic cephalopods are bag-shaped (many octopuses), nektobenthic are flattened (cuttlefish). plankton species small in size, have a gelatinous buoyant body. The body shape of planktonic cephalopods can be narrow or similar to jellyfish, and sometimes spherical (squid, octopus). Benthopelagic cephalopods have a shell divided into chambers.

    The body of a cephalopod consists of a head and a body. The leg is modified into tentacles and a funnel. On the head is a mouth surrounded by tentacles, and large eyes. The tentacles are formed by the head appendages and the leg. These are food trapping organs. The primitive cephalopod - boat (Nautilus) has an indefinite number of tentacles (about 90); they are smooth, worm-like. In higher cephalopods, the tentacles are long, with powerful muscles and bear large suckers on the inner surface. The number of tentacles is 8-10. Cephalopods with 10 tentacles have two tentacles - trapping, longer, with suckers at widened ends,

    Rice. 234. Cephalopods: A - nautilus Nautilus, B - octopus Benthoctopus; 1 - tentacles, 2 - funnel, 3 - hood, 4 - eye


    Rice. 235. Nautilus Nautilus pompilius with a sawn shell (according to Owen): 1 - head hood, 2 - tentacles, 3 - funnel, 4 - eye, 5 - mantle, 6 - visceral sac, 7 - chambers, 8 - partition between shell chambers, 9 - siphon


    Rice. 236. Scheme of the structure of cephalopod shells in sagittal section (from Gescheler): A - Sepia, B - Belosepia, C - Belemnites, D - Spirulirostra, E - Spirula, E - Ostracoteuthis, G - Ommastrephes, H - Loligopsis (C, D, E - fossils); 1 - proostracum, 2 - dorsal edge of the siphon tube, 3 - ventral edge of the siphon tube, 4 - collection of phragmocone chambers, 5 - rostrum, 6 - siphon cavity

    and the remaining eight tentacles are shorter (squid, cuttlefish). The octopuses living on seabed, eight tentacles of the same length. They serve the octopus not only to capture food, but also to move along the bottom. In male octopuses, one tentacle is modified into a sexual (hectocotyl) and serves to transfer the reproductive products into the mantle cavity of the female.

    Funnel - a derivative of the leg in cephalopods, serves for a "reactive" way of movement. Through the funnel, water is forcefully pushed out of the mantle cavity of the mollusk, and its body moves reactively in the opposite direction. At the boat, the funnel has not grown together on the ventral side and resembles the sole of the foot of crawling mollusks rolled into a tube. The proof that the tentacles and funnel of cephalopods are leg derivatives is their innervation from the pedal ganglia and the embryonic anlage of these organs on the ventral side of the embryo. But, as already noted, some of the tentacles of cephalopods are derivatives of the head appendages.

    The mantle on the ventral side forms, as it were, a pocket - a mantle cavity that opens outwards with a transverse slit (Fig. 237). A funnel protrudes from this gap. On the inner surface of the mantle there are cartilaginous protrusions - cufflinks, which fit tightly into the cartilaginous recesses on the body of the mollusk, and the mantle is, as it were, fastened to the body.

    The mantle cavity and funnel together provide jet propulsion. When the muscles of the mantle relax, water enters through the gap into the mantle cavity, and when it contracts, the cavity closes with cufflinks and the water is pushed out through the funnel. The funnel is able to bend to the right, left and even back, which provides different direction movement. The role of the steering wheel is additionally performed by tentacles and fins - the skin folds of the body. Types of movement in cephalopods are diverse. Octopuses often move on tentacles and rarely swim. In cuttlefish, in addition to the funnel, a circular fin serves for movement. Some deep-sea umbrella-shaped octopuses have a membrane between the tentacles - umbrella and can move due to its contractions, like jellyfish.

    The shell in modern cephalopods is rudimentary or absent. In ancient extinct cephalopods, the shell was well developed. Only one extant genus, Nautilus, has retained a developed shell. The shell of Nautilus in fossil forms also has significant morphological and functional features, in contrast to the shells of other mollusks. This is not only a protective device, but also a hydrostatic apparatus. The nautilus has a spirally twisted shell divided by partitions into chambers. The body of the mollusk is located only in the last chamber, which opens outwards with the mouth. The remaining chambers are filled with gas and chamber fluid, which ensures the buoyancy of the body of the mollusk. Through

    holes in the partitions between the chambers of the shell passes the siphon - the posterior process of the body. Siphon cells are able to release gases. When surfacing, the mollusk emits gases, displacing the chamber fluid from the chambers; when lowering to the bottom, the mollusk fills the shell chambers with chamber fluid. The mover of the nautilus is a funnel, and the shell maintains its body in suspension in the water. Fossil nautilids had a shell similar to that of the modern nautilus. Completely extinct cephalopods - ammonites also had an external, spirally twisted shell with chambers, but their partitions between the chambers had a wavy structure, which increased the strength of the shell. That is why ammonites could reach very large sizes, up to 2 m in diameter. In another group of extinct cephalopods, the belemnites (Belemnoidea), the shell was internal, overgrown with skin. Belemnites by appearance resembled shellless squids, but in their body there was a conical shell, divided into chambers. The top of the shell ended with a point - the rostrum. Rostrums of belemnite shells are often found in Cretaceous deposits and are called "devil's fingers". Some modern shellless cephalopods have rudiments of the inner shell. Thus, in cuttlefish, a calcareous plate is preserved on the back under the skin, which has a chamber structure on the cut (238, B). Only in spirula (Spirula) under the skin is a fully developed spirally twisted shell (Fig. 238, A), and in squid under the skin only a horny plate has survived from the shell. In females of modern cephalopods - argonauts (Argonauta), a brood chamber is developed, resembling a spiral shell in shape. But this is only a superficial resemblance. The brood chamber is distinguished by the epithelium of the tentacles, is very thin and is designed to protect the developing eggs.

    covers. The skin is represented by a single layer of epithelium and a layer of connective tissue. The skin contains pigment cells called chromatophores. Cephalopods are characterized by the ability to quickly change color. This mechanism is controlled by the nervous system and is carried out by changing the shape


    Rice. 238. Rudiments of a shell in cephalopods (according to Natalie and Dogel): A - spirula (Spirula); 1 - funnel, 2 - mantle cavity, 3 - anus, 4 - excretory opening, 5 - luminous organ, 6 - fin, 7 - shell, 8 - siphon; B - Sepia shell; 1 - septa, 2 - lateral margin, 3 - siphon fossa, 4 - rostrum, 5 - rudiment of siphon, 6 - posterior margin of proostracum

    pigment cells. So, for example, cuttlefish, swimming over sandy ground, takes on a light color, and over rocky ground - dark. .At the same time, pigment cells with dark and light pigment in her skin alternately contract and expand. If you cut the optic nerves of a mollusk, then it loses its ability to change color. Due to the connective tissue of the skin, cartilage is formed: in cufflinks, the bases of the tentacles, around the brain.

    Protective devices. Cephalopods, having lost the shell in the process of evolution, acquired other protective devices. Firstly, fast movement saves many of them from predators. In addition, they can defend themselves with tentacles and a "beak", which is a modified jaw. Large squids and octopuses can fight with large marine animals, such as sperm whales. Sedentary and small forms have a protective coloration and the ability to quickly change color. And finally, some cephalopods, such as cuttlefish, have an ink sac, the duct of which opens into the hindgut. Spraying the ink liquid into the water causes a kind of smoke screen that allows the mollusk to hide from predators to a safe place. Cuttlefish ink gland pigment is used to make high-quality artistic ink.

    The internal structure of cephalopods

    Digestive system cephalopods bear the features of specialization in feeding on animal food (Fig. 239). They feed mainly on fish, crabs and bivalves. They seize prey with tentacles and kill with jaws and poison. Despite their large size, cephalopods can only eat liquid food, as they have a very narrow esophagus that passes through the brain, enclosed in a cartilaginous capsule. Cephalopods have adaptations for grinding food. To gnaw their prey, they use hard horny jaws, similar to the beak of a parrot. In the pharynx, food is rubbed by the radula and abundantly moistened with saliva. 1-2 pairs of ducts flow into the pharynx salivary glands, which secrete enzymes that break down proteins and polysaccharides. The second posterior pair of salivary glands secretes poison. Liquid food from the pharynx through the narrow esophagus enters the endodermal stomach, where the ducts of the steam liver flow, which produces a variety of digestive enzymes. The hepatic ducts are lined with small additional glands, the totality of which is called the pancreas. The enzymes of this gland act on polysaccharides,

    and hence this gland is functionally distinct from the mammalian pancreas. The stomach of cephalopods is usually with a blind saccular process, which increases its volume, which allows them to absorb a large portion of food. Like other predatory animals, they eat a lot and relatively rarely. The small midgut departs from the stomach, which then passes into the hind intestine, which opens with an anus into the mantle cavity. In many cephalopods, the duct of the ink gland flows into the hindgut, the secret of which has a protective value.

    Nervous system cephalopods is the most highly developed among molluscs. The nerve ganglia form a large peripharyngeal cluster - the brain (Fig. 240), enclosed in a cartilaginous capsule. There are additional ganglia. The composition of the brain primarily includes: a pair of large cerebral ganglia that innervate the head, and a pair of visceral ganglia that send nerve cords to the internal organs. On the sides of the cerebral ganglia are additional large optic ganglia that innervate the eyes. Long nerves depart from the visceral ganglia to two stellate mantle ganglia, which develop in cephalopods in connection with the function of the mantle in their jet mode of movement. The composition of the brain of cephalopods includes, in addition to cerebral and visceral pedal ganglia, which are subdivided into paired ganglia of tentacles (brachial) and funnels (infudibular). The primitive nervous system, similar to the ladder system of lateral nerves and monoplacophorans, is preserved only in Nautilus. It is represented by nerve cords forming a peripharyngeal ring without ganglia and a pedal arch. Nerve cords are covered with nerve cells. This structure of the nervous system indicates the ancient origin of cephalopods from primitive shell mollusks.

    sense organs cephalopods are well developed. Especially complex development they reach the eyes that are most important for orientation in space and hunting for prey. In Nautilus, the eyes have a simple structure in the form of a deep eye fossa (Fig. 241, A), while in other cephalopods, the eyes are complex - in the form of an eye bubble and resemble the structure of the eye in mammals. This interesting example convergence between invertebrates and vertebrates. Figure 241, B shows the eye of a cuttlefish. From above, the eyeball is covered with the cornea, in which there is an opening into the anterior chamber of the eye. The connection between the anterior cavity of the eye and external environment protects the eyes of cephalopods high pressure at great depths. The iris forms an opening - the pupil. Light through the pupil enters the spherical lens formed by the epithelial body - the upper shell of the eye bubble. The accommodation of the eye in cephalopods is different,


    Rice. 240. Nervous system of cephalopods: 1 - brain, 2 - optic ganglia, 3 - mantle ganglia, 4 - intestinal ganglion, 5 - nerve cords in tentacles

    than in mammals: not by changing the curvature of the lens, but by approaching or moving away from the retina (similar to focusing a camera). Special ciliary muscles approach the lens, setting it in motion. The cavity of the eyeball is filled with a vitreous body, which has a light-refracting function. The bottom of the eye is lined with visual - retinal and pigment - cells. This is the retina of the eye. A short optic nerve departs from it to the optic ganglion. The eyes, together with the optic ganglia, are surrounded by a cartilaginous capsule. Deep-sea cephalopods have luminous organs on their bodies, built according to the type of eyes.

    Organs of balance- Statocysts are located in the cartilaginous capsule of the brain. The organs of smell are represented by olfactory pits under the eyes or osphradia typical of mollusks at the base of the gills - in nautilus. The organs of taste are concentrated on the inner side of the ends of the tentacles. Octopuses, for example, use their tentacles to distinguish between edible and inedible objects. On the skin of cephalopods, there are many tactile and light-sensitive cells. In search of prey, they are guided by a combination of visual, tactile and taste sensations.

    Respiratory system represented by ctenidia. Most modern cephalopods have two, while the nautilus has four. They are located in the mantle cavity on the sides of the body. The flow of water in the mantle cavity, which ensures gas exchange, is determined by the rhythmic contraction of the muscles of the mantle and the function of the funnel through which water is pushed out. During the jet mode of movement, the flow of water in the mantle cavity accelerates, and the intensity of respiration increases.

    Circulatory system cephalopods almost closed (Fig. 242). In connection with active movement, they have well-developed coelom and blood vessels and, accordingly, parenchymality is poorly expressed. Unlike other mollusks, they do not suffer from hypokenia - poor mobility. The speed of blood movement in them is ensured by the work of a well-developed heart, consisting of a ventricle and two (or four - in Nautilus) atria, as well as pulsating sections of blood vessels. The heart is surrounded by a large pericardial cavity

    which performs many functions of the whole. From the ventricle of the heart depart the head aorta - forward and splanchnic aorta - back. The head aorta branches into arteries that supply blood to the head and tentacles. Vessels depart from the splanchnic aorta to the internal organs. Blood from the head and internal organs is collected in the vena cava, located longitudinally in the lower part of the body. The vena cava subdivides into two (or four in Nautilus) afferent gill vessels, which form contracting extensions - gill "hearts" that promote gill blood circulation. The afferent gill vessels lie close to the kidneys, forming small blind protrusions into the tissue of the kidneys, which contributes to the release of venous blood from metabolic products. In the gill capillaries, blood is oxidized, which then enters the efferent gill vessels, which flow into the atria. Partially, blood from the capillaries of veins and arteries flows into small gaps, and therefore the circulatory system of cephalopods should be considered almost closed. The blood of cephalopods contains a respiratory pigment - hemocyanin, which includes copper, therefore, when oxidized, the blood turns blue.

    excretory system represented by two or four (in Nautilus) kidneys. With their inner ends they open into the pericardial sac (pericardium), and with their outer ends into the mantle cavity. Excretion products enter the kidneys from the gill veins and from the extensive pericardial cavity. Additionally, the excretory function is performed by the pericardial glands formed by the wall of the pericardium.

    Reproductive system, reproduction and development. Cephalopods are dioecious animals. In some species, sexual dimorphism is well expressed, for example, in the argonaut (Argonauta). The female argonaut is larger than the male (Fig. 243) and during the breeding season she secretes a thin-walled parchment-like brood chamber around the body with the help of special glands on the tentacles for carrying eggs, similar to a spiral shell. The male argonaut is several times smaller than the female and has a special elongated sexual tentacle, which is filled during the breeding season with sexual products.

    Gonads and genital ducts unpaired. An exception is the nautilus, which has preserved paired ducts extending from the unpaired gonad. In males, the vas deferens passes into the spermatophore bag, where the spermatozoa stick together into special packages - spermatophores. In cuttlefish, the spermatophore is shaped like a checker; its cavity is filled with spermatozoa, and the outlet is closed with a complex plug. During the breeding season, the male cuttlefish, with the help of a sexual tentacle with a spoon-shaped end, transfers the spermatophore into the mantle cavity of the female.

    Cephalopods usually lay their eggs at the bottom. In some species, care for offspring is observed. So, the female argonaut bears eggs in the brood chamber, and the octopuses guard the clutch of eggs, which are placed in shelters made of stones or in caves. Development is direct, without metamorphosis. The eggs hatch into small, fully formed cephalopods.

    Modern cephalopods belong to two subclasses: the subclass Nautilida (Nautiloidea) and the subclass Coleoidea (Coleoidea). Extinct subclasses include: subclass Ammonites (Ammonoidea), subclass Bactrites (Bactritoidea) and subclass Belemnites (Belemnoidea).

    Subclass Nautilida (Nautiloidea)

    Modern nautilids include one order Nautilida. It is represented by only one genus Nautilus, to which only a few species belong. The distribution area of ​​​​Nautilus is limited to the tropical regions of the Indian and Pacific Oceans. Fossil nautilids number over 2,500 species. This is an ancient group of cephalopods known from the Cambrian.

    Nautilids have many primitive features: the presence of an external multi-chambered shell, an unfused funnel, numerous tentacles without suckers, and manifestation of metamerism (four ctenidia, four kidneys, four atria). The similarity of nautilids with lower shell molluscs is manifested in the structure of the nervous system from cords without isolated ganglia, as well as in the structure of coelomoducts.

    Nautilus is a benthopelagic cephalopod. It floats in the water column in a "reactive" way, pushing the water out of the funnel. The multi-chamber shell provides buoyancy of its body and lowering to the bottom. Nautilus has long been an object of fishing because of the beautiful mother-of-pearl shell. Nautilus shells have been used to make many fine jewelry pieces.

    Subclass Coleoidea (Coleoidea)

    Coleoidea is Latin for "hard". These are hard-skinned molluscs without a shell. Coleoidea is a thriving group of modern cephalopods, includes four orders, which include about 650 species.

    Common features of the subclass are: lack of a developed shell, fused funnel, tentacles with suckers.

    Unlike nautilids, they have only two ctenidia, two kidneys, and two atria. Coleoidea have high development nervous system and sense organs. The following three orders are characterized by the largest number of species.

    Squad Cuttlefish (Sepiida). The most characteristic representatives of the order are cuttlefish (Sepia) and spirula (Spirula) with rudiments of the inner shell. They have 10 tentacles, two of which are agility. These are nektobenthic animals, they stay at the bottom and are able to actively swim.

    Order Squid (Teuthida). This includes many commercial squids: Todarodes, Loligo, etc. Squids sometimes retain a rudiment

    shells in the form of a horny plate under the skin on the back. They have 10 tentacles, like the previous unit. These are mainly nektonic animals that actively swim in the water column and have a torpedo-shaped body (Fig. 244).

    Order Octopus (Octopoda). This is an evolutionarily advanced group of cephalopods without traces of a shell. They have eight tentacles. Sexual dimorphism is pronounced. Males develop a sexual tentacle - hectocotylus. This includes a variety of octopuses (Fig. 245). Most octopuses lead a benthic lifestyle. But among them there are nektonic and even planktonic forms. The Octopoda order includes the genus Argonauta - an argonaut, in which the female allocates a special brood chamber.

    The practical importance of cephalopods

    Cephalopods are food animals. The meat of cuttlefish, squid and octopus is used for food. The world catch of cephalopods currently reaches more than 1600 thousand tons. in year. Cuttlefish and some octopuses are also harvested for ink liquid, which is used to make natural ink and top quality inks.

    Paleontology and phylogeny of cephalopods

    The most ancient group of cephalopods is considered to be nautilids, whose fossil shells are already known from Cambrian deposits. Primitive nautilids had a low conical shell with only a few chambers and a wide siphon. Cephalopods are thought to have evolved from ancient, creeping shellfish with simple conical shells and flat soles like some fossil monoplacophorans. Apparently, a significant aromorphosis in the emergence of cephalopods consisted in the appearance of the first partitions and chambers in the shell, which marked the beginning of the development of their hydrostatic apparatus and determined the possibility of floating up, breaking away from the bottom. Apparently, the formation of a funnel and tentacles occurred in parallel. The shells of the ancient nautilids were varied in shape: long conical and flat spirally twisted with a different number of chambers. Among them there were also giants up to 4-5 m (Endoceras), which led a benthic lifestyle. Nautilids have undergone several periods of prosperity and extinction in the process of historical development and have survived to the present day, although they are now represented by only one genus of Nautilus.

    In the Devonian, in parallel with nautilids, a special group of cephalopods begins to occur - bactrites (Bactritoidea), smaller in size and less specialized than nautilids. It is assumed that this group of cephalopods descended from a common yet unknown ancestors with nautilids. Bactrites turned out to be evolutionarily promising group. They gave rise to two branches of cephalopod development: ammonites and belemnites.

    A subclass of ammonites (Ammonoidea) appeared in the Devonian and died out at the end of the Cretaceous. During their heyday, ammonites successfully competed with nautilids, whose numbers at that time were noticeably declining. It is difficult for us to judge the advantages of the internal organization of ammonites only from fossil shells. But the ammonite shell was more perfect,


    Rice. 246. Fossil cephalopods: A - ammonite, B - belemnite

    than nautilids: lighter and stronger. The partitions between the chambers in ammonites were not smooth, but wavy, and the lines of the partitions on the shell were zigzag, which increased the strength of the shell. Ammonite shells were spirally twisted. More often, whorls of ammonite shell spirals were located in the same plane, and less often they had the form of a turbospiral (Fig. 246, A). According to some imprints of the body of ammonite fossils, it can be assumed that they had up to 10 tentacles, perhaps there were two ctenidia, beak-shaped jaws, and an ink bag. This indicates that the ammonites apparently experienced oligomerization of metameric organs. According to paleontological data, ammonites were ecologically more diverse than nautilids, and included nektonic, benthic, and planktonic forms. Most ammonites were small, but there were also giants with a shell diameter of up to 2 m. Ammonites were one of the most numerous marine animals in the Mesozoic, and their fossil shells serve as guiding forms in geology for determining the age of the layers.

    Another branch of cephalopod evolution, hypothetically derived from bactrites, was represented by a subclass of belemnites (Belemnoidea). Belemnites appeared in the Triassic, flourished in the Cretaceous and died out at the beginning of the Cenozoic era. In their external appearance, they are already closer to the modern subclass Coleoidea. In body shape, they resemble modern squids (Fig. 246, B). However, belemnites differed significantly from them in the presence of a heavy shell, which was overgrown with a mantle. The shell of belemnites was conical, multi-chambered, covered with skin. Remains of shells and especially their terminal finger-like rostrums, which are figuratively called "devil's fingers", have been preserved in geological deposits. Belemnites were often very large: their length reached several meters. The extinction of ammonites and belemnites was probably due to increased competition with bony fish. And in the Cenozoic, the arena of life enters a new group cephalopods - coleoids (subclass Coleoidea), devoid of shells, with fast jet movement, with a complex nervous system and sensory organs. It was they who became the "primates" of the sea and could compete on equal terms as predators with fish. This group of cephalopods appeared

    in the Cretaceous, but reached its highest peak in the Cenozoic era. There is reason to believe that the Coleoidea have common origins with the Belemnites.

    Ecological radiation of cephalopods. The ecological radiation of cephalopods is shown in Figure 247. From primitive testate benthopelagic forms capable of surfacing thanks to the hydrostatic apparatus, several paths of ecological specialization have been determined. The most ancient ecological directions were associated with the radiation of nautilids and ammonites, which swam at different depths and formed specialized shell forms of benthopelagic cephalopods. From benthopelagic forms, there is a transition to bentonekton (such as belemnites). Their shell becomes internal, and its function of the swimming apparatus weakens. Instead, they develop the main mover - a funnel. Later they gave rise to shellless forms. The latter undergo intense ecological radiation, having formed nektobenthic, nektonic, benthic, and planktonic forms.

    The main representatives of the nekton are squids, but there are also fast-swimming octopuses and cuttlefish with a narrow torpedo-shaped body. The composition of the nektobenthos mainly includes cuttlefish, often swimming

    or lying on the bottom, to bentonekton - octopuses that crawl along the bottom more than swim. Plankton include umbellate, or gelatinous, octopuses, rod-shaped squids.

    The common sepia, or medicinal cuttlefish, is active at night. She preys on fish and small crustaceans. During the day, sepia changes its color and hides in the gorges of underwater rocks.

       Type - shellfish
       Class - cephalopods
       Row - Cuttlefish
       Genus/Species - Sepia officinalis

       Basic data:
    DIMENSIONS
    Body length: 30 cm
    Tentacle length: tentacles used for hunting can reach 50 cm.

    BREEDING
    Mating period: spring and summer.
    Number of eggs: about 300.

    LIFESTYLE
    Habits: keep in small flocks, which attracts different predators: dolphins, sharks and rays.
    Food: fish, shellfish.

    RELATED SPECIES
    About 100 species belong to the family of true cuttlefish. The size of these animals is from 1.8 to 150 cm. The cuttlefish belongs to the class of cephalopods, and its close relatives are nautilus and argonauts.

       Common sepia belongs to the class of cephalopods, that is, it is one of the most developed representatives of mollusks. Nature provided her with a flat body, movable tentacles, well-developed eyes and amazing abilities. Fleeing from danger, sepia can instantly change the color of the body and swim back.

    FOOD

       Sepia hunts at night. She catches fish and shellfish. Because sepia has fine developed vision, she freely covers the whole space with her eyes and easily notices the prey. Sepia moves slowly, with the help of a mantle, the undulating movements of which push it forward. While moving, the sepia's limbs point forward. When the prey is at the right distance, the sepia throws forward two long tentacles with clubs at the ends and snaps the victim with them.

    LIFESTYLE

       Normal sepia prefer shallow water, usually with a sandy bottom. During the day they lie at the bottom. With a change in the color of the pigment cells, the body acquires the color of the environment. Protective coloring perfectly masks the usual sepia. Often, sepia fins throw sand on their backs to become completely invisible for camouflage. At night the animals come out to hunt. Their internal calcareous shell (sepion) has a porous structure. The voids are filled with air, which reduces the mass of the animal.

    BREEDING

       Ordinary sepia are animals of different sexes. They breed in shallow coastal waters. During the mating season, males develop distinct purple and purple colors on their bodies. transverse stripes. When another sepia approaches a male, he raises his hectocotyl. This organ is adapted for the storage and transfer of sperm. If another sepia does not repeat the gesture of the male, then the individual that approached is a female. The male fertilizes her by placing spermatophores with the help of a hectocotyl into the female's seminal receptacles. After some time, the female lays about 300 eggs. Sepia masonry look like grape bosoms. The eggs hatch into small sepia.

    DEVICE FEATURES

       Sepia uses several amazing ways to trick the enemy or attract prey. During the hunt, sepia changes color and completely merges with environment. When several sepia hunt together, the animals move in concert and change color at the same time. Fleeing from the enemy, the sepia closes the hole in the mantle, contracts the strong muscles of the walls of the mantle and abruptly releases water from its body through a narrow funnel. This device, like a jet engine, pushes her forward. A sharp change in speed and direction of movement is possible due to a change in the angle of rotation of the funnel. It confuses the enemy. At the slightest danger, Sepia also uses ink, forming a veil that allows it to escape.
      

    DO YOU KNOW WHAT...

    • Sepia, when attacked, ejects ink at such a speed that within a few minutes it can color 20 cubic meters of water.
    • Wounded or weakened sepia are often washed ashore in waves. Why this happens is still unknown.
    • If a sepia loses one of its tentacles, a new one will soon grow in its place.
    • During the mating season, sepia females glow quite brightly. They have luminous organs.
    • People have been writing in sepia ink for hundreds of years. In addition, for many centuries they have been used to produce a brown paint, which is called sepia.
    • Sepia have a well developed nervous system and brain.
      

    CHARACTERISTIC FEATURES OF SEPIA

       Leather: contains hundreds of pigmented cells that stretch and contract. Thanks to these cells, cuttlefish can change color within a few seconds. Color change has great importance in disguise and during the mating season.
       Limbs: eight shorter arms-tentacles are organs of touch that provide information about the world around. They have 2-4 rows of suckers, with which the cuttlefish attaches to objects and holds food at the mouth opening. Two tentacles are used to catch prey. One of the male's arms (hectocotylus) is adapted to carry spermatophores (sperm containers).
       Mantle: surrounds the body on both sides, serves for swimming and changing the direction of movement.
       Sink, or sepion: this hard calcareous plate is like a shield covering the cuttlefish's body. Consists of several layers.

    PLACES OF ACCOMMODATION
    Common sepia lives in the Mediterranean Sea, it is also found in the northeastern part of the Atlantic Ocean, in the Baltic Sea and the English Channel.
    PRESERVATION
    Sepia has long been an object of fishing. For centuries, people have used her ink to write. In addition, highly valued taste qualities sepia meat. Today, the species is not threatened with extinction.