Sepia fish. The cuttlefish is an amazing jet-powered chameleon clam. The most famous species of cuttlefish are
Paula Weston
Surprisingly complex marine animals live in the waters of the world's oceans. But none of these animals can be compared in their complexity with cuttlefish.
green blood, three hearts and the ability to change the color of the skin... At first glance, you might think that we are talking about some kind of 'bizarre alien' or an animal from a science fiction movie. In fact, it is a seafood delicacy.
Surprisingly complex animals live in the waters of the world's oceans. But none of these animals can be compared in their complexity with cuttlefish. The sea cuttlefish has gained wide popularity because of its shell, which can often be found at the bottom of cages with budgerigars. However, cuttlefish is much more than just a source of calcium for caged birds.
In addition to being able to disguise its body in various environments, it can change the color of its cover, especially when it is in an agitated state. At the same time, the body of this mollusk seems to flash from yellow to red-orange and blue-green colors.
The cuttlefish eye, like the squid eye, has a structure very similar to the human eye. But evolutionists believe that these eyes evolved separately, and that their similarity is just a 'coincidence'.
This mollusk also has a complex system for pushing its body through the water, and also has amazing ability stay on the surface of the water (the buoyancy of the sea cuttlefish can be compared to the buoyancy of submarines). This mollusk also has a sharp ‘beak-shaped proboscis’, with which it cuts the body of its prey as if with scissors. And so he can successfully use his tentacles to 'cut' meat.
The Giant Australian is considered a favorite of divers, especially during the breeding season, when the usually shy underwater animals become friendly and sometimes chase divers through the water, often remaining calm even when petted or scratched.
Cuttlefish belongs to the class of mollusks Cephalopoda, which means 'cephalopods'. This mollusk got its name from two Greek words kephale (head) and podes (legs). It ranges in size from 2.4 centimeters (about one inch) to 90 centimeters (three feet) long (and even more like a species of giant Australian cuttlefish that can reach the size of a small human).
Blood and body of a sea cuttlefish
Unlike human blood, which contains red pigment, hemoglobin, blood cuttlefish blue-green in color, because it contains the pigment hemocyanin, which performs the function of transporting oxygen. The cuttlefish has three hearts - one heart each for a pair of gills and one heart for the rest of the body.
From the body of the cuttlefish extend eight processes in the form of hands, on which there are suction cups, and two grasping tentacles (which can be drawn into the bags located under the eyes). This mollusc mainly feeds on small fish, crustaceans and other mollusks. He hunts in daytime, catching small prey by sucking it up through the proboscis and pulling it out of the sand. Like the octopus, the cuttlefish produces an ‘ink substance’, only she has it Brown and is called sepia. Despite the existence of such protective agent, uses it as a means of protection as a last resort. It relies more on its ability to camouflage than on this protective ink to hunt prey and successfully escape from predators such as sharks and dolphins.
How does a sea cuttlefish change color?
Skin covering cuttlefish consists of three layers of chromatophores (coloring pigment cells) - a light yellow layer on the surface, under which there is an orange-yellow layer and, finally, a dark layer, located under two upper layers. The transition from one color to another, which occurs in less than a second, is regulated by the nervous system. Within just a few seconds, you can see how the body of this mollusk changes its color, using all the colors of the rainbow.
The cuttlefish propels its body through the water with a series of jerky movements, pulling water into a compression chamber that compresses to expel water from a channel under its head. The mollusk changes the direction of its body by turning the opening of this channel and narrowing the speed regulator located in it.
Like a submarine, the cuttlefish fills small chambers in its shell with air, which keeps it neutrally buoyant. This ability helps cephalopods to hover above the seabed, because, despite the possession complex system pushing through the water, their large carapace prevents them from being too active or fast in the water. It is hard to imagine how this type of mollusk, moving so slowly in water, could survive over millions of years of evolution before it had the ability to camouflage, which is very important for it. But evolutionists continue to believe that this is how it happened, although there is no evidence to show how these features came about.
The sea cuttlefish has human eyes.
Cuttlefish eyes are very similar in structure to human eyes, but evolutionists do not believe that this mollusk has any direct evolutionary relationship to humans (i.e. there is not a single possible common ancestor of cuttlefish and humans that would have those eyes). Therefore, this similarity is explained by evolutionists as 'convergent evolution': the eyes of cuttlefish and other cephalopods 'evolved separately and independently' from human eyes. In other words, it's just an evolutionary coincidence.
Staying neutralCuttlefish is a sea dweller. And very often she spends her time sitting in ambush and watching her prey. Due to this lifestyle, these mollusks must maintain neutral buoyancy so that they do not sink or float to the surface of the water. At first glance, it would be enough for the Creator to simply endow the cuttlefish with a stable absolute density so that its own body mass is exactly balanced by the pressure of the environment. water . However, if the depth changes, then the strength of the ‘lift’ out of the water also changes. Therefore, in order to swim at any depth and with varying water density, cuttlefish must be able to adjust their overall density in order to always remain ‘neutral’ in the water. This is achieved through a genetic mechanism. The bony shell actually has many narrow chambers. If they were all filled with gas, they would lift only 4% of the animal's body weight. However, they are only partially filled with gas. The cuttlefish can pump fluid in and out of these chambers to maintain "proper buoyancy." |
Links and notes
- "Dolphins have fun as seasonal tragedy unfolds below", Sydney Morning Herald, September 14, 1996.
- R. Moore, C. Laliker, and A. Fisher, Invertebrate Fossils, McGraw Hill, New York, 1952.
- Clarkson, Invertebrate Paleontology and Evolution, George Allen & Unwin, London (7th edition), 1984.
- Encyclopædia Britannica, (fifteenth edition), 24:322, 1992.
- Reference 1., chapter 8, ‘clams’.
Other sources:
‘Giant Australian cuttlefish’, Geo 9(1), March–May 1987, pp. 58–71. Encyclopædia Britannica, (fifteenth edition), 3:814, 1992.Source-www.answersingenesis.org
Cuttlefish have been known to people since time immemorial. You can even say that they have contributed to the development of human culture - for centuries, people wrote with cuttlefish ink. In addition, the name of brown paint in the language of artists - "sepia" owes its origin to cuttlefish, since this paint was also made from cuttlefish ink.
It should be noted that in Latin the detachment of cuttlefish is called Sepiida, a common cuttlefish - Sepia officinalis. In addition to ink, the supply of which is greater in cuttlefish than in other cephalopods, man used their tender and very tasty meat for food, and the "sepia bone" - the inner shell of the cuttlefish - has long been used in the household.
What kind of animal is this, where is it found and how is it arranged?
In scientific terms, a detachment of cuttlefish ( Sepiida) is included in the subclass of intraconchal cephalopods (Coleoidea), to which all (with the exception of nautiluses) modern cephalopods belong - octopuses, squids, vampyrophores. All these animals have an internal rudimentary shell - the remnant of the former luxurious shell of distant ancestors. The rudimentary shell appears to be a transitional element from the common mollusk shell to the animal spine.
What does a common cuttlefish look like?
This animal has a flattened body, trimmed on the sides with a narrow border of fins. Ten short tentacles (arms) of cuttlefish are armed with two to four rows of suckers. At rest or during movement, the cuttlefish retracts its tentacles into special pockets located on the head under the eyes. In this position, only the tips of the tentacles are visible.
But as soon as a gaping crab, shrimp or small fish is nearby, the cuttlefish instantly throws out its tentacles and sticks them to the victim.
Under the cover of the skin bag - the mantle covering the body of the cuttlefish, there is a shell - sepion, which is a hard calcareous plate consisting of several layers connected by partitions, which makes it similar to honeycombs. The chambers between the partitions are filled with gas. The shell serves not only as a shield covering the back of the cuttlefish, but also acts as a hydrostatic apparatus that increases the buoyancy of the cuttlefish.
Cuttlefish do not move as fast as their squid relatives, although they are armed with a jet funnel.
They usually swim with their fins, but they can also use jet propulsion. The fins can act separately, which gives the cuttlefish amazing maneuverability when moving - it can even move sideways. If the cuttlefish moves only in a jet way, then it presses its fins to its belly.
Often cuttlefish gather in small flocks, moving rhythmically and in concert, while simultaneously changing the color of the body. The sight is very mesmerizing.
The ways of hunting cuttlefish are also peculiar - they often lie on the bottom and, with wave-like movements of their fins, throw sand or silt over themselves and, having changed color to the background of the soil, completely become invisible to the eye. In this state, they lie in wait for prey.
But cuttlefish can hunt not only from ambush. Often they slowly swim above the bottom and wash away the sand with a jet from the funnel, in which small animals - shrimps, crustaceans and other living creatures - take shelter. Hungry cuttlefish can even chase prey, sometimes attacking their smaller relatives that are nearby.
At the slightest danger, the cuttlefish launches ink, arranging an "ink curtain" or making an "ink double".
Like all intrashell cephalopods, cuttlefish have a very developed nervous system that is not inferior in organization nervous system fish. 
The brain of cuttlefish is enclosed in a cartilaginous capsule and consists of lobes. Most The volume of the brain is made up of optical lobes, which process information from the organs of vision. Cuttlefish have a developed memory, they learn well, like octopuses. They solve some problems as well as rats.
Of all the sense organs, cephalopods (except nautiluses) have the most developed vision. Cuttlefish eyes only 10 times smaller size of the whole body.
Among the inhabitants of the seas, cuttlefish are the owners of one of the most keen eyes- up to 150 thousand light-sensitive receptors are located per 1 sq. mm of the retina (in most fish this figure does not exceed 50 thousand). Only in some species of squid the eyes are even sharper.
In addition, cuttlefish, like most cephalopods, have special extraocular photoreceptors that can also perceive light. These photoreceptors are located in the back region of cuttlefish. Their purpose is not fully understood.
But that's not all - like many mollusks, cuttlefish can perceive light with the help of numerous light-sensitive cells located on the skin. These cells control the body color change mechanism of the cuttlefish. Therefore, it is not surprising that vision plays a special role in the life of cuttlefish.
On the suckers of the tentacles (arms) of cuttlefish are tactile and taste receptors, with their help the animal can determine whether the "dish" matches its taste. Those. cuttlefish taste food with their hands, just like octopuses. In addition, the cuttlefish also has olfactory organs located on the head, below the eyes.
The organs of hearing in cuttlefish, like in all cephalopods, are poorly developed. It has only been established that they perceive low-frequency noises and sounds: the noise of ship propellers, the noise of rain, etc.
Cuttlefish are endowed with a very useful property change the color of his body as needed or on a whim. This property is inherent in many cephalopods, but cuttlefish are a real virtuoso in disguise.
The ability to change the color of the body is achieved due to the numerous elastic cells under the skin of the animal, filled with paint, like watercolor tubes. scientific name these amazing cells are chromatophores. At rest, they look like tiny balls, but when, with the help of spiral muscle fibers, they stretch, they take on the shape of a disk. Changing the size and shape of the chromatophore occurs very quickly - in 1-2 seconds. This changes the color of the body.
Cuttlefish chromatophores come in three colors - brown, red and yellow. The body of the cuttlefish can take on the rest of the colors of the spectrum with the help of special cells - irridiocysts, which lie under the chromatophores in a layer and are, in a way, prisms and mirrors that reflect and refract light and decompose it into various components of the spectrum.
Thanks to these amazing cells, the cuttlefish can change its body color as it pleases. In the art of disguise, no animal can compare with the cuttlefish, not even the octopus.
Just now she was striped like a zebra, sank down on the sand and instantly became sandy yellow, lies on the stones - her body repeats the pattern and shades of the ground.
Well, what are the sense organs that correct the change in the color of the body of the cuttlefish? Of course, first of all, vision. If a cuttlefish is deprived of sight, then its ability to "chameleon" will decrease sharply. But it will not completely lose the ability to change the color of the body, since extra-ocular photoreceptors, skin photoreceptors, and, oddly enough, receptors on the tentacles play a certain (insignificant) role in this process.
Cuttlefish reproduce sexually. At the same time, the male of one of the hands, called the hectocotylus, takes out the spermatophores packed in "packages" from the mantle cavity and transfers them to the female's seminal receptacle, where the egg is fertilized.
The clutches, similar to bunches of grapes, are laid by the female in shallow coastal waters, attaching them to underwater objects. Each testicle hangs on a long stem-stalk. The stalks of all the eggs are so carefully intertwined with each other that it seems that a person, with his dexterous fingers, could not do this job more accurately. The female cuttlefish performs this procedure with complex tentacle movements.
After spawning, cuttlefish, like octopuses, die, so they life cycle is only one to two years.
After some time, tiny mollusks hatch from the eggs, which already have a shell and an ink sac filled with ink.
Cuttlefish have long been an object of fishing, which is becoming more intense every year. Currently, several hundred thousand tons of them are mined annually.
Used by man and ink liquid, and tender meat, and even internal organs, going to the preparation of medical and perfumery preparations.
There are cuttlefish in the shallow zone of most tropical and subtropical seas in Europe, Asia, Africa, Australia and Oceania. Numerous in the Mediterranean. There are more than 100 species of them, and almost every year new, previously unknown species are discovered. An interesting detail - in the waters of the seas North America cuttlefish are not found, and cuttlefish shells that come across on the beaches and shores are brought from afar by currents and thrown out by waves onto land.
The largest known cuttlefish is considered wide-arm sepia
(Sepia latimanus), inhabiting the warm waters of the western part Pacific Ocean. The length of her mantle reaches 60 cm, and the total body length is up to 1.5 meters with a weight of about 10 kg.
A little smaller sepia pharaoh
(S. pharaonis) - one of the most numerous cuttlefish of the northern part indian ocean. The length of the mantle of this mollusk can reach 40 cm with a body weight of up to 5 kg.
There are also dwarfs among cuttlefish, for example South African cuttlefish
S. robsonis and S.faurei the body length of which does not exceed 2 cm. Despite the difference in size, outwardly cuttlefish are very difficult to distinguish, since they have a typical appearance and habits.
However, in the seas off Australia, Japan and South Africa many cuttlefish of various bizarre forms. Some of them are equipped with wide leathery rims and ears, some have long flagellated tentacles.
An unusual view of the South African cuttlefish S.confusa. The fins of these sepia fuse behind and form a long soft tail, which trails behind the swimming animal in a train.
In addition to the so-called real cuttlefish, the Sepiida order includes three more families: sepiolids ( Sepiolidae), sepiadriids ( Sepiadriidae) and idiosepiids ( Idiosepiidae), which differ from ordinary cuttlefish in a number of ways. First of all, representatives of these families do not have a calcareous shell. Only a few species (Rossia) instead have a small chitinous feather, like squids, but most do not have skeletal formations at all. These small animals, a few centimeters long, with a short rounded body, large head and bulging semicircular fins, are very similar to the ears of elephants. They live in tropical and subtropical seas of all oceans.
Some species (Rossia) are also found in temperate waters, even in the Laptev Sea. They prefer shallow depths, keeping mainly near the bottom.
At present, the genus Spirula is also included in the sepia order ( Spirula) belonging to the family Spiralidae. The difference between spirules and other sepia lies in the presence of a spirally twisted inner shell, divided by internal partitions into 25-40 sections, through which a siphon passes, filled with gas and serving as a hydrostatic apparatus for the mollusk. 
The shell is located at the back of the body of the spirula, so the mollusc swims upside down. Spirula live at considerable depths (more than 100 meters), so they are almost never found by divers. However, the shells of these mollusks are often washed ashore by currents and waves. Florida beaches are sometimes littered with thousands of spinula shells.
And here are some Interesting Facts relating to the lifestyle of cuttlefish.
Scientists consider the cuttlefish to be one of the most intelligent marine animals. The ratio of the weight of her brain to body weight, of course, does not reach the level marine mammals, but significantly exceeds this figure in fish and other molluscs.
A curious fact has recently been established, testifying to a kind of vindictiveness of cuttlefish. Attacked as a child a certain kind predator cuttlefish, in more adulthood prefers to hunt these predators. As they say - do not offend the little ones!
For divers, meeting with cuttlefish under water does not threaten anything - they are harmless animals. However, potentially, the cuttlefish can bite the annoying "admirer" with chitinous jaws, and the bite can be quite sensitive. But this is only theoretical. So, if you meet a cuttlefish underwater, you can safely admire this wonderful animal.
ArticlesWho is a sea cuttlefish? Hearing this question, an image of some formless and incomprehensible animal immediately appears before my eyes. Although perhaps knowledgeable people they wouldn’t talk like that about cuttlefish, because these animals can be incredibly beautiful, but they can’t be called shapeless at all. Cuttlefish belong to the class of cephalopods.
Appearance of cuttlefish
The body of the animal is elongated-oval and slightly flattened. The mantle forms the bulk of the body. The role of the skeleton is performed by the inner shell - and this is a feature that is unique to cuttlefish. The head and body are fused. The eyes are complex, they are located on the head of the mollusk. Even on the head of the cuttlefish there is something like a beak, this natural “adaptation” helps the mollusk a lot in obtaining food. Like many cephalopods, the cuttlefish has an ink sac.
Broad-armed cuttlefish, or broad-armed sepia (Sepia latimanus) - the most large view these animals The mollusk has eight legs called tentacles. And each such tentacle is literally dotted with small suckers. On both sides of the body are fins, with the help of which the animal makes swimming movements.
The size of the body of the animal is relatively small for representatives of the class of cephalopods. The average adult cuttlefish reaches a length of about 20 centimeters. There are larger cuttlefish, but these are only representatives of individual species.
A notable feature of these mollusks is the ability to change the color of their body. Just like a chameleon! This process in cuttlefish is possible due to chromatophore cells located on the skin.
Most famous species cuttlefish are:
- common cuttlefish;
- Wide-armed cuttlefish (this is the largest of all cuttlefish: its length is about 1.5 meters, and its weight is up to 10 kilograms);
- Painted cuttlefish (the most attractive among these molluscs, but poisonous);
- Striped cuttlefish (nicknamed "pajama cuttlefish", also very poisonous);
- Pharaoh cuttlefish.
Habitat of cuttlefish
The habitats of these mollusks are located in tropical and subtropical zones the seas washing the shores of Africa and Eurasia (parts of the so-called "Old World"). However, striped cuttlefish have even been found off the coast of Australia.
Lifestyle and behavior
Cuttlefish are solitary mollusks. And only in mating season they can be seen in groups. Occasionally, these animals are ready to migrate somewhere, but the majority live in one place all their lives.
These clams are very cautious. They are very easy to scare. Usually behave calmly, prefer unhurried movement under water. The depth of residence is small - these animals always try to adhere to the coastline.
Scientists believe that cuttlefish are one of the most intelligent representatives of invertebrates.
What does cuttlefish eat
Everything that is smaller than it in size and lives in the water falls on the "dining table" to the cuttlefish. The main food for these unusual animals are fish, crabs, shrimps, worms, and other shellfish.
Reproduction of cuttlefish
As for the breeding of offspring, cuttlefish have their own unique feature here: they breed only once in their entire life, after which they themselves die.
The mating season is very interesting. Individuals gather in whole flocks and choose their partners. After the choice has been made, the marriage game. Males and females shimmer with all the colors of the rainbow, thus showing their mood and relationship with their partner. Males gently stroke their "bride" with tentacles, seeking her location.
Striped cuttlefish (Sepioloidea lineolata) - another deadly poisonous species. It lives in the waters of Australia, for a specific color in English language also known as pajamas With the help of the tentacles of the male, male germ cells enter the body of the female. After some time, eggs are laid (then the moment of fertilization also occurs). Egg clutches are attached to underwater plants and are often black in color. After spawning is over, adult cuttlefish die.
Mollusks have been known to mankind since time immemorial, but many people still associate them with formless substances. What does a cuttlefish really look like, where does it live and what does it eat?
Appearance
The cuttlefish is a member of the cephalopod order, which includes squid and octopuses. The structure of her body is oval, slightly flattened. The main part is the mantle, which is a bag of muscles and skin.
The role of the skeleton is performed by a wide calcareous shell. It is located inside the body of the cephalopod and protects the vital organs from damage. The plates in the shell have cavities, due to which the weight of the mollusks decreases, they swim freely. The shape of the fins is fused - it seems that the body is bordered by one continuous fin.
Males and females of sea cuttlefish in the pictures look almost the same - they are distinguished by patterns on the body, and even then not always. Males use the ability of the skin to change color and disguise themselves as representatives of the opposite sex.
The eyes of cephalopods are large and slit-like. Under them are special pockets in which trapping tentacles are hidden. Representatives sea world they are released only during the attack, and the prey is crushed by a beak hidden between the tentacles. At rest, the beak is not visible.
The cuttlefish has 10 legs - 2 long traps with suckers at the ends and 8 short ones. On short tentacles, suckers are arranged in 4 rows.
Ink
Ink bag - special body. It produces ink in greatly more than other members of the order of cephalopods. Structurally, it looks like a capsule divided into two compartments. In one compartment there are cells filled with grains from dyes. Mature cells burst - ink flows out and accumulates in the second chamber. An empty bag needs 30-40 minutes to recover.
Invertebrate ink is valued not only in cooking - it is used as the basis for expensive sepia paint. Sepia written many masterpieces of past centuries.
Individuals are afraid of rustles, people, movements. Over time, they get used to the person, show curiosity, swimming closer and looking at him. But when frightened, they release ink into the water - this is one of the reasons for the problematic maintenance of mollusks in home aquariums. Colored water becomes opaque, dark.
Dimensions
Against the background of the rest of the class, they seem small:
- The usual size is 20-30 cm.
- The smallest - 2 cm, a world record among molluscs.
- The largest measured cuttlefish is 1.5 m. Its weight reaches 10 kg.
Coloring
It is immediately difficult to determine what color a cuttlefish is - it, like octopuses, changes it. In the skin of invertebrates there are special cells - chromatophores. They are filled with multi-colored pigment.
The brain controls these cells by sending them signals. Smart individuals change shades instantly - it seems that the process occurs automatically. In fact, tentacled chameleons do this deliberately - for camouflage, before an attack, during the breeding season.
Environment and habitat features
The habitat of invertebrates is shallow water in the tropics and subtropics off the coast of Eurasia and Africa. They dive shallowly, trying to move along the coast. The detachments live in one place, but sometimes migrate - a few years ago, scientists discovered a striped individual off the coast of Australia.
At the sight of prey, cuttlefish freeze for a moment, and then abruptly and with lightning speed pounce on the victim.
Representatives of this class are promiscuous in food - they eat fish, shrimp, other marine life which are smaller than them. Their weaker relative can become a victim.
reproduction
The average lifespan of a cuttlefish is up to 2 years. During this time they reproduce once. During the mating season, the molluscs are removed from their place in search of a comfortable place for laying eggs. As soon as the female lays them, she dies.
Eggs will hatch into well-formed fry with ink and a developed instinct for self-preservation. Sensing danger, they, like adult males, lie down on the bottom and try to cover themselves with sand.
