Sepia fish. The cuttlefish is an amazing jet-powered chameleon mollusk. The most famous species of cuttlefish are
Paula Weston
The waters of the world's oceans are home to amazingly complex marine animals. But none of these animals compares in complexity to the 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 film. In fact, it is a seafood delicacy.
The waters of the world's oceans are home to amazingly complex animals. But none of these animals compares in complexity to the cuttlefish. The sea cuttlefish has become widely known because of its shell, which can often be found at the bottom of cages with budgies. However, cuttlefish are much more than just a source of calcium for caged birds.
In addition to the ability to camouflage its body in various environmental conditions, it can change the color of its cover, especially when it is in an excited 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 simply 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 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 therefore, 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 in the water, often remaining calm even when scratched or petted.
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). Its sizes range from 2.4 centimeters (about one inch) to 90 centimeters (three feet) in length (and even larger, such as a species of giant Australian cuttlefish that can reach the size of a small person).
Blood and body of sea cuttlefish
Unlike human blood, which contains red pigment, hemoglobin, blood cuttlefish blue-green color because it contains the pigment hemocyanin, which carries out the function of oxygen transport. The cuttlefish has three hearts - one heart for a pair of gills and one heart for the rest of the body.
From the body of the cuttlefish extend eight arm-shaped processes on which there are suction cups, and two grasping tentacles (which can be retracted into the pouches located under the eyes). This mollusk mainly feeds on small fish, crustaceans and other molluscs. He hunts in daytime, catching small prey by sucking it through the proboscis and pulling it out of the sand. Like the octopus, the cuttlefish produces an 'ink substance', only it has it Brown and is called sepia. Despite the presence of such protective agent, uses it as a last resort method of protection. To hunt for prey and to successfully escape from predators such as sharks and dolphins, it relies more on its ability to camouflage rather than on these protective inks.
How do 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 top 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 pushes its body through the water through a series of sharp movements, drawing water into a compression chamber that contracts to expel the water from a channel located 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 maintains its neutral buoyancy. This ability helps cephalopods hover above the seabed, since, despite possessing complex system pushing through the water, their large shell prevents them from being too active or fast in the water. It is difficult to imagine how this type of mollusk, moving so slowly in the water, was able to survive for millions of years of evolution before it acquired the very important ability to camouflage itself. But evolutionists continue to believe that this is how it happened, even though there is no evidence to show how these features came about.
The sea cuttlefish has eyes like a human.
The cuttlefish's 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 no possible common ancestor of cuttlefish and humans that would have such 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.
Remaining NeutralCuttlefish is an inhabitant of the seabed. And very often she spends her time sitting in ambush and watching her prey. Thanks to this lifestyle, these mollusks must maintain neutral buoyancy so that they neither sink nor 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 would be exactly balanced by the pressure of the surrounding water . However, if the depth changes, then the force of ‘lifting’ from the water also changes. Therefore, in order to swim at any depth and in varying water densities, the cuttlefish must have the ability to adjust its overall density in order to always remain 'neutral' in the water. This is achieved using the genetic mechanism. The bony shell actually has many narrow chambers. If they were all filled with gas, they would provide lifting of only 4% of the animal's body weight. However, they are only partially filled with gas. The cuttlefish can pump liquid in and out of these chambers to maintain the “necessary 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.
- Encyclopedia Britannica, (fifteenth edition), 24:322, 1992.
- Reference 1., chapter 8, ‘shellfish’.
Other sources:
‘Australian giant cuttlefish’, Geo 9(1), March–May 1987, pp. 58–71. Encyclopedia Britannica, (fifteenth edition), 3:814, 1992.Source-www.answersingenesis.org
Cuttlefish have been known to people since time immemorial. You could even say that they 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 order of cuttlefish is called Sepiida, A common cuttlefish - Sepia officinalis. In addition to ink, the supply of which cuttlefish have more than other cephalopods, people used their tender and very tasty meat as food, and for a long time the farm used the “sepia bone” - the internal shell of the cuttlefish.
What kind of animal is this, where is it found and how does it work?
In scientific terms, the order of cuttlefish ( Sepiida) is included in the subclass of intrashell cephalopods (Coleoidea), to which all (with the exception of nautiluses) modern cephalopods belong - octopuses, squids, vampirophores. All these animals have an internal rudimentary shell - a remnant of the former luxurious shell of distant ancestors. The vestigial shell appears to be a transitional element from the ordinary shell of molluscs to the backbone of animals.
What does a common cuttlefish look like?
This animal has a flattened body, trimmed on the sides by a narrow border of fins. The cuttlefish's ten short tentacles (arms) 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 gets close, the cuttlefish instantly throws out its tentacles and sticks them to the victim.
Under the cover of the skin sac - the mantle that covers the body of the cuttlefish, there is a shell - sepion, which is a hard calcareous plate consisting of several layers connected by partitions, which gives it a similarity to a honeycomb. The chambers between the partitions are filled with gas. The shell not only serves as a shield covering the back of the cuttlefish, but also serves 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 using fins, but 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 reactive manner, then it presses its fins to its belly.
Often cuttlefish gather in small schools, moving rhythmically and in concert, while simultaneously changing body color. The spectacle is very mesmerizing.
The hunting methods of cuttlefish are also unique - they often lie on the bottom and, with wave-like movements of their fins, throw sand or silt over themselves and, changing color to the background of the ground, become completely 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 with a stream from the funnel they wash away the sand in which small animals hide - shrimp, crustaceans and other living creatures. Hungry cuttlefish can even chase prey, sometimes attacking their smaller relatives nearby.
At the slightest danger, the cuttlefish uses ink, creating an “ink curtain” or making an “ink double”.
Like all intrashell cephalopods, cuttlefish have a very developed nervous system, 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 consists of the optical lobes, which process information from the organs of vision. Cuttlefish have a developed memory and are good learners, just like octopuses. They solve some problems as successfully as rats.
Of all the sense organs in cephalopods (except nautiluses), vision is the most developed. The eyes of a cuttlefish are only 10 times larger smaller size of the whole body.
Among the inhabitants of the seas, cuttlefish have one of the most keen eyes- per 1 square mm of the retina there are up to 150 thousand light-sensitive receptors (in most fish this figure does not exceed 50 thousand). Only some species of squid have even sharper eyes.
In addition, cuttlefish, like most cephalopods, have special extraocular photoreceptors that can also perceive light. These photoreceptors are located in the dorsal region of cuttlefish. Their purpose is not fully understood.
But that's not all - like many mollusks, cuttlefish can perceive light using numerous light-sensitive cells located on the skin. These cells control the mechanism for changing the body color of cuttlefish. Therefore, it is not surprising that vision plays a special role in the life of cuttlefish.
Tactile and taste receptors are located on the suckers of the tentacles (arms) of cuttlefish; 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 hearing organs of cuttlefish, like all cephalopods, are poorly developed. It has only been established that they perceive low-frequency noises and sounds: the noise of ship propellers, the sound of rain, etc.
Cuttlefish are very endowed useful property change the color of your body as needed or on a whim. This property is inherent in many cephalopods, but cuttlefish are a real virtuoso in the matter of camouflage.
The ability to change body color is achieved through numerous elastic cells under the animal's skin, 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. The change in size and shape of chromatophores occurs very quickly - in 1-2 seconds. At the same time, the color of the body changes.
Cuttlefish chromatophores come in three colors - brown, red and yellow. The body of the cuttlefish can receive the rest of the colors of the spectrum with the help of special cells - irridiocysts, which lie in a layer under the chromatophores 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 the color of its body as it pleases. In terms of the art of camouflage, no animal can compare with the cuttlefish, not even the octopus.
One minute she was striped like a zebra, she sank onto the sand and instantly became sandy yellow, lying on the stones - her body repeats the pattern and shades of the ground.
Well, what sense organs correct the change in body color of the cuttlefish? Of course, first of all, vision. If a cuttlefish is deprived of its vision, its ability to “chameleon” will sharply decrease. But it will not completely lose the ability to change body color, since extraocular photoreceptors, skin photoreceptors, and, oddly enough, receptors on the tentacles play some (minor) role in this process.
Cuttlefish reproduce sexually. In this case, the male of one of the arms, called the hectocotylus, takes out the sexual products packaged in “packages” - spermatophores - from the mantle cavity and transfers them to the sperm receptacle of the female, where fertilization of the egg occurs.
The female lays clutches similar to bunches of grapes in shallow coastal waters, attaching them to underwater objects. Each egg hangs on a long stalk. The stems of all the eggs are so carefully intertwined with each other that it seems that even a person with his dexterous fingers could not do this work more accurately. The female cuttlefish performs this procedure using complex movements with its tentacles.
After spawning, cuttlefish, like octopuses, die, so they life cycle is only one to two years.
After some time, the eggs hatch into tiny mollusks, which already have a shell and an ink sac filled with ink.
Cuttlefish have long been the object of fishing, which is becoming more intense every year. Currently, several hundred thousand tons of them are mined annually.
Humans use ink liquid, tender meat, and even internal organs used for the preparation of medical and perfumery preparations.
Cuttlefish are found in the shallow water zone of most tropical and subtropical seas of Europe, Asia, Africa, Australia and Oceania. Numerous in the Mediterranean Sea. There are more than 100 species, and new, previously unknown species are discovered almost every year. An interesting detail - in the waters of the seas North America cuttlefish are not found, and cuttlefish shells found on beaches and shores are brought from afar by currents and thrown onto land by waves.
The largest known cuttlefish is considered to be wide sepia
(Sepia latimanus), living in the warm waters of the western part Pacific Ocean. The length of its mantle reaches 60 cm, and the total length of the body is up to 1.5 meters with a weight of about 10 kg.
A little smaller Pharaoh sepia
(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 whose body length does not exceed 2 cm. Despite the difference in size, cuttlefish are very difficult to distinguish externally, since they have a typical appearance and habits.
However, in the seas off Australia, Japan and South Africa There are quite a few cuttlefish of various bizarre shapes. Some of them have limbs equipped with wide leathery rims and ears, some have long, whip-like tentacle arms.
The South African cuttlefish S.confusa has an unusual appearance. The fins of these sepia grow together at the back and form a long soft tail, which trails like a train behind the swimming animal.
In addition to the so-called true cuttlefish, the order Sepiida includes three more families: sepiolidae ( Sepiolidae), sepiadriids ( Sepiadriidae) and idiosepiids ( Idiosepiidae), which differ from ordinary cuttlefish in a number of features. First of all, representatives of these families do not have a calcareous shell. Only some species (Russia) have a small chitinous feather instead, like squids, but most have no skeletal formations at all. These small animals, several centimeters long, with a short rounded body, large head and convex semicircular fins, are very similar to the ears of elephants. They live in tropical and subtropical seas of all oceans.
Some species (Russia) are also found in temperate waters, even found in the Laptev Sea. They prefer shallow depths and stay mainly near the bottom.
Currently, the genus Spirula is also included in the Sepia order ( Spirula), belonging to the family Spirulidae. The difference between spirula 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 spirula's body, so the mollusk swims upside down. Spirula live at considerable depths (more than 100 meters), so they are almost never encountered by divers. However, the shells of these mollusks are often carried ashore by currents and waves. Florida beaches are sometimes littered with thousands of spinula shells.
Here are some Interesting Facts concerning the lifestyle of cuttlefish.
Scientists consider cuttlefish one of the most intelligent sea animals. Her brain to body weight ratio is certainly not up to par. marine mammals, but significantly exceeds this figure in fish and other mollusks.
An interesting fact has recently been established that indicates a kind of vindictiveness of cuttlefish. Attacked as a child a certain type predator cuttlefish, more mature age prefers to hunt precisely these predators. As they say - do not offend the little ones!
There is no danger for divers to encounter cuttlefish underwater - they are harmless animals. However, the cuttlefish could potentially bite the annoying “fan” with its chitinous jaws, and the bite could be quite sensitive. But this is only theoretical. So, if you meet a cuttlefish underwater, you can calmly admire this wonderful animal.
ArticlesWhat is a sea cuttlefish? Hearing this question, an image of some shapeless and incomprehensible animal immediately appears before your eyes. Although, perhaps knowledgeable people We wouldn’t talk about cuttlefish like that, 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 main part of the body is formed by the mantle. The role of the skeleton is played by the internal shell - and this is a feature inherent only to cuttlefish. The head and body are fused. The eyes are complex and are located on the head of the mollusk. There is also something like a beak on the cuttlefish’s head; this natural “device” greatly helps the mollusk in obtaining food. Like many cephalopods, the cuttlefish has an ink sac.
The broad-armed cuttlefish, or broad-armed sepia (Sepia latimanus) is the most close-up view these animals The mollusk has eight legs called tentacles. And each such tentacle is literally studded with small suckers. There are fins on both sides of the body, with the help of which the animal makes swimming movements.
The animal's body size is relatively small for representatives of the cephalopod class. The average adult cuttlefish reaches a length of about 20 centimeters. There are larger cuttlefish, but these are only representatives of certain 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 thanks to chromatophore cells located on the skin.
Most known species cuttlefish are:
- Common cuttlefish;
- Broad-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 mollusks, but poisonous);
- Striped cuttlefish (nicknamed the “pajama cuttlefish”, also very poisonous);
- Pharaoh cuttlefish.
Habitat of cuttlefish
The habitats of these mollusks are located in tropical and subtropical zones seas washing the shores of Africa and Eurasia (part of the so-called “Old World”). However, the striped cuttlefish was found even 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 mollusks are very careful. They are quite easy to scare. They usually behave calmly and prefer leisurely movements underwater. The depth of residence is shallow - these animals always try to stick to the coastline.
Scientists believe that cuttlefish are one of the most intelligent representatives of invertebrate animals.
What does cuttlefish eat?
Everything that is smaller in size and lives in water ends up on the cuttlefish’s “dining table.” The main food for these unusual animals are fish, crabs, shrimp, worms, and other shellfish.
Reproduction of cuttlefish
As for breeding offspring, cuttlefish have their own unique feature: they reproduce only once in their entire lives, after which they themselves die.
The mating season is very interesting. Individuals gather in entire flocks and choose their partners. Once the choice is made, it begins mating game. Males and females shimmer with all the colors of the rainbow, thus showing their mood and relationship to their partner. Male individuals gently stroke their “bride” with tentacles, seeking her favor.
Striped cuttlefish (Sepioloidea lineolata) - another deadly one poisonous species. It lives in the waters of Australia, due to its specific coloring English language it is also called pajama With the help of the male's tentacles, male reproductive cells enter the female's body. After some time, eggs are laid (the moment of fertilization also occurs). Egg clutches are attached to underwater plants and are often black in color. Once the spawning is over, the adult cuttlefish die.
Mollusks have been known to mankind since time immemorial, but many people still associate them with formless substances. What does cuttlefish really look like, where does it live and what does it eat?
Appearance
The cuttlefish is a member of the order Cephalopods, which includes squids and octopuses. Her body structure is oval, slightly flattened. The main part is the mantle, which is a bag of muscles and skin.
The role of the skeleton is played by a wide calcareous shell. It is located inside the cephalopod's body and protects vital organs from damage. The plates in the shell have cavities, due to which the weight of the mollusks is reduced and they float freely. The shape of the fins is fused - it seems that the body is bordered by one continuous fin.
Males and female sea cuttlefish look almost the same in pictures - they are distinguished by patterns on their bodies, and even then not always. Males take advantage of the ability of their skin to change color and disguise themselves as representatives of the other sex.
The eyes of cephalopods are large and slit-like. Under them there are special pockets in which hunting tentacles are hidden. Representatives sea world They release them only during an attack, and crush the prey with a beak hidden between the tentacles. At rest, the beak is not visible.
The cuttlefish has 10 legs - 2 long hunting legs with suction cups at the ends and 8 short ones. On short tentacles, the suckers are arranged in 4 rows.
Ink
Ink bag – special body. It produces ink in significantly more than other representatives of the cephalopod order. Structurally, it looks like a capsule divided into two compartments. One compartment contains cells filled with dye grains. 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. Many masterpieces of past centuries were written in sepia.
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 keeping of mollusks in home aquariums. Colored water becomes opaque and dark.
Dimensions
Compared to the rest of the class, they seem small:
- The usual size is 20-30 cm.
- The smallest is 2 cm, a world record among mollusks.
- The largest measured cuttlefish is 1.5 m. Its weight reaches 10 kg.
Coloring
It is difficult to immediately determine what color a cuttlefish is - it, like octopuses, changes it. The skin of invertebrates contains special cells called 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, chameleons with tentacles 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 and try to move along the coast. The orders live in one place, but sometimes migrate - several years ago, scientists discovered a striped individual off the coast of Australia.
When they see their prey, cuttlefish freeze for a moment, and then suddenly and with lightning speed they attack the victim.
Representatives of this class are indiscriminate in food - they eat fish, shrimp, and other sea creatures, which are smaller in size. Their weaker relative may become the victim.
Reproduction
The average lifespan of a cuttlefish is up to 2 years. During this time they reproduce once. During the mating season, mollusks move from their place in search of a comfortable place to lay eggs. As soon as the female lays them, she dies.
The eggs will hatch into formed fry with ink and a developed instinct of self-preservation. Sensing danger, they, like adult males, will lie down on the bottom and try to cover themselves with sand.
