Fauna of the ocean and sea depths. Underwater world: inhabitants of the seas and oceans. Flora of the oceans and seas

Yesterday, September 26, was World Maritime Day. In this regard, we bring to your attention a selection of the most unusual sea creatures.

World Maritime Day has been celebrated since 1978 on one of the days of the last week of September. This international holiday was created in order to draw public attention to the problems of sea pollution and the extinction of animal species living in them. Indeed, over the past 100 years, according to the UN, some types of fish, including cod and tuna, have been caught by 90%, and every year about 21 million barrels of oil enter the seas and oceans.

All this causes irreparable damage to the seas and oceans and can lead to the death of their inhabitants. These include those that we will talk about in our selection.

1. Dumbo the Octopus

This animal received its name due to the ear-like structures protruding from the top of its head, which resemble the ears of Disney's baby elephant Dumbo. However, the scientific name of this animal is Grimpoteuthis. These cute creatures live at depths of 3,000 to 4,000 meters and are one of the rarest octopuses.

The largest individuals of this genus were 1.8 meters in length and weighed about 6 kg. Most of the time, these octopuses swim above the seabed in search of food - polychaete worms and various crustaceans. By the way, unlike other octopuses, these swallow their prey whole.

2. Short-snouted pipistrelle

This fish attracts attention, first of all, with its unusual appearance, namely with bright red lips on the front of the body. As previously thought, they are necessary to attract marine life, which the pipistrelle bat feeds on. However, it was soon discovered that this function is performed by a small formation on the fish’s head, called the esca. It emits a specific odor that attracts worms, crustaceans and small fish.

The unusual “image” of the pipistrelle bat is complemented by an equally amazing way of moving in water. Being a poor swimmer, it walks along the bottom on its pectoral fins.

The short-snouted pipistrelle is a deep-sea fish and lives in the waters near the Galapagos Islands.

3. Branched brittle stars

These deep-sea marine animals have many branched arms. Moreover, each of the rays can be 4-5 times larger than the body of these brittle stars. With their help, the animal catches zooplankton and other food. Like other echinoderms, branched brittle stars lack blood, and gas exchange is carried out using a special water-vascular system.

Typically, branched brittle stars weigh about 5 kg, their rays can reach 70 cm in length (in the branched brittle stars Gorgonocephalus stimpsoni), and their body is 14 cm in diameter.

4. Harlequin pipe snout

This is one of the least studied species that can, if necessary, merge with the bottom or imitate a branch of algae.

It is near the thickets of the underwater forest at a depth of 2 to 12 meters that these creatures try to stay so that in a dangerous situation they can acquire the color of the soil or the nearest plant. During “quiet” times for harlequins, they slowly swim upside down in search of food.

Looking at a photograph of a harlequin tubesnout, it is easy to guess that they are related to seahorses and pipefish. However, they differ noticeably in appearance: for example, the harlequin has longer fins. By the way, this shape of fins helps the ghost fish bear offspring. With the help of elongated pelvic fins, covered on the inside with thread-like outgrowths, the female harlequin forms a special pouch in which she bears eggs.

5. Yeti Crab

In 2005, an expedition exploring the Pacific Ocean discovered extremely unusual crabs that were covered in “fur” at a depth of 2,400 meters. Because of this feature (as well as their coloring), they were called “Yeti crabs” (Kiwa hirsuta).

However, it was not fur in the literal sense of the word, but long feathery bristles covering the chest and limbs of crustaceans. According to scientists, many filamentous bacteria live in the bristles. These bacteria purify water from toxic substances emitted by hydrothermal vents, near which “Yeti crabs” live. There is also an assumption that these same bacteria serve as food for crabs.

6. Australian coneberry

This species lives in the coastal waters of the Australian states of Queensland, New South Wales and Western Australia and is found on reefs and bays. Due to its small fins and hard scales, it swims extremely slowly.

Being a nocturnal species, the Australian conefish spends the day in caves and under rocky outcroppings. Thus, in one marine reserve in New South Wales, a small group of conefish was recorded hiding under the same ledge for at least 7 years. At night, this species comes out of hiding and goes hunting on sandbanks, illuminating its path with the help of luminescent organs, photophores. This light is produced by a colony of symbiotic bacteria, Vibrio fischeri, which has taken up residence in the photophores. Bacteria can leave the photophores and simply live in seawater. However, their luminescence fades a few hours after they leave the photophores.

Interestingly, fish also use the light emitted by their luminescent organs to communicate with their relatives.

7. Lyre sponge

The scientific name of this animal is Chondrocladia lyra. It is a type of carnivorous deep-sea sponge, and was first discovered in the California sponge at a depth of 3300-3500 meters in 2012.

The lyre sponge gets its name from its appearance, which resembles a harp or lyre. So, this animal is held on the seabed with the help of rhizoids, root-like formations. From 1 to 6 horizontal stolons extend from their upper part, and on them, at equal distances from each other, are vertical “branches” with spade-shaped structures at the end.

Since the lyre sponge is carnivorous, it uses these “branches” to capture prey, such as crustaceans. And as soon as she manages to do this, she will begin to secrete a digestive membrane that will envelop the prey. Only after this the lyre sponge will be able to suck in the split prey through its pores.

The largest recorded lyre sponge reaches almost 60 centimeters in length.

8. Clowns

Living in almost all tropical and subtropical seas and oceans, fish from the clown family are among the fastest predators on the planet. After all, they are able to catch prey in less than a second!

So, having seen a potential victim, the “clown” will track it down, remaining motionless. Of course, the prey will not notice it, because fish of this family usually resemble a plant or a harmless animal in their appearance. In some cases, when the prey comes closer, the predator begins to move the tail, an extension of the front dorsal fin that resembles a “fishing rod,” which forces the prey even closer. And as soon as a fish or other sea animal is close enough to the “clown”, it will suddenly open its mouth and swallow its prey, spending only 6 milliseconds! This attack is so lightning fast that it cannot be seen without slow motion. By the way, the volume of the fish’s oral cavity often increases 12 times while catching prey.

In addition to the speed of clownfish, an equally important role in their hunting is played by the unusual shape, color and texture of their cover, which allows these fish to mimic. Some clownfish resemble rocks or corals, while others resemble sponges or sea squirts. And in 2005, Sargassum clown sea, which imitates algae, was discovered. The “camouflage” of clownfish can be so good that sea slugs often crawl over these fish, mistaking them for coral. However, they need “camouflage” not only for hunting, but also for protection.

Interestingly, during a hunt, the “clown” sometimes sneaks up on its prey. He literally approaches her using his pectoral and ventral fins. These fish can walk in two ways. They can alternately move their pectoral fins without using the pelvic fins, and they can transfer their body weight from the pectoral fins to the pelvic fins. The latter method of gait can be called a slow gallop.

9. Smallmouth macropinna

Living in the depths of the North Pacific Ocean, the smallmouth macropinna has a very unusual appearance. She has a transparent forehead through which she can look out for prey with her tubular eyes.

The unique fish was discovered in 1939. However, at that time it was not possible to study it well enough, in particular the structure of the cylindrical eyes of the fish, which can move from a vertical position to a horizontal one and vice versa. This was only possible in 2009.

Then it became clear that the bright green eyes of this small fish (it does not exceed 15 cm in length) are located in a head chamber filled with a transparent liquid. This chamber is covered by a dense, but at the same time elastic transparent shell, which is attached to the scales on the body of the smallmouth macropinna. The bright green color of the fish's eyes is explained by the presence of a specific yellow pigment in them.

Since the smallmouth macropinna is characterized by a special structure of the eye muscles, its cylindrical eyes can be in both a vertical position and in a horizontal position, when the fish can look directly through its transparent head. Thus, macropinna can notice prey both when it is in front of it and when it swims above it. And as soon as the prey - usually zooplankton - is at the level of the fish’s mouth, it quickly grabs it.

10. Sea Spider

These arthropods, which are not actually spiders or even arachnids, are common in the Mediterranean and Caribbean Seas, as well as the Arctic and Southern Oceans. Today, more than 1,300 species of this class are known, some representatives of which reach 90 cm in length. However, most sea spiders are still small in size.

These animals have long legs, of which there are usually about eight. Moss spiders also have a special appendage (proboscis) that they use to absorb food into the intestines. Most of these animals are carnivorous and feed on cnidarians, sponges, polychaete worms and bryozoans. For example, sea spiders often feed on sea anemones: they insert their proboscis into the body of the sea anemone and begin to suck its contents into themselves. And since sea anemones are usually larger than sea spiders, they almost always survive such “torture.”

Sea spiders live in different parts of the world: in the waters of Australia, New Zealand, off the Pacific coast of the United States, in the Mediterranean and Caribbean seas, as well as in the Arctic and Southern oceans. Moreover, they are most common in shallow water, but can also be found at depths of up to 7000 meters. They often hide under rocks or camouflage themselves among algae.

11. Cyphoma gibbosum

The shell color of this orange-yellow snail seems very bright. However, only the soft tissues of a living mollusk have this color, and not the shell. Typically, Cyphoma gibbosum snails reach 25-35 mm in length, and their shell is 44 mm.

These animals live in the warm waters of the western Atlantic Ocean, including the Caribbean Sea, Gulf of Mexico and the waters of the Lesser Antilles at depths of up to 29 meters.

12. Mantis crab

Living at shallow depths in tropical and subtropical seas, mantis crayfish have the most complex eyes in the world. If a person can distinguish 3 primary colors, then the mantis crab can distinguish 12. Also, these animals perceive ultraviolet and infrared light and see different types of polarization of light.

Many animals are able to see linear polarization. For example, fish and crustaceans use it to navigate and detect prey. However, only mantis crabs are able to see both linear polarization and a rarer, circular one.

Such eyes enable mantis crayfish to recognize different types of corals, their prey and predators. In addition, when hunting, it is important for the crayfish to deliver precise strikes with its pointed, grasping legs, in which its eyes also help.

By the way, sharp, jagged segments on the grasping legs also help mantis crayfish cope with prey or predators, which can be much larger in size. So, during an attack, the mantis crab makes several quick strikes with its legs, which causes serious damage to the victim or kills it.

Anyone who has not been to the Black Sea coast at least once, has not dived into a gentle transparent wave, or basked on pebble beaches under the rays of the summer or autumn sun, has probably lost a lot! And in the warm water, of course, we repeatedly met the inhabitants of the Black Sea: dangerous and not so dangerous. Read about who lives in one of the most unique seas on the planet in our article.

Uniqueness of the environment

Both in composition and in the nature of settlement by living beings and vegetation, it is unique and very peculiar. It is divided into two different zones in depth. To a depth of 150, sometimes 200 meters, there is an oxygen zone where the inhabitants of the Black Sea live. Everything below 200 meters is a hydrogen sulfide zone, devoid of life and occupying more than 85% of the water mass by volume. So living is possible only where there is oxygen (less than 15% of the territory).

Who lives here?

The inhabitants of the Black Sea are algae and animals. The first - several hundred species, the second - more than two and a half thousand. Of these, 500 are unicellular, 1900 are invertebrates, 185 are fish, 4 species are mammals.

Phytoplankton

Its inhabitants are all kinds of algae: ceratium, peridinium, exuviella and some others. At the very beginning of spring there is a peak in algae proliferation. Sometimes even the water seems to change color, turning from turquoise and blue to brown. This is due to increased division of plankton (water blooms). Rhizosolenia, Chaetoceros, and Skletonema multiply intensively. Whereas the mass reproduction of phytoplankton is confined to the beginning - mid-summer. Among the bottom algae, phyllophora can be noted, which makes up more than 90% of the total mass. Phyllophora is common in the northwest. Cystoseira, another algae, is more often found along the southern coast of the Crimean part. There are many fry that feed and live among the algae (more than 30 species of fish).

Benthic animals

Among the animals that live on the ground or in the soil of the seabed (benthos) are various invertebrates: crustaceans and crayfish, worms, rhizomes, sea anemones and mollusks. Benthos also includes gastropods, for example, the well-known rapana, and other inhabitants of the Black Sea. The list goes on: mussels, mollusks - elasmobranchs. Fish: flounder, stingray, sea dragon, ruffe and others. They form a single ecosystem. And a single food chain.

Jellyfish

The permanent inhabitants of the Black Sea are jellyfish, large and small. Cornerot is a large jellyfish, very common. The size of its dome sometimes reaches half a meter. Cornerot is poisonous and can cause injuries similar to nettle burns. They cause mild redness, burning, and sometimes blistering. To prevent this large jellyfish with a slightly purple dome from stinging, you need to move it to the side with your hand, holding the top and not touching the tentacles.

Aurelia is the smallest jellyfish in the Black Sea. It is not as poisonous as its counterpart, but still meeting with it must also be avoided.

Shellfish

Marine inhabitants of the Black Sea - mussels, oysters, scallops, brine. All these shellfish are edible and provide raw materials for gourmet dishes. For example, oysters and mussels are specially bred. Oysters are very tenacious and can survive without water for about two weeks. They can live up to 30 years. Their meat is considered a delicacy.

Mussels are less refined. Sometimes a pearl is found in a large shell, usually pinkish in color. Mussels are marine water filters. At the same time, everything that was filtered accumulates in them. Therefore, you can enjoy them only after careful processing, and it is better to avoid eating mussels that grew in the port or in other places with heavily polluted water.

Marine inhabitants of the Black Sea - scallops. This peculiar mollusk can move in water using reactive force. It quickly slams the shell doors and is carried by a stream of water over a distance of more than a meter. Scallops also have hundreds of useless eyes. But with all this, this mollusk is blind! These are the mysterious inhabitants of the sea.

Rapana is also found in the Black Sea. This mollusk is a predator, and its prey is the same mussels and oysters. But it has very tasty meat, reminiscent of sturgeon, which makes an excellent soup.

Crabs

There are eighteen species in total in the water area. All of them do not reach large sizes. The largest is the red-barked one. But it is no more than 20 centimeters in diameter.

Fish

The Black Sea is home to about 180 species of all kinds of fish, including: sturgeon, beluga, anchovy, herring, sprat, horse mackerel, tuna, flounder, goby. Rarely does a swordfish swim in. There is a seahorse, pipefish, sea rooster, and monkfish.

Commercial fish include mullet, of which there are three species, and pelengas, brought from the Sea of ​​Japan and which became the object of fishing. Due to severe water pollution, the number of mullet has recently decreased.

Among the original specimens is the stargazer fish, or It burrows deep into the mud, so that one antenna is exposed on the surface, which resembles the appearance of a worm. The fish uses its antennae to attract small fish and feed on them.

Pipefish and seahorses lay their eggs not in the water, but in the skin folds on the backs of males, where they remain until the fry hatch. Interestingly, the eyes of these fish can look in different directions and rotate autonomously relative to each other.

Horse mackerel is distributed throughout the coastal waters of the sea. Its length is 10-15 centimeters. Weight - up to 75 grams. Sometimes lives up to three years. It feeds on small fish and zooplankton.

Pelamida is a relative of mackerel. Reaches a length of up to 75 centimeters and lives up to 10 years. This is a predatory fish that feeds and spawns in the Black Sea and leaves for the winter through the Bosphorus.

Gobies are represented by 10 species. The largest one is the martin, or toad. The most numerous is the round timber.

There are 8 species of greenfinches in the sea. They feed on worms and mollusks. During the spawning period, nests are built between stones.

Kalkan flounder is also found everywhere in the Black Sea. She eats fish and crabs. Reaches a weight of 12 kilograms. Other species of flounder are also represented.

The stingray is a relative of the shark. It eats crabs, shellfish, and shrimp. It has a barbed needle on its tail, equipped with a poisonous gland. Her injection is very painful for a person, sometimes even fatal.

Speaker, or is often caught in spring and summer when it visits these waters for spawning. It feeds on zooplankton. The weight of the perch barely reaches 100 grams. It is considered one of the main types of prey for amateur fisherman.

Sargan is a fish more than half a meter long, arrow-shaped, with an elongated beak. Spawns in May - August. Migrates and winters in the Sea of ​​Marmara.

Bluefish is a predatory and schooling fish. Weighs up to 10 kilograms and reaches a meter in length. The body of the fish is oblong on the sides. The mouth is large, with large jaws. It eats only fish. Previously considered commercial.

Sharks

Katran (or sea dog) rarely grows to two meters. A (scillium) - more than a meter. These two species of sharks found in the Black Sea do not pose any danger to humans. But for many species of fish they are fierce predators. (as well as their liver and fins) are used to prepare various dishes of Black Sea cuisine. A medicine that blocks the proliferation of cancer cells is made from the katran liver.

Katran has a streamlined body, a crescent-shaped mouth and sharp teeth arranged in several rows. Its body is strewn with small but sharp spines (hence the nickname - spiny shark). Katran is a viviparous fish. The female gives birth to up to 15 small fry at a time. The katran stays and feeds in flocks. In spring and autumn - close to the shore, in winter - at depths.

Inhabitants of the Black Sea - dolphins (toothed whales)

There are three species in total in these waters. The largest are bottlenose dolphins. Slightly smaller - white sideds. The smallest are porpoises, or Azovs.

The bottlenose dolphin is the most common inhabitant of dolphinariums. For science, this species is of great importance. It is the bottlenose dolphin that scientists around the world study for the presence of intelligence. They are born circus performers. Bottlenose dolphins enjoy performing a variety of tricks. It seems that they actually have intelligence. This is not even training, but some kind of cooperation and mutual understanding between a dolphin and a person. Bottlenose dolphins understand only affection and encouragement. They don’t perceive punishment at all, then any trainer ceases to exist for them.

The bottlenose dolphin lives up to 30 years. Her weight sometimes reaches 300 kilograms. Body length is up to two and a half meters. These dolphins are well adapted to the aquatic environment. The front fins act as steering wheels and brakes at the same time. The tail fin is powerful and allows it to develop decent speeds (over 60 km/h).

Bottlenose dolphins have acute vision and hearing. They feed on fish and shellfish (they eat up to 25 kilograms per day). They can hold their breath for more than 10 minutes. They dive to a depth of 200 meters. Body temperature is 36.6 degrees, like a person’s. Dolphins breathe, periodically rising outward with air. They actually suffer from the same diseases as people. Bottlenose dolphins sleep half a meter from the surface, under water, periodically opening their eyes.

The lifestyle of dolphins is herd and family (up to ten generations together). The head of the family is the female. Males stay in a separate clan, showing interest in females mainly only during mating.

Bottlenose dolphins have enormous strength. But, as a rule, it is not applied to humans. Dolphins maintain the most friendly relations with people, as if with brothers in mind. In the entire long history of the relationship between man and dolphin, not a single attempt to offend the “big brother” has been noticed. But people often infringe on the rights of dolphins, conducting experiments on them, imprisoning them in dolphinariums.

Much has been written about the language of dolphins. We will not argue, as some scientists do, that it is richer than human speech. However, it contains a huge range of sounds and gestures, which still allows us to talk about some kind of intelligence of dolphins. And the amount of information that they can transmit and their large (larger than human) brain is strong evidence of this.

It remains to add that among the mammals in the Black Sea there are seals, but very few of them have been observed recently due to harmful human activities.

On the land

Not only sea inhabitants and the human tribe feed on seafood. Some species of birds living on land obtain their food in the water. those that forage for food in the sea are gulls and cormorants. They feed on fish. The cormorant, for example, can swim and dive well, eating large quantities of fish even when full. The peculiarities of its pharynx allow it to swallow quite large prey. Thus, birds are the main inhabitants of land, obtaining food in the sea of ​​the Black Sea coast of the Caucasus and Crimea.

Black Sea: dangerous inhabitants

Not all vacationers and tourists who come to the Black Sea coast know that those who swim in the water can face dangers. They are associated not only with storm warnings and underwater rocks, but also with some representatives of marine fauna.

The scorpionfish, or sea urchin, is one of these unpleasant surprises. Her whole head is covered with thorns, and on her back there is a thorny, dangerous fin. It is not recommended to pick up a scorpionfish, as its thorns are poisonous and bring rather unpleasant, albeit short-term painful sensations.

The stingray (sea cat) also poses a danger, sometimes even fatal, to humans. On the tail of the animal there is a bone spike lubricated with poisonous mucus. This jagged thorn sometimes causes lacerated wounds that take a long time to heal. Also, a stingray injection can cause vomiting, muscle paralysis, and an increased heart rate. Sometimes death occurs, so be careful.

Another, seemingly inconspicuous in appearance, fish - the sea dragon - is most dangerous to humans. At first glance, it can be mistaken for an ordinary bull. But on the back of this fish there is a spiny fin, which is very poisonous. The injection is equivalent to the bite of a poisonous snake. In some cases, death is possible.

Cornerot and Aurelia jellyfish that inhabit the Black Sea are dangerous inhabitants for humans. Their tentacles are equipped with stinging cells. A burn is possible (like from nettle and stronger), leaving marks for several hours. So it is better not to touch jellyfish - even dead ones thrown out on the pebbles by the waves.

Neither sharks nor other species of animals and fish pose a danger to people in the waters of the Black Sea. So swim safely when coming to the famous Black Sea resorts of the Crimea and the Caucasus, of course, observing reasonable caution!

The Pacific Ocean is the largest ocean in the world and covers about a third of the Earth's surface area. The depth of the ocean varies from shallow shores to the Mariana Trench, the deepest point of which (Challenger Deep) reaches a depth of almost 11 thousand km. Due to its sheer size, the Pacific Ocean is home to countless species of sea creatures, and some of the most famous animals are:

Penguins

The Pacific Ocean is home to numerous species, including Galapagos penguins, Humboldt penguins, Magellanic penguins, crested penguins, and yellow-eyed penguins. These animals vary in size, from 1 kg in weight and a height at the withers of about 40 cm, to a weight of 35 kg and a height of about 100 cm.

Dugong

Elephant seals

The largest genus distributed in the Pacific Ocean. It includes two species: the northern elephant seal and the southern elephant seal. The northern species is distributed in the northern part of the Pacific Ocean along the North American coast, and the southern one is found near. These enormous marine mammals exhibit sexual dimorphism, with adult males being much larger than females. The average weight of an adult elephant seal is about 2 tons, with some individuals growing up to 4 tons.

Manti

The largest stingrays live in the northern part of the Pacific Ocean - representatives of the Manta genus. They are found near coral reefs, where they hunt fish and tiny fish. Adult manta rays can have a body width of up to 9 m and a weight of 3 tons. The stingray is a solitary animal and surprisingly calm, despite its impressive size. Stingrays are hunted by large sharks and killer whales.

Sea otters

The sea otter is a common inhabitant of the North Pacific Ocean, especially on its northern and eastern coasts. Sea otters are relatively small in size compared to other marine mammals, and adults can reach a maximum weight of about 45 kg and a body length of up to 1.5 m. They feed on small marine animals and seaweed.

sea ​​turtles

Sea turtles are a general term used to describe seven species in the order turtles. These species include: flathead sea turtle, green turtle, hawksbill turtle, Atlantic ridley turtle, leatherback turtle, loggerhead turtle and olive turtle. The leatherback turtle is the largest of all sea turtles, with adults weighing up to 700 kg. Sea turtles are found in tropical areas of the Pacific Ocean.

Sea slugs

Sea slugs are the term used to refer to marine species known as nudibranchs, as well as several gastropods that closely resemble terrestrial slugs. Sea slugs are primarily found in coral reefs and come in a variety of shapes and sizes, but most are partially translucent. Most sea slugs have feather-like structures on their backs that act as gills. Sea slugs are carnivores and they prey on fish, anemones, and planktonic organisms.

Octopuses

It is one of the most common cephalopods in the Pacific Ocean. Different species live in different parts of the ocean. The octopus has one of the largest brain-to-body ratios of any species, and also possesses a complex nervous system. Octopus species vary in size, with the largest being the giant octopus, which can grow up to 50 kg.

Giant squid

The giant squid is a member of the architeutid family ( Architeuthidae). This squid is one of the most elusive Pacific creatures and one of the largest invertebrates in the world (the other being the large Antarctic giant squid). Adults grow up to 13 m in length, and females are relatively larger than males. Giant squids are found in the North Pacific Ocean near Japan.

Pacific white-sided dolphins

Pacific white-sided dolphin - found in the North Pacific Ocean. Animals of this species have a gray back and a creamy white belly and neck. Adult females grow up to 100 kg and have a body length of about 2.2 m, and males weigh up to 180 kg and are 2.3 m long. These dolphins are quite mobile and become victims only of killer whales.

Sea lions

The sea lion is the largest member of the eared seal family ( Otariidae). Adult males can reach a weight of 1000 kg and a body length of 3-3.5 m. This species exhibits sexual dimorphism, and males are larger than females. Males have a massive neck covered with a lion-like mane. These marine mammals are found in the North Pacific Ocean.

Hammerhead sharks

The hammerhead shark is one of the most common sea creatures in the Pacific Ocean. These sharks are easily identified by their head shape, which resembles a hammer. Thanks to this feature, the shark has 360-degree vision. Adult sharks can reach a mass of more than 500 kg and a body length of about 6 m.

The world's oceans are a complex natural system in which water and air, earth and sun interact. And at the same time, it is a single organism that lives and develops according to its own laws.

So the average temperature of the entire ocean - from the equator to the poles, from the very surface to the lowest depths - is only 3.5ºC. It would seem that the waters at the equator should be warmer. However, a complex system of currents redistributes heat throughout the ocean.

The area occupied by the ocean is 510 million square meters. km and occupies 71% of the surface of our planet. The ocean area, just like the land area, is conventionally divided into natural zones: from the Arctic zone to the hot equatorial zone. Each natural zone has its own characteristics, its own climate, characteristic flora and fauna.

Most of the ocean (almost 5%) has a complex topography, and its depth is over 4 thousand kilometers. The deepest place on Earth is the Mariana Trench (11,034 m).

The entire water area of ​​the world's oceans is divided into 4 separate oceans (Pacific, Atlantic, Indian and Arctic) and 54 seas. Other researchers also identify a fifth ocean - the Southern Ocean, citing the fact that the ocean near Antarctica has its own specifics, although its boundaries with other oceans are very arbitrary.

Flora of the seas and oceans

The flora of the ocean and seas is as rich and diverse as the flora of land. Most of the biomass comes from the Pacific Ocean (about 50%). A huge number of plants grow in tropical and subtropical zones in the area between the coasts of Australia and Asia. These are unicellular and red algae, corals that form powerful coral reefs, fucus plants, among which there are sea oaks, sea grapes and king algae. And the coasts of the Pacific Ocean are famous for their magnificent mangroves that can grow in salt water.

(Phytoplankton)

If the Pacific Ocean wins in the mass of plant life, then the Atlantic Ocean has more plant species. Of course, phytoplankton dominates. In addition to it, there are red, green and brown algae, kelp and sargassum. Eelgrass grow in river mouths, and caulepas and valonias grow in the tropics. In the south there is an abundance of different types of brown algae: Lesonia, Fucus and Electus.

The waters of the Indian Ocean have a somewhat turbid color only because most of the plankton is formed by single-celled algae Trichodesmium. It is these plants that color the waters cloudy and dark.

(Dinophyte glow of algae)

In the northern part of the Indian Ocean, closer to the equator, there are amazing dinophyte algae that can glow at night. Calcareous algae, along with corals, participate in the creation of huge coral reefs. And the coasts of the seas belonging to the Indian Ocean are buried in mangroves.

The poverty of the flora of the Arctic Ocean is explained by harsh climatic conditions. Only in the White and Barents Seas is the flora more richly represented. Laminaria, fucus and eoster grow here.

Fauna of the seas and oceans

(Sea stars)

The fauna of the seas and oceans has not yet been studied even by 20%. Currently, biologists have identified and classified more than 1.5 million animal species. But according to experts, there are up to 25 million species of sea creatures in the oceans that have not yet been studied in any way.

Conventionally, all inhabitants of the seas and oceans can be divided into several groups:

Pisces are the most numerous class. Currently, over 250 thousand species of fish have been registered, and this list is replenished with new discoveries every year. Fish are divided into cartilaginous and bony. Cartilaginous are sharks and rays that live in the waters of the Pacific, Atlantic and Indian Oceans in temperate and tropical climates. There are 450 species of sharks alone, and only 4 species pose a danger to humans. And there are over 25 thousand species of bony fish. This is more than all other vertebrate species combined.

Whales are the largest representatives of marine life. These are giant mammals that roam the waters of the Pacific and Atlantic oceans. There are 79 species of cetaceans in the world. The most famous of them: blue whales and sperm whales, minke whales and killer whales, narwhals and porpoises, dolphins and beluga whales. The blue whale, for example, is the world's largest animal. Its heart is the size of a car, and blue whales are larger in size than even dinosaurs known to science. Before the moratorium on whale slaughter was introduced in 1985, the whaling industry generated huge profits. Now most species are under threat of extinction.

Corals are clusters of miniature animals that are equipped with a limestone skeleton. Coral reefs are powerful natural formations that serve as habitat for a huge number of fish and other marine animals. The largest coral reef stretches along the northeast coast of Australia. This is the Great Barrier Reef.

Crustaceans. There are over 55 thousand species of crustaceans in the world. These are the well-known crayfish and lobsters, shrimp and lobsters. Crustaceans are found almost everywhere, with the exception of the northern and southern seas, close to the cold poles.

Mollusks are a family of invertebrate animals, most of which can be hidden in the shell. The largest representative of mollusks is the octopus, which lives in warm seas. But scallops, mussels, oysters and cockerels, crabs and nautiluses are found both in the North Atlantic and in southern latitudes.

Other sea animals

The Northern Seas and the North Atlantic Ocean are inhabited by amphibians such as seals, fur seals and walruses. Polar bears and penguins spend part of their lives on land and part in the cold waters of the Arctic and Antarctic.

But sea turtles prefer warm regions. More than 6 species of sea turtles live in subequatorial, equatorial and tropical climates. Turtles also swim into waters of temperate latitudes.

There is also a genus of echinoderms. These are the well-known sea urchins, stars, lilies and jellyfish. Peculiar animals endowed with the brightest colors.

These are not all representatives of marine and ocean fauna. Scientists have not yet assigned many animals to any species or genus. For example, biologists are still arguing about how to classify sea sponges, although their diversity is simply amazing.

The underwater world is mysterious and unique. It contains secrets that have not yet been solved by man. We invite you to get acquainted with the most unusual sea creatures, plunge into the unknown thickness of the water world and see its beauty.

1. Atoll Jellyfish (Atolla vanhoeffeni)

This jellyfish is capable of emitting a bright red glow, which is a consequence of the breakdown of proteins in its body. As a rule, large jellyfish are dangerous creatures, but you should not be afraid of the Atoll, because its habitat is where no swimmer can reach.

2. Blue Angel (Glaucus atlanticus)

These unusual creatures have an outlandish body shape. They are blue above and silver below. It is not for nothing that nature has provided such camouflage - the Blue Angel remains unnoticed by birds and sea predators. A thick layer of mucus around the mouth allows it to feed on small, poisonous sea creatures.

3. Harp sponge (Chondrocladia lyra)

The harp sponge covers its prey with a bactericidal film and gradually digests it. There are individuals with two or more lobes, which are connected in the center of the body. The more blades, the more food the sponge will catch.

4. Dumbo Octopus (Grimpoteuthis)

Not only the “ears” help to move, but also the peculiar funnels located on the octopus’ body, through which it releases water under pressure. Dumbo lives at very great depths, so we don’t know much about him. Its diet consists of all kinds of mollusks and worms.

Octopus Dumbo

5. Yeti Crab (Kiwa hirsuta)

These amazing animals grow microorganisms on their claws. Some scientists believe that the crab needs these bacteria to purify the water from toxic substances, others suggest that the crabs grow food for themselves on the bristles.

6. Short-snouted pipistrelle (Ogcocephalus)

It obtains food using a special growth - a kind of retractable fishing rod with an odorous bait that attracts prey. The discreet coloring and spiked shell help the fish hide from predators. Perhaps this is the funniest animal among the inhabitants of the world's oceans.

7. Sea slug Felimare Picta

Felimare Picta, although a mollusk, does without a shell. And why does he need her? In case of danger, the sea slug has something much more interesting. For example, acidic sweat that is released on the surface of the body. It's really bad luck for anyone who wants to treat themselves to this mysterious mollusk!

8. Flamingo tongue clam (Cyphoma gibbosum)

Like an ordinary snail, the Flamingo's Tongue hides in its shell in case of impending danger. By the way, the mollusk received this name due to its bright color with characteristic spots. It prefers poisonous gongonaria as food. While eating, the snail absorbs the poison of its prey, after which it becomes poisonous itself.

9. Leafy sea dragon (Phycodurus eques)

Dragons feel comfortable in the shallow waters of warm seas. And these sea inhabitants are also known as excellent fathers, because it is the males who bear the offspring and take care of them.

10. Salps (Salpidae)

In the ocean depths, animals form long chains of colonies, which are easily broken even by a minor wave shock. Salps reproduce by budding.

11. Piglet squid (Helicocranchia pfefferi)

This mollusk is leisurely. It's funny that the piggy squid moves upside down, which is why its tentacles look like forelocks. He lives at a depth of one hundred meters.

12. Ribbon moray eel (Rhinomuraena guaesita)

Growing up to one hundred centimeters, the moray eel turns into a male and turns blue, and at the peak of maturation, the unique fish turns out to be a female and acquires a bright yellow color. Its body has no scales and is covered with bactericidal mucus, its nose resembles two delicate petals, and its mouth is always wide open, which gives the fish a menacing appearance. In fact, the moray eel is not at all aggressive, but keeps its mouth open due to underdeveloped gills.

13. Blobfish (Psychrolutes marcidus)

14. Christmas tree worm (Spirobranchus giganteus)

The bristles are very similar to feathers, but they are just digestive and respiratory organs, and the body is a calcareous tube. The “Christmas Tree” worm is a homebody. He spends his entire life in a hole in the coral, where one day he attaches himself, considering it the most suitable place for his existence.

The editors of the site invite you to get acquainted with the most unusual natural phenomena.
Subscribe to our channel in Yandex.Zen