Organisms that live on the bottom. Who lives at the bottom of the ocean? Animal life at depth. Types of marine life
Plankton, nekton, benthos - three groups into which all aquatic living creatures can be divided. Plankton is formed by algae and small animals that swim near the surface of the water. Nekton consists of animals that can actively swim and dive in the water, these are fish, turtles, whales, sharks and others. Benthos are organisms found in the lowest layers of aquatic habitats. It includes bottom-dwelling animals, including many echinoderms, demersal fish, crustaceans, mollusks, annelids, and so on.
Types of marine life
They are divided into three groups: plankton, nekton, benthos. Zooplankton is represented by drifting animals, which are usually small in size, but can grow to quite large sizes (for example, jellyfish). Zooplankton may also include temporary larval forms of organisms that may grow up and leave planktonic communities and join groups such as nekton, benthos.
The nekton class makes up the largest part of the animals that live in the ocean. A variety of fish, octopuses, whales, moray eels, dolphins and squid are all examples of nekton. This large-scale category includes a number of very diverse creatures that are very different from each other in many ways.
What is benthos? The third type of marine animal that spends their entire life at the bottom of the ocean. This group includes lobsters, starfish, all kinds of worms, snails, oysters and many others. Some of these creatures, such as lobsters and snails, can move on their own along the bottom, but their lifestyle is so closely connected to the ocean floor that they could not survive away from this environment. Benthos are organisms that live on the ocean floor and include plants, animals, and bacteria.
Plankton is the most common form of life in the aquatic environment.
When you imagine life in the ocean, then usually all associations are somehow connected with fish, although in fact fish are not the most common form. The most numerous group is plankton. The other two groups are nekton (actively swimming animals) and benthos (these are living organisms that inhabit the bottom).
Most plankton species are too small to see with the naked eye.
There are two main types of plankton
- Phytoplankton that produce food through photosynthesis. Most of them are various algae.
- Zooplankton that feed on phytoplankton. It includes tiny animals and fish larvae.
Plankton: general information
Plankton are the microscopic inhabitants of the pelagic environment. They are essential components of food chains in aquatic environment habitats, as they provide food for nekton (crustaceans, fish and squid) and benthos. They also have a global impact on the biosphere, since the balance of the components of the Earth's atmosphere is largely dependent on their photosynthetic activity.
The term "plankton" comes from the Greek planktos, which means "wandering" or "drifting". Most plankton spend their existence swimming with ocean currents. However, not all species go with the flow, many forms can control their movements, and their survival depends almost entirely on their independence.
Sizes and representatives of plankton
Plankton range in size from tiny microbes that are 1 micrometer long to jellyfish, whose gelatinous bell can be up to 2 meters wide and whose tentacles can extend over 15 meters. However, most planktonic organisms are animals less than 1 millimeter in length. They survive on the nutrients in seawater and through photosynthesis.
Plankton representatives are a wide variety of organisms, such as algae, bacteria, protozoa, larvae of some animals and crustaceans. Most planktonic protists are eukaryotes, predominantly unicellular organisms. Plankton can be divided into phytoplankton, zooplankton and microbes (bacteria). Phytoplankton carries out photosynthesis, and zooplankton is represented by heterotrophic consumers.
Nekton
Nekton are active swimmers and are often the best known organisms in marine waters. They are top predators in most marine food chains. The distinction between nekton and plankton is not always sharp. Many large animals (for example, tuna) spend their larval stage as plankton, while in the adult stage they are quite large and active nekton.
The vast majority of nekton are vertebrates, these are fish, reptiles, mammals, mollusks and crustaceans. The most numerous group is made up of fish, in total there are approximately 16,000 species. Nekton is found at all depths and latitudes of the sea. Whales, penguins, seals are typical representatives of nekton in polar waters. The greatest variety of nekton can be found in tropical waters.
The most diverse form of life and its economic value
This also includes the large mammal on planet Earth, the blue whale, which grows up to 25-30 meters in length. These giants, as well as others, feed on plankton and micronekton. The largest representatives of the nekton are whale sharks, which reach a length of 17 meters, as well as toothed whales (killer whales), great white sharks, tiger sharks, bluefin tuna and others.
Nekton forms the basis of fisheries around the world. Anchovies, herring, sardines usually make up one quarter to one third of the annual marine harvest. Economically valuable nekton are also squids. Halibut and cod are demersal fish that are commercially important as food for humans. As a rule, they are mined in the waters of the continental shelf.
Benthos
What is the meaning of the word "benthos"? The term "benthos" comes from the Greek noun bentos and means "depths of the sea". This concept is used in biology to refer to the community of organisms at the bottom of the sea, as well as fresh water bodies such as lakes, rivers and streams.
Benthic organisms can be classified according to size. Macrobenthos refers to organisms larger than 1 mm. These are various gastropods, sea lilies, predatory starfish and gastropods. Organisms with sizes from 0.1 to 1 mm are large microbes that dominate the benthic food chains, acting as a biogenic utilizer, primary producer, and predator. The microbenthos category includes organisms smaller than 1 millimeter, these are diatoms, bacteria and ciliates. Not all benthic organisms live in sedimentary rocks, some communities live on rocky substrates.
There are three different types of benthos
- Infauna are organisms that live at the bottom of the ocean, buried in the sand or hiding in shells. They have very limited mobility, live in sediment, are exposed to environment and have a fairly long lifespan. These include sea shells and various molluscs.
- Epifauna can live and move on the surface of the seabed to which they are attached. They live by attaching themselves to rocks or moving along the surface of sediments. These are sponges, oysters, snails, starfish and crabs.
- Organisms that live at the bottom of the ocean but can also swim in the water above it. These include soft - pufferfish, flounders, using crustaceans and worms as a food source.
Relationship between pelagic environment and benthos
Benthos are organisms that play a critical role in the marine biological community. Benthic species are a heterogeneous group that is the main link in the food chain. They filter water in search of food, remove sediment and organic matter, thus purifying the water. Unused organic matter settles at the bottom of the seas and oceans, which are then processed by benthic organisms and returned to the water column. This process of mineralization organic matter is an important source of nutrients and is critical for high primary production.
The concepts of pelagic and benthic environments are interconnected in many ways. For example, pelagic plankton are an important food source for animals that live on soft or rocky ground. Anemones and barnacles serve as a natural filter for the surrounding water. The formation of the pelagic environment at the bottom is also due to the molting of crustaceans, metabolic products and dead plankton. Over time, plankton forms marine sediments in the form of fossils, which are used to determine the age and origin of rocks.
Aquatic organisms are classified according to their habitat. Scientists believe that the habitat of these animals has a huge impact on their evolution. Moreover, most of them have adapted well to life in the specific environment they inhabit. What is the main difference between the groups called plankton, benthos and nekton?
Plankton are microscopic or small animals compared to the other two types. Nekton are free-swimming animals. What is benthos? It includes both freely moving and those organisms that cannot imagine their existence without the ocean floor. And what about organisms that live mostly on the bottom, but can also swim - octopus, sawfish, flounder? Such forms of life can be called nektobenthos.
The ocean is a boundless expanse of trillions of liters of salt water. Thousands of species of living beings have found refuge here. Some of them are thermophilic and live at shallow depths, so as not to miss the rays of the sun. Others are accustomed to the cold waters of the Arctic and try to avoid the warm currents. There are even those who live at the bottom of the ocean, having adapted to the conditions of a harsh world.
The last representatives are the greatest mystery for scientists. After all, until recently they could not even think that someone was able to survive in such extreme conditions. Moreover, evolution has rewarded these living organisms with a number of unseen features.
Beneath the oceans
For a long time there was a theory that there is no life at the bottom of the ocean. The reason for that - low temperature water, as well as high pressure, capable of compressing a submarine like a soda can. And yet, some creatures were able to withstand these circumstances and confidently settled at the very edge of the bottomless abyss.
So who lives at the bottom of the ocean? First of all, these are bacteria, traces of which were found at a depth of more than 5 thousand meters. But if microscopic creatures are unlikely to surprise the average person, then giant clams and monster fish deserve due attention.
How did you find out about those who live at the bottom of the ocean?
With the development of submarines, diving to a depth of up to two kilometers became possible. This allowed scientists to look into the world, hitherto unseen and amazing. Each dive made it possible to open another one to see more and more new species.
And the rapid development of digital technology has made it possible to create heavy-duty cameras that can shoot underwater. Thanks to this, the world saw photographs that depict animals living at the bottom of the ocean.
And every year, scientists go deeper and deeper in the hope of new discoveries. And they happen - for last decade many surprising conclusions have been made. In addition, hundreds, if not thousands, of photographs were posted on the network, which depict the inhabitants of the deep sea.
Creatures that live at the bottom of the ocean
Well, it's time to go on a little trip to mysterious depths. Passing the threshold of 200 meters, it is difficult to distinguish even small silhouettes, and after 500 meters pitch darkness sets in. From this moment, the possessions of those who are indifferent to light and heat begin.
It is at this depth that one can meet a polychaete worm, which, in search of profit, drifts from place to place. In the light of the lamps, it shimmers with all the colors of the rainbow, the word is made of silver plates. On his head is a series of tentacles, thanks to which he is oriented in space and feels the approach of prey.
But the worm itself is food for another inhabitant. underwater world- sea angel. This amazing creature belongs to the class of gastropods and is a predator. It got its name because of the two large fins that cover its sides like wings.
If you go down even deeper, you can stumble upon the queen of jellyfish. Hairy Cyanea, or Lion's Mane- the largest representative of its kind. Large individuals in their diameter reach 2 meters, and their tentacles can stretch almost 20 meters.
Who lives at the bottom of the ocean yet? This is a squat lobster. According to scientists, he can adapt to life even at a depth of 5 thousand meters. Thanks to its flattened body, it calmly endures pressure, and its long legs allow it to move easily along the muddy bottom of the ocean.
Deep sea fish
Fish living at the bottom of the ocean, over hundreds of thousands of years of evolution, have been able to adapt to existence without sun rays. Moreover, some of them even learned to produce their own light.
So, at around 1 thousand meters lives angler. On his head there is an appendage that emits a small glow that lures other fish. Because of this, it is also called the "European anglerfish". At the same time, he himself can change his color, thereby merging with the environment.
Another representative of deep-sea creatures is a drop fish. Her body resembles jelly, which allows her to endure pressure at great depths. It feeds exclusively on plankton, which makes it harmless to its neighbors.
A stargazer fish lives at the bottom of the oceans, the second name is the celestial eye. The reason for this pun was the eyes are always directed upwards, as if looking out for the stars. Her body is covered with poisonous spikes, and near her head are tentacles that can paralyze the victim.
Deep water is the lower level of the ocean, located at a distance of more than 1800 meters from the surface. Due to the fact that only a small fraction of light reaches this level, and sometimes light does not reach at all, historically it was believed that there was no life in this layer. But in fact, it turned out that this level is just teeming different forms life. It turned out that with each new dive to this depth, scientists miraculously find interesting, strange and outlandish creatures. Below are ten of the most unusual of them:
10. Polychaete Worm
This worm was caught this year at the bottom of the ocean at a depth of 1200 meters off the northern coast of New Zealand. Yes, it can be pink, and yes, it can reflect light in the form of a rainbow - but despite this, the polychaete worm can be a ferocious predator. The "tentacles" on its head are sensory organs designed to detect prey. This worm can twist its throat in order to grab a smaller creature - like an Alien. Fortunately, this type of worm rarely grows more than 10 cm. They also rarely come across our path, but are often found near hydrothermal vents on the ocean floor.
9 Squat Lobster
These unique lobsters, which look rather intimidating and look like headcrabs from the Half-Life game, were discovered on the same dive as the polychaete worm, but at a greater depth, about 1400 meters from the surface. Despite the fact that squat lobsters were already known to science, they had never seen this species before. Squat lobsters live at depths of up to 5,000 meters, and are distinguished by their large front claws and compressed bodies. They can be detritivores, carnivores, or herbivores that feed on algae. Not much is known about individuals of this species, in addition, representatives of this species were found only near deep-sea corals.
8. Carnivorous Coral or Carnivorous Coral
Most corals get their nutrients from photosynthetic algae that live in their tissues. This also means that they must live within 60 meters of the surface. But not this species, also known as Sponge-Harp. It was discovered 2000 meters off the coast of California, but only this year scientists have confirmed that it is carnivorous. Similar in shape to a chandelier, it stretches along the bottom to increase in size. It catches small crustaceans with tiny Velcro-like hooks and then stretches a membrane over them, slowly digesting them with chemicals. In addition to all his oddities, he also reproduces in a special way - "sperm bags" - see these balls at the end of each process? Yes, these are packets of spermatophores, and from time to time they swim away to find another sponge and multiply.
7. Fish of the Cynogloss family or Tonguefish (Tonguefish)
This beauty is one of the species of tonguefish that are commonly found in shallow estuaries or tropical oceans. This specimen lives in deep waters, and was fished from the bottom earlier this year in the western part Pacific Ocean. Interestingly, some tonguefish have been observed near hydrothermal vents spewing sulfur, but scientists have not yet figured out the mechanism that allows this species to survive in such conditions. Like all bottom tongue fish, both of its eyes are located on the same side of the head. But unlike other members of this family, his eyes look like sticker eyes or scarecrow eyes.
6. Goblin Shark or Goblin Shark
The goblin shark is a truly strange creature. In 1985, it was discovered in the waters off the east coast of Australia. In 2003, more than a hundred individuals were caught in northeastern Taiwan (reportedly after an earthquake). However, apart from sporadic sightings of this nature, little is known about this unique shark. This is a deep-sea, slow-moving species that can grow up to 3.8 meters in length (or even more - 3.8 is the largest of those that caught the eye of man). Like other sharks, the goblin shark can sense animals with its electro-sensing organs, and has several rows of teeth. But unlike other sharks, the goblin shark has both teeth adapted for catching prey and teeth adapted for cracking crustacean shells.
If you are interested to see how she catches prey with this mouth of hers, here is a video. Imagine that almost 4-meter shark rushes at you with such jaws. Thank God they (usually) live so deep!
5. Soft-bodied Whalefish (Flabby Whalefish)
This brightly colored individual (why do you need bright colors when colors are useless if you live where light cannot penetrate) is a member of the ill-named "soft-bodied whale-like fish" species. This specimen was caught off the east coast of New Zealand, at a depth of more than 2 kilometers. In the lower part of the ocean, in the bottom waters, they did not expect to find many fish - and in fact it turned out that the soft-bodied whale-like fish did not have many neighbors. This family of fish lives at a depth of 3,500 meters, they have small eyes that are actually completely useless given their habitat, but they have a phenomenally developed lateral line that helps them feel the vibration of the water.
This species also does not have ribs, which is probably why the fish of this species look “soft-bodied”.
4. Grimpoteuthys (Dumbo Octopus)
The first mention of Grimpoteuthys appeared in 1999, and then, in 2009, it was filmed. These cute animals (for octopuses, anyway) can live up to 7,000 meters below the surface, making them the deepest-dwelling species of octopus. known to science. This genus of animals, so named because of the flaps on both sides of the bell-shaped head of its representatives and never seeing sunlight, may have more than 37 species. Grimpoteuthis can float above the bottom with the help of jet propulsion based on a siphon-type device. At the bottom, grimpoteuthys feeds on snails, mollusks, crustaceans and crustaceans that live there.
3. Hellish vampire (Vampire Squid)
Hellish vampire (Vampyroteuthis infernalis name literally translated as: vampire squid from hell) is more beautiful than terrible. Although this species of squid does not live at the same depth as the squid that ranks first on this list, it still lives quite deep, or rather, at a depth of 600-900 meters, which is much deeper than the habitat of ordinary squids. IN upper layers its habitat contains some sunlight, so it has evolved the largest eyes (in proportion to its body, of course) than any other animal in the world in order to capture as much light as possible. But what is most amazing about this animal is its defense mechanisms. In the dark depths where he lives, he releases a bioluminescent "ink" that blinds and confuses other animals as he swims away. It works amazingly well just when the waters are not lit. He can usually emit a bluish light which, when viewed from below, helps him to disguise himself, but if he is seen, he turns inside out and wraps himself in his black-colored robe... and disappears.
2. Black East Pacific chimera (Eastern Pacific Black Ghost Shark)
Found deep off the coast of California in 2009, this enigmatic shark belongs to a group of animals known as chimeras, which may be the oldest group of fish to have survived. today. Some believe that these animals, separated from the genus of sharks about 400 million years ago, survived only because they live at such great depths. This particular species of shark uses its fins to "fly" through the water column, and the males have a pointed, bat-like, retractable sex organ that protrudes from its forehead. Most likely it is used to stimulate the female or draw her closer, but very little is known about this species, so its exact purpose is unknown.
1. Colossal squid (Colossal Squid)
The colossal squid really deserves its name, having a length of 12-14 meters, which is comparable to the length of a bus. It was first "discovered" in 1925 - but only its tentacles were found in the belly of the sperm whale. The first intact specimen was found near the surface in 2003. In 2007, the largest specimen known, measuring 10 meters in length, was caught in the Antarctic waters of the Ross Sea and is currently on display at National Museum New Zealand. The squid is believed to be a slow ambush predator, feeding on large fish and other squid attracted by its bioluminescence. Most terrible fact What is known about this species is that scars were found on sperm whales, which were left by the curved hooks of the tentacles of the colossal squid.
+ Bonus
Cascade Creature
Strange the new kind deep sea jellyfish? Or maybe a floating whale placenta or a piece of garbage? Until the beginning of this year, no one knew the answer to this question. Heated discussions about this creature began after this video was posted on YouTube - but, marine biologists have identified this creature as a species of jellyfish known as Deepstaria enigmatica.
organisms living in: the surface layer of water; in the water column; at the bottom of the ocean? please give examples! and got the best answer
Answer from YaisiyaKonovalova[guru]
2. Nekton (Greek nektós - floating, floating) - a set of aquatic actively swimming organisms, mostly predatory, living in the water column, capable of resisting the force of the current and moving independently over considerable distances. More than 20,000 species of fish, squid, cetaceans, pinnipeds, water snakes, turtles, and penguins belong to the nekton.
3. Benthos (from the Greek. βένθος - depth) - a set of organisms that live on the ground and in the soil of the bottom of reservoirs. In oceanology, benthos are organisms that live on seabed; in freshwater hydrobiology - organisms that live at the bottom of continental reservoirs and streams. Animals related to benthos are called zoobenthos, and plants are called phytobenthos.
Answer from Yoanches Sanchesov[newbie]
1. Plankton lives in the surface layer of water. These are small organisms that drift freely in the water column and are unable to resist the flow.
Benthos serves as food for many fish and other aquatic animals, and is also used by humans (eg algae, oysters, crabs, some fish). An example of benthic animals is starfish, oysters, flounders, mussels, methiola, mia, sea cucumber, brittle stars, anemones and many others.
Answer from Kenyul Kadirova[newbie]
And at the bottom is benthos - a set of organisms living in the ground or on it. Pelagic organisms, in turn, are divided into plankton and nekton. Plankton consists of animals and plants that are incapable of independent movement. They move passively - by sea currents and wind; mainly small algae and animals. Nekton includes larger animals that move independently over long distances: fish, marine mammals. The real owners of the water column of the oceans and seas are small crustaceans, cephalopods and jellyfish, and of vertebrates - fish and cetaceans.
In the oceans and seas, as well as on land, plants are the basis of animal life: the inhabitants of the sea feed on them. On land, the main mass of vegetation is higher flowering plants, and in the seas - algae. Large algae - kelp, fucus - grow near the coast, and small, unicellular, float in the water column. In the sea, vegetation can exist only in the upper, sunlit layer. Near the coasts and in inland seas, algae sometimes descend only a few tens of meters. At great depths, up to about 200 m, they can only be found where the water remains clear.
Answer from Nikolai Bulatov[newbie]
1. Plankton lives in the surface layer of water. These are small organisms that drift freely in the water column and are unable to resist the flow.
2. Nekto?n (Greek nektos - floating, floating) - a set of aquatic actively swimming organisms, mostly predatory, living in the water column, able to resist the force of the current and independently move over considerable distances. More than 20,000 species of fish, squid, cetaceans, pinnipeds, water snakes, turtles, and penguins belong to the nekton.
3. Bentos (from the Greek. ?????? - depth) - a set of organisms that live on the ground and in the soil of the bottom of reservoirs. In oceanology, benthos are organisms that live on the seafloor; in freshwater hydrobiology - organisms that live at the bottom of continental reservoirs and streams. Animals related to benthos are called zoobenthos, and plants are called phytobenthos.
Benthos serves as food for many fish and other aquatic animals, and is also used by humans (eg algae, oysters, crabs, some fish). An example of benthic animals is starfish, oysters, flounders, mussels, methiola, mia, sea cucumber, brittle stars, anemones and many others.
Answer from Angelica Petrosova[newbie]
) surface - plankton frogs tadpoles ) in the thickness - crucian carp newt seal whale dolphin octopus turtles
Answer from Valya Fastovshuk[newbie]
1. Plankton lives in the surface layer of water. These are small organisms that drift freely in the water column and are unable to resist the flow.
2. Nekto?n (Greek nektos - floating, floating) - a set of aquatic actively swimming organisms, mostly predatory, living in the water column, able to resist the force of the current and independently move over considerable distances. More than 20,000 species of fish, squid, cetaceans, pinnipeds, water snakes, turtles, and penguins belong to the nekton.
3. Bentos (from the Greek. ?????? - depth) - a set of organisms that live on the ground and in the soil of the bottom of reservoirs. In oceanology, benthos are organisms that live on the seafloor; in freshwater hydrobiology - organisms that live at the bottom of continental reservoirs and streams. Animals related to benthos are called zoobenthos, and plants are called phytobenthos.
Benthos serves as food for many fish and other aquatic animals, and is also used by humans (eg algae, oysters, crabs, some fish). An example of benthic animals is starfish, oysters, flounders, mussels, methiola, mia, sea cucumber, brittle stars, anemones and many others.
Our planet is filled with various living creatures that adorn the Earth and contribute to the ecosystem. But it's no secret to anyone that water depths also teeming with many inhabitants. Although the variety of these creatures is not as abundant as on the surface, these organisms are still very unusual and interesting. So, who lives at the bottom of the ocean, what are their living conditions?
The situation at depth
From space, our planet looks like a blue pearl. This is because the area of all waters is almost three times the size of land. Like the earth, the surface of the oceans is uneven. It is dotted with hills, depressions, plains, mountains and even volcanoes. All of them are at different depths. So, the abyssal plains are submerged at about 4000-6000 m. But even there there is life, although this may be surprising, since at a depth of 1000 m the pressure is 100 atmospheres. And with every hundred meters it increases by 10 units. Also, light does not penetrate there, which is why darkness always reigns at the bottom, therefore, the process of photosynthesis does not occur. In addition, under such a thickness, the water is unable to warm up, in the deepest places the temperature is kept at zero. Such conditions make life in these places, compared to the surface, not very rich, because the lower you go down, the less vegetation grows. Therefore, the question arises: how do those who live at the bottom of the ocean adapt?
Deep sea life
Although it may seem that in such circumstances life is very difficult and even impossible, nevertheless, the local inhabitants are quite adapted to these conditions. Animals that are at the very bottom do not feel strong pressure and at the same time do not suffer from a lack of oxygen. Also, those who live at the bottom of the ocean are able to feed themselves. Basically, they collect the remains that "fall" from the upper layers.
Dwellers of the Deep
Of course, at the bottom, the diversity of life is not as great as on the surface of the waters, and you can count the deep-sea inhabitants “on the fingers”. One-celled ones are found here, there are a little more than 120 species. There are also crustaceans, there are about 110 varieties. The rest are much smaller, the number of each species does not exceed 70. Such a few inhabitants include worms, coelenterates, mollusks, sponges and echinoderms. There are also fish living at the bottom of the ocean, but here the diversity of their species is very small.
Is it really pitch black?
Since the rays of the sun are unable to break through the abyss of water, there is an opinion that all the inhabitants are in constant darkness. But in reality, many of the animals found there have the ability to emit light. Basically, predators have this property of those who live at the bottom of the ocean. For example, a conical periphylla, emitting light, attracts small inhabitants. This is a trap for them, as they become victims of this predator. But the glow can also be created by harmless living beings.
Some fish have certain areas of the body that emit light. More often they are located under the eyes or stretch along the body. Certain types of crustaceans or fish use their eyesight, but the majority of the inhabitants have no eyes or have undeveloped organs. This is not surprising, since such "live" lighting, which is created by bottom creatures, is not enough to make the underwater space observable. To get food, you have to use your sense of touch. To do this, there are modified fins, tentacles or long legs for those who live on the bottom of the ocean. The photo above illustrates one such unusual creature known as the "Atoll" jellyfish. But in the deep abyss, many living inhabitants mostly lead a motionless life, therefore they resemble flowers and plants.