Is there lifein the deep sea
Previously, the question: “Are there any living organisms in the depths of water deeper than a thousand meters?” Was just as relevant as the hypothesis of the existence of extraterrestrial intelligence. Fancy lovers inhabited far-off planets with bizarre little men, and sea abysses - with giant octopuses, swallowing whole ships. Skeptics, on the other hand, argued that at a depth of more than two thousand meters, where sunlight does not fall, and where atmospheric pressure is many times greater than that on the surface of the earth, there simply cannot be any life. But fishing by bottom trawl, and especially the descent of the bathyscaphes, showed: the bottom of the ocean troughs is habitable. Not only worms and crustaceans live there, but also deep-sea fish. Some of them have such a strange appearance and habits that it seems as if they have disappeared from the pages of fiction novels.
In the water column at a depth of seven thousand meters, the atmospheric pressure is 700 times normal. How do deep-water fish survive in such conditions? Ichthyologists have found that some of their species do not have a swim bladder at all, and their body has a jelly-like, gelatinous consistency. Such fish never leave the bottom layers and languidly eke out their existence, passively hunting for crustaceans and worms: they simply open their mouths and wait for them to crawl there. But there are also such species that can rise to the level of 4, 2 thousand and even a thousand meters. Such fish pump gas into their bubble when lifting, and release it during descent.
How do these inhabitants of black and cold hollows eat? Life affects the diversity of species near the surface of the water. But with diving down a decrease is observed not only in the number of fish, but also in their species. The maximum depth of the Pacific Ocean (Mariana Trench) is 8800 m, and that of the Atlantic (Puerto Rico Trough) is 8400. The density of living creatures is there, as in the tundra, but there are still indigenous people there. How do they hunt, because there are no algae in this kingdom of darkness? Many species of such fish have photophores on their bodies. This is a kind of flickering "flashlights". Such deep-water fish like angler fish have a dorsal fin specially arched forward, on the tip of which a small light shines like bait on a hook. This is not a flashlight for movement, but a bait for food.
This is not to say that all the inhabitants of the ocean trenches are blind, like the inhabitants of caves. There are species among them whose eyes have atrophied (typhlonus, rat-tails), but there are those whose organs of sight, on the contrary, have developed very much. In batilichnops there are four eyes, and in batilept and giants they hang on stalks like a snail. Many deep-sea fish have a distinct sexual differentiation. So, anglerfish ceraria breeds in a unique way. Males of this species are much smaller than females - 17–20 mm against the background of a 120-centimeter “lady”. Having met a girlfriend, such a tadpole clings to her in order to ... merge with her forever. His circulatory system grows together with the circulatory system of the "beloved", the jaws, the intestines and eyes disappear as unnecessary. He only produces sperm and nothing else. And on one female several such “gentlemen” can quite comfortably get along. Well, the deepest fish, currently known to science, is wrong. One individual of the species Abyssobrotula galatheae was caught at a depth of 8370 m in the Atlantic. In the Pacific, the record was broken by a bassogigas fish caught at a depth of eight thousand meters.
Bassogigas - the deepest fish in the world
So, get acquainted, bassogigas - fish, which is the absolute record for the deep-water habitat. For the first time, a bassogigas was caught at the bottom of a trench not far from Puerto Rico at a depth of 8 km (!) From the board of the research ship "John Eliot".
As you can see, in appearance our deep-water record holder differs little from ordinary fish, although in fact, despite the relatively typical appearance of his habits and lifestyle, scientists of zoologists still have little knowledge, because conducting research at such great depth is a very difficult task.
But now our next hero is hard to blame for “ordinary”, get acquainted - the fish is a drop, which in our opinion has the strangest and most fantastic appearance.
Like an alien from space, isn't it? A drop of fish lives on the deep ocean floor near Australia and Tasmania. The size of an adult representative of the species is no more than 30 cm. In front of it there is a process resembling our nose, and on the sides, respectively, there are two eyes. A drop of fish does not have developed muscles and in its way of life resembles sloths in some way of life - it slowly swims with its mouth open in anticipation that the prey, which is usually small invertebrates, will itself be near. After that, a drop of fish swallows prey. She herself inedible and also is on the verge of extinction.
And here is our next hero - sea bat, which in its appearance does not even look like a fish.
But, nevertheless, it is still a fish, although it does not know how to swim. The bat moves along the seabed, starting with its fins, so similar to the legs. Bat lives in the warm deep-water waters of the world ocean. The largest representatives of the species reach 50 cm in length. Bats are predators and feed on various small fish, but since they do not know how to swim, they lure their prey with a special bulb growing straight from the head. This bulb has a peculiar smell that attracts the fish, as well as worms and crustaceans (they also serve as food for our hero), while the bat itself patiently sits in ambush and as soon as the potential prey finds itself abruptly enough.
Anglerfish - deep-sea fish with a flashlight
The deep-water anglerfish living, including in the depths of the famous Mariana Trench, is especially remarkable for its appearance, thanks to the presence of the most real fishing rod-flashlight on the head (hence its name).
A angler's flashlight rod is not only for beauty, but also serves the most practical purposes, with its help our hero also lures prey - various small fish, although due to his small appetite and the presence of sharp teeth, the angler does not shun to attack and on the larger representatives of the fish kingdom. Interesting fact: anglers often themselves fall prey to their particular gluttony, as having grasped a large fish because of the peculiarities of the structure of the teeth, it can no longer release its prey, as a result of which it chokes and dies.
But back to his amazing biological flashlight, why is it glowing? In fact, light is provided by special luminous bacteria that live with angler fish in close symbiosis.
In addition to its main name, the deep-water anglerfish has others: “sea devil”, “monkfish”, because by its appearance and habits, it can be safely attributed to the deep-sea monster fish.
The barrel-eye probably has the most unusual structure among deep-sea fish: a transparent head through which it can see with its tubular eyes.
Although the fish was first discovered by scientists in 1939, it still remains poorly studied. Inhabits the Bering Sea, near the west coast of the United States and Canada, as well as near the shores of northern Japan.
6 years ago, American oceanologists discovered living creatures at a record depth of 10 km. - giant amoeba. True, they no longer belong to fish, so among fish, primacy still takes bassogigas, but these giant amoebas are absolute record-breakers among living creatures living at the greatest depth - the bottom of the Mariana Trench, the deepest known on Earth. These amoebas were discovered with the help of a special deep-water camera, and their life research continues to this day.
The deepest fish is the bassogigas. He was able to catch at a depth of more than 8 km from the research vessel "John Eliot". Little is known about the life of these deep-sea fish. It is believed that they feed on the bottom remains of marine animals.
This deep sea bottom fish lives near Australia and Tasmania. The length of an adult individual does not exceed 30 cm. There is a process on the front of the head that looks like a nose, on the sides of which there are two eyes. Fish droplets lack developed muscles. It swims slowly, opening its mouth, or freezes in one place, waiting for the passing of prey and swallowing small invertebrates. Fish-drop is inedible. It is believed that she is on the verge of extinction.
The black live fish of the fish, living at depths of 700 m and below, has adapted to absorb prey, which may be 2 times longer and 10 times heavier than itself. This is possible due to the highly stretching stomach of the black gastrointestinal tract. Sometimes the prey is so large that it begins to decompose before it is completely digested, and the gases released during this process push the fish to the surface of the ocean.
This small deep-sea octopus lives in the Tasman Sea at a depth of 100 to 5000 m, and some species were found at a depth of 7 km. Octopus tentacles are connected by a thin elastic membrane called umbrella. A resident of the sea moves like jellyfish, pushing water out from under the umbrella bell. In nature, there are about 37 species of these octopuses. They feed on snails, worms and mollusks. Individuals of mature age reach a length of 20 cm.
Along with bassogigas deep sea fish is the sea slug. In 1970, this fish was discovered at a depth of about 8 km. Among sea slugs, there are both giants up to 80 cm long and small species that are 8-10 cm long. The color of sea slugs is the most diverse - it depends on the depth of their habitat.
These fish constantly live at great depths (1500–3000 m), in the depth of ocean waters. They have a flat body on the sides. In addition, anglers are equipped with a luminous "fishing rod", the glow of which is created by special bacteria. This bait anglers bait prey. The voracity of these hunters often leads to the death of themselves. Having captured a large fish, the angler fish cannot release it because of the structure of its teeth, therefore it crushes and then dies.
Tripod fish is one of the deepest fish in the world, living at a depth of 1 to 6 km. Tripod fish has very small eyes that it almost does not use. Leaning on the ocean floor with its long, bony rays growing from the tail and pectoral fins, the tripod fish is always facing against the current. This trick allows it to effortlessly absorb shrimp, small fish and crustaceans, which over the course puts the hunter standing in wait in the mouth.
What are deep-sea fish lanterns for?
Despite the fact that the fish living at a monstrous depth (about 3000 m!) Absolutely do not need to illuminate their path, nature, however, "gave" many of them special luminous organs.
Anglerfish, for example, received “fishing rods” (ortsii) with bright “lanterns” (eskami) at the end: it is in them that special glowing - bioluminescent - bacteria are found that react sensitively to the narrowing and expansion of blood vessel walls and begin to glow brighter or, on the contrary more dimly. It is interesting that only females deserve such a generous gift: it is they who, thanks to their huge mouths and strong teeth, with the help of luminous baits easily hunt the gaping sea creatures.
In some fish, “lanterns” are located in the mouth, while in others (for example, hatchet fish) - throughout the body, including and under the eyes. In this case, the luminous organs are called photophores.