15.06.2019

Angler. "Anglerfish": the life cycle of a deep-sea angler fish How an angler fish breeds

At the bottom of the deep seas and oceans, where the water is icy, the pressure reaches colossal values, and the amount of food is minimal, deep-sea angler fish (lat. Ceratioidei). All their existence a prime example how living organisms can adapt to even the most severe and adverse conditions life.

Deep sea anglers are one of the most amazing marine life living at a depth of one and a half to three kilometers. Business card of these fish is a modified ray dorsal fin, acting as a bait and shaped like a fisherman's fishing rod. It is to this feature of their appearance that angler fish owe their name.

Theodore W. Pietsch

At the end of a fishing rod (illicia), hanging over a huge mouth with sharp needle-like teeth, there is a small skin outgrowth (esca), filled with millions of luminous bacteria. It is in his light, like moths on a flame, that other, small and not very, inhabitants of the ocean floor swim. To enhance the effect produced by the esca, the angler is able to control the brightness and frequency of flashes. To do this, it is enough for him to narrow or expand the blood vessels, regulating the amount of oxygen entering the esca, which “ignites” or vice versa, “extinguishes” the luminous bacteria.

At different types anglers, the principle of operation and the design of fishing rods can vary - from the simplest, hanging over their heads, to more complex ones that can be pulled out of the channel on their backs and retracted back, turning future victim right into your mouth.

Anglerfish living at the greatest depths (more than 3500 meters) prefer not to waste energy and hunt lying on the bottom, and fishing rods, for greater convenience, are located right in their huge toothy mouth. Due to their dark coloration and rough, warty skin, deep-sea predators are almost invisible on the seabed.

Anglerfish are so voracious that they are ready to eat everything that fits in their toothy mouth. But the problem is that their mouth is much larger than their esophagus, and swallowing prey three times their size is beyond the power of these fish. Spitting out a large prey back is also not possible - teeth interfere, and very often such attempts to swallow unbearable prey become the last, unsuccessful, dinner in the life of an angler.

However, the most amazing quality of anglers is the way they reproduce. Males, the size of which is tens of times smaller sizes females voluntarily go to turn from full-fledged individuals into primitive appendages that produce sperm.

Justin Marshall/AFP-Getty Images

The female is able to carry up to six males, always and everywhere providing herself with a constant supply of sperm, freeing her from the need to regularly search for partners.

It has an extremely unattractive appearance. According to one version, that is why it was named that way. It lives on the bottom, hiding in the sand or between stones. It feeds on fish and various crustacean mollusks, which it catches using its dorsal fin as a fishing rod with a bait hanging in front of its mouth.

Description

Angler belongs to the order anglerfish, the family of ray-finned. He is also known as European anglerfish. It grows up to 1.5 - 2 m in size, can weigh up to 20 kg or more. In catches, it is usually found up to 1 m long and weighing up to 10 kg. The body is flattened, disproportionate, the head occupies up to two thirds of its length. The color of the upper part is spotty, brown with a greenish or reddish tinge. The belly is white.

The mouth is wide, with sharp, inwardly curved large teeth. The skin is bare, without scales. The eyes are small, sight and smell are poorly developed. The angler fish has leathery folds around its mouth that constantly move like algae, which allows it to hide and camouflage in the benthic vegetation.

The anterior dorsal fin in females plays a special role. It consists of six rays, three of which are isolated and grow separately. The first of them is directed forward and forms a kind of fishing rod hanging down to the very mouth. It has a base, a thin part - a "line", and a leathery luminous lure.

Habitat and varieties

The monkfish is found in fishermen's catches in many seas. The European anglerfish is common in the Atlantic. Here it lives at depths ranging from 20 to 500 m or more. It can be found in the seas along the coast of Europe, in the waters of the Barents and North Seas.

The Far Eastern species of monkfish lives off the coast of Japan and Korea. Occurs in Okhotsk, Zhelty, South China Seas. Usually inhabits depths from 40-50 to 200 m. The American angler lives in the northern part of the Atlantic at shallow depths, and in the southern regions it is more common in the coastal zone. It can be found at depths up to 600 m with a wide range of water temperatures (0 - 20 °C).

Juveniles hatched from eggs differ in appearance from adults. At the beginning of their lives, they feed on plankton, live for several months in upper layers water, and upon reaching a length of 7 cm change their appearance, sink to the bottom, become predators. Intensive growth continues during the first year of life.

Not so long ago, related species of monkfish were discovered in the depths of the ocean. They were called deep sea anglers. They can withstand enormous water pressure. They live at depths up to 2000 m.

Nutrition

Monkfish spends a lot of time in ambush. It lies motionless at the bottom, buried in the sand or disguised among rocks and aquatic vegetation. "Hunting" can take him 10 hours or more. At this time, he actively plays with bait to attract a curious victim. The leathery bulb surprisingly accurately copies the movements of a fry or shrimp.

When an interested fish is nearby, the monkfish opens its mouth and sucks in water along with the victim. It takes a matter of milliseconds, so there is practically no chance to escape from sharp teeth. IN special occasions An anglerfish can jump forward by pushing off with its fins, or use the reactivity of a jet of water released through its narrow gill slits.

Most often, stingrays, eels, gobies, flounders and other demersal fish predominate in the diet of monkfish. He also does not disdain shrimp and crabs. During intense zhora after spawning, it can rise to the upper layers of the water and, despite poor eyesight and smell, attack mackerel and herring. Monkfish have been reported hunting waterfowl. It can be dangerous at such moments for a person.

Monkfish: breeding

The male and female anglerfish are so different in appearance and size that until some time experts attributed them to different classes. Monkfish breeding is as special a moment as his appearance and way of hunting.

The male anglerfish is several times smaller than the female. To fertilize the eggs, he needs to find his chosen one and not lose sight of her. To do this, the males simply bite into the body of the female. The structure of the teeth does not allow them to free themselves, and they do not want to.

Over time, the female and male grow together, forming a single organism with a common body. Part of the organs and systems of the "husband" atrophies. He no longer needs eyes, fins, stomach. Nutrients come through the blood vessels from the body of the "wife". It remains only for the male to fertilize the eggs at the right time.

They are swept out by the female usually in the spring. Fertility sea anglerfish pretty high. On average, the female spawns up to 1 million eggs. This occurs at a depth, looks like a long (up to 10 m) and wide (up to 0.5 m) ribbon. The female can carry several “husbands” on her body so that they fertilize at the right time a large number of eggs.

Monkfish (see photo above) are not able to compare the feeling of hunger with the size of the prey. There is evidence of anglers catching fish larger than themselves but unable to release them due to the structure of their teeth. It happens that a monkfish catches a waterfowl and chokes on feathers, which leads to his death.

"Rod" is only in females. Each species of these fish has a peculiar bait peculiar only to them. It differs not only in form. Bacteria living in the mucus of the leathery bulb emit light of a certain range. For this they need oxygen.

The angler can adjust the glow. After eating, he temporarily compresses the blood vessels leading to the bait, and this reduces the flow of oxygen-enriched blood there. The bacteria stop glowing - the flashlight goes out. It is temporarily not needed, besides, the light can attract a larger predator.

Monkfish, although nasty in appearance, the meat is tasty, and in some regions it is considered a delicacy. The courage and voracity of this predator give reason for fear to divers and scuba divers. From a hungry anglerfish, especially a large one, it is better to stay away.

Fish "monkfish" or, scientifically, the European anglerfish is a representative of the anglerfish family. Most members of this family live at great depths, where they have no natural enemies, which makes this fish one of the representatives of the crown. the food chain within their own small ecosystem. This representative of ray-finned animals got its name because of its extremely specific appearance and general aggressive line of behavior in the flora.

Appearance

The appearance of the "monkfish" differs significantly from other representatives of the class of ray-finned fish, to which this animal belongs. In general, there are several common features characteristic for each angler:

large and strong mouth, filled with sharp teeth for tearing scales;
short body;
the presence of a fluorescent process on the head;
needle fins.

The name "monkfish" was given to this fish because of the general threatening impression. In Russian the closest idiom would be "scary as hell".

The total length of the fish is about 1.5–2 meters, weight - up to 57 kilograms. The body is naked, covered with skin processes, near the mouth there are several layers of skin that move when the animal moves. The body is black, brown, rarely whitish. This appearance provides the "monkfish" with excellent disguise. The creature is almost imperceptible in dense thickets of algae and on a misty bottom.

Fluorescent offshoot of anglerfish

The anglerfish got its name because of the presence of a fluorescent process on its head. This organ occupies an extremely important place in the life mechanism of the devil, since it serves as a bait for food. With the help of a branch an individual lures small fish to itself, after which it eats it. From a distance, the "monkfish" looks like a kind of fisherman. In the natural habitat, the anglerfish is practically invisible, and the process on the head serves as the only source of light and a visible point.

The “rod” itself on the devil’s head is the first ray of the dorsal fin, deformed and modified. The length of this process, also known as the illium, is up to 25% of the body length of the "feature". Placement on the head allows him to successfully hunt, luring with the help of the illitium prey directly to the mouth. The deep-sea anglerfish belongs to the ray-finned class of fish, but has little in common with other representatives of the species.

Habitat

The habitat of the "monkfish" is deep water, where this fish has practically no natural enemies, which is why the anglerfish population is quite large. There is practically no abundant food in deep water, which is why these fish have adapted by growing a fluorescent organ. The main component of the diet of the animal - small fish and crustaceans. The voluminous mouth allows you to swallow prey that is significantly larger than the “devil” itself.

The deep-sea anglerfish is able to hunt by ambush, waiting for prey at the bottom. Powerful pectoral fins, widened at the end, allow the angler easy to move along the bottom, and the general shading of the habitat ensures invisibility to other fish. Average depth Monkfish habitats - 300–350 meters, some members of the family live at a depth of up to 550 meters.

The deep-sea anglerfish is common in Atlantic Ocean, from the coast of Iceland to the Guinea Sea. Some anglers were found in the territory of the Black Sea. In general, this animal prefers cool, deep waters.

Lifestyle and reproduction

The angler fish spends most of its life in search of food, hunting or lying on the muddy bottom. The fish is even able to jump on its prey due to its strong pectoral fins. These fish are solitary and spend most part of time outside the company of your partner or joint. When they reach fertile age, they go to spawn in the British Isles or the Iberian Peninsula, spring and winter, respectively. Spawning occurs at the maximum available depth, sometimes it reaches 2 thousand meters.

Human interaction

The angler fish, nicknamed in society "fish with a flashlight", is an extremely valuable object fishing industry. Its boneless meat is prized in several world cuisines, predominantly in France where "monkfish" is served with white wine as an extremely prestigious and status dish. In 2005–2014, the level of commercial fishing for monkfish reached maximum volumes. The record number of anglers caught was 33.2 thousand tons. Fishing takes place by means of a bottom trawl, which captures most of the individuals buried in the silt. The leaders in fishing are Great Britain and France.

This individual has found its application in such industries:

genetics - scientists are trying to synthesize a fluorescent substance produced by bacteria;
industry - angler meat is extremely valuable;
ichthyology - the anglerfish is the crown of the food chain in its ecosystem.

According to gourmets, monkfish meat is quite tough, but boneless and very nutritious.

Deep under the water column in the seas and oceans, where the pressure is simply enormous, the water is very cold, and there is practically no food, deep-sea angler fish have adapted to life.

Their way of life shows how living beings can adapt even to the most difficult environmental conditions.

Deep Sea Anglers - mysterious creatures living at a depth of about 1.5-3 kilometers. characteristic feature anglerfish is a modified dorsal fin, elongated in the form of a beam and used as a bait.

With such a beam of fish attracts prey, as if on a bait. Thanks to this structural feature, angler fish got their name.

At the end of the fishing rod is a small skin outgrowth in which millions of luminous bacteria live. And the outgrowth hangs over a mouth filled with needle-shaped teeth. When other residents underwater world rush to this light, like moths to a flame, they fall right into the mouth.

Moreover, the angler can adjust the frequency and brightness of flashes, thereby controlling the effect. To do this, it simply expands or constricts the blood vessels, due to which the amount of oxygen supplied to the outgrowth increases or decreases, oxygen, in turn, contributes to the glow or decay of bacteria.

Different types of deep-sea anglers have a special design of the fishing rod: some rods are simple, they just hang over their mouths, while others are more complex - they can be extended and retracted into the channel located on the back, so they lead the victim into their mouth.

Anglerfish living at great depths save energy, so during the hunt they just lie on the bottom. The fishing rods of such anglers are located directly in the huge mouth. Deep-sea anglerfish have a dark color and warty skin, thanks to which they are well camouflaged at the bottom and the victim does not see his killer.

Anglerfish are extremely voracious, they swallow everything that can fit in their mouth. But the problem is that the esophagus is much smaller to graze, so the anglerfish cannot swallow too large prey, but it also fails to spit out the caught fish, since teeth prevent this. Therefore, often such an unsuccessful dinner becomes the last in the life of a deep-sea anglerfish.

The most amazing thing is how anglers reproduce. Males are ten times smaller than females in size. The stronger sex voluntarily transforms from full-fledged creatures into appendages necessary for the production of sperm.

This phenomenon is called "male parasitism", its essence lies in the fact that males initially have fully formed organs, and when they bite into the skin of their partner with their sharp teeth, they do not have to get food and fight for survival, and they begin to degenerate. The male attaches to the female not only with his mouth, but also with blood vessels. That is, the male and female, as if, become one. Also, the male does not need eyes, jaws, stomach and other organs, that is, they also atrophy. The male parasite retains only the reproductive organs.

What kind of creatures did not appear on Earth as a result of natural selection. In harsh conditions, at great depths, where the water is icy, the pressure reaches colossal values, and the amount of food is minimal, deep-sea anglerfish (lat. Ceratioidei) live.

They live at a depth of one and a half to three kilometers. The peculiarity of these fish is a modified ray of the dorsal fin, which acts as a bait and is shaped like a fisherman's fishing rod (in fact, for this reason they were called anglers).

For different types of anglers, the principle of operation and the design of fishing rods can vary - from the simplest, hanging over your head, to more complex ones that can move out of the channel on your back and retract back, leading the future victim right into your mouth.

Amazing, isn't it? However, this is not the most unusual thing about these fish. The breeding method of some species of anglerfish is amazing.

Males, whose size is ten times smaller than the size of females, voluntarily go to turn from full-fledged individuals into primitive appendages that produce sperm.