Is there a moon fish? The largest fish (from the bony class) in the world

When you meet this fish in the ocean, you can be seriously scared. Of course - a giant 3-5 meters long and weighing several tons is capable of inspiring fear with its size and completely implausible appearance.

In fact, the sunfish is completely harmless, because it feeds on jellyfish, ctenophores, small fish, crustaceans and other zooplankton, which, unfortunately, happen to be next to it. This fish does not know how to maneuver and swim quickly in pursuit of prey, but only sucks into its mouth-beak everything edible that happens to be nearby.

Because of its rounded shape, in many languages ​​of the world this unusual creature is called a moonfish, or a sunfish, due to its habit of basking in the sun while swimming on the surface. The translation of the German name means “floating head”, the Polish one means “lonely head”, and the Chinese call this fish an “overturned car”. In Latin, the most numerous genus of these fish is called mola, which means “millstone”. The fish earned this name not only by its body shape, but also by its grey, rough skin.

Sunfishes belong to the order Pufferfishes, which includes pufferfishes and urchinfishes, with which they have much in common. First of all, these are four fused front teeth that form a characteristic non-closing beak, which gave the Latin name to the order - Tetraodontiformes (four-toothed). The family of moonfish, or moonfish, (Molidae) is united by the unusual appearance of these millstone-like animals. It seems that at the dawn of evolution, someone bit off the back of the fish’s body just behind the dorsal and anal fins, and they survived and gave birth to equally strange offspring.

Indeed, representatives of this family have fewer vertebrae than other bony fish, for example, the species mola mola - there are only 16 of them, the pelvic girdle is completely reduced, the caudal fin is absent, and instead there is a tuberous pseudo-tail. The family Molidae includes three genera and five species of sunfish:

Sharptail sunfish, Sharptail mola, Masturus lanceolatus
Masturus oxyuropterus

Ocean sunfish, Mola mola
Southern sunfish, Mola ramsayi

Slender sunfish, Slender sunfish, Ranzania laevis.

Almost all members of the sunfish family live in tropical, subtropical, and sometimes temperate waters. They all reach large sizes and have a rounded, laterally compressed shape of the head and body. They have rough skin, no tail bones, and a skeleton made mostly of cartilage. Sunfishes do not have bony plates in their skin, but the skin itself is thick and dense, like cartilage. They are painted in brown, silver-gray, white, sometimes with patterns. These fish lack a swim bladder, which disappears in the early stages of larval development.

Sunfish are the largest of the bony fish. The largest mola mola measured was 3.3 m long and weighed 2.3 tons. There are reports that fish were caught that reached a length of more than five meters. In the process of development from larvae to adults, all sunfish go through several stages of development, and all forms are completely different from each other. The larvae that hatch from the eggs resemble pufferfish, then wide bony plates appear on the body of the grown larvae, which are subsequently preserved only in fish of the genus Ranzania; in the mole and masturus, the protrusions on the plates gradually turn into sharp long spines, which then disappear. The caudal fin and swim bladder gradually disappear, and the teeth merge into a single plate.

Moonfish - (lat. Mola mola), translated from Latin as millstone. This fish can be more than three meters long and weigh about one and a half tons. The largest specimen of the sunfish was caught in New Hampshire, USA. Its length was five and a half meters, there is no data on weight. The shape of the fish’s body resembles a disk; it was this feature that gave rise to the Latin name.

The most studied are the moonfish of the genus Mola. Fish of the genus Masturus are very similar to mola mola, but they have an elongated pseudo-tail and the eyes are more forward. There was an opinion that these fish are anomalous mola, which retained a larval tail, but studies have shown that during the growth of the fish, the rays of the pseudo-tail appear after the reduction of the larval one. Somewhat different from other sunfish are representatives of the genus Ranzania, which reach a small size of 1 m and have a flatter and elongated body shape.

All moonfish use very long and narrow anal and dorsal fins when moving, flapping them like a bird's wings, while small pectoral fins serve as stabilizers. To steer, fish spit a strong stream of water from their mouths or gills. Despite their love to bask in the sun, sunfish live at a respectable depth of several hundred and sometimes thousands of meters.

It is reported that sunfish can produce sounds by rubbing their pharyngeal teeth, which are long and claw-like.

In 1908, this moonfish was caught 65 kilometers off the coast of Sydney; it became entangled in the propellers of the steamship Fiona, which is why the ship was unable to move further. At that time it was the largest specimen of the moon fish caught, it reached a length of 3.1 m and a width of 4.1 m. Photo: danmeth

Sunfish are record holders for the number of eggs laid; one female is capable of laying several hundred million eggs. Despite this fecundity, the number of these extraordinary fish is declining. Except natural enemies, which prey on larvae and adults, the sunfish population is threatened by humans: in many Asian countries They are considered medicinal and they are caught on a large scale, although there is information that the meat of these fish contains toxins, like urchinfish and puffer fish, and that the internal organs contain the poison tetrodotoxin, like puffer fish.

The moon fish has thick skin. It is elastic, and its surface is covered with small bony projections. The larvae of fish of this species and young individuals swim in the usual way. Adult large fish swim on their sides, quietly moving their fins. They seem to lie on the surface of the water, where they are very easy to notice and catch. However, many experts believe that only sick fish swim this way. As an argument, they cite the fact that the stomach of fish caught on the surface is usually empty.

Compared to other fish, the sunfish is a poor swimmer. She is unable to fight the current and often floats at the will of the waves, without a goal. This is observed by sailors, noticing the dorsal fin of this clumsy fish.

In the Atlantic Ocean, the moonfish can reach Great Britain and Iceland, the coast of Norway, and even go further north. In the Pacific Ocean in summer you can see moonfish in the Sea of ​​Japan, more often in the northern part, and near the Kuril Islands.

Although the moonfish looks quite menacing due to its impressive size, it is not scary to humans. However, there are many signs among sailors South Africa who interpret the appearance of this fish as a sign of trouble. This is probably due to the fact that the sunfish approaches the shore only before the weather worsens. The sailors associate the appearance of the fish with an approaching storm and rush to return to shore. Such superstitions also arise due to unusual looking fish and its swimming method.

Scientific classification:
Domain: Eukaryotes
Kingdom: Animals
Type: Chordates
Class: Ray-finned fish
Squad: Pufferfish
Family: Moonfish (lat. Molidae (Bonaparte, 1832))

Moon fish, sun fish, head fish - these are all names for one ocean fish, family of moon-shaped, or moon-fish, (Molidae). This family includes five species of sunfish, the most common of which is Mola mola.
The sunfish is the largest of modern bony fishes, an adult of which on average reaches 3 m in length and 150 kg in mass. The Guinness Book of Records records data on a fish that was caught in 1908 near Sydney; its body length was 4.26 m and its weight was 2235 kg.

Although there is evidence that in the waters Atlantic Ocean, off the coast of the USA (New Hampshire), a specimen 5.5 m long was caught, the mass of which remained unrecorded.

The habitat of the sunfish is tropical, subtropical and temperate waters of the world's oceans. However, this sunfish goes only to the tropical waters of the Atlantic, Indian and Pacific oceans to spawn. Some adult fish can be carried by warm currents and at the same time penetrate into moderately warm waters.

In the waters of the Atlantic Ocean, fish can be seen near Newfoundland, Iceland, Great Britain, in the Baltic Sea and along the coasts of Norway and Kola Peninsula. You can also meet this fish in the Sea of ​​Japan and the Kuril Islands.

The moon fish surprises with its unusual appearance. Her body is compressed on both sides, while it is very tall and short. If you look at the fish in profile, it seems that it is round and resembles the disk of the full moon, and the full face of the fish rather resembles a millstone of a mill. Also, if you look closely at this giant, it resembles a fish well known to us - flounder. Thanks to this appearance, this fish got its names (moon, sun, head).

The body of the fish is covered with skin, which is quite thick and at the same time elastic, like cartilage. The skin of the fish is protected by small bony tubercles, which serve as scales, since this fish is devoid of true scales. Thanks to this skin structure, the moonfish is not afraid of direct blows from a harpoon; it simply bounces off such armor. The color of the covers is varied; you can see brown, silver-gray, white fish, sometimes with patterns.

The fish does not have a caudal fin, but instead there is a tuberous pseudo-tail. This feature is associated with complete reduction of the pelvic girdle. The dorsal and anal fins are large and fused together. The sunfish swims lying on its side, alternately moving its fins, while the small pectoral fins stabilize the position of the body.

To steer (to control the direction of movement), fish release a stream of water from oral cavity or gills. Having this body shape, the moonfish is a very poor swimmer; it uses passive movement. However, at the same time, it takes advantage of the peculiarities of its anatomy - by exposing its large triangular-shaped dorsal fin from the water, it scares off human fishermen who, due to inexperience, may mistake it for a shark.

Basically, this fish swims at a depth of 100-400m. But there are specimens that rise to the surface of the water. Many researchers believe that only sick fish float on the surface of the water. As evidence, the fact is cited that the contents of the stomachs of fish caught on the sea surface are very small.

During a storm, fish move to shallow water. This feature of the moon fish was noticed local residents coastal islands, and consider its appearance in the coastal waters bad omen, as this is a sign of an approaching storm. On the other hand, it is a reliable harbinger of fishermen.

The fish's head ends in a small mouth, similar to a parrot's beak. This non-closing beak is formed by four fused front teeth. The fish sucks in its prey - zooplankton. In the pharynx there are pharyngeal teeth, which are quite long and perform the function of grinding food.

Confirmation of this can be found by looking at gastric content study data. Crustaceans, small squids, ctenophores and jellyfish were found in it. But there is also evidence of active catching of prey, as the famous Russian scientist - ichthyologist Vedensky, said that he witnessed a previously unprecedented hunt for mackerel by the sunfish. During this, the sunfish accelerates as fast as it can with its body and jumps out of the water, splashing onto the surface and stunning the victim.

The fish's skeleton consists mainly of cartilaginous tissue; it has fewer vertebrae, compared to other bony fish, for example, the species mola mola has only 16. An adult sunfish does not have a swim bladder.

The brain is very small - 4 g, which explains the apathetic behavior of the fish. So, for example, a person can freely approach her in the water at a fairly close distance and she will not be afraid. The sunfish can produce sounds by rubbing its pharyngeal teeth. About which ichthyologist Alfred Bram wrote: “When irritated, the moonfish grunts like a pig.”

These fish are solitary fish; very rarely they can be found in pairs, much less in a school. Their spawning begins in July and ends in October. Mating occurs on the surface of the water. The number of eggs laid by one individual is enormous - 300 million pieces, which indicates high degree death of embryos. The size of each egg is approximately 0.1 cm.

If you lay out all the eggs in a row, you can get a chain 300 km long. When the moon fish fry are born, they are 6 million times smaller than the volume of their mother. Taking into account the limited habitat of the sunfish, it can be assumed that the survival rate of juveniles is very low.

In his life cycle All moon fish go through several stages of development; development occurs with metamorphosis, since all forms are different and not similar to each other. Having emerged from the eggs, the larvae resemble pufferfish (rounded body, large head).

Then, on the body of the larvae that have not died and grown, wide bone plates appear, the protrusions of which will gradually turn into sharp long spines. As the larva grows, the caudal fin and swim bladder disappear, and all the teeth the fish has grow together into a single plate.

Fish larvae and young individuals swim like all bony fish. The fry are very different from the adult fish and until recently they were considered a separate species.

It is difficult for the sunfish to move in the depths of the ocean, so it easily becomes prey for sharks, killer whales, sea ​​lions and others large predators. When hunting them, predators try first of all to bite off the fins in order to completely immobilize the apathetic fish.

The size of the sunfish population is also threatened by humans: in many Asian countries, the meat of this fish is considered medicinal, which is why large-scale fishing is carried out. According to the latest data received by scientists, the meat of these fish is toxic because, like puffer fish, it contains the poison tetrodotoxin, which often leads to death.

But there are still fans who simply eat its meat boiled or fried. In his reviews, Alfred Bram wrote: “The meat of this fish is very tasteless, like glue, with a disgusting smell; If you boil it, you can use it as glue.”

But if you eat the liver, milt or caviar of these fish, then a person will definitely receive serious poisoning, which can lead to death. But for a person in natural environment These fish are not dangerous in their habitat and many lovers of underwater beauty go specifically to Indonesia (Bali) to see it in natural conditions swim next to her.

For aquarium lovers, we can draw a regrettable conclusion - the sunfish is not suitable for keeping in a closed system - captivity (aquarium, pool), since it does not adapt and quickly dies. This is due to the impossibility of providing real living conditions for these fish.

Since the study of the behavior and lifestyle of these organisms was carried out very superficially, out of five existing species- only one has been studied.

The sunfish is different from other fish species due to its unique appearance. If you look at this representative of the underwater world, it is difficult to say that this is a fish and not some other animal. This is due to the fact that the fish's body resembles a disk shape, which indicates its extraterrestrial origin. At least that's what many people think. The easiest way is to compare this fish with an ordinary plate.

This fish also has a second name - mola, as it represents the genus and species of the same name (Mola mola). If the name is translated from Latin, then mola means “millstones”, which have the shape great circle gray-blue hue. Therefore, the name of the fish corresponds to its appearance.

Some sources call this representative of the underwater world a moon fish, and some simply call it a floating head.

Despite different approaches in defining the name - this is the most major representative bony fish. Its average weight reaches 1 thousand kg, although there are specimens whose weight reaches 2 thousand kg.

The fish is characterized by rather bizarre body shapes. Its body is round and laterally flattened, and on it you can see two dorsal and two anal fins. The tail part is also different unique structure, called corns.

This fish is devoid of scales, but its body is covered with durable and reliable skin, which under certain conditions can change its color. The skin is quite elastic and covered with a layer of mucus. This fish cannot be caught by a regular harpoon. Depending on its habitat, its color can vary from brown or brownish-gray to light gray-bluish.

Interesting Facts! The moon fish, unlike other fish species, is distinguished by a smaller number of vertebrae, which indicates a lack of bone tissue in the skeleton. In addition, the fish lacks a classic pelvis, ribs and swim bladder.

And although the fish is quite impressive in size, its mouth is very small, reminiscent of a parrot’s beak. This illusion is created by teeth fused together.

The moon fish inhabits the waters of various continents located in warm and temperate latitudes. Some subspecies of this fish inhabit waters below the equator, within Australia, New Zealand, South Africa and Chile.

The average size of the moon fish is limited to a height of 2.5 meters and a length of 2 meters, and the maximum sizes are 4 and 3 meters, respectively. In 1996, a mola was caught that weighed about 2 thousand 300 kg. To give you an idea, this corresponds to the weight and size of an adult white rhinoceros.

These fish, despite huge size, are not predators, and even more so, are considered absolutely safe for humans. At the same time, they pose a danger to boats and vessels if they move at high speed.

Interesting fact! The cement tanker MV Goliath, which was en route to Sydney Harbour, collided with a 1,400kg mole fish. This happened in 1998. The vehicle was moving at a speed of about 14 knots, but after the collision its speed dropped to 10 knots. At the same time, one of the sections of the ship lost its protective paint, right down to the metal itself.

When the mola is still young, its body is covered with bone spines, which disappear as the individuals grow older.

At first glance, this fish cannot swim at all, but this is not at all true. Even so, it has fins that allow the fish, albeit slowly, to move through the water column. Her movements in the water occur in a circle, which is ineffective, but she succeeds.

The mola's diet includes jellyfish and siphonophores - invertebrate living organisms. In addition, its food source is squid, small crustaceans, deep-sea eel larvae, etc. Although there are plenty of jellyfish in the water column, they are not a nutritious source of food.

It turns out that not much is known about this fish, since even scientists do not know how long the moon fish can live. Some experts claim that fish live for about 20 years. Statements are based on data on the growth and development of fish, depending on habitat conditions. Despite this, according to some data, females can live more than 100 years, and males up to 90 years. No one knows what information is reliable.

The sunfish is a distinct marine species that spends its entire life in the open ocean, so little is known about it. The fish lives in cold and southern waters of the world's oceans.

It is believed that the moon fish in the warm season is in warm layers of water, which are located at depths of up to 50 meters, while the fish from time to time dives to depths of more than 150 meters.

As far as we know, moonfish are found everywhere in tropical, subtropical and temperate latitudes of the world's oceans.

According to experts, the moonfish mainly feeds on jellyfish. As a rule, jellyfish are not nutritious, and in order to grow to such a size and gain impressive weight, the fish dilutes its diet with mollusks, crustaceans, squid and small fish. To do this, it needs to regularly descend to depth in search of more nutritious food components. While long time At depths, and at significant depths, the fish’s body temperature drops, which leads to a slowdown in many life processes. To raise their body temperature, the fish rises to the upper layers of the water and basks in direct sunlight.

As mentioned earlier, this fish has not yet been fully studied, including its reproductive biology. Despite this, the sunfish is known to be the most prolific vertebrate on the planet.

Sexually mature individuals are capable of laying up to 300 million eggs, and the larvae that emerge from the eggs are no larger than a pinhead. When they are born, mole fry have a protective shell in the form of a translucent star or snowflake.

To date, it is unknown where and how the fish lays its eggs. Presumably, for spawning, the fish chooses the waters of the North and South Atlantic, the North and South Pacific Oceans, as well as the waters of the Indian Ocean. For fish, it is important that there is a concentration of rotating ocean currents in the form of gyres.

Interesting fact! The hatched moonfish larvae reach a length of no more than 2.5 mm. To reach sexual maturity, the fish will have to increase in size up to 60 million times.

The appearance of the moon fish surprises almost everyone, but what is most surprising is that the puffer fish is the closest relative of the mola.

When individuals become sexually mature, there are practically no natural enemies for them, with the exception of humans, who are engaged in very wasteful fishing. The main share of fish catches occurs in the waters of the Pacific Ocean, the Atlantic Ocean and the Mediterranean Sea. In these waters, up to 90% of the moon fish are caught, in terms of the total catch. At the same time, fishing is rarely practiced, and it ends up in the net purely by accident.

Despite such facts, moonfish meat is considered a real delicacy in some Asian countries. As a rule, even fish skin and cartilage are used, especially in countries such as Japan and Thailand. In addition, fish is actively used as a medicinal product, although this is only used by ethnoscience. It is impossible to buy this fish in supermarkets or at the market, but you can try it in expensive restaurants where they know how to properly prepare this fish.

A characteristic feature of meat is the repulsive smell of iodine. Despite this, meat is rich in proteins and other useful components. Cutting this fish requires special professionalism, since the liver and bile ducts contain a lethal dose of poison. During unprofessional cutting, if the liver and bile ducts are touched, the poison will get into the meat and then into the food. As a rule, this leads to death.

Considering the fact that the fish is of no commercial value, no measures are being taken to preserve its numbers, although this is absolutely unfair, since everything in nature is interconnected. The fish becomes a victim of uncontrolled fishing, as well as other factors. It often gets caught in fishermen's nets as it often moves closer to the surface. The fish is quite slow due to the structural features of its body, which makes it especially vulnerable to a number of negative factors.

Scientists have calculated that up to 340 thousand sunfish are caught annually within the waters of South Africa. Experts estimate that moonfish makes up about 29% of the total fish catch, which clearly exceeds the need for it.

In the waters of Japan and Taiwan, targeted fishing for mola mola is carried out. This is due to the fact that fishermen supply this fish to local restaurants as a culinary delicacy.

Based on some calculations, we can safely say that the populations of this fish in some waters are declining by up to 80%. In this regard, it is not difficult to assume that the world stocks of this fish are also declining. It is believed that the level of reduction reaches about 30%. This is especially true in relation to the next 3 generations, that is, in the next 25 years. Little is known about the populations of other subspecies, such as "tecata" Mola and Mola "ramsayi", but it is not difficult to assume that they will suffer the same fate.

It is difficult to even imagine that even those species of fish that are not of commercial value suffer from the unreasonable activity of humans. In this case, it is not difficult to imagine the scale of the catch valuable species fish, or at least those that are of commercial interest. It is not surprising that people have already reached the point where they simply need to ban fishing on a global scale. If this is not done, you will simply have to forget about a product such as fish, which is fraught with serious negative consequences for humans. It seems that humanity is waiting for a stage when fish will have to be grown artificially, in specially designated water areas. The reason for this may also be the fact that water resources are polluted at a high rate, which also leads to a decrease in fish stocks on a global scale.

The moon fish is an amazing creature, but for some reason it has been studied very poorly and it is unknown what role this amazing creature plays in the life of all nature and humans in particular. This suggests that even in the 3rd millennium there is a lot of unknown on Earth, which prevents us from having a complete understanding of life on our Planet.

Common moonfish, or sun fish, or fish head(lat. Mola mola) - a species of the genus of moon fish of the family of the same name. These are the heaviest of modern bony fishes. Reach in length three meters. The Guinness Book of Records provides data on an individual caught on September 18, 1908 near Sydney, which was 3.1 m long, 4.26 m high, and weighed 2235 kg.

Common sunfish live in tropical and temperate waters of all oceans. They are found in the pelagic zone at depths of up to 844 m. They have a laterally compressed, disc-shaped body. The dorsal and anal fins are moved back and form a tail plate. The skin is devoid of scales. The teeth are fused into a “beak”. Pelvic fins are absent. The color is bluish or grayish-brown. They feed mainly on jellyfish and other pelagic invertebrates. They are the most prolific vertebrate species, with female common moonfish producing up to 300,000,000 eggs at a time. The fry of this species resemble miniature pufferfish, they have large pectoral fins, a caudal fin and spines that disappear in adulthood. Adult sunfish are quite vulnerable. They are preyed upon by sea lions, killer whales and sharks. In some countries, such as Japan, Korea and Taiwan, their meat is considered a delicacy. In EU countries there is a ban on the sale of sunfish products. Common sunfish are often caught in gill nets.

Taxonomy

The name of the genus and the specific epithet come from the Latin word. mola - “millstone”. The species was first scientifically described by Carl Linnaeus in 1758 as Tetraodon mola. Subsequently, various generic and species names were repeatedly assigned.

Range and habitat

Sunfish are found in tropical and temperate waters of all oceans. In the eastern Pacific Ocean, these fish are distributed from Canada (British Columbia) to southern Peru and Chile, in the Indo-Pacific region - throughout Indian Ocean including the Red Sea, and further from Russia and Japan to Australia, New Zealand and Hawaii. In the eastern Atlantic they are found from Scandinavia to South Africa, and occasionally enter the Baltic, North and Mediterranean seas. In the western Atlantic Ocean, sunfish can be found from the coast of Newfoundland to southern Argentina, including the Gulf of Mexico and the Caribbean Sea. Genetic differences between individuals living in the Northern and Southern Hemispheres are minimal.

During the spring and summer, the population of common moonfish in the northwest Atlantic is estimated at 18,000 individuals. IN coastal waters Large concentrations of small fish up to 1 m in length are observed. In the Irish and Celtic Seas in 2003-2005, 68 individuals of this species were recorded, the estimated population density was 0.98 individuals per 100 km².

Usually these fish are caught at temperatures above 10 °C. Long stay at temperatures of 12 °C and below can cause them to become disorientated and sudden death. Common moonfish are often found in the surface layers of the open ocean; There was an opinion that this fish swims on its side, but there is a version that this method of movement is typical for sick individuals. It is also possible that in this way the fish warm up their bodies before immersing themselves in cold water layers.

Description

Antique image of a common sunfish (1838) as Orthragoriscus mola

Common moonfish have a laterally compressed, high and short body, which gives the fish an extremely unusual appearance for fish. The shape of the body approaches that of a disk, and its length is approximately equal to its height. The pelvic girdle is reduced. In the process of evolution, the tail fin of moon fish disappeared. It was replaced by a tuberous pseudotail - lat. clavus. This elastic cartilaginous plate is formed by dorsal and anal fins moved back and devoid of spiny rays. It is supported by their branched soft rays. This tail plate acts like an oar. It consists of 12 fin rays and ends in rounded bones.

The gill slits are oval-shaped, the eyes and mouth are small, and there are no pronounced ventral or caudal fins. Pectoral fins, located on the sides of the body, are small and fan-shaped.

The common sunfish has a very short spine relative to body length, smallest number among fish there are only 16-18 vertebrae, the spinal cord is shorter than the brain (in a fish weighing 1.5 tons and 2.5 m long, the length of the spinal cord is only 15 mm). The bones of the caudal fin are completely absent, and the skeleton consists mainly of cartilaginous tissue. There is no swim bladder or lateral line.

Moonfish swim using their dorsal and anal fins, with their pectoral fins acting as stabilizers. To perform the turn, they release a strong stream of water from their mouth or gills. In addition, they are able to maneuver a little by changing the position of the anal and dorsal fins, similar to how birds use their wings for maneuvers.

It is believed that moon fish are capable of making grinding sounds with the help of their pharyngeal teeth. The mouth ends in a well-developed beak, characteristic of representatives of the order Pufferfish, formed by fused teeth. The “beak” prevents them from closing their mouth tightly.

Skeleton of a common moonfish

The thick and rather rough skin is devoid of scales and covered with bony projections and mucus. The skin of the tail plate is comparatively softer. Under the skin there is a cartilaginous layer 5-7.5 cm thick, so it is difficult to pierce it the first time even with a harpoon. The color of adults varies from brown to silver-gray with a mottled pattern, which in some cases is characteristic of their habitats. The dorsal surface of the body is colored slightly darker than the ventral one, which is a type of contrasting protective coloring characteristic of pelagic fish. In addition, Pisces moons are capable of changing color, especially in times of danger.

Some sources indicate that internal organs fish of this species contain the neurotoxin tetrodotoxin, like other representatives of pufferfish, but other authors refute this information.

Body size and weight

Adult common moonfish reach an average length of 1.8 m, and the height distance between the tips of the fins is about 2.5 m. The average weight ranges from 247-1000 kg. There are also larger specimens: the maximum recorded length is 3.3 m, and the height, including fins, is 4.2 m.

Biology

Moonfish larva 2.7 mm long

Reproduction and life cycle

The sunfish is the most prolific fish: one female can lay up to 300 million eggs, however total number its small. The diameter of the eggs is about 1 mm, the hatched larvae of the moon fish have a length of about 2 mm and a mass of less than 0.01 g. During individual development Like other representatives of their family, ordinary moon fish go through a complex metamorphosis. The newly hatched larvae look like puffer fish. Upon reaching a length of 6-8 mm, the body stage begins - wide bone plates with large triangular protrusions appear, which are then crushed into small denticles with triangular protrusions, forming long spines, then completely disappearing. At this stage there is still a larval caudal fin, which is absent in adult fish. The potentially achievable size of adult moonfish is 60 million times their size at birth, the largest ratio among vertebrates.

In captivity, common sunfish live up to 10 years, but their lifespan in natural conditions has not been established. Presumably in males and females it can be up to 16 and 23 years, respectively. In captivity, weight gain ranges from 0.02-0.49 kg per day, and length gain averages 0.1 cm per day. The weight of a young individual living in the Monterey Bay Aquarium increased from 26 kg to 399 in 15 months, while the fish reached a length of 1.8 m. Their large size and thick skin make adult sunfish invulnerable to small predators However, the fry can become prey for tuna and corifena. Large fish are attacked by sea lions, killer whales and sharks. In Monterey Bay, sea lions have been observed biting off the fins of moonfish and pushing them to the surface of the water. Probably, with the help of such actions, mammals manage to bite through the thick skin of fish. Sometimes, after throwing the moonfish several times, the sea lions abandoned their prey, and it helplessly sank to the bottom, where it was eaten by starfish.

Nutrition

Despite their hard beak, the diet of common moonfish consists mainly of soft food, although they sometimes eat small fish and crustaceans. The sunfish's main diet consists of plankton, as well as salps, ctenophores and jellyfish. In addition, larvae of eels, sponges, starfish, squid, crustaceans, algae and small fish, this suggests that they feed both on the surface and in the depths. Sunfish food is generally poor nutrients, so they have to absorb it in large quantities.

Moonfish swims on its side near the surface of the water

Ordinary moonfish lead, as a rule, a solitary lifestyle, but sometimes they are found in pairs, and in places where cleaning animals gather they can gather in groups.

The sunfish can often be seen lying on its side on the surface of the water. From time to time, its fins appear on the surface - sometimes they are mistaken for shark dorsal fins. They can be distinguished by the nature of the movement of their fins. Sharks, like most fish, swim by flapping their tail fin from side to side. In this case, the dorsal fin remains motionless. Moonfish move their dorsal and anal fins like oars

Moon fish are amazing and little-studied creatures, striking in their size, appearance and colossal fertility. They belong to a tiny family of only three species: the common sunfish, the sharp-tailed moonfish and the sunfish. This family belongs to the order Pufferfish and is related to species such as triggerfish, puffer fish and pufferfish.

Common sunfish (Mola mola).

The moon fish owes its name to unusual shape bodies. The most famous common sunfish it is almost round, in the ransania and sharp-tailed moonfish it is slightly elongated and resembles a melon or torpedo. At the same time, the body is flattened from the sides, but does not differ in grace. The edges of the body appear torn and resemble a failed pancake. All languages ​​of the world in one way or another contain a reference to this unusual feature. In most European languages, these creatures are called moonfish or sunfish, the Latin name of the species is translated as “millstone”, and in Polish this fish is called “samoglav”, because it seems as if it consists of only one giant head. The body of the moon fish is indeed greatly shortened, but the most surprising thing is that it lacks the main organ of movement - the tail! It is replaced by a blade, devoid of its own muscular system. The body of moonfish appears high due to the highly developed oval-pointed dorsal and anal fins. The pectoral fins, on the contrary, are very small. The eyes are relatively large with a good-natured, stupid expression. The mouth of these fish is also relatively small; sharp teeth form something like jaws, but for gnawing hard objects unsuitable. The skin is very thick, rough to the touch due to the bony plates that dot it, but at the same time elastic.

Although Moon Pisces does not shine with beauty and grace, they cannot fail to inspire admiration. The fact is that these are the largest of all bony fish, second in size only to the whale shark (a cartilaginous fish). The usual size of an adult is 2-3 m in height (since they are longer vertically than horizontally), weight is about 1 ton. The Guinness Book of Records records a sunfish measuring 4.2 m and weighing 2.3 tons! The only “dwarf” in this family is the knapsack, only 80 cm long. The coloring of these creatures also emphasizes their resemblance to the moon or millstones. It is gray, sometimes with whitish spots on the sides. Interestingly, moon fish are able to change color slightly: from slate gray to almost white. These fish do not have sexual dimorphism, so males and females do not differ from each other in appearance.

The sunfish's mouth appears tiny in proportion to its huge body.

Due to the lack of a tail, moonfish are forced to move with the help of fins (in most fish they serve only as rudders), but this method of movement is very ineffective. Making leisurely strokes of their fins, these creatures can swim very slowly, and often prefer to drift with the current. Sometimes sunfish swim on their sides, but these are probably sick or dying individuals. Despite their colossal size, these fish are very peaceful, phlegmatic and defenseless. They are completely unable to resist the attack of predators, and when attacked, they only passively watch as the aggressor tears their body.

Moonfish feed on small prey, which are as sedentary as they themselves. Their food includes jellyfish, ctenophores, salps, small crustaceans and squids. Moreover, they search for food both on the surface of the water and in the depths. They can tear into pieces an animal that does not fit into their small mouth, and grind solid food with their pharyngeal teeth. According to some evidence, sunfish meat can be poisonous, probably due to the consumption of poisonous jellyfish and the accumulation of toxins in the muscles of the fish.

The tiny baby sunfish is armed with spines.

Moonfish do not have special spawning grounds, so they spawn in the same areas where they feed. In terms of fertility, the females of these species have no equal: each can lay up to 300 million eggs! This is an absolute record in the world of fish. Sunfish eggs are extremely small and float in the water column (such eggs are called pelagic eggs). Thanks to this, it can be carried by currents over long distances, contributing to the spread of these slow-moving creatures across the oceans. The tiny fry that hatch from the eggs initially have large spines to protect them from predators. However, the young grow very quickly and by 15 months reach a size of 1.8 m. According to observations in captivity, sunfish can live up to 10 years; life expectancy in nature has not been precisely established.

Despite their large size, moonfish have many enemies. Young individuals can be attacked by tuna, while killer whales and sharks like to hunt adults. There are cases when sea lions played with these fish, biting off their fins and throwing their bodies above the water. Men in different parts The world treats moon fish differently. In Taiwan and Japan, they are considered the greatest delicacy (along with the related species puffer fish) and are eaten from all parts of the body. IN European countries Fishing for these species is prohibited. And in the tropics, sunfish are not eaten, but they are not protected either. Here they are considered pests that steal bait from hooks, so fishermen cut off the fins of caught individuals and condemn them to a slow, painful death in the depths of the ocean.

Common sunfish in the Barcelona Aquarium.

In captivity, these fish are extremely rare, since they require large and deep aquariums, and they are often injured on the walls of containers. Now the aquariums of Osaka, Monterey, Barcelona, ​​Lisbon and Valencia can boast of having these fish in their collections. Sunfish need protection as amazing and still little-studied representatives of the aquatic fauna.