Common sunfish. Moon Pisces How long does a Moon fish live?
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. They reach a length of 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, there is 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.
Range and habitat
Sunfish are found in tropical and temperate waters of all oceans. In the eastern Pacific, these fish are distributed from Canada (British Columbia) to southern Peru and Chile, in the Indo-Pacific region - throughout the 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 suddenly die. Common moonfish are often found in the surface layers 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. The 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, the smallest number of vertebrae among fish - only 16-18, the spinal cord is shorter than the brain (in a fish weighing 1.5 tons and 2.5 m long spinal cord 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 the internal organs of 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, but its total number is 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 attainable 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. Cases have been observed in Monterey Bay where sea lions They bit off the fins of the moonfish and pushed 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
When you meet this fish in the ocean, you can be seriously scared. Of course, a colossus 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, turned out to be next to her. 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 outline, in many languages of the world it is unusual creature called fish moon, or sunfish (sunfish), due to the habit of basking in the sun while floating on the surface. The translation of the German name means " floating head", Polish - " lonely head", 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, which form a characteristic non-closing beak, which gave Latin name order - Tetraodontiformes (four-toothed). Family of moon-shaped, or moon-fish, ( 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 others bony fish, for example, in the species mola mola– there are only 16 of them, the pelvic girdle is completely reduced, the caudal fin is absent, and instead of it there is a tuberous pseudo-tail. The family Molidae includes three genera and five species of sunfish:
- Genus Masturus
- Genus Mola
- Genus Ranzania
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. Largest measured mola mola reached a length of 3.3 m 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 population of sunfish is threatened by humans: in many Asian countries they are considered medicinal and large-scale catching is carried out, although there is information that the meat of these fish contains toxins, like those of hedgehog fish and pufferfish, and in internal organs There is a poison called tetrodotoxin, just 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 Atlantic Ocean The sunfish can reach Great Britain and Iceland, the coast of Norway, and even go even further north. In the Pacific Ocean in summer you can see moonfish in the Sea of Japan, more often in the northern part, and 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 the unusual appearance of the fish and its swimming method.
The heaviest modern bony fish living in ocean waters, is the Common Moonfish, a member of the family of the same name Moonfish. In some countries it is also called sunfish or headfish.
Sunfish very rarely gather in groups of more than two individuals. 
Geography of habitat
The sunfish lives in the waters of all oceans of tropical and subtropical latitudes; during spawning, the fish migrate to tropical waters. So, in the eastern Pacific Ocean this fish lives from Canada to southern regions Peru and Chile, B Indian Ocean fish can be found everywhere, right up to the Red Sea. They live in the Atlantic Ocean from Scandinavian Peninsula to South Africa. They are also found near the Kuril Islands and in the Sea of Japan.
Meet these amazing fish It is possible at a depth of up to 850 meters. According to research by scientists, almost 80% of the time these fish are at a depth of about 200 meters, and the rest of the time, they rise to a depth of 10 meters.
Moonfish in the company of divers. 
Sunfish in the water column. 
Sunfish in the water column. Appearance
Even looking at the photo of the moon fish, it is difficult to imagine how unusual it looks. Their body is quite short, high and flattened on the sides - this is what gives it its physique unusual look, making it look like a disk. They do not have a caudal fin, and the pelvic girdle is reduced. Instead of the caudal fin and them, there is a “pseudo-tail” - a cartilaginous plate formed by the spinal and cartilaginous fin. Pelvic and caudal fins are absent.
The moonfish's mouth ends in a beak formed by fused teeth. The fish have no scales, and the skin is covered with cat growths and mucus. The color of adult sunfish can be from brown to gray-silver with a variegated pattern - it all depends on the habitat. Average length adult individuals are about 1.8 m, height can reach 3 m, and weight varies from 250 to 1600 kg.
Moonfish: front view. 
Quite a large specimen of the sunfish. 
Moon fish, also called sun fish. Nutrition and behavior
The basis of the diet of sunfish consists of: oceanic plankton, salps, ctenophores and jellyfish, in addition they can eat small fish and crustaceans, eel larvae, sponges, starfish, squid, since this food is not particularly high in calories, the fish are forced to absorb it in huge quantities. This diet confirms that these fish can feed both on the surface and at depth.
As a rule, these fish live alone, less often in pairs. They are not considered good swimmers, as they maximum speed a little over 3 km/h. Pisces moons don't live in too warm water, if the temperature rises to 12°C, then the fish lose orientation in space and may even die.
The sunfish's natural enemies include sea lions, killer whales, and sharks.
Sunfish head close-up. 
Sunfish among smaller fish. 
Old sunfish. Reproduction
The head fish is the most prolific creature in the ocean - during one spawning, the female is capable of laying about 300 million eggs with a diameter of about 0.1 cm. Newborn fry weigh about 0.01 grams and look like puffer fish, however time will pass and the size of the fish will increase 60 million times - only these fish have such a huge ratio from birth to adulthood.
The average lifespan of these fish in captivity is about 10 years, in natural conditions 16-23 years.
Giant sunfish. 
Sunfish in the aquarium. 
Sunfish near the surface of the water. - The brain mass of this oceanic giant is 4 grams.
- If you put all the sunfish eggs in a chain, its length will be about 30 km.
- There is a toxin in the body of these fish, so it is undesirable to eat it, and if you eat caviar, milt or liver, it can be fatal.
- Sunfish are often kept in captivity, but sometimes these fish die when they crash against the walls of the aquarium.
- The spinal cord of the sunfish is shorter than the head, length no more than 15 mm.
The giant sunfish is amazing creature, which occurs in tropical waters Atlantic, as well as in the Indian and Pacific Oceans where it spawns. This huge representative bony fish can reach three meters in length and weigh almost one and a half tons. By the way, the giant’s brain weighs only four grams!
What does a sunfish look like?
In Latin, the name of this fish is Mola mola, which means “millstone”. And for good reason, since outwardly this creature is laterally compressed, has a disproportionately short, motionless tail, has high fins, and is shaped more like a disk than an ordinary fish. The sunfish has very thick and elastic skin, covered with small tubercles of bony material, and a tiny beak-shaped mouth, devoid of teeth. They are replaced by an enamel plate.
Character of a giant
Moonfish is a poor swimmer most She spends time lying on her side, near the surface of the water, sleepily moving her high fins, which she alternately exposes to the air. This species is not able to resist strong currents, so you can often see this good-natured monster drifting aimlessly, without even trying to overcome it. True, this statement applies only to adult individuals, and young animals swim like ordinary fish.
Is she unaware of the danger?
Obviously, huge size and its clumsy build have led to the fact that the mola-mola almost does not react to approaching ships; it can even be hit by a hook before this giant realizes to flee. True, it doesn’t matter to her. The fish is easy to catch; it grunts like a pig and rolls its eyes in all directions. But it’s not worth catching it for food, since the meat of the moonfish is more like glue, and also smells bad.
What does the sunfish eat?
In the stomach of this species, zooplankton is found: small crustaceans, squids, leptocephalus larvae, jellyfish and many salps. It is believed that these large individuals can descend to great depths.
Reproduction
By the way, this fish is the most prolific among all its relatives. She alone can produce up to three hundred million eggs. True, only a few of them survive. The newly born fry have an elongated body and normal fins. But as soon as they reach a centimeter size, they acquire a spherical shape and are covered with spines. The babies are so different from their parents that they have long been mistaken for separate species fish
Why does the moonfish cause fear?
Despite its enormous size, mola cannot harm humans. She is absolutely safe for him. But South African fishermen, for example, are afraid of meeting the moonfish. They believe that this fish is a harbinger of trouble. And therefore, as soon as they see her, they immediately return home. True, this is understandable. After all, a fish that cannot swim ends up not far from the coast when it is washed up by an approaching storm. So superstitious fear in this case is completely justified.
We may lose the good-natured giant!
The sunfish, a photo of which you can see in the article, has practically no enemies. Its thick skin and enormous size - reliable protection from predators. But still, occasionally sharks decide to attack this floating “millstone”, biting off the fins of the helpless giant, thereby dooming the fish to inevitable death at the bottom of the ocean. In Japan, as in Taiwan, for example, the meat of this fish is considered a delicacy. And in the southern latitudes, although they don’t eat it, they are considered a pest that needs to be destroyed. So we can lose an amazing little-studied giant - the moon fish.
In Latin it is called Mola Mola, and on English language "Ocean Sunfish" is a fish that looks like the moon, which gives it its name. She looks like she only has one head instead of a body, but it's not that simple.
Imagine an animal weighing 1000 kg having a brain the size of a peanut, weighing only 4 grams!
This explains why this fish is very quiet, calm... and quite stupid.
What does a moon fish look like?
The body is tall, strongly laterally flattened, covered with very thick, elastic skin. No coccyx. High fin dorsal and anal. Small mouth . Adults do not have a bladder.
The largest specimen weighs two tons and is 3 meters long!
The sunfish is also probably the most fertile fish in the world. The average female of this species lays about 300 million eggs!
Where does the moon fish live and what does it eat?
The moon fish lives a rather lonely life, swimming freely in the vast expanses of the ocean. Sometimes, however, they gather in groups and swim sideways on the surface of the water, apparently sunbathing in the sun (hence their English name- Sunfish)
Sometimes these giants accidentally get caught in fishing nets and fishermen are forced to lift them on board using cranes.
Despite their rather formidable appearance, representatives of this species feed on plankton. They also do not disdain jellyfish, calamari and eel larvae, and do not miss shellfish. The moonfish can be found in all tropical waters, and, despite its size, it is absolutely harmless to people, and the places where it appears are often the site of large-scale diving expeditions.
On the other hand, a huge fish poses a serious threat to small ships - a collision with a heading high speed A small yacht can end badly for both fish and sailors.
Moonfish caught on Sakhalin
A fish with a record weight of 1,100 kilograms was pulled out with nets by a fishing seiner from Sakhalin called the Kuril Fisherman. Russian fishermen were working near the island of Iturup, their main goal was pink salmon, and the sunfish turned up by chance.
Photo: Sakhalin.info Nevertheless, they delivered a rare specimen to the base. Since there was no room for it in the cold hold, the fish deteriorated during the passage and loading ashore. She was taken to the Gidrostroy company's landfill, where workers feed and photograph the bears. Very quickly nothing remained of the thousand-kilogram carcass.
Largest size of Pisces moon
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