These sea animals have always fascinated me. Giants, Quiet, calm. They are like seabirds soaring in the depths of the oceans. I’ll be honest, when I first saw them, I couldn’t take my eyes off them for a long time. But these harmless and calm animals are called nothing other than SEA DEVIL.
I suggest you look at them in more detail.
Few people have as many legends about them as the sea devil. By the way, the unfortunate Amphibian Man from A. Belyaev’s science fiction novel was also considered a sea devil.
And in the Baltic there was a legend about the Sea Bishop for a long time - they caught him a couple of times, brought him to the king, tried to communicate in Polish and Latin (since the devil is obliged to know Latin!), but he was still silent, looking at people with sad, suffering eyes. But, they say, one day he showed the Catholic priests with signs that he wanted to go home to the sea, and they persuaded the king. The creature crossed those present (oh, these legends!) and disappeared into its native waters...
Many legends about the sea devil exist in Japan. And in South-East Asia To this day, meeting him is a bad omen. Although it’s easier to meet: both off the coast and in open ocean this is still a common occurrence. According to local beliefs, even if you happen to catch them, you must immediately release them, out of harm’s way.
Manta rays are very different from others sea creatures their curiosity - they willingly make contact and show curiosity themselves. Now the manta ray is on the verge of complete extinction.
Manta rays are the largest living rays. The body width of some individuals can reach more than 7 meters. Previously people they were afraid of manta rays and called them " sea Devil manta ray,” but in fact, manta rays are harmless giants. They feed only on plankton and small fish. At the same time, manta rays are perhaps the most intelligent of all marine inhabitants. They have the largest brain, relative to the total body mass, of all living fish. And it is still unknown why. Scientists still know little about manta rays.
Each manta ray is born with a unique, day-specific set of spots on its belly. In November, manta rays gather off the coast of Mozambique for courtship and mating. When a female manta is ready to mate, she forces the males to simply chase her, so you can often see a whole line of males chasing a large female. Sometimes there are one or two males, and sometimes there are as many as 12. They swim after the female around the reef at very high speeds, and repeat almost every move she makes.
This is a whole ritual, very beautiful and interesting. Typically, manta rays give birth to only one calf. Their pregnancy lasts 12 months. But the manta ray very rarely reproduces every year. Manta rays often take a year or two off between pregnancies, probably to recuperate. This means that manta rays are not capable of restoring their population if their life is threatened, for example, due to negative influence fishing. Given such a low reproductive capacity of manta rays, there is real danger complete extinction of this beautiful animal.
The presence of Chinese syndicates on the Mozambique coast raises serious concerns. Manta ray meat is highly prized in Chinese folk medicine. And hunting for them promises too much great benefit so that local fishermen living in poverty can resist it. Around the world, wherever manta rays are hunted, they are considered a critically endangered species.
The safety of Mozambican manta rays can only be ensured if the coast receives the status marine reserve. In these waters you can see larger number whale sharks than anywhere else in the world. People swim here regularly different kinds whales
Until recently, it was believed that there was only one species in the world manta rays. But recent observations have shown that there is another species - giant manta rays. They are much larger than ordinary manta rays - their body width can reach 7.5 meters. In addition, the pattern on their belly has a much more pronounced color or shape.
The manta ray evolved from electric stingrays millions of years ago. It was believed that during evolution they lost their sting. For smaller manta rays this is true. However, it was possible to establish that giant manta rays still possess remnants of a stinging spine, which is located at the base of their tails. Therefore, giant manta rays can be distinguished as a separate species.
Where do the giant manta rays go after short stay V coastal waters Mozambique? This still remains a mystery. It is believed that manta rays are migratory animals and are capable of covering vast distances. Most They spend their lives in the fish-rich waters of the Indian Ocean.
The name manta (lat. Manta birostris) is also from the realm of terrible legends. After all, translated from Spanish, manta means mantilla, cloak, cloak. The fish, with its cloak (large and strong fins, similar to wings or the flaps of a cloak), hugged the person and dragged him to the bottom. Such deadly embraces have long been attributed to the manta ray.
But in fact, the sea devil (like the Napoleon fish) is one of the safest creatures. There are no spikes, no electricity, no creepy teeth, the elongated tail-lash is not armed with anything. And the character is not malicious, even good-natured. People are not attacked at all. And the manta moves gracefully, leisurely, even phlegmatically; rather, it soars, flies, flaps its wings. A fascinating sight...
True, the manta has an unusually impressive appearance: its body width is from 4 to 7 meters, its weight is up to 2 tons. This is the largest and at the same time the most harmless of all types of stingrays. Manta rays can be seen in all tropical oceans, moreover, both in the water column or on the surface, and above the water. One of her famous features is her impressive jumps into the air to a height of up to one and a half meters. Just imagine. And the sound of falling back into the water can be heard for miles.
Why manta rays frolic so much, jumping out of the water, is not known exactly. Either the mood is good, or the process of courtship is in full swing - and then any somersault-mortale comes into play, or this is such a topsy-turvy “shower”...
Manta meat is rumored to be tasty and nutritious, the liver is beyond praise. Recipes for manti dishes are found in ancient “cookbooks”. But hunting for it is quite a dangerous task, it can capsize a boat, drag it with a harpoon, and even seriously batter it, smash it to pieces, such cases are known. Even with bullet wounds, the manta resists for a long time, fighting for life. And it’s a painfully beautiful creature – we’ll survive without such exotic cuisine.
Moreover, females are capable of bringing only one cub, however, it is also quite large in size - up to 10 kilograms, one meter long. Which will very quickly grow into a beautiful, huge monster. It will plow the seas and oceans, overcome enormous distances, pleasing the eyes of lovers of such beauty: when it cleans its belly coral reef when it puts the tips of its pectoral fins parallel out of the water, scaring you to death (it looks too much like dorsal fins sharks), when it jumps out of the water, it almost does a somersault and splashes into the water with a roar.
The largest of the stingrays, the body width of individual individuals reaches 7 m (mostly 4-4.5 meters), and the mass of large specimens is up to 2.5 tons.
The oral cavity of manta rays is very wide and located on the front edge of the head. On the sides of the mouth there are two blades that direct the flow of water into the mouth. Like other stag rays, mantas have a developed filtering apparatus, consisting of gill plates on which food is filtered - planktonic crustaceans and small fish.
Previously, it was believed that manta rays could attack a diver, hugging them from above with their fin-wings and crushing them to death; There were also beliefs that a stingray could swallow a person. In fact, the only danger to humans comes from a manta ray jumping out of the water: it can accidentally collapse on a boat or swimmer with all its enormous weight.
Man became convinced of the safety of these animals quite recently, and in the 60s of the 20th century. sea devils appeared before people in the form bloodthirsty creatures. Were even filmed art films, where manta rays appeared as killers.
The sea devil's brain is larger than that of other rays or sharks. Due to their intelligence, flexible nature and tamability, manta rays are well-deserved among divers around the world who come to the islands of the Indian Ocean to swim side by side with manta rays. Besides, he is quite curious. When an interesting object appears on the surface, it floats up and drifts on the waves, observing what is happening. Maybe that’s why in ancient times the encounter of a boat with a huge “carpet” that looks at you with an interested gaze gave rise to a wary attitude towards the sea devil?
What do you think of this photo?
Another feature of the manta is its jumping above the water. It is not clear exactly what purpose the devil is pursuing by jumping 1.5 m above the surface of the water. His deafening landing of a 2-ton body can be heard for several kilometers around, and it is possible that this is the purpose of the jump - to attract a partner or to kill small surface fish?
(Manta birostris) is the most big stingray and belongs to the class Cartilaginous fish, subclass Elasmobranchs, superorder Batoidea or Rays, order Dasyatiformes or Stingrays.
It can reach 2 m in length with a “wingspan” of up to 7 m, and its weight reaches two tons. The isolated front parts of the pectoral fins are shaped like horns, which is why the manta ray is also called the sea devil. The mouth of these stingrays is very wide and is located on the front edge of the head. Like other stag rays, mantas have developed a kind of filtering apparatus, consisting of gill plates on which food is filtered - planktonic crustaceans, small fish. Manta rays travel vast distances in search of food, constantly following the movement of plankton. The animal is warm-blooded.
Mantas move beautifully in the water, flapping their “wings” with ease and grace. Sometimes observed lying on the surface of the water. In this case, one of the pectoral fins bends so that its edge sticks out.
The ability of sea devils to jump out of the water is well known. At the same time, they can rise 1.5 m above its surface. The sound of a large specimen falling on the water is heard like thunder and can be heard for several miles.
Manta rays are completely safe for humans because they are not aggressive. However, touching her skin, which is covered with small spines, is fraught with bruises and abrasions. Manta rays feed on plankton, crustaceans and small fish. The back is black, the belly is bright white.
Giant manta rays are found in tropical waters of all oceans. They live in the water column and are sometimes found even in the open ocean.
Manta rays have teeth only on the lower jaw, each of which is the size of a pinhead. The tip of each tooth has a blunt surface with three faint grooves. These teeth are often indistinguishable from teeth in the mouth and are not involved in the process of eating food. They can play a sanitary role and are important during the courtship period.
Like sharks and other rays, manta rays undergo internal fertilization. Male Mantas have a pair of penis-like organs (claspers) that develop on the inside of their pelvic limbs (like limbs, of course). Each clasper has a depression through which sperm enters the female's body, where fertilization occurs. During courtship, several Mantas can try for quite a long time to achieve the love of the female. But ultimately, the most successful Manta grabs the top of its mouth wings with its teeth (which we have already written about) and pushes it into the stomach. And somehow it turns out that it is at this moment that one of his claspers penetrates the cloaca. Copulation lasts 90 seconds. The female manta bears a single, but very substantial calf, about 125 cm wide and weighing 10 kg. When it is born, it emerges from the mother's womb tail first, curled into a cylinder, and immediately turns around, beginning to flap its pectoral fins.
Manta with yellow fish. Scientists have found that the manta ray may be one of the most... smart creatures in the ocean. (Andrea Marshall)
A young manta ray feeding: With a fin span of up to 7.5 meters, manta rays are the largest of the diamond rays. (Guy Stevens)
Manta ray view from below. Typically, females of this species give birth to one young. Pregnancy lasts 12 months. (Andrea Marshall)
The results of the study showed that one of the giant stingrays, named Magellan, swam 1,126 km in 60 days. (Andrea Marshall)
Several manta rays feed together in Landaa Lagoon in the Maldives. (Guy Stevens)
More than a hundred manta rays gather in the Maldives to find food. (Andrea Marshall)
Stingrays gather during the monsoon season. (Andrea Marshall)
The process of filming a film about manta rays. (Andrea Marshall)
Giant stingray with divers. With a fin span of up to 7.5 meters, the giant manta ray is much larger than reef rays. (Andrea Marshall)
The abundance of plankton in the coastal waters of Sharm el-Sheikh attracts large manta rays and every diver can try his luck. Camel Dive Club videographers managed to film several manta rays and we are happy to offer you this sketch.
The manta ray is one of the large fish living in the World Ocean. Thanks to the unusual arrangement of the pectoral fins, which form peculiar horns on the head, the name “sea devil fish” was assigned to the manta. But they have nothing “devilish” in their lifestyle and behavior. These are peaceful and calm creatures, as well as those that feed on plankton, filtering it from the water.
In the fish system, the manta ray (scientific name Manta birostris) is in the class cartilaginous fish. It belongs to the order of tail-shaped stingrays (without a poisonous spine on the tail) and the bracken family, within which there is a subfamily of horned stingrays (the second name is manta rays, Mobulidae).
The name staghorn comes from the similarity of the processes located on the head with horns. And the Eagle family probably got its name due to its wide pectoral fins, which resemble the spread wings of an eagle. When an eagle ray swims, it looks like a huge underwater bird, because the movements of its fins resemble the movements of its wings.
Features of the sea devil's lifestyle
The manta ray is found in the waters of all oceans (except the Arctic Ocean). It inhabits marine areas of the tropics and subtropics, and is partially found in temperate zone. The boundaries of its distribution are 35 degrees north and south of the equator. The lifestyle is pelagic, with some features:
They swim by flapping their large pectoral fins, slightly extended to the sides, like wings.. Being far from the shore, they swim in a straight line at a constant speed; in shallow water they often rest on the water or slowly circle in place.
The manta ray fish is known for its ability to jump high out of the water (up to a height of one and a half meters). When a large individual falls onto the water after a jump, a sound similar to thunder is heard that can be heard for several miles in the area.
Appearance, feeding habits and enemies
The pectoral fins of the devil fish are huge, due to which the shape of the disk (body) looks like an elongated diamond. The distance from the tip of one pectoral fin to the tip of the second is more than 2 times the length of the body of this stingray fish. The maximum recorded span of manta fins is about 9 meters, the average is 4.5 meters.
The manta ray fish has three pairs of limbs that actively function, which is an exception for vertebrates:
- Pelvic fins moved towards the tail.
- A pair of pectoral fins, which the manta flaps like wings when swimming.
- The cephalic fins are the elongated anterior part of the pectoral fins. They are long enough and play important role when obtaining food.
The head fins of manta rays are usually curled and look like spiral “horns”. They straighten out in order to direct the flow of water along with planktonic organisms directly into the open mouth.
Plankton mining
The devil fish has a huge mouth located on the front of its head. For this position of the mouth is an exception, because in all other representatives of this superorder the mouth opening is located at the bottom. Small teeth in the form of tubercles are located in rows on the lower jaw (the upper edentulous). central part The jaw has 18 rows of teeth; towards the corners of the mouth the number of rows of teeth is reduced to 12.
Based on its feeding method, this giant sea devil is a harmless filter feeder. It has a good apparatus for straining plankton: brownish-pink plates with a spongy structure, located between the gill arches, which retain plankton (crustaceans and small fish). The sea devil fish needs to swim long distances to search for food, following plankton, which does not stand still, but is constantly moving.
Vision and smell are the main senses that help manta rays find food. The feeding process is very interesting:
- At first, this huge fish slowly moves around the accumulation of plankton, driving it into a large pile.
- Then the stingray accelerates and swims quickly with a wide open mouth to the center of this cluster.
- Long head fins, which are curled during normal movement, help direct water along with food into the mouth.
When a very large concentration of planktonic organisms is encountered, the giant sea devil can go into a state of feeding frenzy, as seen in sharks.
Enemies in their natural habitat
At sea, manta rays can be attacked by killer whales and large sharks(stupid, and).
How do they reproduce?
Like everything else, the giant sea devil reproduces by ovoviviparity. The fertilized eggs develop in the mother's body, where the offspring hatch, and then the female gives birth to a single baby, ready for independent life.
Manta rays become sexually mature when they reach the age of 5–6 years. The breeding season lasts from December to April. At this time, fish exhibit interesting mating behavior:
- First, one or more males chase the female’s tail for 20–30 minutes and attack her several times.
- Then one of the males, approaching the female, grabs the edge of her pectoral fin with his mouth and turns his partner over with her belly up.
- Then mating occurs: the male’s pterygopodium is inserted into the female’s cloaca. They can remain in this position for one to two minutes.
Manta rays mate in the upper layer of water. One or two males can mate with one female and fertilize her.
Embryo development
Developing in the mother’s body in a special organ similar to the “uterus” of mammals, the embryo initially receives nutrition from the yolk sac. These nutrients are not enough for the full development of the little stingray’s body, so after some time a source of additional nutrients from the mother is connected. Through specialized structures that form in the “uterus,” the embryo begins to receive fluid enriched with fat and protein components.
The manta embryo develops for a very long time (approximately one year).
Young stingrays are very large at birth: the disc reaches more than one meter in width (up to 130 centimeters). Weight can be from 9 to 12 kilograms. A female manta gives birth to one calf (rarely two). This happens in shallow water, where the young ones fatten up over the next few years.
Long-term gestation and the small number of young born are one of the reasons for the vulnerability of this ray and the decline in numbers. This trend has been observed over the past two decades (due to overfishing). Therefore, the giant sea devil received from International Union nature conservation status "vulnerable species".
Manta ray or giant sea devil is a species of stingray of the genus of the same name in the eagle family of the caudal-shaped order, a superorder of stingrays. Representatives of the subfamily Mobulinae, which includes manta rays, are the only vertebrates that have three pairs of functioning limbs. This is the largest of the stingrays, the body width of individual individuals reaches 9.1 m (in the bulk 4-4.5 meters), and the mass of large specimens is up to 3 tons.
Translated from Spanish The name of this fish is translated as “cloak” or “blanket”. And indeed, floating in the depths clear water The manta ray is very reminiscent of a kind of flying carpet, elegantly and majestically soaring in the sky.
Manta is one of the most known species stingrays He owes his fame, first of all, to huge size and amazing appearance, which caused the appearance of various legends, stories and fables about this amazing fish since ancient times.
The appearance and size of the manta ray are truly unique. Even a newborn baby bird reaches more than 150 cm in fin span, and an adult can reach a wingspan of almost 8 m and weighs more than 2 tons! This is a real sea giant.
To be fair, it should be said that the manta ray is not the record holder among rays in terms of body length - the “podium” in this competition is occupied by saw-throated rays, some species of which reach 7.6 m from the tip of the snout to the tip of the tail. The manta's body does not grow longer than the 2 meter mark. But due to the massiveness and breadth of the wing-fin span, the manta ray, according to the unanimous opinion of biologists, is considered the largest ray from known to science.
The appearance of this fish does not allow it to be confused with any other stingray or marine animal. Her body resembles a diamond-shaped carpet, black on top and snow-white on the ventral side. Wide wings formed by pectoral fins, whip-shaped short tail, and characteristic horns on the head formed by the anterior tips of the pectoral fins. With these horns, the stingray increases the flow of water into the cavity of its huge mouth. Why does the manta need increased water circulation in its mouth? Yes, for the simple reason that these rays are planktivorous marine animals, like whales, cetaceans and giant sharks. Even the manta's mouth is shaped like the mouth of a whale shark, differing, however, in the structure of the dental apparatus.
The ability of sea devils to jump out of the water is well known. At the same time, they can rise 1.5 m above its surface. The sound of a large specimen falling on the water is heard like thunder and can be heard for several miles. Manta rays are completely safe for humans because they are not aggressive. However, touching her skin, which is covered with small spines, is fraught with bruises and abrasions.
On their way to collect plankton, stingrays can travel thousands of kilometers. Stingrays live in warm waters all oceans except the Arctic. More often they are found in Indian Ocean, where they form entire flocks. They usually hover in the water column, absorbing plankton crops, and often rest near the surface, exposing the tips of their pectoral fins to the surface.
Mantas swim by flapping their pectoral fins like wings. In the open sea they move at a constant speed in a straight line, and near the shore they often bask on the surface of the water or lazily circle. They are found both singly and in groups of up to 30 individuals. They are often accompanied by other fish, as well as seabirds.
Interestingly, manta rays are the most “brainy” fish in the World Ocean. The specific gravity of the manta's brain (relative to body weight) is the largest fish known to science. It is possible that manta rays are the most “smart” fish on Earth.
The main danger to manta rays is humans. Stingray meat is tasty and the liver is rich in fat. Therefore, in their habitats, artisanal fishermen and sports fishermen hunt mantas. It’s not easy to get a huge fish out of the water, so it’s prestigious. This is causing manta ray numbers to decline, causing concern among conservationists. Currently, work is underway on artificial breeding these animals are in captivity. In 2007, a baby manta ray was born for the first time at the Okinawa Aquarium (Japan).
The manta ray is one of the largest fish in the world. But, oddly enough, science knows surprisingly little about them.
text: Juliet Irmer
photo: Takako Uno and Stephen Wong
Four black and white giants emerge from the darkness of the ocean. On both sides, their flat bodies turn into wide fins, which they flap like wings. A school of fish flies in the water like a flock of birds.
Manta rays soar over the reef with their mouths wide open. One of them heads towards the divers and turns sharply right in front of them, showing its light belly. A flash flashes. Huge fish circle over the reef, and scuba divers signal each other to surface.
Two hours later, Andrea Marshall downloads the photos onto her computer. The thatch-roofed research station in Tofo, a village in southern Mozambique, is as hot as a greenhouse. The fan doesn't help. The sound of the surf can be heard from afar.
For ten years now, 31-year-old hydrobiologist Andrea Marshall has been studying the world's largest species of stingray. The manta ray, or giant sea devil, is one of the most... big fish on the ground. An adult stingray weighs up to two tons, the span of its lateral fins can reach seven meters - almost like a football goal.
There is only one species of manta ray, according to the Fish Catalog, a large three-volume reference book sitting on Marshall's shelf. But the marks on her world map tell a different story. The researcher marked the habitats of all known manta populations with red and blue dots. Blue color means one type, red means another. This map is her personal proof of the theory that there are not one, but two varieties of these fish.
Today's photographs taken by Marshall and her colleague, New Zealand biologist Simon Pearce, appear on the monitor. Three of the four stingrays they met were old acquaintances, to whom scientists assigned very American nicknames: Compass, 50 cents and Apple Pie. Scientists distinguish them by spots and scars on the belly and the lower part of the lateral fins. In each fish they form a unique pattern. For example, the 50-cent stingray has streaks on its belly that resemble the numbers “5” and “0,” and the right fin, bitten by a shark, curves in the shape of the letter “c,” which begins the word “cent.”
Marshall looks at photos of the fourth stingray. This is a female. The dark spots on her belly look like a lion's paw print. The researcher compares the photo with photographs of other females in the database. There are no matches. Marshall names the newcomer Simba after the lion cub from The Lion King.
Simba is the 743rd stingray in her catalog. There are few manta ray populations in the entire world as large as here, off the coast of Mozambique, near the village of Tofo. None of them have been studied better than here.
Manta rays live in warm seas. The points on the map are concentrated at East Coast Australia, in the Pacific archipelagos, off the coast of California and in the Caribbean Sea. But most of them are in the Indian Ocean: off the East Coast of Africa, as well as off the coast of Thailand and Indonesia. How many manta rays live in the world's oceans? What are average duration their lives and habits? Science does not yet have a clear answer to all these questions.
Andrea Marshall was the first to describe marriage ritual manta rays During the breeding season, each female is relentlessly followed by up to 20 males. They, like a living train, repeat her every maneuver, until finally the female chooses one male. Pregnancy in manta rays lasts about a year, the female gives birth to one fry, the span of which reaches one and a half meters. From the very first minute of life, the little stingray is left to its own devices.
Relatively total weight Mantas have the largest brains of any fish. Many scientists believe that a gregarious lifestyle promotes brain growth. Mantas feed in groups and swim together for “hygienic procedures” in places where cleaner fish gather. It is assumed that in flocks of manta rays there is a hierarchy between older and younger individuals. Manta rays regularly emerge from the water and splash onto the sea surface. Marshall suggests that this is how they exchange signals. She generally considers manta rays to be very sociable creatures and is sure that there are individuals among them. Some are curious and playful, others are timid and indecisive.
Based on observations of manta rays off the coast of Mozambique, an American woman is trying to uncover other secrets of their behavior. About half of the recorded stingrays live here permanently, and Marshall regularly encounters them on dives. For example, she has already seen females Compass and 50 cents dozens of times. But in her database there are another hundred individuals that she observed off the coast of Mozambique, just one at a time over eight years. Is this a coincidence?
Andrea Marshall first came to Tofo ten years ago. Then she was still a hydrobiology student in Brisbane, Australia, and was interested in underwater photography. One of her friends advised her to dive off the coast of Mozambique.
Marshall grew up near San Francisco. She received her diving certificate at age 12; By the age of 15, she had logged half a thousand scuba dives. But nowhere in the world had she seen such a rich underwater world, like off the coast of Mozambique. And most importantly, you could see stingrays here every day. At other popular dive sites, these fish must be tracked from an airplane.
Returning to Brisbane, Andrea Marshall decided to write her dissertation on manta rays. Professor Michael Bennett “looked at me like I was crazy. Of course, these animals are little studied. But there is an explanation for this: stingrays are rare, and studying them is an expensive pleasure. And in general: how can you write a dissertation in Africa at the age of 22?!” Marshall recalls.
But she decided to take a risk. After selling her car and furniture in Brisbane, Andrea flew to Mozambique. In the village of Tofo, she settled in a hut without water or light. The fishermen took her by boat to one of the reefs and then took her back. Later she was joined by a specialist whale sharks Simon Pearce. But in the early years, she constantly violated the main commandment of a diver - never dive alone.
Six months have passed since arriving in Tofo. One evening, while looking through photos of stingrays, Andrea Marshall noticed something strange. Some fish seemed to her larger and darker than others. “At first I thought they were older individuals,” she says. But she soon noticed other differences. It turned out that the giant manta rays fed and swam separately from the smaller rays. In addition, she rarely came across them, unlike the smaller manta rays that she saw every day. Does this mean that rays - like killer whales - are divided into two groups: sedentary and migratory? Over time, another possible explanation occurred to her.
A year and a half later, Andrea returned to Brisbane and shared a theory with her professor: there are two types of manta rays. “He didn’t even listen, but my other observations impressed him.” The dissertation topic was approved.
Andrea Marshall consulted five other stingray experts, but none of them supported her hypothesis. Manta rays are distributed almost throughout the world, and geographic isolation contributes to the formation of new biological species. It was unlikely that two species would have evolved in the absence of natural barriers, they argued. Moreover, when comparative analysis No differences were found in manta ray DNA. This is another argument against her theory.
It starts to bake at seven in the morning. Marshall looks out to sea from the shore. This is the fourth day already south coast A long green cloud of phytoplankton stretches across Mozambique. These microscopic algae are at the beginning of the food chain of the World Ocean. We must wait for the wind to change and carry this mass out of the bay into the open sea. IN muddy water it is difficult to track down her charges.
Marshall decides to try his luck. The day before, a group of divers noticed huge manta rays underwater. A researcher wants to install a satellite transmitter on one of the fish. She attaches miniature acoustic radio transmitters to the skin of smaller mantas. When a tagged stingray swims within 500 meters of a radio receiver, its transmitter signals are picked up and recorded. Marshall installed 12 radios along the 100-kilometer coastline in Tofo Bay. This way she can determine where the mantas swim most often.
But acoustic transmitters are not suitable for tracking migrating manta rays. Marshall considers those stingrays that she has met only once to be migratory. They appear as if from nowhere, spend a day or two in the bay and disappear. Where are they going? Where do they mate and produce offspring?
The researcher is trying to prove that giant manta rays roam the World Ocean in search of food. It has already equipped nine such stingrays with 20-centimeter satellite transmitters. Every time a manta ray comes to the surface, the device transmits the coordinates of the fish to the satellite. Each transmitter costs $5,000. And it is often lost a few months after installation.
The GPS navigator signals your arrival at given point. Andrea Marshall and Simon Pearce don scuba gear, take a camera and a meter-long copper spike to implant transmitters, and dive into the sea. The current here is strong, visibility in the muddy water is limited. The underwater landscape with corals, crevices and caves seems to be covered in a veil. Scuba divers swim past reticulated moray eels, radiant lionfish and impressive potato grouper. And suddenly they stop.
To prove the existence of a new biological species, we need strong arguments. One of the main criteria is external differences. Biologists describe in detail the shape and structure of the animal’s body, its organs, coloring and lifestyle. This description is almost always accompanied by genetic analysis data.
In 2007, Marshall did without them. By then, she had been studying manta rays off the coast of Mozambique for almost five years, having completed 1,300 dives. She traveled to Mexico, Thailand and Ecuador to research local manta populations. More and more points appeared on her map. She marked the habitats of small mantas in red, and the habitats of giant mantas in blue. But her hypothesis about the existence of two species of these fish remained unconfirmed.
In May 2007, she went to Indonesia, where commercial fishing for giant manta rays is underway off the coast of the island of Lombok. She needed one copy for anatomical study. At a local market, with the help of fishermen, she turned over the carcass of a stingray and noticed a protrusion at the base of the tail. She carefully cut the skin. And she was stunned.
Our ancestors had a manta ray on their tail poisonous thorn; in some species of stingrays it is still preserved. And among manta rays it disappeared during evolution. So, in any case, scientists thought. Small manta rays really don't have it. But sticking out of the tail bones of a giant manta ray at a market on the island of Lombok was... a sharp protrusion several millimeters long - a miniature spike. “Finally, I found a 100% anatomical difference!” - says Marshall.
The luck continued. Marshall named the first two giant manta rays for which she installed satellite transmitters after the great navigators Cook and Magellan. Cook lost the transmitter three weeks later, but Magellan sailed 1,100 kilometers south along the coast of Mozambique in two months and lost the transmitter just past Durban (South Africa). This confirmed Marshall's assumption that giant manta rays are "ocean wanderers." The results of genetic tests proved her right. There are actually two types of manta rays in the world.
In July 2008, Andrea Marshall presented a report on her many years of research at the Congress of Hydrobiologists in Canada. The genus "manta", she declared, includes two species - the giant manta (manta birostris) and the smaller reef manta (manta alfredi). After her speech, silence fell in the hall.
With her hair wet from her dive, Andrea Marshall sits down at the table. Today's searches were fruitless; he and Pierce did not find a single “giant” under water. But fate is already throwing the researcher new challenge. Andrea takes out a world map. Recently, along with red and blue dots, yellow marks have appeared on it. They are concentrated in the Gulf of Mexico and the Caribbean Sea.
One day, on the Internet, she found a photo of a stingray that may be a representative of a third species of manta, Marshall says. “I saw a photo of a manta ray and thought: wow, I don’t know one like that!”
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