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These animals aren't like any other living creatures on Earth. They look like they came from some other planet. Biologically speaking, they are quite different from all other terrestrial beings, which has put them in the spotlight a long time ago. At the same time, they look very funny, especially when dancing in the water.
The offspring of these creatures are born not by females as usual, but by males, which sets them apart from all other terrestrial beings. The smallest species of these creatures are only two centimeters long, and the largest are up to 30. Their body is covered with spikes. They serve both as camouflage and protection from predators because they don't know how to defend themselves.
At the same time, they're very successful predators with a whooping 90% hunting success rate, which far exceeds the rate of such dangerous predators as leopards, white sharks, or killer whales. They can also mimic chameleons by changing their body color. They merge with the vegetation, thereby avoiding the attention of both predators and potential prey.
They need to eat continuously throughout their lives, otherwise they run the risk of starving to death. Since they don't have a stomach, the ingested food is absorbed and waste is removed right away. Their eyes can look in different directions at the same time. Very few living creatures on Earth actually have this ability. Strictly speaking, they are fish, and it's the slowest fish in the world. The smallest representative of this species can swim only one and a half to two meters an hour.
So, what are these creatures? Our story today is about seahorses, mysterious and completely unique inhabitants of the world's oceans. In this video, you will learn where these amazing creatures come from, why male seahorses get pregnant and give birth to the offspring, some facts about their lifestyle, body structure, the benefits of an upright position, after all, they swim vertically like almost no other oceanic creature, the reason for not having a stomach, how these slow fish hunt, why is it nearly impossible to keep them in fish tanks, and many other fascinating and unusual facts.
Seahorses [Music]
The first seahorses emerged on Earth at least 13 million years ago. According to paleontologists, this is exactly how old their oldest fossilized remains are. This period was marked by the emergence of such mountain systems as the Himalayas and Alps, and there were still 12 million years left before the Homo antecessor genus appeared, which gave rise to the human race.
For many years, paleoichthyologists have wondered about seahorse's origin and evolution, and while earlier their origin was considered a mystery, there's been some substantial progress in this field in recent years. Fossils show that as far back as 13 million years ago, these fish looked almost like modern ones, which means that they had originated and evolved much earlier.
A number of genetic studies on nuclear and mitochondrial DNA prove the existing hypothesis that seahorses originated through evolutionary transformations from pipe horse, which happened 25 million years ago. Indeed, if we mentally bend the pipe horse into a chess horse figure, get rid of its tail fin, twist the remaining stem into a spiral, and add more outgrowths, horns on the muzzle, we would get a regular seahorse. It's likely that during its evolution, the pipe horse separated from the classic pipe fish that already had a twisted tail and a slightly curved body, which later gave rise to typical seahorses. Using the most modern methods, paleontological research fully proves this theory. Therefore, the hypothetical alien origin of seahorses is just a beautiful mystical idea that was completely debunked by science.
But where does this strange reproduction come from? After all, the pipe horses, who are the seahorse's ancestors, breed in the most common way, while in seahorses, it is the male that bears the offspring. This is also a very interesting story, more about that in a minute.
Seahorses live in coastal shallow areas of tropical and subtropical seas and oceans, and cold water is actually harmful to them. There are about 50 species of these creatures, and each can flaunt a unique appearance and color. What makes them special is that they seem to have combined body parts of various animals, and not only marine ones. The head resembles a horse, but has a pointed mouth, beak like an anteater. The 360-degree vision and separately rotating eyes, as well as the ability to change colors and merge with the environment, are something that seahorses share with a chameleon. An abdominal pouch for bearing offspring resembles that of a kangaroo, and a twisted tail that seahorses use to cling to vegetation reminds us of some primate species. A miracle of nature, nothing less, nothing more.
By fish standards, seahorses swim very poorly and slowly. Because of this, they lead a predominantly sedentary lifestyle, attaching their tail to sea plants, merging with them, and thus waiting for prey, becoming hard to spot for larger predators. That is why they live in shallow grassy areas of the world's oceans. We're swimming vertically is an advantage that allows you to masterfully blend into the environment. Vertical blades of grass and corals easily hide vertical fish, provided that it completely blends in with the environment's color and texture. Typically, seahorses live for four to five years.
Seahorses live in colonies, but they can't be called schooling fish. They swim and prey alone and breed in pairs. When seahorses choose a partner, most often they don't separate all their lives. Perhaps this isn't the most accurate comparison, but seahorses colonies and lifestyle resemble not that of fish, but you won't believe it, people. We also settle in colonies, otherwise known as cities or towns, and each person lives separately or creates a couple. Seahorses have a very similar way of life.
Seahorses are the only vertebrates whose males bear children and give birth. And many known animals, fathers incubate eggs, protect and feed offspring, but only in seahorses do males bear fertilized eggs and give birth. Early in the morning, males perform a ritual dance. Each male swims around his chosen one, demonstrating that he is ready to breed. During the mating period, the male's shell and the chest turns dark.
Seahorses are talented dancers who like circling each other or a floating object, flashing iridescent colors and intertwining tails in a courtship that sometimes lasts for several days. Bowing his head, the seahorse moves and circles around the female with his tails slightly touching the bottom. This elaborate courtship dance takes place every day, but mating requires the male and female to mature at the same time. On a mating day, at a certain moment during the greeting ritual, the female abruptly raises her head and swims up, and the male follows her. At this moment, you can easily see the female's ovipositor and the male widely opens up his pouch. The female directs the ovipositor into the wide opening of the pouch and lays eggs, which are fertilized by the male at the same time. The whole process takes only six seconds. It's hard to believe such high efficiency, but nature is rich in miracles, and science proves this fact with the help of videos and research.
The male brood sac is analogous to the placenta in female mammals, preventing oxygen and nutrients to growing embryos. But why, contrary to all the logic and reason, this function is given by nature to seahorse males? While this is a mystery to scientists, the only plausible theory that wasn't refuted by other hypotheses is that in this way, nature allows seahorses to produce the maximum number of offspring. After laying the eggs and entrusting the male with bearing embryos, the female begins to produce eggs again, thus making the process of reproduction virtually continuous. This is very true in a population of creatures where less than 0.5% of newborns survive until adult child-bearing age. After all, seahorse fry, although fully formed and ready for living independently after birth, don't yet have armor and spikes like their parents and become easy prey in the ocean jungle.
Childbirth is a complex biological process that in pregnant female mammals and reptiles is controlled by hormones, including oxytocin. It causes contractions of the smooth muscles of the uterus. Smooth muscles are a special type of muscle that cannot be controlled consciously and are found in the walls of most internal organs and blood vessels. Scientific studies have shown that in male seahorses, the bulk of the brood pouch muscles are skeletal muscles, which are under conscious control. In other words, male seahorses decide when they give birth. Thanks to the six-pack abs, male abdominal skeletal muscles that are much bigger than in females, future fathers literally shoot batches of tens or even hundreds of fry, up to 1500 eggs during childbirth, quickly emptying the brood pouch. Despite the differences between the brood pouch and the mammalian uterus, the daddy fish can experience very strong labor pains during childbirth, making this a very exhausting process for the male.
The male carries the eggs for 9 to 45 days until the seahorses hatch fully developed but very small. The younger then released into the water, and the male will often mate again within hours or days during the breeding season. While seahorses aren't known to mate for life, many species form pairs that last at least through the breeding season. Some species show a higher level of couple fidelity than others. However, many species willingly change partners when the opportunity arises. The mating habits of many other species haven't been studied, so it's unknown how many species are actually monogamous and how long these bonds last. The females have the final say when choosing a mate, not the males.
In fish and other animals that don't have brilliant intelligence, monogamy is very rare to come by. However, the lack of intelligence, or rather, the lack of long-term memory in fish, can separate a couple, and they will no longer feel a liking for each other after just a few days of being apart. They will simply forget each other. Immediately after birth, seahorse fry begin to live independently from their parents, not being under their care in any way. Like most newborn animals on Earth, as early as the first minutes of life, they begin to feed on microscopic crustaceans. However, they may become food themselves for other aquatic creatures due to their defenselessness, unformed armor, and small size.
The structure of the body and tail is another unique feature of seahorses that calls for special attention. The body structure. The vast majority of marine animals protects them from predators. Razor-sharp fins, venomous spikes and needles, armor-like carapaces, skin pattern that mimics the environment. All these features are designed to ensure one's protection and survival in the ocean jungle. The defense that seahorses have is completely different from most living creatures known to us. Their body is covered with movable bony plates that slide parallel to each other, providing greater maneuverability during movement. This armor works better than, for example, in crustaceans, and at the same time is much more durable than fish scales. They are difficult to bite through or break and can only be bent, allowing the seahorse to survive in the most dangerous situations.
The seahorse's tail is square, not round like in all other animals. The skeleton of a seahorse's tail is made from L-shaped bone pieces that fit together to form these squares. The squares line up in rows and become progressively smaller towards the tail tip. Muscles attached to the skeleton allow the tail to move and even grasp objects. Compared to an oval-shaped tail like in our beloved dogs and cats, the seahorse tail was found to be stiffer, stronger, and more resilient under shock loads. The tail of square prisms bends much better and combined with the structure's rigidity, which almost doesn't allow the tail to twist, makes it possible to grab the surrounding objects more firmly. Grasping tails of any kind are super rare among fishes. Out of some thirty thousand kinds of fish, only seahorses and their close relatives called pipe horses can get a tail grip. Yet, within the seahorse family, the rare fishtails that bend into a hook have evolved independently several times. Square segments press more surface area against the body of the seahorse than round segments. This allows square tails to have better grip control and promote seahorse survivability. An important part of their hunting and camouflage. In addition, scientific experiments have shown that when crushed, square tail plates are flattened, which prevents damage to the spinal column and saves seahorse's life when attacked. See how the square plate bends but doesn't break.
Nature has given seahorses a unique body and tail structure. Of all the fauna, only they and some other types of chameleons have square-shaped tails. But they are no swimmers, and the problem is not the vertical position, but the fins. The seahorse has only three of them: a small dorsal fin, two gill fins near the head, which in fact serve as a steering wheel that allows them to choose movement direction. Pelvic and pectoral fins are absent. Because of this, some types of seahorses cannot swim faster than a few meters per hour. However, with a sedentary lifestyle, this isn't a problem for them. They don't rely on speed for survival or hunting like other fish, but rather on their slowness. If they need to migrate to a new, more suitable place, seahorses travel on top of a larger fish, clinging to their fins with their tails, and leaving their transport after reaching a suitable place like their favorite kelp beds.
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The seahorse's swim bladder is located along the entire body and is divided by a septum that separates the head from the rest of the body. The cephalic bladder is larger than the abdominal one, which ensures the vertical position of the seahorse when swimming. In this position, which makes them strange and unusual creatures in the underwater world, is also their great advantage, allowing them to hunt as efficiently as possible and have the status of one of the most successful hunters on the planet.
What makes their hunting successful? This question haunts many scientists, and a lot of research was done to answer this question, including a video recording of seahorse hunting and even the creation of mathematical models that allow us to accurately calculate the algorithm of their hunting success. Few of the inhabitants of the underwater world can boast of such a high rate, and the answer is as follows: hiding in algae or corals, seahorses slowly bring their head closer to the unsuspecting prey, and then they instantly suck it up through their tubular snout. This technique is known as pivot feeding. It relies on moving the mouth towards the prey by tilting the head upwards, which pivots at the neck joint. The suction is so fast that even frame-by-frame filming doesn't allow you to see this. This means that the process takes not tenths, but hundredths of a second.
This is where the real speed of seahorses comes into play. It requires a lot of energy, which the seahorses can accumulate in the tendons associated with the head rotation and then release, creating a powerful suction force. And the seahorse's elongated muzzle creates a calm zone around itself where small crustaceans and shrimp, their main source of food, don't feel threatened and can come up very close. In this way, seahorses managed to achieve a hunting success rate of up to 90%, one of the highest hunting success rates among any predators in the world. To put this into perspective, less than half of the attacks by great white sharks, which terrify most aquatic inhabitants, end in success. Graceful yet powerful leopards catch their prey only 74% of the time, and highly intelligent and cunning orcas, that hunt seals, dolphins, and whale calves in well-organized groups, sometimes for hours on end, achieve success in up to 80% of cases. Meanwhile, small, slow, harmless-looking, and slightly ridiculous seahorse excels at hunting more than all of them.
However, seahorse's hunting success is not a whim of nature but a basic survival need because they have neither teeth nor a stomach. How do they eat and digest food then? Well, the seahorse actually digests food with the rest of its digestive system, not with one particular organ. A special gland, similar to the mammalian pancreas, secretes digestive enzymes directly into the intestines, allowing food to be broken down as it passes through the body. Due to the absence of a stomach, this process occurs much faster than in other animals and fish, so the seahorse has to eat almost continuously and be an excellent hunter. Adult seahorses eat 30 to 50 times a day, and in some cases, the number of meals can be several hundred times.
But if you decide to watch these amazing creatures on your own, remember that seahorses don't tolerate fish tanks because they are prone to stress. Once in an unfamiliar environment, they constantly feel frightened and nervous and often refuse to eat, eventually dying of hunger and nervous exhaustion. For example, shaking and rocking will almost certainly kill them if you decide to transfer a vessel of seahorses by a car or a ship.
In total, there are about 50 species of seahorses in the world, but 30 of them are on the verge of extinction. The greatest danger for them is people. They're actively caught for souvenirs because of their unusual appearance. According to official statistics, only in China, 20 million of these unusual fish are caught annually, and this is not counting the massive cases of poaching that aren't taken into account.
The depths of the world's oceans hide many secrets and wonders, incredible monstrous creatures, and perhaps those creatures that we don't even know about yet. But the seahorse, living in shallow water, has been well studied by scientists. That is why it is so delightful, demonstrating nature's incredible ability to create strange yet almost perfect beings, combining seemingly incompatible things into one: a horse's head and a kangaroo's pouch, unique hunting skills and a bizarre look.
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