CATDOLL : CATDOLL: How to distinguish male and female depth bombs (ornamental small puffer fish)

How to distinguish male and female depth bombs (ornamental small puffer fish)

That is also called green pufferfish. Unfortunately, you can't tell the male from the female. You can only tell the difference when it is an adult. And don't keep it with other fish. It is ferocious. It opens its eyes and is poisonous when it grows up. It closes early and eats shrimps and small fish. It doesn't like to eat bloodworms. It is very difficult to keep. I have kept one and it died.

Sorry, I'm here to help you gain popularity, but I've only drunk depth charges, I've never raised one...

The "depth charge" pufferfish generally refers to the submarine fish, also known as the green pufferfish. It is difficult to distinguish between male and female submarine fish at ordinary times, but the male fish in estrus is brighter in color than the female fish, and the center of the outer edge of the tail fin becomes pointed, while the female fish's tail fin is still round, and the dorsal and anal fins are more rounded and blunt. The male and female fish are similar in length and size, but the female fish has a swollen abdomen.

Green river is also called submarine fish, golden doll, dog head, chicken bubble fish, belongs to the family of ornamental fish, and can be called spotted green river. The scientific name is Tetraodon nigroviridis. In the wild, it can grow up to 17CM, but in the aquarium, the big hail tank usually does not grow that big, and most of the ones sold on the market are about 5CM. It is a very popular family of ornamental fish in the current tropical ornamental fish group, and belongs to the same family as the river. The juvenile is non-toxic (about 3cm), and the adult is poisonous.

Information about whales

[Edit this section] Introduction to whales

The giant beasts of the ocean - cetaceans

The Latin name of whales is derived from the Greek word for "sea monsters", which shows the awe that the ancients had for these huge creatures that live in the ocean. In fact, the body shapes of whales vary greatly, with small ones only about 1 meter long and the largest ones over 30 meters long. Most of them live in the ocean, and only a few species live in freshwater environments. Their body shapes are very similar to those of fish, and they are streamlined and suitable for swimming, so they are commonly called whales, but this similarity is just a convergence phenomenon in biological evolution. Because whales have the characteristics of viviparity, lactation, constant temperature and breathing with lungs, which are completely different from fish, they are mammals. A whale's heart beats only 10 times a minute.

[Edit this paragraph] Characteristics of whales

The common feature of whales is that their body temperature is constant, about 36.0℃. Their skin is bare and hairless, with only a few bristles on the snout. They have no sweat glands or sebaceous glands. The fat under the skin is very thick, which can maintain body temperature and reduce the body's specific weight in water. The skull is well-developed, but the brain is small and the face is large. The frontal bone and maxilla are significantly elongated, forming a very long snout. The neck is not obvious, the cervical vertebrae are fused, and the head is directly connected to the trunk. The forelimbs are fin-shaped, the toes are not separated, there are no claws, and the elbow and wrist joints cannot move flexibly, which is suitable for swimming in water. The hind limbs are degenerate, but there are still traces of the pelvis and femur, which are residual bone pieces. The tail degenerates into a fin, and the skin at the end expands horizontally to the left and right to form a pair of large tail lobes, but they are not supported by bones. The vertebrae gradually become thinner in the narrow tail stem and finally disappear before entering the tail fin. The tail fin is different from that of fish. It can swing up and down and is the main organ for swimming. Some species also have a dorsal fin to balance the body. Their bones have spongy tissue and there is more fat in the body cavity, which can increase the body volume, reduce the body weight and increase buoyancy.

Their eyes are very small, without tear glands and nictitating membranes, and their vision is poor. They have no external ear shells, and their external auditory canals are also very thin, but their hearing is very sensitive, and they can sense ultrasound, relying on echolocation to find food, contact companions or escape from enemies. There are 1-2 external nostrils located on the top of the head, commonly known as blowholes. Generally, the more the nostrils are located at the back, the higher the degree of evolution. They breathe with lungs, one on each side, which have many capillaries, which are elastic and can help oxygen circulation, adapting to gas exchange on the water surface. They need to surface for breathing every once in a while, and can also dive for a long time. There are 10 to 20 pairs of ribs. The stomach is divided into 4 chambers. Most of the kidneys are tumor-shaped. The testicles of male animals are located in the abdominal cavity. Female animals give birth and breastfeed in water. The uterus is bicornuate, with a pair of breasts located in the cleavage on both sides of the genital fissure, with slender nipples. The milk is rich in calcium, phosphorus and a lot of fat. All calves have teeth during the embryonic period, but the teeth of baleen whales are replaced by baleen by the time they are born, while the teeth of toothed whales are retained throughout life.

Whales are mammals that live in water. They have the same physiological characteristics as terrestrial mammals, such as breathing with lungs and giving birth to live young. They also have some special physiological structures that have evolved to adapt to the aquatic environment. Whales are classified as belonging to the kingdom Animal, the phylum Chordata, the class Mammal, and the order Cetacea.

A whale's heart beats only nine times a minute. This is because whales are mammals that live in water. They have the same physiological characteristics as land mammals and breathe with lungs. They can hold their breath and slow down their heartbeats in water for a long time. That's why they can lurk in water for a long time.

The order Cetacea is further divided into two suborders, namely the Mysticeti (baleen whales) and the Odontoceti (toothed whales). The division of these two groups is mainly based on their different feeding methods. The main morphological characteristics of the Mysticeti are that they have no teeth, but have large baleen that can be used to filter plankton. Therefore, they are filter feeders. The main characteristics of the Odontoceti are that they have teeth and are predatory. The number and arrangement of their teeth vary depending on their feeding habits. There are 13 families and about 79 species in the world.

Although the word "whale" has the word "fish" in its name, it is not actually a fish, but a mammal. It has many characteristics that are very different from fish. For example, fish generally swing their tail fins left and right to move their bodies forward, while whales move forward by swinging their tail fins up and down. They use the flippers at the front to maintain body balance and control the direction of force. Some whales also have fins on the upper part of their backs that can keep their bodies vertical! The biggest difference between whales and fish is that whales have nostrils like humans and breathe with lungs, while fish breathe with gills; whales have smooth skin without scales, while fish generally have scales; whales are warm-blooded animals, while fish are cold-blooded animals; fish lay eggs, while whales give birth to baby whales directly; mother whales have two breasts under their bellies, and baby whales grow up by eating their mother's milk. When they are hungry, they use their mouths to wipe their mother's breasts, and the mother whales use strong force to spray milk directly into the baby's mouth.

Whales are herd animals. They usually live in groups in the sea. However, when whales breathe, they need to swim to the surface. They use the blowholes on their heads to breathe. When they exhale, the moisture in the air condenses and forms the familiar fountain. Experts can even identify the type of whale by the height, width and angle of the water spray! There are many types of whales, which can be roughly divided into two categories: toothed whales and baleen whales.

There is a very thick layer of fat under the skin of whales, which is commonly known as whale oil. It can keep the whale body warm and store energy for emergency use. Because whales have many special structures in their bodies, they can hold their breath and slow down their heartbeats for a long time in the water. Therefore, when they sink to the bottom of the sea, they always have to wait for a long time before they surface again. In addition to having a structure to store oxygen, when a certain part of the body needs a large amount of blood supply, there is also a special function in the body to concentrate the supply!

The water column sprayed by baleen whales is tall and thin, while the water column sprayed by toothed whales is thick and short. Some people can even judge the type of whale based on the water column!

Whales are mammals that live in the ocean. Some whales are very large, with the largest reaching 30 meters in length. The body of a whale is like a fish, fusiform. It has a large head, small eyes, and completely degenerate ear shells. The neck is not obvious. The forelimbs are fin-shaped, and the hind limbs are completely degenerate; most species have fins on their backs; the tail is horizontally fin-shaped and is the main organ of movement. There are teeth or no teeth. There are one or two nostrils, which are opened on the top of the head. Adults are hairless (many species only have some hair around their mouths). There is a thick layer of fat under the skin, which can keep warm and reduce the specific gravity of the body. It breathes with lungs, and dives into the water after inhaling air on the surface, and can swim underwater for 10 to 45 minutes. It generally feeds on zooplankton, mollusks and fish. It is viviparous, usually giving birth to one calf per litter, and feeds the calf with milk. But many people classify them as fish, but in fact they are not fish but mammals. They are distributed in oceans around the world.

Whales are distributed in all oceans of the world. They are aquatic mammals that breathe with lungs. There are two types of whales: baleen whales, which have no teeth, baleen, and two nostrils, such as fin whales, blue whales, humpback whales, and gray whales; and toothed whales, which have teeth, no baleen, and one nostril, such as sperm whales, narwhals, and killer whales. Most of the oxygen in the ocean and 60% of the oxygen in the atmosphere are produced by phytoplankton. Baleen whales can kill zooplankton, the enemy of phytoplankton. In addition, toothed whales also help maintain the ecological balance of fish. Toothed whales feed on large mollusks that feed on fish. Therefore, if there are no whales in the world, humans will perish.

Whales have a very poor reproductive capacity, giving birth to a calf every two years on average. Due to human hunting and environmental pollution, the number of whales has been drastically reduced. For example, nearly 360,000 blue whales were killed in the 20th century, and there are less than 50 left today. Many species of whales, which have lived on Earth for more than 50 million years, are now on the verge of extinction.

The ancestors of whales were originally animals that walked on land with four limbs. They were probably insectivores or carnivores who lived mainly on the coast. Later, they were attracted by fish and other food in the water. After a long time, they returned from land to the sea and gradually adapted to marine life. The earliest whales were the protocetids, protodontids, and protocetids in the middle of the Eocene Epoch, about 55 to 36 million years ago. Compared with the existing whales, they have smaller skulls, nostrils located in the front of the head, and have not yet moved to the top of the head. Their teeth are similar to those of ancient insectivores and carnodonts, with 44 or less teeth. Their tooth shapes and skulls are also very similar. There are only a few differences, but they already have a body shape similar to fish that is adapted to living in seawater.

"The appearance of tail fins may have been the final step in the transition of whales from land to sea," explained paleontologist Mark Euhorn of the Alabama Museum of Natural History. Euhorn analyzed recently discovered fossils to explore this mysterious process. The fossils were found by amateur bone enthusiasts on the banks of rivers in Alabama and Mississippi. They are bones formed after the death of the ancient whale Volotegeorgia. Volotegeorgia lived about 40 million years ago and swam in the Gulf of Mexico in North America. This ancient whale was about 3.7 meters long and mainly relied on its sharp teeth to prey on fish. The earliest known whale with tail fins is closely related to the genus Volotegeorgia. But Euhorn found that when Volotegeorgia split from other whales just 2 million years ago, it was obviously without tail fins.

Euhorn focused on analyzing a newly discovered tail vertebra that is about 5 cm long. This vertebra is one of the approximately 20 tail vertebrae of Volot Georgiacetus. After analysis, it was found that this vertebra is not similar to the vertebrae near the whale's tail. Therefore, Euhorn believes that Volot Georgiacetus mainly relies on swinging its hind legs to swim. Previous studies have also believed that this ancient whale had huge hips, indicating that they also had huge hind legs. Strangely, scientists have also found that their pelvis is not connected to the spine. Until now, this phenomenon remains an unsolved mystery. Euhorn said, "The point we have confirmed is that this ancient whale mainly relied on swinging its hips and paddling its feet to swim in the water. This is very similar to the way modern whales swim, but modern whales mainly rely on the ups and downs of their bodies to swim."

In the history of biological evolution, there has always been a missing link from ancient terrestrial quadrupeds to today's aquatic mammals. Therefore, scholars believe that the ancient whale fossils discovered above just fill this gap. However, why did the ancient whales move from land to water? It turns out that the reproduction and feeding of ancient whales were all carried out on land, just like today's amphibians such as sea lions, fur seals, and seals. However, the evolution of organisms is often affected by environmental changes. About 50 million years ago, because the ratio of food and predators in the water was easier for ancient whales to survive than on land, they began to enter the water; about 10 million years ago, the descendants of ancient whales evolved to be very similar to modern whales, with tails and short necks, and their hind feet also degenerated into fin-like appendages, and they no longer came ashore.

[Edit this paragraph] Types of whales

Baleen whales are huge, with the smallest species being more than 6 meters long. There are no teeth in the mouth, and only degenerate teeth can be seen during embryonic development. However, there are 150-400 horny whiskers arranged in a comb-like pattern from the palate to the pharynx on both sides of the upper jaw. The color, shape and number of whiskers vary from species to species, and are one of the important bases for classification. There are two external nostrils located on the top of the head, which can spray two jets of water when breathing. The skull is extremely large, and some species can reach 1/3 of the body length, and are symmetrical. The cervical vertebrae are fused or separated. The sternum is small, with only 1-2 pairs of ribs connected to the sternum, and the thorax is incomplete. There is no clavicle. The flippers generally have 4 fingers. There is a cecum in the digestive tract. It mainly feeds on small crustaceans such as krill, and some species also eat small schooling fish, as well as bottom-dwelling fish and shellfish. There are three families of baleen whales in the world: right whales, gray whales and fin whales, with a total of about 6 genera and 11 species.

Toothed whales have a large variation in body shape. The smallest species is only about 1 meter long, and the largest is more than 20 meters long. They have conical teeth in their mouths, but the shape and number of teeth of different species vary greatly. The smallest has only one single tooth, and the largest has dozens of teeth. Some are hidden in the gums and are not exposed, so they are also one of the important bases for classification. There is only one external nostril, so it can only spray a stream of water when breathing. The skull is asymmetrical. There are 5 fingers on the flippers. The sternum is large. There is no clavicle. There is no cecum. They mainly feed on squid, fish, etc., and some can also prey on seabirds, seals and other large animals such as other whales. There are 8 families of toothed whales in the world, including pufferfish, sperm whales, sword-beaked whales, narwhals, sharp-nosed dolphins, porpoises, dolphins and pilot whales, with about 34 genera and 72 species.

The blue whale is the largest mammal in the world. It can grow up to 30 meters long and weigh an average of 150 tons. Its mouth can be opened wide enough for 10 adults to enter and exit freely. The blue whale is full of treasures. Its fat can be used to make soap; its meat is nutritious; its bones can be used to extract glue; its liver contains a lot of vitamins; and its blood and internal organs are high-quality fertilizers.

Ancestors of whales

"Ambiuro Keitaus"

About 1 million years after the appearance of Pachicataeus, whales took another step towards the ocean. The representative animal of this stage is a 4-meter-long "Ambilocaetus", which means amphibious whale or walking whale. If Pachicataeus is similar to a wolf, then Ambilocaetus is similar to a crocodile. Ambilocaetus was discovered earlier than Pachicataeus. Researchers believe that Ambilocaetus is a transitional animal in the development of whales.

The biggest ecological feature of Ambiurocetaus is that it lives in the sea and on land, mostly eating marine fish and drinking seawater. It is generally believed that all mammals form teeth and bones through oxygen atoms in water molecules in food. Oxygen exists in three isotopes in nature, and when they have a specific ratio, the ratio in seawater and freshwater is different. Therefore, when analyzing the skeletal fossils of Ambiurocetaus, it shows that the isotope ratio of freshwater is higher, which means that Ambiurocetaus ate animals on land, thus creating its own bones and body shape.

Its ecology is somewhat similar to that of modern crocodiles. Its eyes are very small. If its body is in the sea, its eyes are above the water surface to observe the surrounding situation. Analysis of its skeleton shows that its hind toes are long for swimming in the water, and its front toes are not so long, which is convenient for crawling out. They often lurk in shallow waters, keeping an eye on all directions, waiting for an opportunity to attack passing animals.

"Lodekaitaus"

After Ambiurocaetus, an animal with the appearance and size of an otter and Rhodecaetus, which still retained many characteristics of Ambiurocaetus, appeared one after another, and other ancestors of whales appeared one after another. Moreover, this Rhodecaetus animal is believed to have fully adapted to living in the water. It took about 3 to 4 million years from the appearance of Pakicataetus to the appearance of Rhodecaetus. However, this is a brief moment in paleontology.

Dalton and Losaurus Brazil

About 39 million years ago, whales with streamlined bodies and able to swim smoothly in the ocean, such as Dalton and Losaurus brasiliensis, appeared. They no longer had the long tails of their ancestors, but instead had tail fins. Dalton, 4.5 meters long, had skeletons similar to those of modern dolphins, but with some traces of degeneration of the hind legs. Losaurus brasiliensis had an eel-like slender body, about 18 meters long, which was larger than most whales in the world today. But it also had two small hind legs.

Whales such as Basilisk and Loxasaurus are all called extinct species of protocetids in taxonomy. Among them, Dalton, which has more modern whale body characteristics, later evolved into modern toothed whales and baleen whales. However, scientists believe that no animal bone fossils related to Dalton and modern whales have been found.

However, it is generally believed that the global sea level dropped when protocetids evolved into baleen whales and toothed whales, which was about 34 million years ago. There should be many places in the world where the strata can be excavated at this time. If people are lucky, they will find fossils of transitional species from protocetids to modern whales sooner or later.

[Edit this paragraph] The value and protection of whales

Whales have been hunted by humans since ancient times due to their great economic value. However, due to backward hunting methods, the amount of hunting was small in the past, which was not enough to affect the number of whales. In modern times, people have switched to using ships and artillery to hunt whales, which has greatly increased the lethality, causing a sharp decline in the number of whales, and many species are on the verge of extinction.

Now, as countries around the world have imposed strict restrictions on the number of whales caught each year, whaling is no longer a major concern for scientists who monitor the number and survival of whales. However, in the entire world, the unprecedented marine pollution caused by human economic development has posed a great threat to whales, and the degree of the threat is far greater than that of hunting. In addition, the rapid development of industrialized fishing has also greatly affected the food source of whales and other marine mammals, which is another major factor affecting their survival. People used to imagine the ocean as a vast and free world and a symbol of adventurous activities. Therefore, while plundering marine resources unscrupulously, not only is there a lot of ocean noise generated by the shipping industry and a large amount of ballast water discharged every year, but also a large amount of garbage is dumped into the ocean. About 100,000 chemicals have also reached the ocean through sewage discharge and air. Difficult to decompose organic chlorides have increased the content of marine organic matter, making marine pollution more and more serious and bringing serious consequences.

The results of modern scientific research show that the ocean is a giant container for storing waste gas carbon dioxide. The cold and hot ocean current systems have a great impact on the earth's climate. In the deep sea, which has not been studied much, there are many unknown animals and plants that are beneficial to humans, including many potential sources of food and medicine for humans, which are of great value. The increasing degree of marine pollution will destroy these precious resources. Due to the destruction of the ozone layer, the population density of krill living in the waters around Antarctica has dropped sharply. The number of krill per 1,000 cubic meters of seawater has dropped sharply from 177.8 before 1982 to 1984 to 41.2 from 1984 to 1985. Krill is a crustacean in the ocean and an important bait for marine fish, whales and other marine mammals. It has an extremely important position in the marine food chain. Moreover, it has also attracted great attention as the largest protein resource remaining on the earth. Since marine mammals such as whales are at the end of the food chain, marine pollution, especially irritating substances such as heavy metal pollution, seriously weakens their immune systems, making them extremely vulnerable to attacks by viruses and bacteria. Pollution also prevents females from conceiving or causes miscarriage, greatly reducing their reproduction rates.

Whales have a very poor reproductive capacity, giving birth to one baby whale every two to three years on average...Due to human hunting of whales and pollution of the marine environment...the number of whales has gradually decreased...For example, 360,000 blue whales were slaughtered in the 20th century!!! There are less than 50 left now~! Many species are on the verge of extinction...

[Edit this section] Whales in my country

my country has abundant cetacean resources. So far, 9 families, 26 genera and 38 species have been found in my country's waters, including blue whales with a body length of more than 30 meters and finless porpoises with a body length of only about 1 meter. In particular, we also have a unique freshwater cetacean - the white-fin dolphin (extinct), which is a rare gem among cetaceans. Except for the white-fin dolphin and the Chinese white dolphin, which are listed as first-class protected animals in my country, all other species of cetaceans in China are listed as second-class protected animals.

my country has discovered a whale weighing nearly four tons, about 17 meters long, whose tongue alone weighs as much as a dozen large fat pigs! It is spacious enough for four people to sit inside and read.

[Edit this section] Whale stranding in China

On the morning of March 28, 2008, a whale carcass was washed up on the beach of Sanya Bay in Sanya City. The carcass has begun to rot, and the cause of death and the specific species are not yet determined. Previously, a large group of whales were stranded and died in Australia. There should be more and more attention paid to protecting whales!

This is not the first time that a whale has been stranded in my country. It happens even more frequently in the world, and the reasons behind it are thought-provoking.

On March 10, 2005, a whale 8 meters long and weighing about 4 tons was stranded and died in Wuchuan, Guangdong.

A giant whale, a national first-class marine protected animal, which was more than 8 meters long and weighed about 4 tons, was found stranded and dead on the coast near Liangmei Village, Dashanjiang Street, Wuchuan City on the afternoon of March 10, 2005.

On March 11, 2008, a whale weighing more than 2 tons was stranded and died in Hainan.

In the early morning of March 11, 2008, a whale weighing more than 2 tons was found stranded and dead in the Chaotan Port of Jinshan Town, Wenchang City, Hainan Province. At present, the relevant departments have buried the whale and will extract the skeleton of the fish to make a specimen for research.

September 1, 2008, a 3,000-pound whale was stranded on Golden Beach

According to the Qingdao Morning Post, on the evening of August 30, 2008, an adult Japanese beaked whale weighing 3,000 kilograms was stranded in the Golden Beach area of ​​Qingdao Development Zone.

【Cause Exploration】

[1] Even giants are helpless: the helplessness behind whale strandings

What exactly causes such tragedies to happen so frequently? Let’s see what the experts say.

Is the whale confused?

Scientists have not been able to explain why these whales are stranded, but most explanations are related to the echolocation system in their bodies. The eyes of a giant whale are only as big as a small watermelon, and its vision is extremely degraded. Generally, it can only see objects within 17 meters, which is very inconsistent with its huge body. They do not rely on their eyes to navigate, measure objects and hunt, but have a highly sensitive echo ranging ability. They emit ultrasonic waves with a very wide frequency range. When these ultrasonic waves encounter obstacles, they are reflected back to form echoes. Whales accurately judge the distance between themselves and obstacles based on the round-trip time of these ultrasonic waves.

Internal discomfort, parasites, or problems with the system itself can cause the echolocation system to malfunction, causing the whale to lose its way and run around. Some scientists also believe that when whales mistakenly enter flat waters in order to hunt, they will be stranded once the tide recedes; and when they swim into the bay to chase fish and emit ultrasonic waves toward the beach with a large slope, the echoes are often very inaccurate, or even completely unreceived, and they will lose their way. Whales are gregarious animals. If one whale runs into the beach and gets stranded, the others will follow without hesitation, causing a tragedy of group deaths and injuries.

As early as December 2004, the American magazine Science reported that according to the research of scientists from the Woods Hole Oceanographic Institution in the United States, some scientists believe that the cause of the whales' death may be that they floated to the surface too quickly. Two scientists from the institute found small pits after studying the bones of sperm whales that died from stranding. They explained that this was a phenomenon of bone necrosis in the bones of sperm whales. Sperm whales can dive to a depth of more than 3,200 meters underwater to hunt. If they float to the shallow sea quickly, the nitrogen in their bodies will surge out to form bubbles. These bubbles entangled in the tissues will compress the nerves, block the capillaries, cause the muscles to be deprived of oxygen, and even affect the bones to cause regional necrosis, leaving multiple small pits. This shows that the "suicide" of sperm whales is likely the price they pay for rising too quickly when foraging.

Is nature also contributing to the problem?

In 1997, about 300 whales committed mass suicide off the coast of the Falkland Islands. Argentine scholars analyzed the situation and believed that the intense activity of sunspots at that time caused anomalies in the geomagnetic field and a "geomagnetic storm", which destroyed the echolocation system of the migrating whales and caused them to make "directional" errors.

Experts at the National Marine Aquarium in the UK have also speculated that the sound shock waves generated by low-frequency earthquakes on the seabed may have interfered with the echolocation systems of these mammals, causing them to mistakenly go to the beach.

Is it humans' fault again?

Environmental pollution is also considered by environmentalists and scientists to be the cause of whale strandings. Scientists believe that chemicals that pollute the seawater may disrupt the whales' senses. In addition, Dr. Collet, deputy director of the La Rochelle Marine Mammal Research Center in France, believes that the sound waves emitted by warship sonars and echo sounders and the noise of underwater explosions can disrupt the whales' echolocation system.

A few years ago, the U.S. Navy used large sonar equipment in the deep sea off Panama Island, and then some whales and dolphins were stranded and died. Investigators from the National Marine Fisheries Service and the Navy said that the noise from the sonar caused the death of marine life. They found that the whales' ears were severely damaged by the noise, and there were bloodstains around the whales' brains and ear bones. Scientists say that marine mammals are actually very fragile and can be frightened by the slightest disturbance. Human maritime exercises can also cause them to panic.

From the above aspects, it can be seen that the reasons for whale stranding are diverse, but to a large extent, it is also due to changes in the ecological environment. I hope that everyone can pay attention to ecological protection in the future and pay more attention to information in this regard so that such tragedies will not happen again.

The Latin name of whales is derived from the Greek word for "sea monsters", which shows the awe that the ancients had for these huge creatures that live in the ocean. In fact, the body shapes of whales vary greatly, with small ones only about 1 meter long and the largest ones over 30 meters long. Most of them live in the ocean, and only a few live in freshwater environments. Their body shapes are very similar to those of fish, and they are streamlined and suitable for swimming, so they are commonly called whales, but this similarity is just a convergence phenomenon in biological evolution. Because whales have the characteristics of viviparity, lactation, constant temperature and breathing with lungs, which are completely different from fish, they are mammals. A whale's heart beats only 9 times a minute.

From an anatomical point of view, many characteristics of whales show a high degree of adaptation to life in the sea. However, anatomical evidence is not enough to answer many questions about the origin of whales. However, from a biochemical and genetic point of view, whales are closely related to ungulates, and the fossil record (about 50 million years ago) also supports that whales evolved from ungulates.

The ancestors of whales are most likely terrestrial ungulates found in North America, Europe, and Asia - the Mesonychidae family. Some members of the Mesonychidae are as small as domestic dogs, while others are as large as bears. However, many animals evolve from small to large, so whales may have evolved from small Mesonychidae.

It is speculated that these mesonychids, which had few teeth and fished in shallow waters, gradually transformed into an amphibious lifestyle and then, in the long process of evolution, became today's various whales and dolphins.

It is currently known that the earliest whales were the Protocetidae family of the Archaeocetes suborder.

Protocetidae all appeared 50 million years ago, and their fossils are found in Asia, Africa, and North America. Scientists know more about Pakicetus, which was found in present-day Pakistan. This fossil, which lived 53-50 million years ago, was an animal with a blowhole (nostril) that had moved to the back, a narrow brain ventricle, and still had hind limbs. Fossil evidence found in Indian rock formations of the same period also shows that there was already an unimaginable high degree of ecological diversity among early whales.

The more advanced Archaeocetes are the Basilosauridae, which were once identified as reptiles. The animals of this family lived about 45-38 million years ago. Although they were first discovered by American geologists in Louisiana, similar fossils have also been widely found in New Zealand and even Antarctica. This discovery shows that Archaeocetes had spread to southern waters 40 million years ago.

Another branch of the more advanced Archaeocetes, the Dorudontinae, includes at least six species. They have narrower jaws, which may be for filter feeding; or, like most living toothed whales, they can use this structure to quickly clamp fish, squid, and birds.

After a long evolutionary process, the Archaea finally went extinct in the Oligocene. However, the other two branches of the whale family, the Mysticeti and Odontoceti, have gone beyond the past and derived 13 families and nearly 80 species of fascinating creatures, enriching our marine vitality.

【Morphological characteristics】

A completely aquatic mammal. The body length is 1 to 30 meters, the body is similar to that of a fish, the skin is naked, only a few hairs are on the snout, and there are no sweat glands and sebaceous glands. The forelimbs are fin-shaped, the hind limbs are completely degenerate, and there is only a pair of small bones in the body. The skin at the end of the tail expands to the left and right to form a horizontal tail fin. There are no auricles, because there is a thick layer of fat under the skin, which keeps warm and reduces the body weight, which is conducive to swimming. Some species have dorsal fins. The eyes are small, there is no nictitating membrane, and there is no tear gland. The vision is poor, and some mainly rely on echolocation to find food and avoid enemies. There are 1 to 2 external nostrils, located on the top of the head, commonly known as blowholes. Although there are no auricles, the hearing is sensitive. There is one lobe on each side of the lung. It breastfeeds in water. The stomach is divided into 4 chambers. It generally feeds on mollusks, fish and zooplankton. Some species can also prey on seals, fur seals, etc. Distributed in oceans all over the world.

【Biological description】

Like all mammals, whales breathe with lungs and are warm-blooded. Their young are fed by breast milk and have a little hair. Their lungs are large, and they breathe thoroughly with each breath. They use oxygen economically after diving, so whales can dive for 30 to 70 minutes, or even longer, before surfacing to breathe. Most small whales are shallow divers, while some large whales can dive deep, such as sperm whales, which can dive 900 to 1,134 meters. The whale's forelimbs form fins, the hind limbs are completely degenerate, the tail becomes a tail fin, and the nostrils are on the top of the head. The blue whale is particularly noteworthy. It is the largest animal in the world, with a body length of up to 30 meters and a weight of 180 tons.

Whales are considered predators. Their food is very diverse, ranging from microorganisms to large fish. All mammals, including whales, need to sleep, but whales can only keep one hemisphere of their brain asleep because they try to stay awake to breathe. So whales never fall asleep but still get the sleep they need. Whales "sleep" about 8 hours a day.

The male whale uses the vas deferens to discharge sperm into the female's body. After the fertilization process is completed, the sperm and egg combine in the mother's body. The mother whale usually gives birth to one calf. The gestation period is basically about one year. Some calves may need a year of nursing, and the nursing period is longer. Some calves will even follow their mothers for several years after birth before being weaned. In their living environment, they will encounter predation by sharks, so a very strong relationship will be established between mother and child. Some whales mature very late, about seven to ten years. The reproductive organs of whales retract into the body to avoid resistance when swimming. The mother whale has a pair of nipples, and relies on the contraction of the muscles around the breasts to squeeze milk into the mouth of the calf to feed the calf. The life span of a whale is about 60 to 70 years.

【Subjects】

The order of Cetacean contains about eighty large species of placental mammals that live in the ocean. Whales belong to the order of Cetaceans, and the order of Cetaceans also include dolphins and small whales. The definition of "whales" itself is relatively vague and can contain all cetaceans, some large or specific families of cetaceans. However, killer whales and giant whales belong to dolphins (Delphinidae). The order of Cetaceans can be divided into two suborders: Mysticeti - baleen whales - and Odontoceti - toothed whales.

The existing species can be divided into the suborder baleensis and the suborder toothed.

Mysticeti

Baleen whales include the largest existing animal species in the world. There are 3 families and 10 species, all of which are marine.

Balaenidae, such as: black right whales (black true whales) Eubalaena glacialis, southern right whales Eubalaena australis, Arctic right whales (bowback whales) Balaena mysticus, small right whales Caperea marginata, right whales (Note: Some are divided into Neobalaenidae)

Eschrichtiidae, Grey whale, Eschrichtius robustus

Balaenopteridae such as: blue whale (blue whale, razor whale), Balaenoptera musculus, mink whale (small whale), Balaenoptera acutorostrata, humpback whale (humpback whale, big winged whale) Megaptera novaeangliae, fin whale, baleenoptera (whale), Bryde's whale, Balaenoptera edeni, Sei whale

The size is huge, and the smallest species is also larger than 6 meters long. There are no teeth in the mouth. There are 150 to 400 keratinous whales on both sides of the maxilla. The color, number and shape of whales vary from species to species, which is an important basis for classification. There are 2 outer nostrils, located on the top of the head. The head is extremely large, and some species can reach 1/3 of the body length. Only 1 to 2 pairs of ribs are connected to the small sternum, without clavicles, and fins generally have 4 fingers. They have cecum. They use whales to filter plankton from seawater. They feed on krill and cephalopods, and some also eat small fish and benthic shellfish.

Odontoceti

Only a few species of toothed whales are born in freshwater, and most of them are produced in the ocean. There are more than 80 species in total. (Note: The sub-order scoring families of toothed whales have certain different opinions. They can be roughly divided into three groups with relatively large differences, dolphins, beaked whales and sperm whales. Each group is divided into one to multiple families.)

Platanistidae is also known as the freshwater family. Such as: Lipotes vexillifer (Platinidae) Lipotes vexillifer, Indian pufferfish Platanista indi, Gangetica Platanista gangetica, Amazon pufferfish Inia geoffrensis, Madeira pufferfish Inia boliviensis, La Plata pufferfish Pontoporia blainvillei.

Dolphin family Delphindae, such as: real dolphin Delphinus delphinus, short-beaked real dolphin Delphinus delphinus Linnaeus, long-beaked real dolphin Delphinus capensis Gray, bottlenose dolphin Tursioops truncatus, Amazon white dolphin Sotalia fluviatilis, orcinus orca, dolphin, Chinese white dolphin, giant whale (pilot whale, black round head whale) Globicephala melaena, big kiss pilot whale, long-limbed pilot whale, short-limbed pilot whale, melon-headed whale, Arctic killer whale, pseudorca crassidens, and pygmy killer whale. (Note: Some are divided into Pilot whale family Globiphlidae)

Phocaenidae, such as: Neophocaena phocaenoides

Monodontidae, such as Monodon monoceros, and Delphinapterus leucas, (Note: Sometimes Orcaella brevirostris are also classified into this family.)

Hyperoodontidae, eg: Mesoplodon densirostris

Physeteridae, Physeteridae, for example: sperm whale Physeter catodon

Kogiidae, a small sperm whale, Kogia breviceps, and Kogiasimus

The body sizes vary. There are teeth in the mouth and only one outer nostril. The fins generally have 5 fingers. Except for the Ganges puffer fish, there is no cecum. This animal has a unique ability to perceive the environment through echolocation. It mainly feeds on squid, squid, crustaceans, and fish.

【Economic Value】

China has rich cetacean resources and a long history of whaling. It has great economic value. Meat is edible, skin can be used to make leather, whale brain oil can be used to extract industrial lubricating oil, fat can be used to make mechanical oil, soap, candles, bones can be used to make bone meal, and internal organs can be used as vitamin preparations.

【Protect】

Due to environmental deterioration and large-scale hunting by humans, cetacean members, especially some large members, are widely hunted due to their high economic value, and many cetaceans are on the verge of extinction.

The International Whaling Commission (IWC) is an international organization responsible for managing whaling and cetacean protection. After commercial whaling caused a sharp drop in whales, the IWC decided to take action to protect cetaceans. These include the temporary ban on commercial whaling since 1986, and the establishment of the Indian Ocean Cetacean and the Southern Ocean Cetacean in 1979 and 1994 respectively. However, since 1986, Japan and Norway have hunted more than 25,000 whales under the banner of "scientific whaling". The countries currently hunting whales include Norway, Iceland and Japan, as well as some indigenous tribes in Siberia, Alaska and Northern Canada.

whale

Whales are mammals living in the ocean. Some whales have large bodies, with the largest body length up to 30 meters. The body shape of whales is like a fish, and is stumbled. The head is large, the eyes are small, and the ear shell is completely degenerated. The neck is not obvious. The forelimbs are fin-shaped, and the hind limbs are completely degenerated; most species have fins on the back; the tail is horizontal, which is the main organ of motor. There are teeth or no teeth. One or two nostrils, open on the top of the head. The adult body is hairless (many species only have some hairs at the mouth). There is a thick layer of fat under the skin, which can keep warm and reduce the specific gravity of the body. Breathe with lungs, inhale on the water surface, and then dive into the water for 10 to 45 minutes. Generally, feed on zooplankton, mollusks and fish. Viviparous birth, usually produce one baby per fetus, feeding young whales with milk. But many people divide them into fish, but in fact they are not fish but mammals. Distributed in all oceans around the world.

Whale is distributed in all oceans around the world. It is an aquatic mammal and breathes with the lungs. Its species are divided into two categories: baleen whales, without teeth, with baleen and two nostrils, such as baleen whales, blue whales, humpback whales, gray whales, etc. The toothed whales have toothed whales, without baleen, and one nostril, such as sperm whales, narwhales, killer whales, etc. Most of the oxygen in the ocean and 60% of the oxygen in the atmosphere are made of phytoplankton. Baleen whales can destroy the enemy of phytoplankton, zooplankton. In addition, toothed whales also help maintain the ecological balance of fish. The food of toothed whales is large mollusks that feed on fish. Therefore, if there are no whales in the world, humans will perish.

We divide cetaceans into two groups:

Toothed cetaceans: toothed marine giants, such as sperm whales, orcas, dolphins, and porpoises.

Baleen whales: bearded whales. In fact, these beards are angular flakes that grow in their mouths, used to filter water and catch shrimps and other small animals that whales eat, which replace the teeth.

Whales are viviparous mammals, not fish. Small whales need to eat breast milk for a year before they can develop and mature. Fish are oviparous vertebrates. Parents generally do not take care of the habits of small fish. The "fins" of whales actually evolved from limbs. Fish are not. Whales breathe with lungs. Fish breathe with gills. Whales are constant temperature animals, while fish are warming animals. You cannot distinguish whales from fish if there are scales. Because many fish do not have fish scales.

1. According to the species, baleen whales have two different methods of predation.

Defat type: Like a white whale, filters plankton during the slow swimming process, with its mouth half open and water flows in from the joint.

Devouring: When this whale is close to a large stall of shrimps at the bottom of the sea, it opens its mouth and swallows a lot of water and puts it in a stretched and folded belly. When the mouth is closed, the whale tongue will swish the water filtered by the whale teeth. For example, a blue whale can swallow 25,000 liters of water at a time.

Every year, some whales leave the food-rich polar ocean to find warmer seas to give birth to offspring. They travel thousands of kilometers in a very certain period of time. Every winter, many tourists sail thousands of miles to meet them in the Hawaiian Sea and the Gulf of Mexico. For sperm whales, males cannot migrate because there is no enough calamari to be found in breeding areas.

Whales are mammals that live in water for life, and are so dependent on water that they cannot live once they leave the water. In order to adapt to life in water and reduce resistance, their hind limbs disappear and their forelimbs become paddling boards. The body becomes streamlined, resembling fish. Therefore, their diving ability is very strong. Dolphins (small toothed whales) can dive to a depth of 100-300 meters for 4-5 minutes. Bruce whales can stay 300-500 meters underwater for 1 hour. The largest toothed whales, the sperm whales, can dive to less than kilometers and last for 2 hours in the water. In 1955, a sperm whales were discovered in the sea near Ecuador, which was sluggished by submarine cables, with a diving depth of 1,133 meters. In the 2,200 meters water depth in the water near Lisbon, the capital of Portugal, a sperm whales slugged by cables were found. This is the deepest record of mammals diving so far.

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: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : But many people divide it into fish, in fact, they are not fish but mammals. They are distributed in the oceans of the world.

Whale is distributed in all oceans around the world. It is an aquatic mammal and breathes with the lungs. Its species are divided into two categories: baleen whales, terrier whales, baleen, and two nostrils, baleen whales, blue whales, humpback whales, gray whales, etc. Toothed whales, toothed whales, without whales, and one nostril, sperm whales, narwhales, killer whales and other species. Most of the oxygen in the ocean and 60% of the oxygen in the atmosphere are made of phytoplankton. Baleen whales can destroy the enemy of phytoplankton, zooplankton. In addition to being known as dust tremor, toothed whales also help maintain the ecological balance of fish. The food of toothed whales is large mollusks that feed on fish. Therefore, if there are no whales in the world, humans will perish.

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: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : Young people have teeth during the embryo, but the teeth of baleen cetaceans are replaced by whiskers at birth, and the teeth of toothed cetaceans are retained for life.

Cetaceans are mammals that live in water. They have the same physiological characteristics as mammals on land, such as lung breathing, viviparous growth, etc., and have prepared some special physiological structures evolved to adapt to the aquatic environment. Whales are classified as "the kingdom Animel, phylum Chordata, class Mammrha, and orderCetacea.

Below the cetaceans, there are two suborders, namely the suborder Mysticeti, blaleenwhales and the suborder Odo-ntoceti, toothed whales. The groupings of these two categories are academically determined based on the different feeding methods. The main morphological characteristic of the suborder Baleenwhales is that they have no teeth, but have large whales, which can be used to screen plankton. Therefore, they are filter feeding. The main characteristics of the suborder toothed whales are toothed and predatory. The number of teeth and arrangement of their teeth will be different from the direction of feeding. There are about 79 species of 13 families in the world.

Although whales have the word "fish", they are not fish, but mammals. They have many very different characteristics from fish. For example, fish generally swing their tail fins left and right to make their bodies move forward, while whales swing their tail fins up and down. They use the flippers at the front to maintain balance and control their strength. Some whales also have fins that can keep their bodies vertical.

Whales are clustered animals. They usually live in the sea in groups, but when whales breathe, they need to swim to the water surface. At this time, whales use the water spray hole on their heads to breathe. When they exhale, the moisture in the air will condense to form the fountain-like shape we are familiar with. Experts can even identify the species of whales from the height, width and angle of the spray water. There are many types of whales, roughly divided into two categories: toothed whales and baleen whales.

There is an extremely thick layer of fat under the skin of a whale, which is commonly known as whale oil. It can keep the whale body warm and can also store energy to supply immediate needs. Since the whale has many special structures, it can breathe in the water for a long time and slow down the heartbeat. Therefore, when it sinks to the bottom of the sea, it will always take a long time before it will surface again. In addition to the structure that stores oxygen, when a certain part of the body needs a large amount of blood supply, the body will also have special functions of centralized supply.

The water column emitted by baleen whales is tall and thin, and the water column emitted by toothed whales is thick and short. Some fishermen can even judge the type of whales based on the water column.

Due to human hunting, at least five of the 13 species of whales around the world are on the verge of extinction. To protect cetaceans, the International Whaling Commission has banned commercial whaling since 1986, but the ban in 1987 has loosened, allowing limited whaling activities “for research purposes”. Despite widespread opposition, some countries still hunt large quantities of whaling under the name of scientific research every year.

Whales come to the water surface every once in a while to breathe. Its nostrils are on the top of the head. When they float out of the water, they spray back and forth. Different whales have different water columns. Experienced people can calculate the species, size and age of whales when they look at the water column. We also know that whales are not fish.

Alias: sickle-fin dolphin, sickle-fin pattern dolphin, short-cut dolphin. The snee protrusion is very short, but the boundary is clear with the forehead. The dorsal fin is tall and eye-catching, with a sickle-shaped curved posterior, and a wide base. The dorsal fin is black or black gray, the abdomen is white, the anterior part of the head and upper jaw, the lower jaw is only black, and the rest is white. The side of the body side of the body is white or gray, and the side of the body along the lower side of the dorsal trajectory to the caudal base is from the white band, and the corner of the mouth to the anterior part of the fin comb. And there is a black band between the anus of the entire anus through the posterior part of the dorsal fin. 1/3 of the front part of the dorsal fin is black, and the posterior part is gray. The front part of the fin limb is also black, and the posterior part is gray. The upper and lower part of the caudal fin is black or black gray. The body color varies greatly. There must be 23 to 36 teeth on each side.

The adult body length can reach 2.5 meters, the male is slightly larger than the female, and the weight can reach 180 kilograms. It is mostly a large group of dozens to hundreds of heads, divided into small groups when feeding, and gathered into large groups when resting or moving. It is active, swims fast, and often jumps out of the water. It is about 1.8 meters long.

The feeding is mainly small clustered fish and squid.

my country's East China Sea and South China Sea are distributed.

Whales are important members of sea beasts, and are like fish, commonly known as whales.

There are many species of whales, with more than 80 species in the world, and more than 30 species in my country's sea area. They are generally divided into two categories: burning, destruction and trapping. One type has beards and no teeth in the mouth, called baleen whales, with a total of 11 species; the other type has toothless whales, with a total of more than 70 species. The length of whales ranges from 1 meter to more than 30 meters.

Although there are few species of baleen whales, they are all very large, and the smallest known type is also greater than 6 meters in length.

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Humpback whales are clever in preying on the water. They first fire a bunch of bubbles upwards underwater, forming a large circle on the water surface. The bubbles frighten krill like air guns and concentrate in the center of the circle. Humpback whales spread out from the center of the circle and swallowed it. Because humpback whales have a large mouth and are very efficient in feeding, each right whale needs to eat 3 to 4 tons of krill every day.

The reason why whales prefer to eat small shrimps: In fact, the ones who prefer to eat small shrimps are baleen whales. Because they have no teeth and have small throats, they cannot chew and can only survive by eating small fish and shrimps. When they eat fish and shrimps, they only need to put their mouths on their mouths, and the fish and shrimps enter their mouths with the sea water, and then close their mouths. The sea water flows out of the whiskers, and only food is left.

The whale is full of treasures. The leather can be made of leather, and leather shoes, leather bags, leather jackets, etc. made of whale skin have soft textures and beautiful patterns, no less than cowhide. The whale's subcutaneous fat layer is very thick, reaching more than ten to ten centimeters, and can be refined, eaten or used as other chemical raw materials.

A blue whale can produce more than 30 tons of oil, equivalent to the total fat of 1,700 pigs or 8,000 sheep. The bones and internal organs of whales can be used as medicine or fertilizer. A giant whale can be called a priceless city. Therefore, many countries in the world such as Japan and Norway compete to hunt, which has put many whales on the verge of extinction. The International Whaling Commission had to decide to stop commercial whaling.

Research on "Language Master" in the cetacean kingdom shows that killer whales can make 62 different sounds, and different sounds have different meanings. The "linguistic tone" they use varying degrees, similar to human dialects, so researchers call it "dog whales dialect". Sometimes, a large number of fish in a certain sea area, and the killer whales come from all directions to feed. But their calls are different. Researchers speculate that killer whales can talk through "language". As for how they understand each other's "dialects" and whether they are also equipped with translation like humans, it is still an unsolvable mystery.

sperm whale

Sperm whales pay great attention to unity. If a partner Yu is not killed, the whale group will save the victim regardless of their own danger. Even if they cannot be saved, they will die with the victim.

[Edit this section] Introduction to whale

The Chinese character "whale" clearly means that the ancients believed that whales were a big fish, not to mention the word "whale". We cannot blame the character makers for lacking biological knowledge, because cetaceans, including whales, dolphins and porpoises (small dolphins) are really too similar to fish: their long bodies are streamlined, their tails are shaped like leaves, and their hind limbs are degenerated and shrinking to nowhere, and only a little remains can be found inside the body. These characteristics are all suitable for living in the water.

Scientists believe that mammals are on the stage of evolution at about the same time as dinosaurs, and lived in a very proud era of huge reptiles. It was not until a mass extinction event, which was generally believed to have hit the Earth 65 million years ago, destroyed the dinosaur family, and it flourished in disguise. In the Third Age 50 to 65 million years ago, all mammals lived on land, and the ancestors of modern cetaceans were no exception. For some reason, some animals that ran on the earth with their limbs began to return to rivers and oceans during the Eocene 50 million years ago, and in less than 8 million years, their body shape and living habits changed dramatically.

These findings, especially the ancient Pakistani whales (Pakicetidae), are enough to excite scientists because they are transitional between terrestrial mammals and modern cetaceans, once again providing beautiful evidence for evolution. However, these transitional fossils are more inclined to the other side of the whale, either amphibious or fully adapted to marine life. There are two important questions that have not been answered: What do the terrestrial ancestors of cetaceans, the most primitive cetaceans that can only run and not swim? Which of the existing mammals in the world is closest to the relatives of cetaceans?

Scientists are committed to more detailed evolutionary history of cetaceans, and people of different professions have different methods. According to the fossil's teeth and ear characteristics, paleontologists tend to believe that whales are related to mesonychians, a now extinct ungulate animal that lives in the Tertiary and is now extinct. Molecular biologists who study the DNA characteristics of existing animals prefer hippos, believing that this modern ottooth animal is the closest relative of whales.

On September 20 this year, Thewissen published a report in the British journal Nature that his group had discovered two new Pakistani ancient whales, which were completely terrestrial. Just the next day, Gingerich reported in the American journal Science that two other ancient whales were also dug in Pakistan, with well-developed limbs and can be amphibious. (It seems that only a few big names in each field come and go, and these two probably have a bit of competition. It is quite interesting to publish reports on the same topic in two magazines with equal status.) Both of their new discoveries show that even-hoofed animals such as cattle, hippos, pigs, camels and giraffes are closely related to whales. For Gingerich, it may take a little more effort to make this point, because he originally advocated that mesonychians were close relatives of whales.

In Greece, the word "whale" represents marine behemoths. We divide cetaceans into two groups:

Toothed cetaceans: toothed marine giants, such as sperm whales, orcas, dolphins, and porpoises.

Baleen whales: bearded whales. In fact, these beards are angular flakes that grow in their mouths, used to filter water and catch shrimps and other small animals that whales eat, which replace the teeth.

As for the entire sea beast, whales are the most species and the number is also the most considerable. Whales can be divided into two categories: one is the one with no teeth in the mouth and only whiskers, which is called baleen whales; the other is the one with no whiskers in the mouth and keeps teeth without whiskers, which is called toothed whales. Although there are few species of baleen whales, their bodies are huge and become the main objects of human capture. Among them are blue whales with huge bodies and unparalleled bodies, right whales with slow movements, humpback whales with short arms and long arms, and mink whales with small tips, etc. There are many types of toothed whales. Except for sperm whales, the rest of their bodies are generally smaller, such as extremely ferocious orcas and dolphins. Although the body of whales has different lengths and thickness, they are all streamlined and look like fish, so people often call it a whaler. However, whales are beasts. They also constantly float out of the water to breathe air like humans. Sometimes we can see white mist columns spurted out by whales when they exhale. Some are as high as ten meters high, like a fountain, which is very spectacular.

Whales are mammals that live in water for life, and are so dependent on water that they cannot live once they leave the water. In order to adapt to life in water and reduce resistance, their hind limbs disappear and their forelimbs become paddling boards. The body becomes streamlined, resembling fish. Therefore, their diving ability is very strong. Dolphins (small toothed whales) can dive to a depth of 100-300 meters for 4-5 minutes. Bruce whales can stay 300-500 meters underwater for 1 hour. The largest toothed whales, the sperm whales, can dive to less than kilometers and last for 2 hours in the water. In 1955, a sperm whales were discovered in the sea near Ecuador, which was sluggished by submarine cables, with a diving depth of 1,133 meters. In the 2,200 meters water depth in the water near Lisbon, the capital of Portugal, a sperm whales slugged by cables were found. This is the deepest record of mammals diving so far.

[Edit this section] The ancestors of whales

In the early 21st century, scientists discovered two mammal fossils in Pakistan that lived about 50 million years ago. These two animals look a bit like dogs and are only as big as wolves and foxes, but scientists believe it is the ancestor of the largest animal on Earth, whales.

In the early Territory period 50-65 million years ago, all mammals lived on land. Therefore, modern aquatic mammals such as whales and dolphins must have evolved from certain terrestrial mammals. However, due to the lack of fossil evidence, the question of which type of mammals is the ancestor of whales has been unsolved. The anatomical forms of the two newly discovered fossils in Pakistan show that these two animals live on land, have carnivorous teeth, look a bit like dogs, but are not canines. Their tails are longer than dogs, have more ferocious mouths, and have smaller eyes. There are several peculiar bones on their ears, which are very similar to bones unique to the same parts of cetaceans.

[Edit this section] [Chinese Characters]

whale

[Edit this section] Basic explanation

1879 Answerer: 58.55.120.* 2009-9-24 20:58

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The Latin scientific name of cetaceans is derived from the Greek word "sea monster", which shows the ancients' awe of these behemoths living in the ocean. In fact, cetaceans vary greatly in size, with the small ones only about 1 meter long, and the largest ones reaching more than 30 meters. Most of them live in the ocean, and only a few live in freshwater environments. The body shapes are very similar to fish, and they are all streamlined and suitable for swimming, so they are commonly known as whales, but this similarity is just a convergence phenomenon in biological evolution. Because cetaceans have the characteristics of viviparous growth, breastfeeding, constant temperature and lung breathing, they are completely different from fish, so they belong to mammals. The whale has only 10 heartbeats in a minute.

Whale information: whale information How many years is the lifespan of a whale? How many meters is the largest whale? Can a killer whale have fought a great white shark?

In 60-70, the blue whale was the largest, and the killer whale was the most ferocious whale.

About whales' overall introduction to hunger:

Whales are giant creatures in the ocean, and are surrounded by dolphins. (but they are larger than dolphins, have shorter orifices, have flat fins in the forelimbs, and have degenerate hind limbs, have shell fins, have wide and flat tails, and have a pore. The upper part of the order of Cetaceans (the order of the toothed whales and the order of the baleus and the extinct ancient whales) - the order of the baleus and the extinct ancient whales. The cetaceans that cannot be classified as the dolphin family of the toothed whales are classified as the family of the dolphin family.

It is widely distributed, and it can be seen in waters around the world. It is a good and foreign nature. It adopts more group activities in behavior and rarely acts alone. Like dolphins, they like to have fun when foraging, such as jumping to the waves, ascension of whale tails, whale tails, whale tails, and floating peeping, etc.

Whale species:

Whales inhabiting the Southern Ocean are divided into two categories: baleen whales and toothed whales, with about 12 species. Larger baleen whales include blue whales, fin whales, blackboard whales, syringe whales, giant-armed whales and right whales; larger toothed whales include sperm whales and orcas.

The largest one is the blue whales, and the most numerous are the fin whales. Giant-armed whales and right whales are now almost killed, with few survivors.

Whales are widely distributed in the Southern Ocean, and they are traced almost south of the Antarctic conjugation zone. Their distribution is closely related to the distribution of krill groups. Blue whales are mainly distributed in the floating ice zone, and the giant-armed whales and blackboard baleen whales live in the southernmost part. Onyx whales can overwinter in the Antarctic waters, while right whales are mainly distributed in the sub-Antarctic region; toothed whales are distributed in the Antarctic conjugation zone and migrate with seasonal changes.

The life habits of whales:

Poncer whales are accustomed to living alone, and males coexist in the same sea. Male poncer whales can also use “singing” to attract female poncer whales hundreds of kilometers away to feed breeding grounds to mating male poncer whales. Because the frequency of “singing” of whales is similar to that of certain military or commercial sonars, sonars may interfere with the breeding of bale whales, making this species with a lower breeding rate more difficult.

Narwhal has a white belly, a black back, and a blue-gray or black-gray spot pattern. It has a long horn about 1 to 2 meters on its head, which is actually a tooth. At present, most people believe that the teeth of a narwhal are just a sign of a secondary sexual characteristic, which is similar to the mane on the head of a male lion on land. (Habits are still to be examined)

Whales were originally considered to be animals that walked on land with limbs. Later, due to foraging problems, they "go into the sea" and practice monogamy. For example, "big-winged whales" usually live alone, while other whales also live in groups. Their pregnancy period is usually around 12 months, one child, and the young whales are breastfeeding for 10 months, and their lifespan is about 60 to 70 years.

Whales swim back in certain areas of cold zone and warm waters, and have a fixed return route. They live in the cold zone in summer, and after supplementing nutrition, they begin to move to warm waters in autumn in order to reproduce.

Whales eat bran shrimp, squid, fish, etc., while murderous whales eat penguins, seals, dolphins, whales, etc. The socks refer to the tongue that especially likes to eat whales. Wild murderous whales have a fierce temperament, but they can be tamed since childhood, and have a high IQ that can be used for performance.

(Note: The killing whales have a huge appetite. There was a record that a killing whales ate 13 dolphins and 15 seals.)

References: Internet