In the water flow of Changbai Waterfall in the northern foothills of Changbai Mountain, tourists find a round and slippery animal, which appears from time to time in the faster current, as if foraging, seeing the crowd on the shore, frightened and wandering, and the tail does not swing. But within 10 minutes, I climbed up a rock to rest. Round and cute, it looks like a mouse, but what mouse can swim in the water? Later, someone used the map reading software to look it up and found that it was a small animal called the water shrew.
The water shrew is an amphibian mammal found mainly in Eurasian rivers and lakes north of 40° north latitude. In China, the water shrew is a rare animal, and it has only been found in Changbai Mountain in Dunhua, Yanbian Korean Autonomous Prefecture, Jilin Province, Xiaoxing'anling in Dajingshan County, Yichun City, Heilongjiang Province, Guiyang City and Weining County in Guizhou Province, and Xinjiang and Inner Mongolia. Abroad, there are currently a small number of distributions in Russia in Europe and Canada and the United States in North America, as well as Mongolia and North Korea in Asia.
The water shrew does not live entirely in the water, on the contrary, most of the time, the water shrew is active on land, building nests in dry places. They usually inhabit the grass of rivers or swamps, or live along rivers and streams, which makes it easier for them to avoid predators, which can easily escape from waterways.
<h1 class = "pgc-h-arrow-right" >01 weighs less than 20 grams, has a dense mouth of red teeth, and has short hard hairs on the feet</h1>
The water shrew belongs to the mammals, shrews, shrews, shrews, shrews, amphibians of the genus Shrew, Latin scientific name Neomys fodiens, commonly known as water rats, northeast people call it pointed-billed rats, stinky rats, Inner Mongolian people call it blind rats, xinjiang people call it medicine rats.
Like other shrews, the water shrew is small, slightly flattened and slender, and the adult body is 7.2-8.5 cm long, about the size of a thumb, and weighs less than 20 grams, only about 15-19 grams.
Its neck is inconspicuous, basically invisible; the eyes are small, the snout is sharpened; the sides of the nasal snout are covered with thick tentacles, generally white and a small amount of black; the mouth is split herringbone; the nostrils are very small, and the nostrils are open at the top of the snout; interestingly, there are valves inside the outer ear shell to prevent the ear from entering the water when diving.
The skull is low and flattened, the mouth is densely packed with teeth, the upper jaw incisors are cylindrical, long and curved forward, and there is no gap between the molars. All teeth are red crowns with iron, which I heard is meant to enhance the wear resistance of the teeth. For water shrews, tooth wear is a very serious problem because their teeth do not continue to grow.
They have 5 toes on each of their four legs and claws on their toes. What is different is that they have short spike-like hard hairs on the outer edge of the soles of their feet. These hairs automatically stand up when diving downwards, which increases the surface area of the soles of the foot, but when it swims upstream, it can be folded together to reduce the resistance of the water.
They pride themselves on having a waterproof fur. The dorsal ventral surface of the body is very different in color , the head and back are brownish gray , and the abdomen is off-white. Its long hair is waterproof, and when diving into the water, its fur not only isolates the air, but also plays a dual role of waterproof and warm.
<h1 class= "pgc-h-arrow-right" >02 The water shrew looks too much like a mouse and is often mistakenly called "water mouse", which has nothing to do with mice</h1>
In nature, the animals that are most likely to be mistaken for rats are the most likely to be mistaken for rats, and if the water shrew ranks second, then no one really dares to rank first, because the water shrew looks too much like a mouse and is often mistaken for a "water rat" or "water rat".
So why is it so similar? Shrews appeared earlier than rodents, but due to their close body size and similar living environments and conditions, they tended to evolve somewhat.
But it's clear from this guy's long, narrow skull and mouth full of sharp teeth that can tear apart meat, it's clear that they're not rodents. In fact, there is a clear difference between the water shrew and the mouse:
First, the degenerated and shrunken eyes and ears are also smaller than ordinary mice; in terms of body color, rats are generally brownish yellow, and water shrews are black and gray.
Second, the water shrew has a long body of hair, its tail, feet and toe edges have long hairs, so that the long hair on the water shrew unique effect, is conducive to the swimming of the water shrew.
Third, in terms of classification, the water shrew and the mouse are also completely different, the water shrew and the mouse have no relationship, nor are they rodents, the water shrew is the shrew family, and the rat is the rodent family.
<h1 class = "pgc-h-arrow-right" >03 The youngest "diver" among mammals, he warms up like a human before diving in cold water</h1>
Of all mammals, the water shrew is supposed to be the smallest "diving expert". Although from the outside, it looks no different from its "dry duck" cousins.
This guy, you just put it by the creek and plunge into the water with a jerk, swim away quickly, and then disappear into the grass by the river. In this way, the water shrew is more like a fish than a mammal.
The water shrew is an animal that does not hibernate, and diving into the cold stream in winter is bound to consume a lot of energy, so keeping warm is crucial for them.
For the water shrew, living in the water is a deadly killer, but this guy must have mastered some different skills of the species in order to survive tenaciously in the natural world of survival of the fittest.
In this regard, Dr. Campbell of the University of Winnier Manitoba in Canada has the most say, according to his research, the water shrew will also do the warm-up exercise like a diver before entering the cold water, so that the body temperature will rise by about 1.5 degrees Celsius.
Dr. Campbell explained that by warming up, the water shrew instantly increases its body temperature, and then quickly makes a quick decision to shorten the hunting time in cold water, so as to obtain more hunting opportunities and more abundant meals, thus ensuring their life system.
<h1 class= "pgc-h-arrow-right" >04 When preying in water, it is not by sight, but by smell to lock on to prey</h1>
You don't look at its small size, only the size of a thumb of the water shrew is very strong in combat, it is a veritable underwater "assassination master", can be called a miniature version of the otter. When the water shrew dives into the water, it is impossible to rely on its sensitive sense of smell to lock on to its prey, but its predation method is very peculiar, and it has a set of "unique martial arts secret skills", and many times it has special skills but hides it.
When fish and shrimp are preyed upon in the water, they do not rely on vision – they look through their eyes and lock in their prey with their sensitive sense of smell. The whole process goes like this:
First, when foraging underwater, when approaching prey, they exhale air through their nostrils and form small blisters in the water that rush directly onto each other.
They then re-inhale these small bubbles that already have each other's odor into the nasal cavity so that they can collect relevant odor information.
Finally, they perceive their prey through their tentacles. The snout of the shrew is flanked by thick tentacles that are radiatively scattered. It is precisely by using their sense of touch that the water shrew finds and chases the prey that is about to flee.
On land, they also have the "Anesthesia Dafa". Its salivary glands can secrete a venom, although not highly toxic, but can play the role of "ten fragrant soft tendons". If a small animal is bitten, it will lose consciousness and cannot move, so it will be left to be slaughtered.
What should I do if I encounter a predator? The shrew also has a pair of stink glands on its hind legs, which can release a spicy musk-scented gas, which is a secret weapon against the enemy.
<h1 class = "pgc-h-arrow-right" >05 can eat 3 times their own weight food, less than 20 grams but dare to prey on crayfish</h1>
The shrew looks so small, but it is a veritable "big foodie". The shrew is an omnivore with a very good appetite and eats non-stop all day long. Their total daily food weight is 2 times their weight, and at most, they can eat food equivalent to 3 times their body weight every day, and they can also catch 5 times their own weight.
On land, it lives by eating some earthworms, and sometimes it also preys on some insects, of course, it eats mostly pests.
As soon as it reaches the water, it is arrogant, can catch small fish of the same weight as itself, even water dragonflies, snails dare to attack, even the ferocious crayfish can not escape the palm of its hand.
On the surface, the small size of the water shrew compares to the lobster's huge pincer foot, which makes people wonder whether they can really successfully prey on lobsters. In fact, lobsters are destined to be the losers in this contest and become the shrew's meal on the plate.
<h1 class="pgc-h-arrow-right" > concluding remarks:</h1>
One more interesting thing to tell you, the water shrew is magical, its cerebral cortex is only 8.5% and 6.5% used to process visual and auditory information, while as much as 85% is used to process tactile information, of which about 70% is used to process the information perceived by the tentacles.
Snow Spirit Valley Animal Lab/Production
References: Science and Technology Daily, Nature Exploration, Life Science Network, Institute of Zoology, Chinese Academy of Sciences