- Wild animals
- >>
- Mammals
The naked mole rat is not charming or attractive, but it undoubtedly is an amazing animal, because it has many unique features that are not characteristic of other rodents. We will try to analyze the life activity of the mole rat, describing not only its external features, but also the habits, behavior, diet of the animal, its permanent locations and reproductive characteristics.
Origin of the species and description
Photo: Naked mole rat
The naked mole rat is a rodent belonging to the mole rat family. This unusual family includes African burrowing mammals; scientists have identified 6 genera and 22 species of mole rats. Delving into history, it is worth noting that this extraordinary family of rodents has been known since the early Neogene; in that distant period, this species of rodents also lived in Asia, where it is no longer found.
The naked mole rat was first discovered back in the 19th century by the German naturalist Ruppel, who found the rodent by chance and mistook it for a sick mouse that had lost its fur due to illness. At that time, little attention was paid to the mole rat; some scientists only studied their unusual social structure. When technologies for studying the genetic code appeared, scientists discovered many amazing features of these hairless rodents.
Video: Naked mole rat
It turns out that naked mole rats do not age at all with age, remaining active and healthy. Their bone tissue remains as dense, their heart is strong, and their sexual function is normal. Surprisingly, all life characteristics are constant, without deteriorating as they grow older.
Interesting fact: The life span of naked mole rats is six times longer than the life span of other rodents. For example, rodents live from 2 to 5 years, and a mole rat can live all 30 (and even a little more) without aging at all!
By studying these unique creatures, scientists have discovered many striking features inherent in mole rats, including:
- insensitivity to pain;
- fearlessness and resistance to acid (are not afraid of thermal and chemical burns);
- composure;
- Possession of unsurpassed immunity (practically do not suffer from cancer, heart attacks, strokes, diabetes, etc.);
- the ability to go for as long as 20 minutes without oxygen;
- long life span for rodents.
Literature
- Overcoming aging. Part II. Children of the Underground;
- Delaney MA, Ward JM, Walsh TF, Chinnadurai SK, Kerns K, Kinsel MJ, Treuting PM (2016). Initial case reports of cancer in naked mole-rats (Heterocephalus glaber). Vet. Pathol. 53 (3), 691–696;
- Tian X., Azpurua J., Ke Z., Augereau A., Zhang ZD, Vijg J. et al. (2015). INK4 locus of the tumor-resistant rodent, the naked mole rat, expresses a functional p15/p16 hybrid isoform. PNAS. 112 (4), 1053–1058;
- Miyawaki S., Kawamura Y., Oiwa Y., Shimizu A., Hachiya T., Bono H. et al. (2016). Tumor resistance in induced pluripotent stem cells derived from naked mole-rats. Nat. Commun. 7, 11471;
- There was a simple cell, it became a stem cell;
- A snowball of pluripotency problems;
- iPSC fuse;
- Ben-David U., Benvenisty N. (2011). The tumorigenicity of human embryonic and induced pluripotent stem cells. Nat. Rev. Cancer. 11 (4), 268–277;
- Ohnishi K., Semi K., Yamamoto T., Shimizu M., Tanaka A., Mitsunaga K. et al. (2014). Premature termination of reprogramming in vivo leads to cancer development through altered epigenetic regulation. Cell. 156 (4), 663–677;
- Dannenmann B., Lehle S., Essmann F., Schulze-Osthoff K. (2015). Genome surveillance in pluripotent stem cells: Low apoptosis threshold and efficient antioxidant defense. Mol. Cell Oncol. 3 (2), e1052183;
- Small RNA of great importance;
- Miyawaki S., Kawamura Y., Hachiya T., Shimizu A., Miura K. (2015). Molecular cloning and characterization of the INK4a and ARF genes in naked mole-rat. Inflamm. Regen. 35, 42–50;
- Senile vagaries of nature: why people stop aging, but mice do not have time to live.
Appearance and features
Photo: Naked mole rat underground
The dimensions of the naked mole rat are small, the length of its body does not exceed 12 cm, and its weight ranges from 30 to 60 grams. It should be noted that males are much smaller than females, which can weigh half as much as their male counterparts. The entire physique of the mole rat can be called cylindrical, the rodent’s head is quite massive, and its short limbs are five-fingered.
Interesting fact: Only at first glance does the mole rat seem bald; nevertheless, he has some hairs scattered throughout his body, especially in the paw area they are better visible.
Thanks to their wrinkled skin, mole rats turn masterfully in tight spaces, giving the impression that the rodents are doing somersaults inside their skin when they make a turn. Diggers have chisel-like incisors that protrude from the outside of their mouths, which the animals use to dig like the buckets of an excavator when outside. The labial folds located behind the incisors protect the diggers from getting soil into their mouths. It should be noted that the well-developed jaw of mole rats is very powerful and has large muscle mass.
Mole rats are practically blind, their eyes are very tiny (0.5 mm) and distinguish between flashes of light and darkness. They can navigate in space with the help of vibrissae, located not only in the muzzle area, but throughout the body; these sensitive hairs act as tactile organs. Although the ears of these rodents are reduced (representing a leathery cushion), they hear excellently, picking up low-frequency sounds. Diggers' sense of smell is also quite good. In general, the leathery surface of the mole rat's body is pink in color and is all dotted with wrinkles.
Where does the naked mole rat live?
Photo: Naked mole rat
All mole rats inhabit the hot African continent, namely its eastern part, choosing places south of the Sahara Desert. As for the naked mole rat, it is most often found in savannah and semi-desert areas in Somalia. Diggers also inhabit Kenya and Ethiopia, occupying arid savannas and semi-deserts for permanent residence. Scientists were able to find out that diggers once inhabited Mongolia and Israel; this became known thanks to the remains of animals found in these countries. Nowadays, diggers live exclusively in Africa.
As already noted, mole rats live in open spaces (in savannas and semi-deserts), rodents love sandy and loose soil, and can climb mountains to a height of up to one and a half kilometers. These unusual creatures are accustomed to living in the bowels of the earth, digging out entire underground labyrinths with their powerful incisors, consisting of many ornate tunnels, the length of which can be several kilometers. Diggers almost never get to the surface, so it is not possible to see them.
Sometimes young animals may appear outside for a short time during the resettlement period. Even very dry soil with a consistency similar to concrete does not bother naked mole rats; in it they are able to dig (or rather, gnaw through) a whole series of catacombs, plunging deep into the ground from one and a half to two meters.
General information
The Australian red claw crayfish (Cherax quadricarinatus), also known as the Red claw crayfish, is a freshwater crustacean from the order Decapods. It has become widespread, first of all, as a commercial species, which is actively used in aquaculture. The meat of these crayfish is considered a delicacy and is not much inferior in taste to sea lobsters.
However, its beautiful appearance and unpretentiousness to the conditions of detention have made it popular in the aquarium hobby. This exotic animal is not yet often found in home aquariums, but every year there are more and more crayfish lovers among those who want to have an unusual pet. And most often the choice of novice crayfish breeders falls on the Australian red-clawed crayfish.
Watching the life of a cancer is a fascinating activity. Just look at regular “designer” rearrangements in the aquarium. You don’t even have to try to carefully arrange stones, shells and other small decorations. Once the crayfish's claws reach them, it will place them wherever it sees fit, and will be very unhappy if you try to disturb the created landscape.
Best articles: The largest straits of the Atlantic Ocean - list, characteristics and map
Keeping freshwater crayfish is not much different from keeping aquarium fish, but it also has its own nuances.
What does the naked mole rat eat?
Photo: African naked mole rat
Naked mole rats can confidently be called vegetarians, because their diet contains dishes exclusively of plant origin. The diggers' menu consists of rhizomes and tubers of plants, both cultivated and wild.
Interesting fact: It happens that when a digger finds a tuber, he eats only part of it, and the rodent pours earth into the hole that he gnawed out, so that the potato grows further, so a smart digger tries to provide himself with food for future use.
These rodents get their food only underground. Animals also get the moisture they need from roots and tubers, so they don’t need water. To prevent dirt from getting into the diggers' nostrils while searching for food, they are protected from above by a special fold of skin, which is called the “false lip.” It is worth noting that the mole rat does not have an upper lip.
These unique rodents have a very slow metabolism, because... have a surprisingly low body temperature of 30 to 35 degrees. Due to this, animals do not require as much food as compared to other mammals of similar sizes. When naked mole rats eat, they are like hamsters, able to hold their snack in their front paws. Before they start eating, they shake off the earth from it, cut it into separate pieces using sharp incisors, and then chew thoroughly using their small cheek teeth.
Compatibility
Despite their size and formidable claws, Australian crayfish pose no threat to most fish or even small species of shrimp. In rare cases, they are able to grab a small fish. Snails, fish eggs and, of course, living plants, which will definitely be cut and eaten, can suffer from their actions.
When selecting neighbors, you can pay attention to moving medium-sized fish (mollies, swordtails, barbs, irises, thorns), as well as catfish - ancistrus, thoracatum. It is better not to combine aggressive species (astronotus, acar, large cichlases) with crayfish, as these fish can destroy their neighbors during the molting period
It is better not to combine aggressive species (astronotus, acar, large cichlases) with crayfish, as these fish can destroy their neighbors during the molting period.
Features of character and lifestyle
Photo: Naked mole rat
Naked mole rats are classified as eusocial animals, i.e. they have the highest level of social organization; their lifestyle is similar to social insects (ants, bees). The underground colonies of these rodents usually number from 70 to 80 animals.
Interesting fact: There is information that scientists have observed colonies of mole rats, in which about 295 animals lived.
The entire length of underground labyrinths, which is the habitat of one colony, can extend over a distance of 3 to 5 km. The earth that is thrown out when digging tunnels reaches a mass of three or four tons per year. Typically the tunnel has a 4-centimeter diameter and is located at a depth of two meters.
Tunnels serve to connect with each other:
- nesting chambers;
- aft rooms;
- restrooms.
Digging underground passages is a collective work; people begin to do it more actively during the rainy season, when the earth softens and becomes more pliable. A chain of 5 or 6 diggers moves in single file, following the first working individual, which bites with its incisors into the layer of soil, which the rodents following the first animal help to rake out. From time to time, the first digger is replaced by the next animal behind.
All mole rats living within the same colony are related. The head of the entire settlement is one single female breeder, who is called the uterus or queen. The queen can mate with a pair or three males; all other individuals of the colony (both male and female) are workers and do not participate in the reproduction process.
Depending on the dimensional parameters, workers have a number of functions. Large individuals are considered to be soldiers engaged in protecting their fellow tribesmen from ill-wishers. Small mole rats are tasked with maintaining the tunnel system, nursing the young, and searching for food. The activity of medium-sized individuals is intermediate; there are no clear distinctions between the castes of mole rats, as is typical for ants. Throughout her life, the female queen is busy only with the reproduction of offspring, giving birth to more than one hundred offspring.
Interesting fact: From one observation it is known that in 12 years the queen gave birth to about 900 mole rats.
It is worth adding that naked mole rats have very developed sound communication; in their vocal range there are at least 18 types of sounds, which is much more compared to other rodents. Maintaining a constant body temperature is not typical for mole rats; it (temperature) can fluctuate, depending on the temperature regime of the environment. To slow down the temperature drop, mole rats gather in large groups and can bask for a long time in burrows located near the surface of the earth. Possessing a slow metabolism contributes to the survival of mole rats where there is a lack of oxygen in the bowels of the earth and an increased content of carbon dioxide, which is fatal to other living beings.
Social structure and reproduction
Photo: Naked mole rats underground
As mentioned earlier, the female, called the queen or queen, is responsible for reproduction in naked mole rats. For mating, she uses only a few fertile males (usually two or three); all other inhabitants of the underground labyrinth do not participate in the reproduction process. The female queen does not change partners, maintaining constant relationships with these chosen males for many years. The duration of pregnancy is about 70 days, the uterus is capable of producing new offspring every 80 days. There can be a maximum of 5 litters annually.
Naked mole rats can be called very prolific; compared to other rodents, the number of cubs in one litter can vary from 12 to 27 individuals. Each baby weighs less than two grams. Although more than two dozen cubs can be born at a time, the female has only 12 nipples, but this does not mean that some of the offspring die. Thanks to research by American scientists, it became known that infants of naked mole rats feed in turns, because The female mother has a lot of milk. Thanks to this method of feeding, babies realize the importance of social connections at a very early age.
The queen mother feeds her babies milk for a month, although they begin to eat solid food already at two weeks of age. Cubs tend to eat the feces of other workers, so they acquire the bacterial flora necessary to digest the vegetation they eat. At three or four weeks of age, young mole rats already become workers, and rodents become sexually mature when they reach one year of age. As already noted, mole rats live a very long time for rodents - about 30 years (sometimes more). Scientists have still not been able to figure out exactly why this unique mechanism of longevity functions.
Interesting fact: Although it is prestigious to be a female queen, they live much less than other working mole rats. Researchers have found that the lifespan of a uterus varies from 13 to 18 years.
Natural enemies of the naked mole rat
Photo: Naked mole rat rodent
Due to the fact that diggers lead an underground and secretive lifestyle, they practically never come to the surface, these rodents do not have many enemies, because it is not easy to find a digger in the bowels of the earth, where he dives up to two meters deep. Despite the protected and safe living conditions of these rodents, they still have ill-wishers. The main enemies of diggers are snakes. It is rare, but it happens that a snake directly underground pursues a single rodent, following it through a dug tunnel. This doesn’t happen often; usually snakes watch over animals on the surface.
Mole snakes hunt naked mole rats at the moment when the rodents throw out excess soil from their burrows. An insidious creeping creature waits for the appearance of a digger, sticking its head right into the hole. When a rodent appears to throw away dirt, it grabs it with a lightning-fast lunge. It should be noted that even though mole rats are almost blind, they can distinguish smells very well, they can immediately recognize their relatives from strangers, and the animals are very intolerant of the latter.
The enemies of naked mole rats can also include people who consider these creatures to be pests of crops and try to kill rodents. Of course, diggers can cause damage to the crop by feasting on roots and crops, but we should not forget that, like moles, they also have a beneficial effect on the soil, draining it and saturating it with oxygen.
You can live forever
The fight against cancer is perhaps the main challenge for modern medicine. However, the tasks of researchers in the laboratory of bioorganic chemistry of enzymes are not limited only to cancer tumors. Alzheimer's disease, HIV, all kinds of neurodegenerative diseases - this is a short list of diseases that can be defeated, scientists from the Institute of Chemical Biology and Fundamental Medicine of the SB RAS are sure. But it is still possible to solve the long-standing dream of humanity and extend life to fantastic, by today’s standards, years.
Related news
The most frightening disease. How is cancer treated in Russia and abroad?
However, it may turn out that scientists will have no time to deal with their direct responsibilities, and those discoveries that Novosibirsk chemical-biologists are on the verge of today will be “frozen” for years. Because drugs based on laboratory discoveries should be created by “specially trained people, not researchers,” scientists say.
“Now the government of the country requires that scientists work for a “tangible result.” I think this is a big mistake regarding fundamental science,” says Olga Lavrik. – Scientists who are engaged in serious research should not engage in applied problems. Otherwise, they won’t have time for their main job.”
Classic problems for our country also remain. Money is allocated for scientific research; laboratories can receive funding from the Ministry of Education and Science, for example, through a special lot system. However, the system is so mired in bureaucracy that the whole process turns into a “walk through agony.”
“There are both federal and local programs that provide grants to young scientists. But the organization of the process is very intricate. You need to endlessly write some papers, reports, notes. This distracts from scientific work, from experiments, seminars, writing articles, turning a scientist into a clerk. We need such a system so that the laboratory can receive a decent grant, sufficient to work at a high level and for a long period of time, without a lot of intermediate reports,” said Olga Lavrik.
Last year, the Nobel Prize in Chemistry was awarded to Englishman Thomas Lindahl and American Paul Modrich for their discovery of key DNA repair mechanisms. This field of molecular biology is rapidly developing, and the whole world is closely following this research.
