Naked mole rats possess a number of adaptations that they have acquired through many years of living underground. These adaptations range from having very poor eyesight, to having strategically placed body hair, to being able to survive hypoxic conditions in a low-oxygen environment.

Let's first take a look at the differences between naked mole rats and the typical laboratory mouse. Looking at these differences can help show the distinguished adaptations the naked mole rat has made in order to survive in its environment. Let's first take a look at a study that shows the differences between naked mole rats and laboratory mice in many different areas of each rodent's life.

One test was conducted by a group of scientists to see how naked mole rats would react when placed in a cage with a man made tunnel filled with either food pellets or bedding. It was observed that the naked mole rats typically did not burrow very much compared to the mice. This was measured by how much of the food or bedding was displaced from the tunnel by the animals. This result is not what the experimenters were expecting since naked mole rats must burrow in order to form their intricate, complex tunnel systems that they call home. We learned previously, though, that they are eusocial mammals and depend on the work of the group as a whole to survive, not the work of just one organism (Deacon et. al, 2012).

However, in the digging test, naked mole rats were measured to dig more, and for longer bouts at a time than the mice, although they were not as quick to begin digging.

One last set of tests which we will discuss deals with the naked mole rat's overall strength. When you think of a typical rodent you probably automatically think of a mouse or a rat; both of which are very good at climbing and clinging to wire mesh with their tiny toes. They have very good grip. An inverted wire mesh test was done to test the strength of the naked mole rat's grip and compare it to the grip of the mouse. The results were quite shocking. The naked mole rats tended to fall almost immediately after the wire was inverted, where the mice could cling upside down for about a minute. The next test was a static rod test. A rod was placed horizontally over the ground with one end attached to a stationary object, like a chair. The organism being tested was placed at the far end, away from the chair, and facing away from the chair. It was then timed how long it took for the animal to turn itself around and walk down the rod to the other end. The times recorded for the naked mole rats were significantly longer than the times for the mice. This, again, shows the naked mole rat's poor performance in agility and strength. Finally, the last test was a pull-up test. The experimenter held the animals hind feet, and lowered the head down so the organism was hanging upside down. The time it took for the animal to curl up and touch either a front paw or snout to the experimenter's hand was recorded. In the study, the naked mole rat took approximately a minute to complete the pull-up, whereas the mouse took no longer than 2 seconds (Deacon, et. al, 2012).

These tests show that naked mole rats essentially have no grip in their feet, causing them to fail the inverted mesh test and the static rod test. It is also shown by these tests that they do not have very strong muscles elsewhere in their body, such as their abdomen (Deacon, et. al, 2012).

Living underground for the entirety of life would not be possible for most mammals, including humans. This is because there are very low levels of oxygen in the soil, and we would end up suffocating. However, the naked mole rat has been able to adapt to the hypoxic environment and thrive in the oxygen-deprived habitat. How do they do this you may ask? We are about to find out.

There was a study done on slices of a naked mole rat's brain, which were then tested in order to understand how they survive the hypoxic conditions. The study showed that naked mole rats have made many adaptations in order to live underground. One such adaptation is that the hemoglobin in the red blood cells of naked mole rats has a much higher affinity for oxygen than the hemoglobin in our red blood cells. This allows them to capture more oxygen from the air, and use it more efficiently. Another adaptation is that their weight-specific metabolic rate is about one-third less than that of their other rodent relatives. One final adaptation that has been recently found is in the hippocampus. It has recently been discovered that hippocampal brain slices in adult naked mole rats maintained synaptic transmission at low oxygen concentrations. When mice were exposed to the same environment of low oxygen levels, brain slices of their hippocampus showed that this transmission was greatly decreased or even stopped altogether. It was shown in hippocampal slices of naked mole rats that they also maintained electrophysiological function more than three times as long as their mouse counterparts (Peterson, et al., 2012).

A third study I will discuss is about a possible inbreeding prevention mechanism.  Inbreeding is a very common practice among animals that live in colonies like naked mole rats. This mechanism promotes out-breeding by producing organisms that are morphologically, physiologically, and behaviorally distinct from the normal colony organism. These distinct group members are normally laden with fat, possess high levels of luteinizing hormone, and have a strong urge to disperse. Since they prefer to breed with members from a different colony, they are helping to prevent the continuous inbreeding of the colony (O' Riain, et. al, 1996).

Finally, a study done on the longevity of naked mole rats found multiple reasons as to why naked mole rats are the longest- living rodents known; most tended to lead back to their habitat. Since naked mole rats live underground their entire lives, they are sheltered from the potentially harsh environment outside. Their tunnels act as a temperature buffer and maintain a relatively constant temperature year round. Also, because they live underground, they are protected from almost all predators they may have encountered above ground. The exception being some snakes or bats, which are attacked by multiple group members if the colony is being threatened (Buffenstein, 2005).

All of these adaptations that the naked mole rat has made are what make them such a unique and interesting organism to study.

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