Reptiles have evolved an impressive array of behaviors and morphological adaptations that allow them to survive in their diverse ecosystems. Some of these strategies can be misinterpreted by hobbyists or clinicians and may look like disease or injury.
도마뱀분양For instance, a lizard that raises a diagonal pair of legs to sun itself can appear dead. This is actually a display for thermoregulation.
Skull Flexibility
Skull flexibility is an important feature of reptiles, and it can affect their ability to sense their surroundings. For example, snakes have a more flexible neck than lizards. This allows them to move their head freely in order to scan the environment for prey and other dangers.
The neck is a complex structure composed of bones, muscles, nerves, blood vessels and lymphatics that connects the head to the rest of the body. It is responsible for the movement of the head and is extremely important in allowing us to see, smell, taste, touch, hear and speak. It is also the most elongated portion of the vertebral column.
Reptiles are ectotherms, meaning that their primary source of heat comes from the surrounding environment, rather than from their metabolism. As a result, they are able to regulate their internal temperature by absorbing or losing heat as needed.
One of the main reasons why reptiles can regulate their internal temperature so well is because they have a thick layer of keratinized scales, known as armor. This occlusive skin prevents water loss from the body and, therefore, helps them to stay warm. It is a key adaptation that helped reptiles to live on land instead of in water like amphibians.
Hibernation
The ability of some reptiles to enter a state of hibernation, or torpor, allows them to survive extreme cold. They do so by reducing their body temperature, slowing their metabolism and storing fat.
This enables them to survive periods when food is scarce or impossible to find. It also makes them less vulnerable to predation and other dangers. Hibernation also allows them to save energy because they don’t need to warm themselves up by eating.
In order to hibernate, some animals prepare a den or burrow by lining it with insulating material such as grass or mud. Other species, such as ground squirrels and lemurs, bury themselves in snow or under the ice of lakes and ponds. Bears, polar bears and bats spend the winter in caves.
During hibernation, animals can drop their internal temperature to as low as freezing. They can do this because they have large amounts of brown fat, which collects around vital organs and keeps them warm. In addition, their blood is able to remain liquid at such temperatures.
Although it was once thought that hibernation was an adaptation developed to allow mammals to live in very cold environments, research now shows that hibernating animals occur across a wide range of climates. For example, the echidna, a monotreme, hibernates in Australia. This suggests that hibernation evolved before the monotremes and marsupials separated from placental mammals.
Autotomy
Autotomy is the ability of animals to voluntarily shed parts of their bodies that have been grasped by a predator, or even entire body segments. This behavior can improve the animal’s chance of escape or reduce further damage to its body. It has evolved independently in many species of invertebrates (including crickets and grasshoppers) as well as some vertebrates, including lizards. For example, some lizards can drop their tails when grabbed by predators; this allows the lizard to wriggle and distract the predator while it escapes.
Specifically, caudal autotomy is the ability of certain extant squamates to break off their tails when threatened by predators and then regenerate them later. It is most commonly observed in agamid lizards and snakes, but not in true chameleons or monitors, which rely on their tails for defense or climbing. This is because these reptiles lack the fracture plane that enables caudal autotomy: a vertical plate of cartilage, containing no bone, that passes through each of the spinal vertebrae, or centrum, and neural arch.
This ability, however, carries significant costs for the organism, impacting locomotion, foraging, mating, habitat use, and social status. It also requires a substantial amount of energy to grow new tissue and may slow the animal’s growth or reproduction. Hank Green explains this in this great SciShow video.
Tail Regeneration
Many lizard species use caudal autotomy, the ability to self-amputate their tails and regenerate them, as an anti-predation strategy. Despite the negative trade-offs associated with losing a tail, it has been suggested that regenerated tails may restore some of the biological functionality of the original ones. However, previous research has been contradictory.
A key issue is that, unlike scarring, regeneration is a highly energy-consuming process. It is therefore important to know how this energetic cost affects the organism’s performance and fitness.
To address this question, we compared growth performance of hatchlings with intact and regenerating tails of the wall lizard P. muralis under a range of conditions. Our results reveal that regenerating lizards have lower body growth rates than lizards with intact tails, at least when food availability is limited. This is probably a result of the fact that regenerating lizards need to invest more of their resources in their tails than intact lizards.
In contrast, when lizards were fed ad libitum, regenerating individuals had the same growth rate as intact lizards. This suggests that regenerating lizards can balance the energetic costs of tail regeneration with other metabolic processes. It is thus likely that the regenerated tails of P. muralis contribute to the overall locomotor performance of these lizards by providing them with additional support when they move through dense grasses.