The animal kingdom is home to loads of animals with different characteristics, attributes, behavior, defense mechanisms, so on and so forth. It’s quite amazing how animals were so complicatedly made, to the point that each animal is unique and each attribute they have plays an important role.
There are a lot of attributes present in an animal, but for now, we will be focusing on one and this would be an animal’s skin.
An animal’s skin varies in texture, thickness, and purpose. For now, we will be tackling animals with thick skin. What exactly is the purpose of thick-skinned animals? Are these some kind of defense mechanism for them?
Animals With Thick Skin
The number is abundant when it comes to animals with thick skin, and these mainly include mammals. Although, there are also other animals with thick skins that belong to other families in the animal kingdom.
1. Crocodile & Alligators
Just by looking at the textured skin of crocodiles and alligators, we can see how thick it is. It’s coarse in texture and it serves as armor for crocs and alligators.
Some people would have a common question: how can both crocodiles and alligators feel something touch against their skin, provided that it’s thick?
An amazing fact about their skin is it actually has a heightened sense of touch. The way these reptiles can sense things is due to the tiny domes that cover their bodies. When it comes to alligators, the placement of these domes is located in the areas of their face and jaws.
So how exactly is this claim proven? Thanks to a study called the Journal of Experimental Biology, researchers have discovered that the small domes in the skins of both crocodiles and alligators have much more complicated and sensitive sensors to vibrations and pressure compared to human touch/human hands.
Scientists have given a name for these sensitive tiny domes and the name is integumentary sensory organs or ISO for short. During researches, scientists are trying to figure out and hypothesize the function of the ISOs.
They have come up with several hypotheses such as:
- The dots on the small domes secrete oil to keep the crocodiles and alligators clean.
- Pressure and vibration detectors.
- Electric field detectors.
- Magnetic field detectors.
- Used in detecting the salinity (concentration of salt in water) of water
Take note that the information stated above is purely hypotheses and these have not been proven to be facts unless proved through means of experiments.
Another discovery by a biologist at the University of Maryland has aided in identifying yet another helpful hypothesis. This hypothesis would be about the sensitive domes’ ability to detect ripples in the water despite being distracted by other noises (e.g. white noise).
Scientists were determined to find out the most acceptable hypotheses that would indicate what the function of these ISOs is. Lo and behold the numerous hypotheses aforementioned were debunked by a graduate student named Leitch.
Leitch discovered that the sensors in the tiny domes on the skin of crocodiles and alligators are connected to their brains.
To be specific, the exact part of their brains in which the sensors are located is called the trigeminal ganglia (this part of the brain is responsible for providing sensations to the face and jaws in the human anatomy).
Furthermore, the studies that Leitch did have proven the previous hypotheses mentioned to be false. The sensors in the skin of both crocodiles and alligators were beneath the skin and not on the outer skin itself, this was the main point that debunked the other hypotheses.
With that being said, their studies have concluded that the sensors in both the reptiles mentioned here are truly exceptional in terms of their functions. These sensors are able to not only detect prey in the water but also detect their prey’s location so they can strike for the kill.
2. Whale
There is a variety of whales in marine life, all of which have thick skin. Although whales and other marine mammals are known for their blubber instead of the skin, nonetheless their skins are also one of their main attributes.
For instance, a beluga whale’s skin is 100 times thicker compared to land mammals. Beluga whales have their fat to thank for that since it’s also a part of what makes their skin so thick, to be more specific, their blubber makes up 10 cm of their skin’s thickness.
In addition, this blubber takes up about 40% of a whale’s total weight, and blubber also has its own unique function and this is to provide warmth for marine mammals in cold environments and it also stores energy.
3. Rhinoceros
A land mammal that is known to most people is the rhinoceros and these animals are so easy to remember due to their thick skin and large horn on the top of their noses.
A rhino’s skin is 1.5 – 5cm thick and is composed of layers of collagen as well and the pattern of the skin is crisscross-like.
The thickness of their skin would depend on what type of rhino they are, but the general fact that applies to every kind of rhino would be their thick skin being sensitive.
The sensitive but thick skin on a rhino is designed the way that it is because this would protect the rhino from injuries and such.
4. Porcupine
The skin of a porcupine is relatively thick and in order to measure the thickness of their skin, scientists came up with three skin divisions: muscle thickness, epidermal skin thickness to the hypodermis and, the skin’s thickness overall.
The thickest layer of a porcupine’s skin would be located in the lumbar region, while the thinnest layer on the other hand would be located in the lumbosacral area.
The skin of a porcupine is covered in quills, while this may not be classified as skin, it’s a type of defense mechanism that’s embedded in a porcupine’s skin. Their quills are categorized as hair rather than skin.
5. Turtles & Tortoises
The skin seen in most turtles and tortoises is thick and textured, however, there are also some that have smooth skin, it would depend on what type of species they are, to be honest.
For most turtles, their thick leathery skin sits beneath their large carapace.
An example of a turtle with thick skin would be the sea turtle called the leatherback. These turtles have thick and rubbery skin to protect them from the cold temperatures in the depths of the sea.
The thick skin on a leatherback can withstand the cold better than other sea turtles.
6. Arthropods
Animals under this family have thick exoskeletons, although the tough skin that protects the bodies of arthropods is referred to as cuticle.
The cuticle is made up of proteins and chitin and this makes it a tough outer layer. In addition, the cuticle is a non-living material that protects animals under arthropods.
The animals classified under arthropods would be crustaceans, arachnids, and insects.
7. Elephants
An elephant’s skin would have a general thickness of 1.5in, however, this thickness doesn’t apply to its entire body since the thickness of the skin on elephants would vary depending on its body part.
Similar to rhinos, the skin on an elephant is sensitive to touch, meaning, despite being thick, it’s sensitive enough to feel external factors such as insects and changes in climate.
8. Pachyderm
These are big mammals that have thick skin and the term itself, pachyderm, translates to thick-skinned animals, below are some examples:
- Elephants
- Hippopotamus
- Rhinoceros
- Pigs
- Tapirs
9. Manatees
Manatees are mammals that dwell underwater and they have thick leathery skin that would have a thickness of 50mm.
Unlike whales, who are also aquatic mammals, manatees may have thick skin but they don’t have that much blubber as whales do, so they can’t generate enough warmth for themselves.
Manatees also look fat due to blubber, but the thing is, their massive fat is composed of intestines and their stomach, not blubber.
Why Do These Animals Have Thick Skin?
The animals included in this list have thick skin for purposes like defense mechanisms and regulating temperature. The bottom line function of thick skin would be to keep animals alive.
Animals that have thick skin would have a few advantages compared to animals that don’t have thick skin, namely, these would be added protection against external factors and other animals.
Humans Are Mammals, Do We Have Thick Skin Too?
Yes, we humans have thick skin as well.
Although this may not be similar to the thick skin that animals have, it’s still pretty thick. It’s important to note however that the entire human body isn’t made up of thick skin. There are only specific areas in our body that are thick-skinned.
For instance, body parts such as the hands, lips, and soles of the feet are thick-skinned. These body parts were designed the way that they are because these are primarily used for activities that require a bit of toughness.
Resources:
https://indianapublicmedia.org/amomentofscience/thick-skin.php
https://parasite.org.au/para-site/contents/arthropod-intoduction.html
http://www.tulane.edu/~bfleury/diversity/labguide/arthropod.html
