I've been toying with biological mechanisms for species in my current work in progress by combining or enhancing features in unusual ways. This question is about a canine design.

Dogs, like all animals, regulate their own body temperature. Muscle activity increases it, panting decreases it, etc. This results in an average canine body temperature around 39° C.

However, Earth's canines have fur, which traps heat. This particular species of extraterrestrial canine has decimated the native shark population and stolen their dermal denticles for themselves. (I jest; the shark population is doing just fine.)

Since sharks are aquatic animals, they're more concerned with trapping heat than dispelling it. As such, I've found it hard to identify research indicating the thermoregulation properties of shark skin.

This canine species, it should be noted, is an apex endurance predator. It combines the pronghorn antelope's light build and long legs with the tendon-style legs of an ostrich, allowing it to outpace prey in the sprint. It's large lungs are attached to its muscles, so the faster it runs the better it breathes; this allows it to top the charts in the marathon hunt.

But all this activity will surely cause a buildup of unwanted heat that must be expelled.

So my question to the community is this:

What's the best thermoregulation system this creature can utilize to avoid overheating, whether actively hunting or hanging out with friends on a sunny day?

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    $\begingroup$ What's wrong with the mechanism currently used by dogs? That is, what problems does the ordinary cooling mechanisms used by dogs have, problems which need to be solved? As for the "thermoregulation properties of shark skin" of course you didn't find anything, because ir does not have any thremoregulation properties; sharks don't have any internal thermoregulation mechanisms to speak of. If they have to get cooler they seek cooler water; if they need to get warmer they seek warmer water; and that's all they can do. $\endgroup$ – AlexP Dec 9 '20 at 20:54
  • $\begingroup$ @AlexP (a) I bring it up because I don't know if denticles makes it easier, harder, or has no impact on the current canine thermoregulatory system. (b) Some sharks do regulate their body temperature, such as white sharks (which I have researched extensively for various projects). $\endgroup$ – Frostfyre Dec 9 '20 at 21:07
  • $\begingroup$ @AlexP Further, "the current one, and here's why..." is a valid answer. $\endgroup$ – Frostfyre Dec 9 '20 at 21:09
  • $\begingroup$ I cannot answer "the current one", because the question does not tell why it is unworkable or insufficient. (Dogs don't sweat, so that the skin doesn't do much for thermoregulation; there must be other unexplained changes which require a new thermoregulation mechanism.) $\endgroup$ – AlexP Dec 9 '20 at 21:16
  • $\begingroup$ @AlexP ...I did mention this. Specifically: As such, I've found it hard to identify research indicating the thermoregulation properties of shark skin. Do denticles trap more heat than fur, so they have to pant so hard/much that it becomes unfeasible? Do they need to pant less? I don't know. $\endgroup$ – Frostfyre Dec 9 '20 at 21:21


Since regular dog have very few sweat gland, one of their main way to dissipate heat is through panting. Shark-skinned dog could have an improved panting, for example with stronger respiration or more productive saliva gland.

Avoiding heat

Your canine can stick to colder places like pond, shady place or underground burrow to have less heat to dispel and go out only when necessary, like hunting. Additionally, switching to a night activity allow to lower temperature.

Limbs rich with blood vessels

Usually ears or tails, theses limbs can allow a lot of blood to pass through them in order to cool off with the outside environment. When the temperature decreases, blood vessels shrink to avoid hypothermia. You can give your shark-skinned dog long ears like rabbits or/and long tail like mice.


Human sweat

The power of humans is in part in their ability to sweat nearly all over. This is incredibly efficient in expelling heat. It would probably be the best option for the narrow question you asked. Although this does make it more difficult to stay warm when in rest, as you need to shed your skin for this to work, so a bit more about that.

If you want the best of both worlds, get a skin that traps heat so you don't need the fur. When the body starts heating up, you can open the blood vessels towards the skin more, allowing for more heat transfer with the air/sweat. Assume it isn't as clear cut as this, but it can point you in the right direction.

  • $\begingroup$ My question about human-style sweating is: Would dermal denticles impede this capability? Humans sweat through glands in the skin. Can denticles have sweat glands without compromising their integrity? $\endgroup$ – Frostfyre Dec 10 '20 at 13:07
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    $\begingroup$ Downside of sweat it requires a lot of water. horses and humans go through a lot of water. so no deserts for the dog-things. $\endgroup$ – John Dec 10 '20 at 14:34

One novel way to deal with excess heat would be for the creatures to be faculative thermophiles, so that in addition to the natural heat-loss of the body, they could just survive the heat that their exertion produces. Advantages would be that it could use this heat to injure its prey, and that a creature that can turn blisteringly hot as it runs just seems really cool


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