Is this creature plausible on Mars?

[caters]

I am thinking of writing a story about a Martian civilization. It might involve humans, but, I think it will be more interesting if there are creatures adapted to the Martian lifestyle as well. So, here is a proposed creature to live on Mars:



A burrowing reptilian, or so it seems. Photosynthesis is a tricky one. On the one hand, less light arrives at Mars than at Earth. On the other hand, the thin atmosphere means the light doesn't get as scattered. I decided that this creature would have photosynthetic skin, because it means the creature wouldn't have to worry as much about being sunburnt. When the creature is likely to be cold-blooded, that is important. Also, this can provide oxygen for the creature to survive since Mar's atmosphere is almost entirely carbon dioxide. I mean, yes, the creature would be more adapted to an anaerobic lifestyle, and when hibernating would probably go full on anaerobic, but, when active, it probably won't be fully anaerobic.

There are light sensors on top of its head, these connect to the part of the brain responsible for circadian rhythm. When they sense light, the creature wakes up. If they don't sense much light for a few hours, the creature goes back into its burrow to sleep. If after a day or two, there still isn't much light sensed, because, say, there is a global dust storm, the creature goes into hibernation. The Martian winter also forces the creature into hibernation but for a different reason. The Martian winter, even at the equator, is way down in the negatives. At night, it gets much colder still. An active creature during the Martian winter, if it isn't tiny, is going to freeze like an ice cube. Hibernation means that the little geothermal energy there is on Mars will be enough to prevent the creature from freezing to death in the winter.

As I mentioned already, this is a burrowing creature. It also is a nesting creature. This creature lays eggs during the spring, so that its offspring have plenty of time to prepare for hibernation. Because the chance of a global dust storm during any Martian year is 1/3, those that are unlucky to hatch during a year with a global dust storm will not survive, because they aren't well prepared enough. But, most hatchling deaths do not have to do with global dust storms happening at the wrong time. More are from lack of food, deformity, and predation than from global dust storms.

As the hatchlings grow, they rely less and less on aerobic metabolism. And the hatchlings start off tiny enough that photosynthesis can easily provide oxygen to all the cells, so oxygen storage isn't a huge concern for this creature. An oxygen storage system still develops though, while it is an embryo, just in case it has to flee or defend itself and thus needs extra oxygen that photosynthesis alone can't provide at a fast enough rate.

And this brings me nicely to the eggs themselves. When an adult eats another creature(yes, they go from complete autotrophs to a combination of an autotroph and a heterotroph as they grow and photosynthesis can't provide the full metabolic demands anymore), they inevitably will eat some iron oxide dust in the process. Instead of discarding all that iron in their waste products, in females, when they ovulate, some of the iron gets used to make egg shells. And because the egg shells are iron rich, they virtually blend in to the Martian landscape, which on the one hand, makes it much harder for predators to spot them without sensing infrared, but on the other hand, makes other burrowers more likely to damage the eggs, so the females will strategically place their nesting burrows to avoid this damage from other burrowers.

What do you think of my proposed Martian creature? Of course, there would be many more, but I can't ask about all of them. Is this a plausible creature to live on Mars? A hexapodal, burrowing, photosynthesizing, cold-blooded, hibernating animal?

[Mechalich]

If you mean in the currently extant environment of Mars it is not plausible for anything macroscopic to exist at all. It's too cold, the atmosphere is all wrong, and there's insufficient liquid water (probably none most of the time). Photosynthesis and anaerobic metabolism aren't going to get you there (especially as going anaerobic for long periods builds up waste products internally, a bacterium can just dump them, but a macroscopic animal has problems in this area), the math just doesn't work out. Mars is significantly colder and more hostile than Anarctica. The largest terrestrial animal living in Antarctica is this flightless midge, and it's restricted to the milder Antarctic Peninsula.

[Draconi Redfir]

i think the idea is to go for something "Close enough", like yes nothing lives on mars right now, but with enough work and pseudo-science, you might be able to get something that SOUNDS like it'd work.

From what little i know of mars, the lizard thing presented doesn't sound like it'd clash too much. maybe work in something like thick and dense scales to protect it from the low atmospheric pressure, so that it's innards don't pull it out at the seams. If it's getting a lot of iron in it's diet, then the shell and exo-scales could be where that iron is put to use.

if you're going for photosynthesis, i think you want to maximize surface area, much like a Tree's leaves, the skin and presumably shell being able to do it may help, but it might not be sustainable. fins along it's back and sides could help with that, consisting mostly of Photosynthetic material that's able to provide for itself and blood vessels to take oxygen and deliver nutrients. When not in use, these fins fold up again to make the creature more maneuverable. Perhaps it's effectively holding it's breath when the fins aren't deployed, and needs a system in place to store large amounts of oxygen in it's cells or body somewhere.

i'd imagine these things don't move around a whole lot, and tend to jump between hibernation and sunbathing quite regularly.

[Ashtagon]

Photosynthetic anything is pretty much incompatible with burrowing anything.

Photosynthetic anything is also pretty much incompatible with Mars life generally. Mars receives 43% of the solar intensity that Earth does.

That said, this is not an absolute. Seaweed is an example of life on Earth that gets vastly attenuated solar intensity, due to water depth. However, there is no known macroscopic self-mobile life on Earth that uses photosynthesis. It simply doesn't provide enough energy to support animal (or "animal") life as we know it.

otoh, photosynthesis relies on maximising surface area. Think about how plants have a leaf+branch structure for that purpose. That isn't really compatible with the compact body form of most animals, especially not the one drawn here.

Light sensors: Are these different from "eyes" in any way?

A more interesting question is, without meaningful amounts of water on this planet, how does an egg-laying animal even evolve?

[Draconi Redfir]

i get the feeling that the Photosynthesis is more to supplement the creature rather then fully support it. it probably still east and breathes, it's photosynthesis just helps with that a bit.