Avatar

Reblogged Stuff

@fragrantman

I reblog stuff.
Avatar

Mr. Leech I need your help: I found out about this snail called Leptopoma nitidum, and it looks like its eyes aren't on stalks? Are those really their eyes? If so, why would they evolve so differently from other snails?

Avatar

It's actually only unusual for *land* snails, though not unheard of! Here's another land snail with eyes at the base of the tentacles:

It's also the case for most freshwater aquatic snails:

Other water snails have eyes kind of "mid way" up the tentacles:

And in the ocean, it seems like the most common setup, especially for larger species, are tentacles forking off from eye stalks:

In fact, I'm not sure if there are any water-dwelling snails with tentacles JUST ending in eyes; it seems like that's mainly a special innovation by most of the air-breathing groups, which likely all evolved from one ancestor that had it first! So the snails like Leptopma evolved from aquatic snails and just didn’t move their eyes up their stalks, or just didn’t do so yet. Like any adaptation there must be both advantages and disadvantages to each method. If your eyes are on stalks you have a greater and more flexible field of view, but if those stalks are injured you’ll be blind until they grow back! Gastropods with eyes at the base are keeping them safer while the tentacles serve other sensory functions. Gastropods with the forking method are trying to balance both worlds and can pull their eyes into the shell without putting the “antennae” away. EDIT: what @teratomarty said is correct!

“IIRC, the tentacles in marine snails are chemosensitive. The theory is that eyes shifted forward in land snails because air is a much worse medium for scent than water, so sight became more important.”

What’s interesting is that both the land snails I’ve shown with low-set eyes are from rainforests, so, places where the air is really humid anyway!

Avatar
Avatar

uuhh some bread puppies (bruppies!!) i designed that twidder decided they really liked so you guys get them too!

Avatar

You can see more art examples via. my art tag and @thewormlogs! Keep in mind I have a lot of classes (at least until late June) so I will update you if your commission will take longer! DM me if interested! (If it is easier for you, we could also DM on discord, I will provide my tag in DMs though.) Edit: An anon asked for me to clarify a couple no-go fandoms! Some fandoms I absolutely won’t work with are: Cookie Run, Omori, Danganronpa, and Homestuck (These come to mind immediately, Ill let you know if Im uncomfortable working with anything.) REBLOGS ARE VERY APPRECIATED, thank you! <3