Hey! sorry this is late but i will try to answer. so i first looked this up on googlle and found this answer : Land snails have a very simple breathing system which is located in a small cavity between their shells and their bodies. Air enters into this cavity through a small opening or pore on the side of the snail's body, just underneath the bottom edge of the shell. im not sure but this could be refering to the pneumostomes since i also saw people call them pores (breathing pore to be specific) i do also have a small theory about this before we continue. so i know theres a hole in their foot wich they use to lay eggs and poo, but that could be what they use to breathe when retracted? i will comfirm/deny this theory if i find an answer later.
Thanks for the answer. I wish there were diagrams on the page you linked to (at least, I didn't see any). Then I could definitively say the "cavity" referred to isn't the pneumostome. The way I'm reading it, it appears to be a separate feature, aside from making complete sense, since the pneumostome gets sealed off.
Hey im not sure if this will help, since im a bit busy i wasnt able to find a more detailed diagram but heres a link to something that might help(??) factsaboutsnails.com/snail-facts/pulmonate-snails-and-slugscopy025-copy/ i just looked it over for a second but yeah, i think the pneumostome and the breathing thing are seperate things, since the pneumostome is on the outside of the foot.
I appreciate your help. It's almost like I hired you for the job. LOL
Yep. I've seen physiological illustrations... therein lies the original conundrum. If the pneumostome is the only "breathing pore", I can only assume that they can hold their breath for a really long time, or they'd suffocate while retracted.
I dunno. Maybe I'm making too much of this. I was just puzzled by it.