Hello fellows of tumblr
I have many thoughts on the workings of Merfolk biology
Here is my first rant of many to come
(copy and pasted from a discord server with my friends)
Mer biology rant 1
Okay so like, mermaids have gills but can also breath through their mouths
Anyways, so assuming their lungs work similarly to our own, they wouldn't do well being filled with water, as well as with there being two sets of breathing apparatuses, I'd like to propose mermaids having two sets of lungs
Lungs that can fully compress themselves closes for when they're in the other medium they use to breat
Like, being underwater, the air lungs are completely deflated and sandwiched between the ribs and water lungs, and inversely when above water their lungs for water are similarly deflated and compressed between their spine and air lungs
This also puts forth the idea that they'd either need bigger ribcages to manage both sets of lungs OR be able to use oxygen more efficiently than humans can, thus resulting in a lower amount to be breathed in