Cw: mention of pregnancy and birth in paragraph 5. Feel free to skip if it makes you uncomfortable.
The general idea of the appearance is that of merfolk
In spite of what kind of nolosha badda they’re bonded with, the Aquallia have gills while under water and lungs when on land. When on land the places where their gills were now look like faint clean scars.
The Aquallia do have nipples but only because they can switch between land and sea forms and thus the nipples remain in case the need for breast feeding arises.
For pregnancy how the child is born is dependent on whether the pregnant person was on land or in sea. But typically because Aquallia are in the sea, the pregnant person lays eggs and then the eggs are fertilized, just like fish! But regardless of whether they’re on land or sea the gestation period is a lot shorter than for Elesaan
On the topic of clothing: it’s a stylistic choice purely because Aquallia don’t fuss over nudity. It’s a natural state of being. However you’re more likely to see that in more traditional regions as slowly, due to their adventurous brethren, they’ve adopted clothes as a fashionable statement. If you’re young it can be seen as uncool to not have some garment on. Again this is more region dependent, the closer the region is to a shore the more likely it is that they’ll incorporate clothing. The further away the more likely they won’t and if they’re really far away they may find you odd for wearing anything at all.