Opdagon
Inkling
Specifically, what respiratory organs do they use? The main options I'd say are that they use their gills, or they've evolved a lung like in snails. If the later, there's also the question of where this lung is. My idea is that they have a lung, which opens on the right shoulder, opposed to the cloacal structure on the left. This makes most sense to me, as mollusc gills seem pretty frilly and hard to adapt. The position would provide symmetry to their bodies, which would provide aesthetic benefits