I only recently became aware that this is apparently a topic of debate in vegan circles. Oysters and mussels lack a brain and central nervous system, and they are immobile. Thus unlikely to experience pain or any sort of sentience.
Being vegan for ethical reasons, I haven't really found any convincing arguments for why we shouldn't eat them (during my limited research so far). Most vegans seem to be against it. The two most common arguments I saw were "they could feel pain in a way we don't know about, so we should err on the side of caution" or simply "they're animals and vegans don't eat animals". The first one seems a bit too close to the classic "but what if plants have feelings" argument, and the second is just semantics.
I don't really see myself incorporating bivalves into my diet any time soon, since they weren't a part of my diet even before I went vegan, but I thought it was an interesting topic. What do you ladies think about it?
Some links: https://theanimalist.medium.com/on-the-consumption-of-bivalves-bdde8db6d4ba https://vegancalm.com/bivalvegan-diet/