Horseshoe crabs aren't crabs. They're distantly related, although both are arthropods. Not much brain activity going on there. But honestly pain and suffering

Horseshoe crabs aren't crabs. They're distantly related, although both are arthropods. Not much brain activity going on there. But honestly pain and suffering are so hard to nail down outside the tetrapods. I'd say the fact that until we started harvesting their blood more sustainably, they pretty much all died is enough of a reason to harvest them more sustainably, regardless of how we define the ability to suffer. They're an important food source for a lot of different animals and we shouldn't be damaging their numbers when we can get the same product without killing them. Also, they like to hump fishermen's boots during breeding season, which is absolutely hilarious and I think well worth preserving the species.