Okay so, it seems like there’s two options: One, they’re cleaning their swimmerets and it causes a reaction because the swimmerets are very sensitive. And two, it’s a failed molting attempt.

I think the main thought behind the second option is the “sneeze” physical reaction is very similar to how shrimp get out of their molted skin. But usually shrimp are very still and observant right before attempting a molt, because it’s such a vulnerable and dangerous time for them wrt predators.

Seeing as this shrimp is vibing and cleaning itself like normal right before the sneeze, that makes me believe that it’s option one. It truly is a shrimp sneeze :]