This was the first time I’ve seen an Atlantic horseshoe crab (Limulus polyphemus) swimming and this little “saucepan” was cruising! This is not the normal way they swim. Not sure how but apparently, this one had been turned over. Or maybe he’s just a unique creature that likes doing things differently.
I do know that being upside down on land can be fatal, there’s even an outreach program in Delaware that asks people to flip them over (complete with a catchy theme song).