horseshoe crab swimming?

Okay, so I know that horseshoe crabs are not the best for reef tanks now, but when I purchased one I didn't know that and it was some time ago. I placed him in my 92g reef. He has been scooting around and burying himself for a long time now with anything strange. Yesterday I came home about mid day and found him swimming kind-of upside down about mid way in the tank. He would swim around and then land and scoot and do it again. He did it for about 1 hour that I saw. Today it happened again. Isn't this strange, and does anyone know what is happening to him.
This is probably not affecting him, but the tank is empty of fish right now due to an ich breakout. There are crabs, snails, a red starfish, and 2 serpent stars in the tank with coral right now.


Active Member
i had two small ones once and they would swim up when they were hungry. it is probably due to lack of food. but i'm not a horseshoe crab expert.