I came across this the other day:
I pulled it out, its not a dead crab, appears to be a molt (silver dollar size). Couldn't find any posts on it so I thought I would post my experience.
90gal reef, about an inch of sand.
Horseshoe crab added to the system on 9/30/16.
He was very visible for the first couple months, then disappeared for weeks without any sand disturbance. Last time I saw a moving sand ripple was 3/10/17. Found this molt 5/21/17 near an area of sand disturbance. I've never feed him directly. He must be doing well enough to keep growing. The tank/sand has been running for a year and a half before he was introduced. I don't have any sand sifting critters in the tank.
I pulled it out, its not a dead crab, appears to be a molt (silver dollar size). Couldn't find any posts on it so I thought I would post my experience.
90gal reef, about an inch of sand.
Horseshoe crab added to the system on 9/30/16.
He was very visible for the first couple months, then disappeared for weeks without any sand disturbance. Last time I saw a moving sand ripple was 3/10/17. Found this molt 5/21/17 near an area of sand disturbance. I've never feed him directly. He must be doing well enough to keep growing. The tank/sand has been running for a year and a half before he was introduced. I don't have any sand sifting critters in the tank.