Originally Posted by MiaHeatLvr
Thats not a good idea, these things belong on the ocean and not in the home aquarium, they walk miles all day and a 40 is really 2 small for 1 neverind 2, it will find itself running into your tank walls, flailing and knocking things over and swimming upside down. They also get a foot long or longer, these need like a 250g minimum.
Actually, I was thinking about this possibility. THe big ones yes get to be huge, and certainly belong in the ocean for sure, but I found this other site that has them for sale both as eggs and as actual "crabs" even though they are not actually crabs. They say the size is average compared to other aquarium inverts (as in a smaller species) and this is what they say:
Horseshoe Crabs
Sand Stirer , Detritus Eater
The Horseshoe Crab is very strange in appearance and can be unique captives for an aquarium. Very hardy , they can be a good choice for beginners. Horseshoe Crabs are bottom dwellers, and in the wild usually burrow in mud or sand flats in tidal areas or estuaries. In the aquarium, your Horseshoe Crab will generally do best in a sandy substrate. They are helpful in cleaning an aquarium or sifting sand. In the substrate, the Horseshoe Crab will move about, scavengiong detritus or other materials that have fallen to the bottom. Algae, smaller bivalves, worms, and bits of fish are the mainstays of a Horseshoe Crab's diet. To grow, the Horseshoe Crab sheds a layer of its carapace, or molts. This process is accomplished at longer and longer intervals as the Horseshoe Crab ages. In general, Horseshoe Crabs are not aggressive; they are scavengers, not hunters.
REEF SAFE
$7.99 each