Freshwater Crabs

Two crabs, and they are not interchangeable. The micro spider crab is genuinely tiny, fully aquatic, and picks food out of the water column in a planted shrimp tank. The red claw crab is a brackish animal that climbs out of the water and needs somewhere dry to sit. Both are sold non-quarantined.

Red claws are the ones people get wrong. Kept fully submerged in fresh water they weaken over months, and any tank holding one needs a lid, because a crab that can climb will. The micro crab has the opposite problem: it is small enough to be food, so keep it with shrimp and nano fish.