Hobbies And Interests
How Do They Eat?
The sand crab burrows backwards into the sandy beach along the wash zone where waves repeatedly hit the shore. The crab sticks its feathery antennae and eyestalks above the sand. Waves wash over the antennae and the crab catches minute particles of algae and plankton in them. The crabs eat these particles from their antennae and stick them back up above the surface. They also reach out and grab interesting-looking food that washes up on-shore.
Diet
Crabs of the family Hippoidea eat very small particles of diatoms and are also scavengers. The sand crabs mainly subsist on algae and plankton. They also scavenge food from dead jellyfish, fish and other creatures that wash up on-shore. These crabs tend to graze all day long in order to get enough food, since their diet is made up of tiny pieces of organic matter. The sand crab is nature's cleaner, keeping the beaches clean.
Appearance
Sand crabs have a narrow egg-shaped body with a firm outer shell. The creatures are generally 1/2 to 2 inches long with feathery antennae and two eye stalks on top of a small head. Each has five pairs of legs, allowing the crab to dig, swim and walk, all of which is done backwards. Sand crabs are generally grey or sand-colored, helping them to blend in with the sand. The crabs don't have pincers.
Predators
Lots of animals like to eat members of this family. The crabs are very small and lack defensive weapons, so can only hide and burrow for protection. Fish, waterbirds and shorebirds all eat the sand crabs. Otters and sea lions will eat the crabs when they can catch them. Humans even catch sand crabs and use them as bait or cook a bunch up for soup broth. Sometimes, the sand crabs eat plankton with high levels of domoic acid, making them toxic to other animals.