This crab was lucky enough to find this delicious mole crab (which is much larger than the crab itself), that was originally caught by another crab, but the waves made the captor lose its prey, and the one in the video took advantage of it. Now, this crab is very determined to not have the same fate as the previous one and lose its food to the sea, and refuses to let go of its prey even when the water comes and take them both away, leaving our friend upside down in the sand! What an impressive animal!
Mole crabs, also known as sand fleas, sand crabs, and sand bugs, are decapod crustaceans that burrow in the sand in the swash zone, using their antennae for filter feeding. They get the name Mole Crab from that burrowing habit, but they can only in wet sand; they cannot dig in sand that is too firmly packed or dry; there must be enough water to separate the grains and make the sand penetrable. They are herbivores, and feed on diatoms and dinoflagellates, feeding when the waves recede. They use their legs to burrow backwards into the sand when there is an incoming wave. The eyes and small first antennae, which are used as sort of a snorkel for breathing, project from the sand. When the wave goes out, their large, feathery second antennae are curved backward and used as nets to capture the phytoplankton, which is then scraped from the antennae by other specialized, brush-like appendages, and brought to the mouth.
Very few juvenile mole crabs reach adulthood, as most of them become food for other animals when washed back out to sea. Adults are also food for a variety of other animals, such as shorebirds, fish, and even mammals. They are sometimes used as bait for fishing.