The army of spider crabs crowded under the sea

The moment hundreds of thousands of spider crabs emerge from the deep seabed to peel in shallow water into the lens of filmmakers.

The army crawled along the sea floor to the waters of Mornington Bay in Victoria, Australia when the winter came, Sun yesterday reported. They climb on each other to create high mounds to protect themselves while replacing the cramped old crust with another shell.

Crawling spider flock are superimposed to form high mounds.(Video: BBC).

Because the shells of spider crabs cannot grow bigger, they are forced to go to the furry zone to peel, allowing the body to grow under a larger shell. After the crabs peel off their old shells, they have to wait a few days for the new crust to harden and can protect them safely from predators like 4-meter rays that hang around.

Natural documentary filmmakers record the annual gathering of spider crabs."Like all crabs, their bodies are covered by a hard shell that cannot expand. Therefore, to grow up, they have to get out of there, enabling the soft shell below to be sturdy." David Attenborough, host of Blue Planet II, explains.

This crustacean is almost harmless.

Although the scene of a spider crawling in a stratosphere seems scary, this crustacean is almost harmless."We searched back and forth for hours, until we saw a slightly different color of water. It was amazing to get close to the foot mass and the first time it was huge. The crabs didn't seem to care. One or two children often crawl on my legs while recording, "said Alex Vail, the cinematographer of the show.