Wildlife

Massive Crab Swarm

A massive crab swarm at the bottom of the Pacific Ocean near Panama was captured for the first time.

The swarm, consisting of thousands of red crabs, represents a new southernmost range for the species, Pleuroncodes planipes. Researchers aboard the submersible Deep Rover 2 were both astounded and mesmerized by the unexpected sight, which they recorded about 1,200 feet below the ocean’s surface.

The large aggregation of red crabs was observed along the Northwest flank of the seamount in acidic water with very low levels of oxygen. These crabs have been detected before in similar low oxygen conditions. It could be that these low oxygen waters provide a refuge for this species from predators.

The frenzy to stay in this crowded spot makes sense when considering the nickname for these crustaceans: tuna crabs. Yellowfin tuna love to eat them, as do many birds, marine mammals and other fish. Humans can eat them too, but do so at risk. That is because the crab’s food source consists of phytoplankton

Despite their efforts to stay alive, the crabs might have perished not long after the video was recorded. Just a few months after the expedition, thousands of red crabs washed ashore onto Southern California beaches during a massive stranding associated with El Niño warming conditions.