After diving over a thousand feet underwater off the coast of Panama, a group of scientists witnessed a sight never caught on tape before, when thousands of crabs were filmed swarming across the ocean floor in the Hannibal Seamount. As the group of scientists descended in their submersible called Deep Rover 2, they began noticing a cloud of dust, only to find that red crabs were the cause behind of it.

The team was set to study the biodiversity of the Hannibal Bank Seamount, which is described as the counterpart in the sea of a tropical jungle on earth. Even though the three scientists on board of the Deep Rover 2 first thought was that the ocean floor was covered in rocky structures, once they began to move the idea was quickly ruled out.

A team of biologists filmed thousands of crabs across the ocean floor in the Hannibal Seamount, Panama. Credit:

Massive amounts of crabs are not a new development whatsoever; yet getting them on film is a first, as it is described in the study published in the journal PeerJ. Jesus Pineda, one of the three scientists on board of the Deep Rover 2 at the moment of the finding, claimed he had no idea what he was looking at when the dust cleared.

A biological oceanographer at the Woods Hole Oceanographic Institution in Massachusetts, Pineda was able to capture the whole event on film, which was later published. Strangely enough for scientists involved in the study, the crabs are known to enjoy floating up and down in the water column in order to eat plankton, which raises questions about what they were doing there.

The massive crab swarming on the ocean floor was deeper than normal for the species, as well as a low-oxygen area, unusual for this type of crab. Oddly enough, the Pleuroncodes planipes, or red crab, is typical from the coasts of Mexico and given that scientists found them off the coast of Panama, there’s no explanation for their apparent migration.

Swarming crab patches on film

In the paper published by Pineda and his team on the journal PeerJ, they claim this is the first time this event is recorded on film as well as the first time red crabs are spotted so far from their usual habitat. El Niño could have caused this considering it has been responsible for plenty of natural alterations across the globe.

The red crabs may have been forming patches and swarms in order to harness oxygen somehow or for mating purposes, yet scientists are still trying to determine the exact causes for this event.

As seen in the video, the crabs are swarming like insects on the forest, which could also suggest they were in the middle of their mating season. Yet further studies are needed in order to provide answers to all the questions brought to light after Pineda and his teammates captured the event on film.

Source: Ars Technica