Green shore crab thrives in harsh conditions thanks to its gills

A species of resilient crab is quickly invading new parts of the ocean and has been put on Canada’s Department of Fisheries and Oceans watch list for invasive animals.

The North Sea native green shore crab is a cannibalistic predator that can survive extremely harsh conditions like low oxygen and rapid changes in water salinity.

This ability to persist in even the most unlikely of areas has baffled scientists, but now researchers have gained new insight into what gives the green shore crab its edge.

Green shore crabs can use their gills to absorb nutrients from the water. If food is low, the crab won’t go hungry thanks to this remarkable dual function in the gills.

However, this also means that the crab species is incredibly resilient to most ecosystems.

It was previously thought that the crabs were not able to soak up nutrients in the water because of their hard exoskeletons, but research has proven otherwise.

“We found that their gills, these specialized and delicate tissues that are designed for transporting things in and out of the body, are way more important than we originally thought,” said Tamzin Blewett, the study’s lead author. “While we knew that the crab gill takes up oxygen and deals with ions and toxicants in the environment, they are also being used for nutrition.”

For the study, the researchers observed green shore crabs at the Bamfield Marine Sciences Centre on Vancouver Island.

The observations showed that the crab’s gills absorbed the amino acid leucine through its nine sets of highly specialized gills.

The green shore crabs have made their way from the North Sea to Canada’s west coast, and according to the researchers, they are everywhere. Now, thanks to this new study, researchers have a greater understanding as to why the crabs are so adaptable to new environments.

The gills might do more than just take in food, but further research will need to be done to fully understand how the green shore crab is able to withstand such harsh environments.

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By Kay Vandette, Earth.com Staff Writer