A blue crab (Callinectes sapidus) eats clams in an aquarium at the laboratory of the Mediterranean Institute of Oceanography (MIO) in Marseille, southeastern France, on May 28, 2026. A "super predator" and "super breeder," nothing seems able to stop the blue crab which, having come from America, is threatening the ecosystems of the French Mediterranean, with only one way so far to limit its spread: eating it. (Photo by MIGUEL MEDINA / AFP via Getty Images)