Keystone species mussel population explodes uncontrollably, driving out most other species. These creatures need not be apex predators. Sea stars are prey for sharks, rays, and sea anemones. Sea otters are prey for orca. The jaguar, whose numbers in Central and South America have been classified as near threatened, acts as a keystone predator by its widely varied diet, helping to balance the mammalian jungle ecosystem with its consumption of 87 different species of prey. The lion is another keystone species. Keystone mutualists are organisms that participate in mutually beneficial interaction and the loss of which would have a profound impact upon
Predator (fictional species) 'Operation Stargazer', only for this Predator to escape to find missing parts of its armor that were taken by army sniper Captain Quinn MacKenna, who discovered the Predator's escape pod and was able to mail the items to himself before he was captured. When the armor is discovered by Quinn's autistic son Rory, Rory is able to translate the Predator language, just as MacKenna discovers that the Predator has escaped and is now hunting his son. Joining forces with Doctor Casey Bracket- an evolutionary biologist brought in to study the Predator- and a group of soldiers suffering from various PTSD