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) rare or exotic weapon) as a sign of respect. A learner's first successful Alien hunt is completed with the marking of his helmet and forehead with the acidic blood of his kill. The hunter generally operates alone. Even when hunters appear in groups, they rarely perform anything that resembles teamwork. Predators use Aliens as prey, creating artificial gaming reserves by keeping Queens and even Facehuggers in captivity. It is shown in a brief scene in "Aliens vs. Predator: Requiem" that Predators have had prior contact with a race of creatures resembling the "Space Jockey" in the film "Alien". This is