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) Design changes included tribal ornamentation on the forehead, which was made steeper and shallower, brighter skin coloration and a greater number of fangs. This Predator was made less reliant on his plasma caster, and more cunning with the use of nets, spears and bladed weaponry. In "Alien vs. Predator", the appearance of the Predators was redesigned to make them seem more heroic. Redesigns included a reduction in head and waist size, broader shoulders, a more muscular physique, piranha-like teeth on the upper jaw, and dryer and less clammy skin to further differentiate them from the Aliens. In "Aliens vs. Predator: