Zoo officials announced the new arrivals Wednesday.
The Francois' Langurs were brought from the San Diego Zoo. They are active and noisy medium-sized primates, native to the rainforests and wetlands of China, Vietnam and Laos.
Their population has been cut in half over the past 35 years because of hunting and loss of habitat.
The monkeys were brought to the L.A. Zoo for its species survival plan.
The giant otters are native to the rain forests and wetlands of north and central South America.
There are just a few thousand left in the wild. They are also threatened by loss of habitat and hunted for their pelts.
When fully grown the largest otters on earth can be up to six feet long.
The Associated Press contributed to this report.