A five-week-old baby otter was transferred to the Shedd Aquarium in Chicago after being rescued and nursed back to health at the Monterey Bay Aquarium.

At 22.6 inches long and weighing just under six pounds, Pup 681, as the baby otter is called, arrived at the Shedd Aquariium on Nov. 4 where she will be receiving continued care. The orphaned otter is the second southern sea otter pup to be taken to Shedd.

"Pup 681's situation was urgent. As an organization dedicated to marine mammal care and conservation, we were perfectly positioned to ensure that this little pup had a home, providing the long-term care needed to survive. This rescued animal provides an opportunity for us to learn more about the biological and behavioral attributes of this threatened species and to encourage people to preserve and protect them in the wild," said Tim Binder, Shedd vice president of animal collections.

Pup 681 was found when she was just one week old, abandoned in California's Coastways Beach. A citizen called The Marine Mammal Center after hearing the baby otter's cry while taking a walk. The TMMC then got in touch with the Monterey Bay Aquarium as the aquarium had a sea otter program, allowing them to provide the care the otter pup will need.

According to Karl Mayer, Monterey Bay Aquarium's animal care coordinator for the Sea Otter Program, Pup 681 arrived at their facility weighing just 1kg, a weight too tiny even for a newborn otter pup. As the baby otter had already been separated from her mother for at least 16 hours, it was critical that she was fed as quickly as possible.

Round-the-clock care was provided for Pup 681, with six to eight expert staff members giving care and attention to the aquarium's newest guest. As the baby otter got used to her new surroundings, she started eating solid food like clams and shrimp, aside from drinking formula from a bottle, and has learned to climb on top of white towels after getting wet to help her groom as well as regulate body temperature.

Southern sea otters have grown in number through the years but they remain on the threatened list under the U.S. Endangered Species Act. According to the U.S. Geological Survey, 2,944 southern sea otters were reported to be in existence in 2014.

Aside from Pup 681, there's one more southern sea otter living in Shedd Aquarium's Abbott Oceanarium, alongside three northern sea otter pups.