The California Academy of Sciences introduced a group of pyjama sharks to its popular African Penguin exhibit. The two species are natural neighbors off the coast of South Africa.
For several months, biologists have been training the sharks to feed at a target location, allowing them to closely monitor each animal's progress.
The pyjama sharks were introduced, two at a time, to the aquarium's African penguin exhibit on July 31, 2012.
Each animal received a physical exam before being introduced to the exhibit in African Hall.
Biologists built underwater caves for the shy pyjama sharks, which live with a colony of African penguins at the Academy.
Biologists take care in building underwater cave homes for pyjama sharks at the Academy.
The aquarium at the California Academy of Sciences has 18 African penguins (shown here) in its exhibit. Read more about the penguins.
African penguins grow to about 23 to 25 inches (58 to 64 cm) tall and can weight 5 to 9 pounds (2-4 kilograms).