This is the amusing moment a sea lion pup played in an aquarium in Washington.

Pepper, the eight-month-old female pup, was spotted playing like a rhythmic gymnast underwater at Point Defiance Zoo and Aquarium in Tacoma.

Footage shows the sea creature performing somersaults with a rope tied to its flipper, resembling a ribbon dancer.

It can be seen diving and briefly emerging from the water repeatedly.

The adorable pup was initially weighed at an estimated 15 lbs (7 kg), and is now tipping the scales at 74 lbs (34 kg), growing stronger.

Zoo staff said: 'Pepper continues to nurse and share a close bond with her mother, Eloise, while seamlessly integrating with the zoo's other seals and sea lions, including her father, Boomer.

'She even hit a significant milestone in her journey toward adulthood—she's begun playing with fish and squid and recently ate her first fish.'

The zoo management said that Pepper is the first of her kind to be born at the zoo in its 120-year legacy.

Juvenile sea lions often practice behaviors they will use in adulthood, such as chasing, pouncing, and diving. These activities help them refine their coordination and hunting abilities, even though they aren't hunting for food just yet.