A skinny sea lion pup with a taste for the finer things in life turned up on Thursday inside a fancy San Diego restaurant, where it settled down into a booth.

The malnourished mammal appears to have arrived at The Marine Room after sauntering down a ramp from the beach and going through a door left open by a cleaning crew, said Chef Bernard Guillas.

The early morning guest quickly made an impression on the establishment's staff, as the female pup climbed into a booth "almost like she wanted to have dinner," the chef said.

The menu at the white table-cloth restaurant, which juts out into the Pacific Coast and is buffeted by waves during high tide, includes rarified dishes like "ginger kalbi lacquered tofu" and "ahi tuna and foie rossini."

But the pup was hardly given a chance to get comfortable. A rescue team from the SeaWorld San Diego theme park was called in to pull the barking mammal from the booth and place it in a net. The mammal was then taken to SeaWorld for care, said David Koontz, a spokesman for the tourist centre.

The lethargic pup is eight months old and weighs only 20 pounds (9 kg), less than half the normal size for its age, Koontz said. But SeaWorld staff is "guardedly optimistic" they can nurse it back to health and return the animal to the wild, he said.