The call "Free Octavia!" is rising in San Pedro as activists decry the living quarters of a newly captured octopus on display at the Cabrillo Marine Aquarium.

The orange-red giant Pacific octopus with a tentacle span of 13 feet is residing in a 4-by-5-foot tank. That enrages some mollusk advocates who denounce the tank as being much too small.

So about two dozen of Octavia's fans protested outside the city-owned aquarium Friday, calling on its operators to return the octopus to her native ocean depths, or at least to provide her with the comforts of a more spacious abode.

"Please Let Me Go Home!" read one protester's sign, which showed a forlorn-looking octopus shedding tears.

A coldblooded mollusk with eight sucker-lined arms, the \o7 Octopus dofleini \f7 would seem an unlikely catalyst for such an outburst of public affection. It lacks the stately grace of the whale, the winsome personality of the dolphin. But those concerned insist that octopuses, too, deserve compassion and the freedom to stretch their many limbs.

They dismiss the 600-gallon tank as a mere sink.

"For an animal that size that's used to living on the ocean floor, it's inexcusable cruelty," said Lisa Lange, international campaigns manager for People for the Ethical Treatment of Animals, a national animal rights group that spearheaded the protest. Some even worry that Octavia will fall victim to a form of stress they describe as "Octopus Automutilation Syndrome" unless she is set free.

But the aquarium's exhibits director, Mike Schaadt, argues that octopuses do not need abundant space.

"They like close quarters," Schaadt said. "That's where they feel most comfortable and most safe."

The 58-pound Octavia is the first giant Pacific octopus to go on display at the Cabrillo aquarium.

Caught by a fisherman off San Clemente Island, the octopus was donated to the aquarium by a fish market where fishermen had taken it. She arrived at the aquarium Jan. 22.

Aquarium attendance tripled the first weekend she was on display, and T-shirts emblazoned with an orange octopus are on sale at the aquarium gift shop.

Contrary to the charges of animal rights activists, the Cabrillo aquarium did not take its new tenant lightly, Schaadt said. It consulted other West Coast aquariums about the kind of habitat Octavia would desire. Workers went scuba-diving off the Palos Verdes Peninsula to gather rocks for her tank and the water temperature was lowered from the typical 60 degrees to 56 degrees to resemble the cool ocean floors where she once lived.