People for the Ethical Treatment of Animals said restaurants Sik Gaek and East Seafood Restaurant have been serving san-nakji, which comes from Korean and Chinese waters, without properly killing the sea creatures first, the New York Daily News reported Tuesday.
The group has been picketing the establishments and has sent letters to the district attorney's office in the city's Queens borough seeking animal cruelty charges against the businesses.
San-nakji is prepared by chopping the tentacles into small pieces that continue to writhe while being served with garlic and jalapeno peppers.
A Sik Gaek worker said the tentacles continue to move because they are served quickly after the animal is killed by having its head split open and its brain removed.
Tim Carpenter, curator of fish and invertebrates at the Seattle Aquarium in Seattle, said the tentacles continue to move due to nerve activity, the newspaper reported.
"There is a lot of nerve activity that occurs in an octopus' tentacles. It doesn't matter if it's dead or alive," he said.