Animal activists filed a lawsuit against SeaWorld Wednesday that seeks to grant some constitutional rights to five killer whales that they say are being enslaved as performers at marine parks.

The lawsuit, filed in US District Court in San Diego by People for the Ethical Treatment of Animals (PETA), claims that the orcas are being held at SeaWorld parks in violation of the 13th Amendment, which abolished slavery in the US and prohibits involuntary servitude.

The group argues in the lawsuit that the five orcas are, by definition, slaves, as they were forcibly taken from their families to be put in captivity, where they are denied their natural environment, subject to sperm collection and forced to perform tricks for SeaWorld’s profit.