(CNN) -- Can killer whales sue SeaWorld for enslavement? A lawsuit filed Wednesday by People for the Ethical Treatment of Animals and other "next friends" of five SeaWorld killer whales takes that novel legal approach. The 20-page complaint asks the U.S. District Court in Southern California to declare that the five whales -- Tilikum, Katina, Corky, Kasatka, and Ulises -- are being held in slavery or involuntary servitude in violation of the 13th Amendment. A PETA statement said the lawsuit is the first of its kind in contending that constitutional protections against slavery are not limited to humans. "Plaintiffs were forcibly taken from their families and natural habitats, are held captive at SeaWorld San Diego and SeaWorld Orlando, denied everything that is natural to them, subjected to artificial insemination or sperm collection to breed performers for defendants' shows, and forced to perform, all for defendants' profit," the lawsuit says, arguing that those conditions amount to enslavement and/or forced servitude.
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PETA: This is the first lawsuit seeking constitutional protection against slavery for non-humans
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The complaint alleges that five killer whales are SeaWorld slaves
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SeaWorld calls the lawsuit a baseless publicity stunt
"@placeholder has once again showed that it prefers publicity stunts to the hard work of caring for, rescuing and helping animals," the SeaWorld statement said.