In February, a crowd gathered around Mexico City’s Lake Xochimilco to witness the release of endemic salamanders called axolotls, culturally revered amphibians at risk of extinction because of the lake’s pollution.

After a ritual ceremony with prehispanic flutes and incense, mayors from different wards of the city dropped six bred-in-captivity axolotl (pronounced AK-suh-laa-tl) into the lake as a statement of commitment to preserve the species and its habitat.

But Óscar Camacho Flores, founder of the national civil organization Preservacf A.C., called it “a sacrificial ceremony rather than one to ask for their salvation, because it was obvious that they were going to die.”

Late last month, Camacho filed a lawsuit in the Attorney General’s Office against José Carlos Acosta Ruiz, the Xochimilco community mayor, for illegal environmental actions and animal cruelty, given the contamination in Lake Xochimilco (pronounced sochi-MILK-o). They didn’t have the required environmental permits, Camacho claims, nor did they follow the suggested protocols to release the axolotls.