Green anacondas are among the world largest snakes, and their welfare in captivity requires specialized environments that meet their complex thermal, aquatic, and spatial needs.
Green anacondas in suboptimal captive environments suffer from conditions that are often invisible to casual observers. Inadequate humidity causes respiratory infections; insufficient water access forces primarily aquatic animals to exist terrestrially in a manner contrary to their ecology. Space constraints prevent thermoregulation across gradients and reduce the ability to move normally. Over-feeding from misplaced concern about "keeping them happy" creates obesity, hepatic lipidosis, and shortened lifespan. Accredited zoos with the space and resources to provide genuinely anaconda-appropriate environments — large naturalistic pools, consistent tropical conditions, appropriate feeding regimes — can maintain these animals well, but facilities that cannot meet these needs should not house them.