Captive rearing of hellbenders is a strategy used in hellbender conservation efforts as a way of increasing the survival rate of young hellbenders. The hellbender population has decreased by 77% since the 1980s, with habitat loss and water quality being the main causes of their decline. Survival is especially low in young hellbenders, with many dying before they reach sexual maturity or adulthood.
Universities and zoos across the country participate in these captive rearing programs. Eggs are collected from rivers where adult hellbenders spawn, with each female laying 200-400 eggs. The eggs are kept in climate controlled rooms with continuous water flow. After 72 days, the eggs hatch into larvae that still retain their yolk sac for the first few months. After 1.5 years, the hellbender larvae lose their external gills and more closely resemble an adult hellbender. Hellbenders reach adulthood at 5 to 8 years, at which point they are released back into the wild in suitable habitat.