General: Tropical Aquarium Fish (several non-native species) have been released into springs and ponds around Las Vegas, especially the warm-water springs. These fish cause problems for native fish, such as pupfish, by eating them or competing with them for food, nest sites, and other resources. They also cause problems for native frogs (eating eggs and tadpoles) and native spring snails (eating them).

Never release non-native fish into natural ponds and springs. While it might feel good to "free willy," these non-native fish damage the ecosystem and cause tremendous harm to the native species that depend on springs and other water sources in the desert for survival. If you must release them, put them in neighborhood ponds or ponds on golf courses around Las Vegas.

Springs that have been damaged by non-native fish around Las Vegas include Ash and Crystal springs in the Pahranagat Valley, Rogers and Blue Point springs at Lake Mead NRA, several springs at Ash Meadows National Wildlife Refuge, and White Rock Spring at Red Rock Canyon NCA.

Jack Dempsey Cichlid (Family: Cichlidae, Rocio octofasciata). Because of its aggressive nature, this fish is names after the famous 1920s boxer Jack Dempsey.

Dark-phase Short-fin Molly (Family: Poeciliidae, Poecilia sphenops). Males of this species can change color from dark to light.

This cichlid might be a hybrid between a Jack Dempsey and another less colorful species.