Attention Parents!

For all of you whose children must have an aquarium, scientists have found you a better guppy.

A tropical fish that lives in mangrove swamps across the Americas can survive out of water for months at a time, similar to how animals adapted to land millions of years ago, a new study shows.
The Mangrove Rivulus, a type of small tropical killifish, seeks refuge in shallow pools of water in crab burrows, coconut shells or even old beer cans in the tropical mangrove swamps of Belize, the United States and Brazil.

More than once I had fish flop out of my tank, so this would sure be convenient.