“It is a surprise,” says Peter Dijkstra, a biologist at Central Michigan University and senior author of a study published today in Biology Letters. “It really is a lot.”

Mouthbrooding is common among fish, particularly cichlids, colorful freshwater species that are popular as aquarium pets. After their eggs are fertilized, A. burtoni moms will shelter them in their mouths for roughly two weeks to protect them from predators. (Read about other long-suffering animal moms.)