 In North American streams, the male cutlip minnow "Exoglossum maxillingua", long, assembles mounds that are high, in diameter, made up of more than 300 pebbles 13–19 mm in diameter (a quarter to half an inch).The fish carry these pebbles one by one in their mouths, sometimes stealing some from the mounds of other males.The females deposit their eggs on the upstream slope of the mounds, and the males cover these eggs with more pebbles.