Percopsis omiscomaycus also known as the trout-perch, the grounder or the sand minnow, is one of two species in the family Percopsidae. They are freshwater fish that prefers clear to slightly turbid water. They are most often seen washed up on beaches and are rarely seen alive or correctly identified. They are found in rivers and lakes throughout North America. Its name comes from the Greek root words perc, meaning perch and opsi meaning appearance.