Hyporthodus nigritus, or the Warsaw grouper, is a species of marine fish in the family Serranidae, found in the Western Atlantic from Massachusetts to the Gulf of Mexico, Cuba, Trinidad, and south to Brazil (Rio de Janeiro). Its natural habitats are open seas, shallow seas, subtidal aquatic beds, and coral reefs. It is threatened by habitat loss.
The Warsaw grouper is a US National Marine Fisheries Service Species of Concern. Species of Concern are those species about which the National Oceanic and Atmospheric Administration and National Marine Fisheries Service have some concerns regarding status and threats, but for which insufficient information is available to indicate a need to list the species under the Endangered Species Act.