Genus Istiophorus is a group of billfish or large predatory fish found in the Atlantic, Pacific, and Indian Oceans. One of the most well-known species in this genus is the sailfish, Istiophorus platypterus, which is highly prized as a game fish. Synonyms for the genus Istiophorus include Xiphias platypterus, Xiphias gladius, and Istiompax platypterus. These different names were assigned at different times by taxonomists who were trying to classify these fish based on their physical characteristics and genetic makeup. While there may be different names for this group of fish, their characteristics, habitat, and behavior remain the same across different sub-species and populations.