Published records indicate that Heteroteuthis dispar (Ruppell, 1844) is found in the North Atlantic Ocean and that Heteroteuthis dagamensis Robson, 1924 inhabits the South Atlantic Ocean. However, specimens recently collected in the northern Gulf of Mexico (n = 123) show that H. dagamensis is the only species of the genus common in the Gulf of Mexico based on identification of male specimens. Also, comparison of DNA barcodes for three morphologically similar species of Heteroteuthis, H. dispar, H. dagamensis, and Heteroteuthis hawaiiensis (Berry, 1909) confirm that all are distinct species and indicate that H. dagamensis and H. hawaiiensis are closer genetically than either is to H. dispar.