Rachycentron canadum (Kaup 1826; 2m) is the extant cobia. Like remora but without the adhesion disc, this fish also follows larger prey seeking the spoils and detritus. The first 'dorsal fin' has 6 to 9 short sharp spines. Females spawn 30 times a season, producing thousands of planktonic eggs 1.2mm in diameter.

Ductor vestenae (Blot 1969; Early Eocene; 9cm) was considered a perch or a pilot fish. Here it nests as a tiny cobia (Rachycentron), basal to remoras.