Cobia are not strong swimmers. They are large fish with heavy bodies, and often swim with their pectoral fins extended and stiff in appearance. Related to remoras, and often swim near sharks tails. Cobia are opportunistic feeders, scavenging off of sharks leftovers as they swim in the wake of the shark. Jacks are primarily found hunting near coral reefs.
Jacks have large eyes, excellent eyesight.
They are typically light in color, usually silver, often with red pigmentation which disappears in dark ocean water. Jacks have a slender base to their tail. They are typically found in mid to deep water, but may be found near the surface at dusk and dawn. Jacks are often found swimming with sharks, but they usually school as a defense mechanism. Jacks are strong-swimming carnivores that are often found hunting in open water by coral reefs.