Bar Jack
Caranx ruberBar Jacks can be seen traveling alone or in schools of 100 or more. Often close to the surface feeding on schools of fry. Bar Jacks usually have the distinctive blue over black stripe along their back and on to their lower tail fin. However during feeding and cleaning sessions, Bar Jacks can turn almost black in color making the blue stripe almost invisible. At other times They can pale quit substantially and again the blue line almost disappears. In the right light, you can't see it at all. At these times, identification is possible by elimination. The Horse-eye and Yellow Jacks have a yellow tails. The Blue Runner has black on both the upper and lower tips of their tails. The another clue that you are seeing a Bar Jack rather then Blue Runner is that Bar Jack almost always swim with their dorsal fin erect, the Blue Runners almost always have theirs down. See my YouTube Video "Bar Jack Attack!"