The Threadfin Herring (Opisthonema oglinum) or commonly called a greenback is a popular bait fish. It has a very long thread-like fin at the back of its dorsal that accounts for its name. Commonly in the 6-8 inch range, they make good King Mackerel baits. They also make a very good cut bait when bottom fishing.
They can be caught with a cast net but a heavy, large mesh net is required. Sabiki jigs are another common method of catching them. They are somewhat difficult to keep alive for long periods of time in a live well but can be penned if the pen is large and in an area with a good water exchange.
