They are visual feeders that hunt in schools and will attack anything that moves or slightly resembles food. The cause for this migration is unknown, but it is speculated that it is due to seasonal changes in light intensity and the length of the day (Bachand 1994 Agbayani, 2001).īluefish are strictly carnivorous, eating squid, shrimp, crabs, and fish, such as herring, atlantic mackeral, menhaden, spot, butterfish, and mullet. Each year, beginning in January, bluefish begin their annual migration northward. As the schools move through the water, they will attack other schools of fish, destroying large numbers of excess prey. Pomatomus saltatrix are constantly moving, as they travel in schools that can extend 6 to 8 km in length. The newly hatched bluefish then migrate into estuaries and bays until they reach a weight of approximately 3 lbs. Depending on water temperature, the free-floating, oil-filled eggs can hatch within 44 to 48 hours of fertilization. Males then spread their milt and fertilization occurs. The females extrude between 0.6 and 1.4 million eggs in spurts as they migrate along the coasts. During their second year, bluefish reach sexual maturity. However, males mature at an earlier age but their eventual size is not an indicator of gender.