Found inshore in summer, but at least some moving into deeper water in winter. Adults are found in near surface waters (Ref. 38984), usually in shallow areas overlying continental shelf, in greatest abundance immediately adjacent to major estuaries (Ref. 4639). Juveniles are also generally pelagic, with smallest size groups farthest up river (Ref. 38986). Form large and very compact schools, both of juveniles and adults. Migrate north - south; also in and out of bays and inlets. Feed by filtering phytoplankton (diatoms (Ref. 5951)) and zooplankton (small crustaceans, annelid worms and detritus (Ref. 5951)). High water temperatures apparently limit breeding. Spawn probably all year; nursery areas in estuaries. Larvae are pelagic (Ref. 38985), probably spend about a month in waters over continental shelf (Ref. 38983), entering estuarine waters at about 10 mm and larger (Ref. 844). Marketed fresh, salted, canned or smoked. Mainly used for production of oil, fertilizer and fishmeal (Ref. 188). Parasites found are isopods, copepod, cestodes and trematodes (Ref. 37032).