|Herrings are small schooling fishes, mostly silvery with compressed bodies. Their mouths are distinctive, having a lower jaw that is short and deep, hidden by the wide rounded upper jaw, giving an oblique appearance. Many have a serrated (saw-toothed) keel on their belly. Most are marine but some prefer low salinities and may migrate up rivers to spawn or live permanently. Herrings are usually not prized as food, but some are important commercially as fish meal or bait. An important commercial purse fishery for menhaden exists in northern Texas and Louisiana where the fishes are processed for fish meal. Herrings are also important food fishes for many other species.