The anadromous migratory allis shad belongs to the herring-like fishes (Clupeidae), which search for the middle and upper reaches of larger rivers for spawning in spring, unlike Salmonidae (salmon, sea trout). Allis shad usually reaches a length of 30-50 cm, a maximum weight of 3 kg and feeds mainly on zooplankton. This fish species can be found in European coastal waters from the western Baltic Sea to the Mediterranean. Adult animals generally die after they have spawned. After a short time, the baby fish hatch and drift away during the summer months towards the estuary. The nourishment for the young fish, as well as for the adults in these areas consists mainly of small planktonic crabs.

Like other migratory fish species, allis shad is also endangered due to a multitude of dams and pollution pressures. For this reason, this fish species is subject to systematic repopulation in larger European river basins. Allis shad was the fish of the year 2004.