Alosa kessleri Alosa kessleri Alosa kessleri, also referred to as the Caspian anadromous shad, the blackback, or the black-spined herring, is a species of clupeid fish. It is one of the several species of shad endemic to the Caspian Sea basin. This is an anadromous species which ascends from the Caspian to the Volga river up to the Volgograd to spawn. Before the construction of th Volgograd dam it migrated up to the Kama and Oka tributaries. Few fish enter the Terek and Ural Rivers. While the migration upstream is broken, it seems the fish have found new breeding grounds south of
American herring gull American herring gull The American herring gull or Smithsonian gull ("Larus smithsonianus" or "Larus argentatus smithsonianus") is a large gull that breeds in North America, where it is treated by the American Ornithologists' Union as a subspecies of herring gull ("L. argentatus"). Adults are white with gray back and wings, black wingtips with white spots, and pink legs. Immature birds are gray-brown and are darker and more uniform than European herring gulls, with a darker tail. It occurs in a variety of habitats including coasts, lakes, rivers and garbage dumps. Its broad diet includes invertebrates, fish, and many other items.