Allis shad Allis shad The allis shad ("Alosa alosa") is a widespread Northeast Atlantic species of fish in the herring family, Clupeidae. It is an anadromous fish which migrates into fresh water to spawn. It is found in the eastern Atlantic Ocean, the western Baltic Sea and the western Mediterranean Sea. In appearance it resembles an Atlantic herring but has a distinctive dark spot behind the gill cover and sometimes a row of up to six spots behind this. It sometimes hybridises with the twait shad ("A. fallax"). This fish becomes mature when three or more years old and migrates to estuaries,
Alosa agone Alosa agone Alosa agone is a species of ray-finned fish in the genus "Alosa". "Alosa agone" is an endangered species of the "Alosa" genus. "Alosa agone" are common in the Mediterranean and the western Balkans. There are also landlocked populations found in Italy. The distribution of reproductive communities and the conservation status of Alosa agone in the central and eastern parts of the Mediterranean areas are poorly known. Alosa agone’s numbers have declined due to barriers such as dams in their local areas. These barriers prevent them from getting upstream to their spawning grounds and reproducing. Improved water quality in