River Tywi these fish to over in weight. In summer and autumn there is also a substantial run of Atlantic salmon ("Salmo salar"). In May the Tywi has a run of the rare and protected twaite shad ("Alosa fallax") and allis shad ("Alosa alosa"). The Tywi also contains brown trout, eels, pike, and a variety of small fish species, and is home to brook lampreys, river lampreys and sea lampreys. The Tywi has the distinction of having accidentally produced by far the biggest fish ever taken on rod and line in fresh water in Britain. This was a sturgeon ("Acipwienser sturio") weighing
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