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
Fish Hook River Fish Hook River is considered to begin in the city of Park Rapids, at a dam forming the Fish Hook River Reservoir, which was constructed to supply hydropower at the site of rapids on the river. From Park Rapids the Fish Hook River flows south-southeastwardly through Todd, Straight River, and Hubbard townships, collecting the Straight River from the west. It flows into the Shell River from the north in Hubbard Township. The Fish Hook River Reservoir flows from Fish Hook Lake, which collects the river's northern watershed. The Portage and Potato rivers flow short distances to the lake from Portage