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
Chaca (genus) Chaca (genus) Chaca is the only genus in the catfish family Chacidae. These fish are commonly known as squarehead catfishes, frogmouth catfishes, or angler catfishes. These unusual fish have a sedentary lifestyle and spend much of their time motionless. The name "Chaca" is because, when removed from the water, they will rapidly repeat the sound "chaca". Only "C. chaca" makes these sounds; the other species do not. The four currently recognized species in this genus are: "Chaca" species are found in fresh water from eastern India to Borneo. "C. chaca" is found in rivers, canals, and ponds of grassland, scrubland,