(only exceeded by the anadromous beluga sturgeon). Such lengths are rare and unproven during the last century, but there is a somewhat credible report from the 19th century of a wels catfish of this size. Brehms Tierleben cites Heckl's and Kner's old reports from the Danube about specimens long and in weight, and Vogt's 1894 report of a specimen caught in Lake Biel which was long and weighed . In 1856, K. T. Kessler wrote about specimens from the Dnieper River which were over long and weighed up to . (According to the Hungarian naturalist Ottó Hermann [1835-1914], catfish of 300–400 kilograms were also caught in Hungary in the old centuries from the Tisza river.) Most adult wels catfish are about long; fish longer than are a rarity. At they can weigh and at they can weigh . Only under exceptionally good living circumstances can the wels catfish reach lengths of more than , as with the record wels catfish of Kiebingen (near Rottenburg, Germany), which was long and weighed . Even larger specimens have been caught in Poland (2,61 m. 109 kg.), the former Soviet states (the Dnieper River in Ukraine, the Volga River in Russia and the Ili River in Kazakhstan), France, Spain (in the Ebro), Italy (in the Po, where a record 2.78m long wels catfish was caught, and Arno), Serbia (in Gruža Lake, where a long specimen weighing was caught on 21 June 2018 and the Danube river, where a catfish measuring 275 cm and weighing 117 kg was caught at Đerdap gorge in the same year), and Greece, where this fish was introduced a few decades ago. Greek wels grow well thanks to the mild climate, lack of competition, and good food supply. Wels catfish have also been observed thriving in the cooling ponds of the damaged Chernobyl Nuclear Power Plant. Although popularly believed to have been mutated into large sizes as a result of radioactive fallout, in reality the fish are growing to such proportions due to the absence of hunting and fishing, which have been outlawed in the exclusion zone following the accident, and being fed by tourists visiting the area. The largest accurate weight was for a long specimen from the Po Delta in Italy. Exceptionally large specimens are rumored to attack humans in rare instances, a claim investigated by extreme angler Jeremy Wade in an episode of the Animal Planet television