The Wels Catfish (Silurus glanis) is a species of Catfish native to Northern and Eastern Europe. It is one of the largest species of catfish in the world.
The Wels first appears in the episode European Maneater. Jeremy Wade travels to Spain's River Ebro to investigate if the Wels catfish is truly a maneater, as he saw depictions of young children being swallowed by the beast, as well as medieval depictions portraying the Wels as a maneater. Medieval drawings showed the beast as being absolutely enormous. The episode consists of many exciting events such as underwater cameras capturing the wels on tape. Wade also comes very close to a wels near the shore, where he discovers the fish has no fear of man. He ends up battling with and catching three enormous wels, two of which attack him while releasing, however not too severely.
Although Spain is in Europe, the Wels is native to Eastern European areas like Chernobyl, modern-day Ukraine, where a radioactive supersize Wels (in Ukrainian: Сом Som) was blamed for grizzly attacks, even removing a man's hand. However, these regions are cooler than the Río Ebro, and it is becoming an invasive species in Spain.
Jeremy Wade searched for the Wels again in Mighty Rivers Season 1. He was fishing on the main channel of the Danube, a place where this fish has become nearly extinct. He was able to catch a medium-sized specimen here and was happy that they still exist.
When on the hunt for the monster of Lake Garda, Jeremy Wade originally suspected that an Adriatic Sturgeon had survived in the lake long enough to grow to large sizes. However, Jeremy then heard that many of the new sturgeon released into the waterways were being consumed by Wels Catfish. they also come from Canada.
Jeremy then searched a nearby lake, and saw that Wels had reached this region in force. Fishermen were losing their livelihoods as a result of the catfish damaging their nets. Jeremy then obtained access to fish at a dam on the river Po. While fishing into the night, he caught a Wels specimen that measured 7 feet 2 inches. This was within the size estimate of the Lake Garda monster.
While the Wels Catfish may explain the more recent sightings, older sightings from the middle ages were certainly not from the invasive Wels. These could be explained by Adriatic Sturgeon which can potentially grow to a similar size.
The wels catfish is one of the largest catfish in the world. Only the Piraíba and the Mekong Giant Catfish have been known to rival this species in terms of size. On average a wels catfish is 4-5 feet long, and weighs 40-50 lbs. Specimens over 6.5 feet long are rare but known to exist. The official world record, caught on Italy's river Po, was 9 feet 1 inch long, and weighed 317 lbs. But, some historic reports tell of specimens over 16 feet long, and weighing 880 lbs. Other reports tell of specimens 10 feet or more in length, and weighing 440-550 lbs. However, the usual maximum size is about 250-300 pounds. This is the largest catfish in Europe and the only catfish native to Europe.
Most Wels catfish will eat annelid worms, gastropods, insects, crustaceans and other fish. Larger individuals will eat frogs, mice, rats, and aquatic birds. It uses its large mouth to swallow prey whole. In places where it was introduced it will also eat pigeons. In Italy, Wels are even known to eat young Adriatic Sturgeon, which is devastating to a species already hard pressed by commercial fishing.