I started my conservation career working for what was then called the Iowa Conservation Commission (now the IDNR). I was a young impressionable college student at Iowa State University studying Fisheries and Wildlife Biology. My second summer of seasonal employment was at the Red Rock Wildlife Management Unit. Not far from the North unit headquarters was an area along the Des Moines River called the boxcars. It was known by that name due to the fact that the railroad had cabled several old boxcars together and anchored them to the riverbank as erosion control in an effort to guard their right of way grade from being eaten away.
It was a popular fishing hole. Fishing articles in such magazines as Outdoor Life referred to the boxcars as a good fishing spot in Iowa. The boxcars had become famous and infamous as I was to learn that a boy had drowned years before after falling into the river while fishing. Divers were called to search for the boy's body and the story always finished with a quote that went something like this: "There are catfish down there big enough to swallow a man whole! Divers searching saw them and swore they'd never go down again."
Perhaps you've heard that legend. If not, you likely have heard a similar story in some other location in Iowa, or even other states because like stories surround most every dam and river in the country.
In my job, I swap stories with hundreds of folks every year. This story (and a few thousand others) surface often enough that I've investigated to see whether they might have some truth to them.
Unfortunately, most of these big fish stories can't stand up to scientific scrutiny. An examination of this one proves it to be a myth.
Catfish in this part of the world just don't get big enough to swallow humans. Here in Iowa we have Channel Catfish, Flathead Catfish throughout the state and some Blue Catfish in places like the Missouri River. None of which can grow to the necessary proportions for human consumption. Here are the Iowa records: Channel Catfish 38 pounds, Flathead Catfish 81 pounds, and Blue Catfish 74 pounds. As near as neighboring Missouri, we will find larger Blue Catfish. Even then, the current Missouri record blue cat weighed 117 pounds (the international record Blue Cat wasn't much bigger weighing in at 121 pounds). Flathead Catfish can grow to a similar size with the current world record flathead weighing about 123 pounds.
So a life of eating and lounging results in the growth of some hefty catfish but not the man-eating size. Divers might report huge fish because underwater, objects appear about 25 percent larger than they actually are. This is due to the refraction of light in water through the lens of a scuba mask.
And, of course, it is a fact that fish and fishing lend themselves to stories, and human nature being what it is, it's inevitable that those stories become more wonderful and mythic with each retelling.
Another reason is probably that the people telling the stories aren't the ones who saw the catfish. It's always some anonymous person, a friend of a friend, some friend of an in-law's, or someone else of unknown identity who isn't available for verification. This is a crucial element of all myths - huge fish (or some mountain lion reports, too).
So if a story begins, "I know a fella who said he knew someone who said.."