rCreepy things inhabit Iowa streams

An incident Sunday on the Wapsipinicon River bumped the turkey vulture off the top of my personal list of creepiest Eastern Iowa animals.

Despite having mucked around in Iowa's rivers and creeks for more than 50 years, I did not even suspect that my new champion – the American brook lamprey, a type of fish, I guess – even existed.

My first clue came during an intense outing that lasted only slightly longer than it took me to hook, land and string up five walleyes ranging from 17 to 22 inches.

I knew something had to account for the concentration of voracious walleyes in a confined location at the mouth of a feeder creek, but I did not know what until I started cleaning the fish.

The intestines of all five walleyes bulged with worm-like creatures in various stages of digestion. Most of them were about 6 inches long and about the diameter of a lead pencil.

At first I'm thinking nightcrawlers or maybe even baby snakes, but a closer examination revealed a vaguely fishy creature with eyes on both sides of a pointed head, a downward-pointing suction cup of a mouth lined with tiny teeth and a series of gill openings reminiscent of the portholes on the front fender of a Buick.

Department of Natural Resources fisheries biologist Greg Gellwicks told me they are Iowa natives whose reclusive lifestyle allows them to live under most people's radar.

Adolescents, which lack eyes and the suction mouth, burrow into the mucky substrate of streams, where they subsist for several years as filter feeders upon such organic detritus as comes their way.

You could not seine one if you tried because they live beyond the reach of a net, according to Gellwicks, who said the DNR sees them only when their electroshock apparatus brings them to the surface.

After four or five years, in the autumn of their year of maturity, they metamorphose into adults, with eyes and the suction mouth, which is actually useful only in their spawning ritual.

The male, usually in April, uses his mouth to remove pebbles from a saucer-shaped nest and to attach himself to the head of the female, who uses her suction cup to cling to the bottom. You know the rest.

Shortly after the adults spawn, they die, either of natural causes or in the intestines of opportunistic game fish.

Unlike some lampreys, the American brook lamprey is not a parasite and will not be seen attached to another fish.

Despite their unappealing eel-like qualities, they don't hurt a thing and pretty much pass their lives unnoticed until they drift from their spawning nests into the open mouth of a hungry predator.