Back

Conservation-Chinese Mystery Snail By: Nick Buseman, Grundy County Conservation Operation Supervisor
July 26, 2018

Share

Phone calls and verbal discussions about people wading or swimming at the Grundy County Lake this past week has been very popular. Upon investigation we found that a group of people of foreign decent are collecting Chinese Mystery or trapdoor snails that have established a population in the lake. These snails are large in size and are very abundant in the lake. This non-native snail has created a population in both Grundy County Lake and Stoehrs Fishing Area. This non-native snail has infiltrated our freshwater areas through the aquarium and home pond market. Over the years people have dumped their aquarium contents and or pond snails into our lakes after they were done using them causing an outbreak of snails. After discussion with our DNR conservation officer, I found out that no license is needed to harvest these snails since they are not a freshwater mussel. In Iowa, all freshwater mussels are protected. So everything these people are doing in the lake is perfectly legal as long as they are not swimming. In witnessing these people they were wading the shorelines, feeling the bottom with their hands and collecting snails. We are not sure if they are collecting the snails to resale in the aquarium trade or harvesting them for food. I do not recommend eating the snails, but after discussion with our conservation officer, I do believe that this ethnic group is harvesting them for consumption. The Chinese Mystery snails is native to Asia and were shipped to California in the 1800's for Asian seafood markets, and later were distributed across the US in the aquarium and home pond trade. These snails are very popular in aquariums and ponds for their ability to consume algae therefor cleaning the bottom or glass of an aquarium. Chinese Mystery snails measure two inches from tip to trapdoor, roughly the size of a golf ball. The main characteristic of the snail is its trapdoor opening from which it protrudes when feeding or moving. Dark in color, they blend into the rocks and soil of the lake floor. I am unsure of their food value to fish, so I am unaware of any predators they might have. The Grundy County Lake has a thriving population of Chinese Mystery snails. I am unsure of any benefit they are having to our lakes and ponds but so far haven't seen any negative effects. All I know is they are not hard to find. Pick any shoreline on either area and just look in the shallows - you will see several.

Share

Regular Size Northern-Sun Print