The New Zealand Mudsnail is a non-native, freshwater snail that have been reported in 13 counties of Pennsylvania, including both York and Cumberland County. It is believed that this species was spread inadvertently through global shipping trade. These tiny snails reach a maximum length of 6mm and can reproduce both sexually and asexually. The New Zealand Mudsnail can reach extreme densities in invaded waters. Some estimates suggest densities of 299,000 snails per m^2. Like many native aquatic invertebrates, the New Zealand Mudsnail feeds primarily on detritus and organic materials within sediment. Infestations of these mudsnails can result in decreased native macroinvertebrate abundance and loss of biodiversity.
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A few studies have been done on the impact of this species on the higher trophic levels. One study showed that trout will consume the invasive species but will lose weight due to the poor nutritional value of the New Zealand Mudsnail compared to native macroinvertebrates.
The Pennsylvania Fish and Boat Commission along with the Department of Environmental Services has put together an
Aquatic Invasive Species Control Plan that describes management strategies to control the spread and infestation of this species.