Meeting Abstract

P1.20  Sunday, Jan. 4  The Distribution of Crayfish Species in the Tributaries of the Grand River, MI THOMAS, N.M.*; FRISBIE, J.; SNOAP, T.; BERGMAN, D.A.; Grand Valley State University; Grand Valley State University; Grand Valley State University; Grand Valley State University thomasno@student.gvsu.edu

Invertebrate animals make up the greater part of the world’s biological diversity and are present in about all habitats, where they perform essential ecological functions. Their survival is fundamental to the maintenance of life. Large numbers of invertebrate species are under severe threat of extinction, or are already extinct due to the extreme transformations that habitats have suffered due to human activities. Crayfish are one such important invertebrate under pressure and applying pressure to other organisms in ecosystems. Crayfish are keystone species in most aquatic systems. Keystone species are those species that are most important in shaping the total ecology of a system. Crayfish are often keystone species because they are an important resource for many other animals and can affect species diversity and abundance directly. Specifically, crayfish can adversely affect systems by removing plants from an aquatic system making the water turbid, and prey on fish eggs reducing their numbers. There are over 415 species of crayfish in North America. It is recognized that at least eight species of crayfish are found in the state of Michigan. For these reasons, crayfish are an important organism to study. We examined crayfish biodiversity and distribution within the Grand River drainage system. Our study identified three species of crayfish in the Grand river system, as well as the invasive zebra mussel that could alter crayfish populations.