Examination of crayfish biodiversity and distribution within the Grand River, Michigan
Invertebrate animals make up the greater part of the world's biological diversity and are present in about all habitats in the world, where they perform essential ecological functions. Their survival is fundamental to the maintenance of ecosystems. 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 an ecosystem. 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. In our study, we found three species, Orconectes virilis, O. propinquus, and Cambarus diogenes, in the tributaries of the Grand River. An invasive species, Orconectes rusticus – “rusty crayfish”, was found south of the Grand River and its tributaries, but not in the Grand River water drainage. Our results indicate that the Grand River’s crayfish population is diverse for Michigan and at least at this time seems to be safe from the invasive crayfish species, Orconectes rusticus.
Faculty Mentor: Daniel Bergman, Biomedical Sciences
Norrissa presented at the Annual Meeting of the Society for Integrative and Comparative Biology January 3-7 in Boston, MA.
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