Research Article
Thomas P Simon and Nicholas
Abstract
We evaluated habitat models that determined relative abundance relationships among microhabitat, reach and watershed-scale factors important for predicting habitat selection. Thirty stream reaches in central Indiana were sampled to determine relationships between habitat associations and relative abundance, size, and age associations of the Northern Clearwater Crayfish, Orconectes propinquus. Females are significantly more abundant than males and the frequency of crayfish in gravel substrate was significantly higher than that of cobble substrate. The sizes of crayfish in cobble substrate were significantly larger than individuals found in gravel substrates, while females were significantly larger than males in gravel substrates. Watershed variables were not significantly related to crayfish abundance. The only reach scale variable that proved to be significant was boulder substrate. Microhabitat variables showed a significant increase between CPUE and cobble and gravel substrates. Habitat models provide valuable information on the conservation status and habitat parameters responsible for determining species preferences, life history strategies, and relative abundance.