Unionidae, Pyganodon, Potamilus, Lampsilis, habitat, reservoir, depth, fetch, bottom slope, substrate, spatial distribution, population density
A rapid drawdown (<4 weeks) of a reservoir allowed us to determine the combined influence of water depth, maximum effective fetch, bottom slope, and substrate characteristics on abundance of three species of freshwater mussels. The three principal mussel species were significantly (P<0.001) correlated in different ways with characteristics of their physical habitat, implying separation of habitat requirements Pyganodon grandis (Say) was most abundant on deeper shelves (ca. 3 m depth, slope 1 km), and sediment organic matter content was moderate (<3.5%). (Lampsilis siliquoidea (Barnes), however, was most abundant in shallow water (<1.5 m), in flat, sheltered areas with low slope (<0.10 m/m) and fetch (<0.4 km), on substrates with 1-3% organic matter content. (Potamilus alatus (Say) had a more cosmopolitan depth distribution, but was found only on bottoms with low slope (<0.01 m/m), where fetch was less than 0.8 km. The results of this study agree with previous studies with one important exception. Abundance of Pyganodon grandis was found to be negatively affected by increasing substrate organic matter content. This result stands in contrast to other studies that have suggested that abundance of Pyganodon grandis was positively correlated with substrate organic matter content.
Journal of the Iowa Academy of Science
© Copyright 2000 by the Iowa Academy of Science, Inc.
Straka, J. R. and Downing, J. A.
"Distribution and Abundance of Three Freshwater Mussel Species (B1valv1a: U ntontdae) Correlated with Physical Habitat Characteristics in an Iowa Reservoir,"
Journal of the Iowa Academy of Science: JIAS: Vol. 107:
, Article 3.
Available at: http://scholarworks.uni.edu/jias/vol107/iss2/3