Abstract
AbstractRusty crayfish (Orconectes rusticus) have invaded streams of the upper Susquehanna River catchment (New York, USA), replacing native crayfish and probably increasing overall crayfish density. Crayfish are important consumers and agents of disturbance in aquatic communities, so the introduction and expansion of rusty crayfish could affect the invaded community through the change in crayfish species composition, the increase in crayfish density, or some combination of the two. Other macroinvertebrates are prey of, competitors with, or subject to disturbance by crayfish and so are likely to be affected by changes in the crayfish assemblage. We conducted correlative field sampling and an enclosure experiment to investigate the effects of invading O. rusticus on the abundance, diversity, and composition of the stream macroinvertebrate assemblage. We sampled crayfish and macroinvertebrates at 13 sites on 4 streams in the upper Susquehanna River catchment that varied in crayfish species composition and density. Total macroinvertebrate abundance, taxon richness, diversity, and density of individual taxa were not significantly correlated to either total crayfish density or the relative abundance of O. rusticus. We also conducted an experiment in stream enclosures to test the effects of O. rusticus density on the macroinvertebrate assemblage. Increasing crayfish density caused a significant decrease in total macroinvertebrate density but did not significantly affect macroinvertebrate taxon richness or diversity. The density of some individual taxa were also significantly affected by crayfish density. Our experiment shows that rusty crayfish density can affect the stream community; the mechanism of these effects, and whether they differ from those of native species, remain to be determined.
Highlights
Introduction & BackgroundIntroduced rusty crayfish (Orconectes rusticus) are expanding in the upper Susquehanna River[1]Pine Lake Environmental Center O. rusticusO. rusticus replace native crayfish species[1 ] O. propinquusO. obscurus Figure 2
Invasion of the upper Susquehanna River watershed by rusty crayfish
less common taxa grouped at higher taxonomic levels
Summary
Introduced rusty crayfish (Orconectes rusticus) are expanding in the upper Susquehanna River[1].
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.