Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Influence of an Invasive Crayfish Species on Diurnal Habitat Use and Selection by a Native Crayfish Species in an Ozark Stream

M. R. Rabalais and D. D. Magoulick
The American Midland Naturalist
Vol. 155, No. 2 (Apr., 2006), pp. 295-306
Stable URL: http://www.jstor.org/stable/4094645
Page Count: 12
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Influence of an Invasive Crayfish Species on Diurnal Habitat Use and Selection by a Native Crayfish Species in an Ozark Stream
Preview not available

Abstract

The crayfish Orconectes neglectus chaenodactylus has recently been introduced into the Spring River drainage in southern Missouri and northern Arkansas and appears to be displacing the native species O. eupunctus. To determine if O. eupunctus and O. neglectus chaenodactylus compete for habitat, we examined if either species shift habitats when in the presence of one another. Habitat use of juvenile and adult crayfish was determined in six habitat types (backwater, pool, riffle, run, stream margin and vegetation) with a quadrat sampler during July/August 2003 at three sites: (1) an upstream site where O. neglectus chaenodactylus occurs, (2) a zone of overlap where both species occur and (3) a downstream site where O. eupunctus occurs. Habitat selection was determined by comparing habitat use to habitat availability. Redundancy Analyses were used to determine the relationship between crayfish densities and measured environmental variables (current velocity, water depth and percent boulder, cobble, pebble and sand). Orconectes eupunctus showed no shift in habitat use, habitat selection and species-environmental relationships between the downstream site and the zone of overlap. However, O. neglectus chaenodactylus did show a shift in habitat use and habitat selection between the upstream site and the zone of overlap, although no shift in species environmental relationships was found. Competition for habitat between O. eupunctus and O. neglectus chaenodactylus did not appear to cause the habitat shift by O. neglectus chaenodactylus since O. neglectus chaenodactylus shifted into habitats used and selected by O. eupunctus. This study suggests that O. eupunctus and O. neglectus chaenodactylus may not compete for habitat. It is possible that habitat is not limiting in this system or that competition is taking place, but at a microhabitat level. Further study is needed to examine other potential mechanisms causing the displacement of O. eupunctus.

Page Thumbnails

  • Thumbnail: Page 
295
    295
  • Thumbnail: Page 
296
    296
  • Thumbnail: Page 
297
    297
  • Thumbnail: Page 
298
    298
  • Thumbnail: Page 
299
    299
  • Thumbnail: Page 
300
    300
  • Thumbnail: Page 
301
    301
  • Thumbnail: Page 
302
    302
  • Thumbnail: Page 
303
    303
  • Thumbnail: Page 
304
    304
  • Thumbnail: Page 
305
    305
  • Thumbnail: Page 
306
    306