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.

Indigenous Fishes of Western North America and the Hypothesis of Competitive Displacement: Meda fulgida (Cyprinidae) as a Case Study

Michael E. Douglas, Paul C. Marsh and W. L. Minckley
Copeia
Vol. 1994, No. 1 (Feb. 1, 1994), pp. 9-19
DOI: 10.2307/1446665
Stable URL: http://www.jstor.org/stable/1446665
Page Count: 11
  • Read Online (Free)
  • Download ($12.00)
  • 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.
Indigenous Fishes of Western North America and the Hypothesis of Competitive Displacement: Meda fulgida (Cyprinidae) as a Case Study
Preview not available

Abstract

Recent invasion of low-elevation streams in the Colorado River basin of western North America by the nonnative red shiner (Cyprinella lutrensis) seems linked with the dramatic decline of a threatened cyprinid (spikedace, Meda fulgida) native to the Gila River subbasin. The mechanism by which red shiner impacts spikedace is unknown. Two hypotheses have been offered: displacement of the native through competitive interaction with invader, and replacement of native by nonnative as a result of environmental perturbation. To ascertain whether spikedace was being actively displaced by red shiner, we compared niche requirements of each in syntopy, allotopy, and disjunct allopatry. Fishes were collected by seining one to three sites in each of six different stream reaches; and current velocity, substrate particle size, and water depth were measured at each site. Red shiner occupied similar microhabitat whether allopatric, allotopic, or syntopic with spikedace. Spikedace occupied the same microhabitat when allopatric or allotopic to red shiner. However, spikedace syntopic with red shiner displayed a niche shift into currents significantly swifter than those selected when in isolation. Displacement of spikedace by red shiner suggests negative interspecific interactions potentially detrimental to the indigenous species.

Page Thumbnails

  • Thumbnail: Page 
9
    9
  • Thumbnail: Page 
10
    10
  • Thumbnail: Page 
11
    11
  • Thumbnail: Page 
12
    12
  • Thumbnail: Page 
13
    13
  • Thumbnail: Page 
14
    14
  • Thumbnail: Page 
15
    15
  • Thumbnail: Page 
16
    16
  • Thumbnail: Page 
17
    17
  • Thumbnail: Page 
18
    18
  • Thumbnail: Page 
19
    19