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.

Intraspecific Variation in the Pharyngeal Tooth Formulae of Some Cyprinid Fishes

Joseph T. Eastman and James C. Underhill
Copeia
Vol. 1973, No. 1 (Mar. 5, 1973), pp. 45-53
DOI: 10.2307/1442356
Stable URL: http://www.jstor.org/stable/1442356
Page Count: 9
  • 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.
Intraspecific Variation in the Pharyngeal Tooth Formulae of Some Cyprinid Fishes
Preview not available

Abstract

Forty-two species of cyprinids were studied to determine the amount of intraspecific variation in their pharyngeal tooth formulae. Widely different degrees of variation were found to exist. The percentage of arches, in a given species, bearing variant half-formulae ranged from 0 to 49.2%. The 0,4-4,0 formula was almost invariable whereas most of the species with 0,5-5,0; 2,5-4,2; or 1,4-4,1 formulae exhibited small or intermediate amounts of variation. The 2,4-4,2 condition was the most variable with four species possessing high percentages (5.8% to 49.2%) of deviant half-formulae. Some of the variability in certain formulae was attributed to evolutionary trends tending to decrease the number of minor-row teeth or increase the number of major-row teeth. A functional mechanism influencing the trends was offered. Faulty tooth replacement was also thought to contribute to some of the variation encountered. Because of the variability in certain formulae, it is suggested that pharyngeal arch and tooth characteristics should also be included in species descriptions and keys.

Page Thumbnails

  • Thumbnail: Page 
45
    45
  • Thumbnail: Page 
46
    46
  • Thumbnail: Page 
47
    47
  • Thumbnail: Page 
48
    48
  • Thumbnail: Page 
49
    49
  • Thumbnail: Page 
50
    50
  • Thumbnail: Page 
51
    51
  • Thumbnail: Page 
52
    52
  • Thumbnail: Page 
53
    53