Morphological Variability of Big-Scaled Redfin Tribolodon hakonensis (Cyprinidae)

Abstract

Morphological variability of seven characteristics of two forms of the big-scaled redfin Tribolodon hakonensis from ten reservoirs of the Far East is studied. Three indicators are analyzed—fluctuating asymmetry, geographical variability, and variability of characteristic values. Differences in the level of fluctuating asymmetry of T. hakonensis from different samples are due to different conditions of embryonic and early postembryonic development. The northern form differs from the southern one by a large average value of the sum of dispersions in all characteristics; this indicates a reduced stability of development. The geographical variability of T. hakonensis is manifested in six characteristics. Forms reliably differ from each other by average values of features, except for the number of infraorbital bones. The average values ​​of the coefficient of variation of characteristics vary considerably; the forms do not differ among themselves, and this indicator is noticeably higher only by the number of postorbital bones in the southern form. The largest number of significant differences in the dispersion of fluctuating asymmetry, average values ​​of characteristics, and coefficients of variation is most often observed when comparing between samples of the northern form, while that for the southern one is always minimal or absent altogether; this may be a result of sampling of the northern form from a much larger part of the area and a higher level of nucleotide variability in the northern form compared with the southern one.