7259

• UCREFRP Catalog Number: 7259
• Author: Rosenfeld, M. J.
• Title: Preliminary Electrophoretic Study of the Colorado River Chub ‎(Pisces
• USFW Year: 1986.
• USFW - Doc Type: Cyprinidae, Genus
• Copyright Material: NO

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complicated taxonomic history (reviewed in ~inckley, 1973), but

most researchers accept the validity of three biological species

(Joseph et a1., 1977; Smith et a1., 1979; Wydoski et al., 1980).

Environmental changes due to man are considered responsible for

much of the variability, p3rticularly the existence of inter-

grades or intermediate types (Holden, 1968; Holden and Stalnaker,

1970, 1975).

Explanations for the diversity of morphologies

include developmental responses to wide within-species habitat

tolerances (Miller, 1946) and interspecific hybridization (Minck-

ley, 1973; Tyus et al., 1932).

Observed variation may have an

origin that precedes any human influence.

Baird and Girard

(1853a,b), in the first studies on Colorado River Gila 133 years

ago, may have confused or misclassified specimens because of it

(see Plates I-III in Appendix 1).

Understanding the dynamics of chub populations on the basis of

morphology alone may be difficult due to the uncertainties of

morphological limits among and between species (Feder, 1979).

qelatedness within the chub complex as well as the genetic and

geographic components of variability might be better understood

with protein electrophoresis.

This methodology has been used to

address such questions in fishes (Utter et al., 1973; Allendorf

et al., 1977), including those involving morphological inter-

grades (e.g., Menzel, 1977; ~Jiseman et a1., 1978; Buth and
''layden, 1981).

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