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<br />will be further substantiated with more extensive sa~pling. The <br /> <br />utility of electrophoresis for finding true hybrids was demon- <br /> <br />str2ted with respect to the "roundtail" chub. <br /> <br />Two hybrids from <br /> <br />the Dexter National Fish Hatchery were diagnosed without know- <br /> <br />ledge of ancestries but were correctly resolved regarding their <br /> <br />"roundtail" chub parentage. <br /> <br />There still remains the question of biological species status for <br /> <br />the "bonytail" and "humpback" chub. <br /> <br />The two "species" samples <br /> <br />may have been taken from within the same species since electro- <br /> <br />phoretic differentiation (relative to a small sample size) was <br /> <br />riot great. <br /> <br />Other studies do not argue against this hypothesis. <br /> <br />Recent morphological analysis of the Colorado River chubs (based <br /> <br />on a total of 79 specimens; Smith et 31., 1979) did not resolve <br /> <br />the question of variability with respect to species. <br /> <br />Research <br /> <br />on hatChery-produced larval and juvenile fishes has also failed <br /> <br />to give significant distinction between the two supposed species <br /> <br />(Snyder et aI., 1981). <br /> <br />Meristic characters appeared to be either <br /> <br />overlapping or conjunctly continuous (e.g., a-b-c-d in Taxon <br /> <br />and e-f-g in Taxon 2) with one exception. <br /> <br />Although a gap in gill <br /> <br />raker numbers, with bony tail chubs having the higher counts, <br /> <br />perhaps indicative of two species was noted in Snyder et al. <br /> <br />(1981), such may also be a consequence of geographic origins and <br /> <br />natural selection. <br /> <br />The bony tail chubs were the progeny of <br /> <br />lake-dwelling parents, likely to have undergone selection for <br /> <br />greater numbers of gill rakers, while the hu~pback chub stock was <br /> <br />8 <br />