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The observed reduction in diversity might be explained by over-representation of some females in the 1990 year class. Initial comparison of average number of ova per female recorded in DNFH Annual Reports indicates no difference between the 1990 year class (approximately 0.94 x 105 eggs/female, N=17) and 1982-1989 year classes (0.83 x 105 eggs/female, N=590). These statistics have little meaning, however, since large fish have more ova than small ones and the unrecorded sizes of individual broodfish likely varied from 40 to 60 cm SL. On the other hand, survival from fertilized ova to swim-up was only 11.1% in 1990 (N=17 females), substantially lower than the minimum of 22.5% (mean 40.1%, maximum 71.4%, N=590) calculated from DNFH Annual Reports for the 1982-1989 year classes. Because fertilized ova from several individuals are pooled, fertilization success and embryo viability from specific females or coatings cannot be determined. As a result, it is possible that some individuals or coatings contribute little or nothing while others contribute proportionately large numbers of progeny to a given year class. This becomes especially important when few females are involved. The observed results must at a minimum involve an interaction between the number of females and viability of their offspring. The relationship between intrinsic and extrinisic factors may have been further confounded by variation in broodstock composition over time. Because of their importance to these results and future conservation efforts, we present a l.istory of broodstock and year-class production at DIvFH in Appendix II and detail directly below the actions which potentially affected results of this study. A maximum of 79 females captured in Lake Mohave in 1981 and 1982 (hereafter 81+82-WILD j contributed to a year class of F1 broodfish which, along with an ever-declining number of 81+82-WILD fish, formed the basis for razorback sucker production at:DNFH 2l