NOTE Safford and Booke Stock delineation of Clupea harengus harengus 



205 



Dfscrimlnant function These eight char- 

 acters were used to derive a discriminant 

 function (Snedecor and Cochran 1967, Sokal 

 and Rohlf 1969). Each measurement in sub- 

 sequent samples was adjusted to the SL of 

 the original sample to eliminate bias due to 

 differences in the SL. Details of the con- 

 struct of the discriminant function and the 

 formulae used to adjust the subsequent 

 measures can be found in Appendix A and 

 Safford (1985). 



The discriminant function was tested for 

 spatial and temporal stability with addi- 

 tional samples from both 1983 and 1984. 

 The additional sample data were treated as 

 described in Appendix A to yield a z-score 

 so the fish could be classified according to 

 spawning group. The cut-off value for the 

 z-score was set at zero, where fish wnth a 

 z-score >0 were classified as Trinity Ledge 

 fish and those with a z-score <0 were classified as 

 Jeffries' Ledge fish (Norusis 1979, Safford 1985). 



Statistics A stepwise function employing the F-value 

 of each character, (p<0.05), to accept or reject a char- 

 acter was derived to rank the variables. The distribu- 

 tion of phenotypic variation was measured by a nested 

 analysis of variance (ANOVA), with years nested 

 within groups, generated by nested procedures using 

 PC-SAS packaged programs (SAS 1985). One-way 

 ANOVA generated by the general linear models pro- 

 cedure in PC-SAS packaged programs (SAS 1985) was 

 used to analyze differences in morphometric measure- 

 ments, both between years within a spawming group 

 and between spawning groups within a year. 



Electrophoresis 



Enzyme visualization Traditional starch gel elec- 

 trophoresis of white muscle tissue samples as described 

 by Utter et al. (1974), with some modifications, was 

 used to resolve the enzymes. A detailed description of 

 the gel composition and running conditions can be 

 found in Safford (1985). Four polymorphic loci— phos- 

 phoglucomutase, PGM-2* (5.4.2.2), glucose-6-phos- 

 phate isomerase, GPI-2* (5.3.1.9), and two of lactate 

 dehydrogenase, LDH-1 * andLDH-2* (1.1.1.27)-were 

 analyzed. The enzyme abbreviations and numbers 

 follow the suggestions of Shaklee et al. (1989). Two 

 buffer systems, Ridgway et al. (1970) and Markert and 

 Faulhaber (1965), were used. The Ridgway gel buffer, 

 used for LDH and GPL was modified by doubling the 

 amount of Tris (Sigma Chemical Co., St. Louis) in the 

 recipe, which raised the pH to 8.5 and made the bands 

 more distinct. The Markert-Faulhaber buffer was used 



for PGM because it improved band resolution. Stain 

 recipes and techniques followed Shaw and Prasad 

 (1970) v^nth modifications which are detailed in Safford 

 (1985). Photographs were taken immediately upon 

 staining. 



Statistics Allelic frequencies were compared between 

 samples by chi-square contingency table analysis. 

 Genotypic frequencies were tested for conformation to 

 the Castle-Hardy-Weinberg (C-H-W) equilibrium with 

 a chi-square goodness-of-fit test (Zar 1974). Gene diver- 

 sity analyses were conducted according to Nei (1973), 

 Chakraborty (1980), and Chakraborty et al. (1982). 



Results 



Morphometries 



Group means of eight morphometric characters were 

 found to be significantly different (p<0.01) between 

 samples taken from the two spawning areas in 1983. 

 No overlap in range was found within the 95% con- 

 fidence interval for seven of these variables, and over- 

 lap at the eighth variable was very small (Table 1). 

 Therefore, it was concluded for this study that 50 fish 

 from each sample were sufficient. The stepwise dis- 

 criminant function accepted the first seven of these 

 eight variables. Multiple analysis of variance of the 

 eight characters versus locality for the 1984 samples 

 revealed that only three of these characters— distance 

 between insertions of the pelvic and dorsal fins (PVD), 

 anal fin height (AH), and distance between the inser- 

 tions of the pectoral fins (PCI)— were significantly dif- 

 ferent (p<0.01) between the two groups. Two of these 

 characters, PVD and PCL were among the three which 



