FISHERY BULLETIN: VOL. 74, NO. 3 



together contained approximately the same 

 quantity of protein as found in band 1 of C. 

 arenarius. We believe that band 1 (100% occur- 

 rence) in C. nebulosus contains at least one protein 

 which exhibits polymorphism. Since other proteins 

 (frequency 100%) in this band mask the identity of 

 the protein in question, it is not possible at the 

 level of sensitivity of this system to distinguish 

 the mode of inheritance for this polymorphism. 

 The same situation seems to be true of bands 3 and 

 B in this species. 



Band 1 is consistently found in lower concen- 

 tration in C. nothus {n = 35), but the reverse is 

 true of band 2, which exhibits continuously greater 

 concentration than the comparable band in any 

 other seatrout. Band 3 is found in the highest 

 concentration in C. arenarius (n = 12); a slightly 

 lower concentration occurs in the composite of 

 bands 3 and B in C. nebulosus, and a still lower 

 concentration is found in C. regalis and C. nothus. 

 Band 4 is present in approximately the same 

 concentration in all four species. It should be 

 emphasized that these are average values; small 

 intraspecific differences were noted from sample 

 to sample. 



Qualitative pattern differences were also noted. 

 Bands A and B are unique to C. neb2ilosus. A third 

 band, designated C, was found in 2 of 12 samples of 

 C. arenarius, but not in any other species. A 

 fourth variant, designated D, was found in C. 

 nebulosus, C. arenarius, and C. nothus, but not in 

 C. regalis. Lastly, a band migrating farthest 

 anodally in C. nebulosus was designated E. These 

 qualitative as well as quantitative differences in 

 eye lens patterns are summarized in Table 3. 



Myogens 



Electropherograms derived from soluble muscle 

 proteins provided the most clearly discernible 

 measure of biochemical relationship. Compared 

 with serum patterns, only minor intraspecific 

 variations were evident. A typical grouping from 

 the four seatrouts is shown in Figure 4, and the 

 patterns are diagrammed in Figure 5. The broken 

 lines indicate two minor bands that occurred in a 

 variable manner and in relatively low frequencies; 

 hence, they were not considered further. All other 

 bands occurred in 100% of the samples and are 

 designated as comprising the typical species- 

 specific patterns. A remarkable degree of similar- 

 ity in the patterns is obtained for C. regalis and C. 

 arenarius; they share not only 12 and 13 bands in 



^^BB^* 



A BCD 



Figure 4. -Electropherograms derived from protein extracts of 

 epaxial musculature. (A) Cynoscion nothus, (B) C. arenarius, (C) 

 C. regalis, (D) C. nebulosus. 



^^^ 



2 



3 



5 ^-^ 



Figure 5.-Diagrammatic representation of the protein bands 

 occurring in myogen extracts of four seatrouts. (A) Cynoscion 

 tiothus, (B) C. arenarius, (C) C. regalis, (D) C. nebulosus. 



common (as indicated by electrophoretic mobility 

 and sieving characteristics), but also compare 

 favorably in the quantities of protein comprising 

 each band (Figure 6). Although some variation 

 occurred in relative peak heights from sample to 

 sample (within a species), the densitometer trac- 

 ings shown in Figure 6 are representative of each 

 species. A close relationship clearly exists between 

 C. regalis and C. arenarius both in the distance of 

 migration and in the quantity of protein making 

 up the individual bands (Figures 5, 6). Although 

 the other two species shared the same general 

 generic pattern, they varied in the composition of 

 several major bands. Cynoscion nebulosus always 

 has a high concentration in band 2 in each of the 12 

 samples processed, and has a second band im- 

 mediately adjacent of the same thickness (denoted 

 J on Figure 5). These bands (2 and J) were not 

 resolved as separate peaks in a series of densi- 



602 



