WEINSTEIN and YERGER: PROTEIN TAXONOMY OF CYNOSCION 



C- nolhus 



Figure 6.- Densitometer tracings of representative myogen 

 patterns of four seatrouts (Cynoscion). Intensity of particular 

 bands are indicated by relative peak heights. 



tometer tracings; however, observation of gels and 

 photographs clearly indicated their double nature. 

 Band 1 was not present in any of the samples of C. 

 nebulosus; however, a band designated as H oc- 

 curred in a more cathodal direction (above position 



I). 



Bands D and E in C. nothus are slightly dis- 

 placed; i.e., they have a slightly different electro- 

 phoretic mobility from their "counterparts" (F 

 and G) in the other three species. This difference 

 could be an artifact, but duplicate experiments 

 indicate otherwise. Cynoscion nothus also lacks 

 bands B and C found in the other species. Band A 

 is absent in C. nebulosus, but present in the other 

 seatrouts. 



DISCUSSION 



Morphological Taxonomy 



In his review of the seatrouts of the Atlantic and 

 Gulf coasts of the United States, Ginsburg (1929) 

 recognized C. nebulosus as the most distinctive 

 morphologically on the basis of its color pattern 

 and its scaleless dorsal and anal fins. Cynoscion 

 nebulosus also differs ecologically from the other 

 Cynoscion; it is primarily an estuarine form while 

 the others have a closer affinity to the marine 

 environment. 



The remaining species are less easily distin- 

 guished. Of the many criteria used, size and color 

 are most important. Cynoscion regalis is readily 

 recognized in the adult stage by the longitudinal 

 rows of small spots on its back, which produce a 

 mottled appearance. The paler, C. arenarius of the 

 gulf lacks conspicuous pigmentation. Cynoscion 

 nothus is similar in color to C. arenarius, but 

 differs in several other respects including verte- 

 bral and anal-fin ray counts. Cynoscion nothus 

 may not attain as large a maximum size as C. 

 arenarius, although this observation may be a 

 sampling artifact. Gunter (1945) noted that C. 

 nothus occurs at slightly greater depths than the 

 other seatrouts. Therefore, the main populations 

 of C. nothus may not have been adequately 

 sampled. 



Taxonomically, the status of C. arenarius has 

 never been satisfactorily resolved. Guest and 

 Gunter (1958) accorded full species rank for C. 

 arenarius, as does the current list of the American 

 Fisheries Society (Bailey et al. 1970), and the 

 recent investigation by Mohsin (1973). However, 

 the original description leaves room for consider- 

 able doubt. Ginsburg (1929) stated in a footnote 

 that, "An unbiased study of the data here pre- 

 sented shows, I believe, that there is room for 

 difference of opinion as to the degree of difference 

 between this form [C. arenarius] and ragalis 

 [regalis] from the Atlantic coast-whether they 

 should be regarded as species or subspecies." 

 Furthermore, by Ginsburg's (1938) own criteria of 

 the "arithmetical" definition of a species, the 18% 

 intergradation of the most "divergent" character 

 (the number of articulated dorsal rays) would give 

 the two forms only subspecific status. 



Protein Taxonomy 



Our primary purpose in this study has been to 



603 



