1 



H M 



, - 



V V 



Id  t» 



(18 DC 53 4' 



8 



1 



4 • 



* r 



10 





11 



12 



|| Lh |0 #5 II Itf 



13 14 15 16 17 18 



II 60 10 II 



& 



Aft 



19 



20 



21 



22 



23 



24 



Figure 1.— Giemsa stained karyotype (upper row) and C-banding karyotype (lower row) of the same 



yellowfin tuna. 



among all chromosomes, and terminal banding was 

 weakly developed on eight pairs of chromosomes 

 (Fig. 1). As in the albacore, no intercalary banding 

 was observed in the yellowfin. The following sig- 

 nificant differences were observed in the C-banding 

 patterns between the skipjack and the other two 

 species: 1) all chromosomes except 10 and 19 had 

 C-banding in the centromeric region, 2) there was 

 great variability in the intensity of staining in the 



472 



centromeric region, 3) terminal banding was notably 

 prominent in chromosome pair 4, and 4) there were 

 intercalary bands on all chromosomes except pairs 

 17 and 24. 



Discussion 



Our results assist in understanding speciation pro- 

 cesses that have occurred in the evolution of the 



