106 



Fishery Bulletin 94( 



1996 



Figure 6 



Vas deferens filled with sperm from three yellowfin tuna, Thunnus albacares (A and B; C and D; E and F) 

 sampled during 1201-2400 h. The rectangles in left panels indicate the regions shown under higher mag- 

 nifications in right panels. Bar = 1 mm in A, C, and E; 0.1 mm in B, D, and F. e = epithelium; m = myoid 

 tissue; s = sperm. 



(Quintero-Hunter et al., 1991). The fish from group 

 1 are characterized by a vas deferens relatively de- 

 void of sperm, an extremely convoluted duct, and a 

 darkly stained vas deferens epithelium (Fig. 7). 



The percent-correct classification for the pooled 

 1986 and 1987 data was a total of 82.0% , with 81.8% 

 for group 1 and 82.1% for group 2 (Table 3). The his- 

 togram of the canonical variable (Fig. 8) from this 

 analysis for the two groups shows the two distribu- 

 tions. The six fish sampled during the 0001 to 1200 h 

 period that were not classified into group 1 showed 



no characteristics of spawning within 12 hours and 

 were thus misclassified into group 2. Of the five fish 

 misclassified into group 1, three fish were sampled 

 during the spawning period, two at 2245 and one 

 at 2300 h, and showed characteristics of the other 

 individuals in group 1 that had spawned within 12 

 hours. Another fish sampled at 1300 h showed char- 

 acteristics more similar to those of group 1, and the 

 other fish showed intermediate characteristics be- 

 tween the two groups but were more similar to those 

 of group 1. 



