FISHERY BULLETIN: VOL. 85, NO. 4 



Figure 3. — Photomicrograph of a cross section of the dorsal aorta containing parasites and host inflammation 

 of a heavily infected yellowfin tuna. The host inflammation (I) and cross sections of the parasites (W) can be 

 easily differentiated. Hematoxylin and eosin stain. 



DNA ratios. RNA/DNA ratios were compared di- 

 rectly (rather than by calculating relative RNA/ 

 DNA ratios) because they were found not to be 

 correlated with body weight (correlation coeffi- 

 cient - 0.04). 



Data from unparasitized fish collected in Au- 

 gust and September 1985 were analyzed sepa- 

 rately from all remaining unparasitized fish. This 

 was done because we found dramatically lower 

 rates of infection (11%) during those 2 months 

 than during the preceding 2 months (67% in- 

 fected) and assumed this to be due to an influx 



of a new group of small yellowfin tuna into the 

 Hawaiian fishery. New regression parameters for 

 body weight on fork length, heart weight on body 

 weight, and liver weight on body weight were 

 calculated using data from unparasitized fish ex- 

 cluding those caught during August-September 

 1985. Mean relative condition factors and relative 

 organ weights were then recalculated. 



Table 3 shows mean relative condition factors, 

 mean relative liver weights, and mean relative 

 heart weights for unparasitized fish captured dur- 

 ing August and September 1985, unparasitized 



Table 3. — Relative condition factor, relative liver weight, and relative heart 

 weight from uninfected yellowfin tuna sampled during August and September 

 1985, from all other uninfected yellowfin tuna, and all infected fish. 



Group 



Mean (±SD) 



relative 



condition factor 



t^ean (±SD) 



relative liver 



weight 



Mean (±SD) 



relative 

 heart weight 



August-September 

 1985 uninfected fish 



All other 

 uninfected fish 



Infected 

 fish 



1.11 (±0.08)* 

 W = 36 



1.00 (±0.09) 

 N = 73 



1.01 (i 

 N 



0.06) 

 = 35 



1.24 (±0.28)* 

 N = 35 



1.01 (±0.17) 

 N = 47 



0.937 (±0.102) 

 N = 22 



'Uninfected groups different at P = 0.01 level. 



1.22 (: 



N = 



1.00 (: 

 N = 



:0.18)* 



36 



:0.09) 



52 



1.00 (±0.09) 

 A/ = 32 



772 



