500 



CHOLESTEROL (MILLIGRAMS PERCENT) 



1,000 



15 



LIPID PHOSPHORUS (MILLIGRAMS PERCENT) 



20 



Figure 5. — Cholesterol of blood of adult pink salmon in 

 three stages of maturity. (C, sexes combined; F, 

 females; M, males; single asterisk, early rim; double 

 asterisk, late run.) 



Figure 6. — Lipid phosphorus of blood of adult pink 

 salmon in two stages of maturity. (C, sexes com- 

 bined; F, females; M, males; single asterisk, early 

 run; double asterisk, late run.) 



The function of cholesterol in the metabol- 

 ism of fishes (reviewed by Shell, 1961) re- 

 mains obscure. In my study, however, choles- 

 terol showed an inverse correlation with lipid 

 phosphorus (significant at the 1-percent level). 



LIPID PHOSPHORUS 



Concentrations of lipid phosphorus in sam- 

 ples from the prespawning and spawning 

 stages and the early and late spawning runs 

 are compared (fig. 6). No data are available 

 from the migi-ating group. The increase in 

 lipid phosphorus levels from the prespawning 

 to the spawning stage was significant at the 

 1-percent level. The values for males in the 

 spawning stage in the early part of the run 

 (fig. 6) were also significantly higher than in 

 the late run (at the 1-percent level.) The high 

 values for lipid phosphorus in the females sam- 

 pled in the late run may be due to a terminal 

 increase in 17-hydroxycorticosteroids in fe- 

 males as values at that time are dropping in 

 males (Hane and Robertson, 1959). Although 

 Shell (1961) found a direct correlation be- 

 tween lipid phosphorus and the blood proteins 

 (albumin and globulin), no such correlation is 



evident in my data. Comparisons between in- 

 dividual animals, however, indicated a positive 

 correlation (1-percent level of significance) 

 with glucose. The results suggest a mechanism 

 whereby the concentration of lipid phosphorus 

 increases as cholesterol and glucose decrease. 



URIC ACID 



The values for uric acid are discussed for 

 males and females in the three stages of ma- 

 turity. The decline in uric acid concentration 

 in the blood of males from the migrating to the 

 prespawning stage is significant at the 1-per- 

 cent level (fig. 7). The further drop in uric 

 acid from the prespawning to the early part of 

 the spawning stage (in the early run only) is 

 also significant at the 1-percent level. No such 

 drop is apparent, however, in the comparison 

 of the males of the prespawning and the late 

 part of the spawning stage (fig. 7). Within the 

 prespawning stage, uric acid values were high- 

 er in the females than in the males (sig- 

 nificant at the 5-percent level). Uric acid con- 

 centrations in females from the late spawning 

 stage average only slightly higher than tho.se 

 in the males (table 2). If uric acid is accepted 



200 



U.S. FISH AND WILDLIFE SERVICE 



