comparisons of amount of concentrations between 

 tissues or species cannot be made if different ex- 

 traction methods are used. 



Lipofuscin Concentration 



The total concentration of extracted lipofus- 

 cin in Dover sole brain tissue was positively 

 correlated with fish length (Fig. 2A) 

 {Y = -15.4 + 0.516X,r2 = 0.43;6 ^0,P<0.01, 

 t - 5.1, df=34). Furthermore, total extracted 

 lipofuscin content in the brain was positively cor- 

 related with age in organisms estimated by annu- 



5 300 



>- 

 cr 



Q 



LlI 



o 



CO 



UJ 



cc 

 o 



200 



100 



lar increments in otoliths to be from 2 to 15 years 

 old (Fig. 3A) (Y = -2.5 + 1.0 X, r'^ = 0.75; 6^0, 

 P < 0.01, t - 5.5, df = 10). On the other hand, in 

 older Dover sole (estimated age from 20 to 45 

 years; n = 26) the total extracted lipofuscin in the 

 brain did not increase with their estimated age. 

 The concentration of lipofuscin in the brain (ex- 

 tracted lipofuscin concentration per unit of g dry 

 weight) followed a similar pattern (Fig. 3B). The 

 concentration in the brain increased linearly with 

 age for fish 2-15 years old (7 = 30.39 + 14.85 X, 

 r2 = 0.79, b i=0, P < 0.01, t = 6.66, df = 10) but 

 fishes older than 15 years did not show an in- 

 crease in pigment concentration with age. 



The total extracted lipofuscin content extracted 

 ft-om rainbow trout brains increased with age 

 (Fig. 4A) (Y = 0.14 + 0.18 X, r^ = 0.37; 6^0, 

 P < 0.01, t = 3.75, df = 23), as did the content of 

 the heart (Fig. 4C) (Y = -0.54 + 0.82 X, 

 r2 = 0.67; 6 ^ 0, P < 0.01, t = 7.36, df = 23), and 

 liver (Fig. 4E) (Y = -2.86 + 5.81 X, r^ - 0.62; 

 b i=0,P < 0.01, t = 7.54, df = 34) from 3 months 

 to 3 years. The concentration of extracted lipo- 

 fuscin per unit wet weight of heart tissue did 

 not change with age (Fig. 4D) whereas that of 

 brain and liver tissue decreased with age (Fig. 

 4B, F). 



< 



cc 



CD 



CC 

 UJ 

 CL 



UJ 

 O 



111 

 o 



(O 



UJ 



cc 

 o 



Z) 



10 



200 400 



LENGTH (mm) 



600 



oo o 



Figure 2. — Dover sole, Microstomas paciftcus, brain: 

 (A) Extracted lijwfuscin per unit of dry weight as a function of 

 fish length (mm) (n = 36); (B) brain dry weight (g) as a func- 

 tion of fish length (mm). Fluorescence units: the intensity of 

 fluorescence normalized to a standard solution of quinine sul- 

 fate (1 mg L-i in IN sulphuric acid). 



Figure 3. — Lipofuscin in Dover sole. Microstomas 

 pacificas, brain tissue as a function of age in = 36). 

 (A) Total lipofuscin content per brain; (B) weight- 

 specific (g dry weight) lipofuscin in brain. 



I 

 a 



UJ 



>- 

 cc 



Q 



to 



I- 



UJ 



to 



UJ 



cc 

 o 



300 



200 



100 



o B 



o o° 



Yn.,<s = 30 4 +I4 85X 



-J I I I L 



10 20 30 



AGE (years) 



40 



404 



