and is common in culture of larval fishes. Such 

 variability may be reduced in nature, where 

 runts may be subject to intense predation. 



Lipofuscin analysis may be usefijl only when 

 applied to postmitotic tissue, such as nervous tis- 

 sue in mature fish, or to whole organisms whose 

 mitotic growth has essentially ceased, such as 

 adult copepods or insects (since the methods ap- 

 pear usefiil in arthropods — Ettershank et al. 

 1983; Sohal and Donato 1978). In these organ- 

 isms, the vagaries of growth are reduced, and the 

 accumulation of lipofuscin during starvation or 

 exercise might show that lipofuscin concentration 

 is interpretable as a measure of physiological age, 

 habitat quality, and net growth efficiency. 



Lipofuscin is known to be a polytypic sub- 

 stance, probably variable in composition among 

 different organisms. We have assumed that a con- 

 stant proportion of the same substance is ex- 

 tracted. This may not be true (Vernet et al. 1988), 

 and considerable work remains to be done on the 

 basic biochemistry of the component substance(s). 

 Though the extraction and fluorometric measure- 

 ment is tantalizingly simple, it may well be that 

 the microscopical method used to quantify "ceroid 

 bodies" is the best approach. Fluorescent tech- 

 niques used in histochemical research (Brizzee 

 and Jirge 1981), combined with automatic imag- 

 ing procedures, might decrease the tedium of 

 staining and visual microscopy. 



Acknowledgments 



We thank Refik Orhun and Steve Cadell for the 

 larval white seabass and halibut, and Maria Ver- 

 net and two referees for helpful comments. Re- 

 search was supported by California Department 

 of Fish and Game project C-921 and National Sci- 

 ence Foundation grant OCE86-00742. 



Literature Cited 



Bentle, L a.. S Dutta, and J Metcoff. 



1981. The sequential enzymatic determination of DNA 

 and RNA. Anal. Biochem. 116:5-16. 

 Brizzee, K R , and S K Jirge. 



1981. Fluorescent microscope techniques for the visual- 

 ization and histological quantification of autofluorescent 

 lipofuscin bodies in brain tissues. In J. E. Johnson (edi- 

 tor). Current trends in morphological techniques, Vol. 

 III. CRC Press. 



CSALLANY, A. S , AND K L AYAZ 



1976. Quantitative determination of organic solvent solu- 

 ble lipofuscin pigments in tissue. Lipids 11:412-417. 



DoRSEY, T E , P W McDonald, and O A Roels 



1977. A heated Biuret-Folin protein assay which gives 

 equal absorbance with different proteins. Anal. Bio- 



chem. 78:156-164. 

 DOWSON. J H 



1982. The evaluation of autofluorescence emission spec- 

 tra derived from neuronal lipopigment. J. Microsc. 

 128:261-262. 



Ettershank, G. 



1984a. A new approach to the assessment of longevity in 

 the Antarctic krill Euphausia superba. J. Crust. Biol. 

 4(Spec. No. l):295-305. 

 1984b. Methodology for age determination of Antarctic 

 krill using the age pigment lipofuscin. Biomass Handb. 

 No. 26. SCAR/SCOR/LABO/ACMRR. 

 Ettershank, G., I MacDonnell, and R Croft. 



1983. The accumulation of age pigment by the fleshfly 

 Sarcophaga bullata Parker (Diptera: Sarcophagiidae). 

 Aust. J. Zool. 31:131-138. 



Fletcher, B L . C J Dillard. and A L Tappel. 



1973. Measurement of fluorescent lipid peroxidation 

 products in biological systems and tissues. Anal. Bio- 

 chem. 52:1-9. 

 Frey. H W 



1971. California's living marine resources and their uti- 

 lization. Calif. Dep. Fish Game, Resour. Agency, 148 p. 

 May, R C 



1971. Effects of delayed initial feeding on larvae of the 

 grunion Leuresthes tenuis (Ayres). Fish. Bull., U.S. 

 69:411-425. 

 MiQUEL, J , J Org, K G. Bensch, and J E Johnson, Jr. 



1977. Lipofuscin: fine-structural and biochemical studies. 

 In W. A. Pryor (editor). Free radicals in biology, p. 133— 

 182. Acad. Press, N.Y. 



NICOL, S 



1987. Some limitations on the use of the lipofuscin ageing 

 technique. Mar. Biol. (Berl.) 93:609-614. 



Shimasaki, H., N Veta, and O. S. Privett 



1980. Isolation and analysis of age-related fluorescent 

 substances in rat testes. Lipids 15:236-241. 

 Sohal, R. S , and H Donato. 



1978. Effects of experimentally altered life spans on the 

 accumulation of fluorescent age pigment in the housefly, 

 Musca domestica. Exp. Gerontol. 13:335-341. 



Theilacker, G H , AND M F. McMaster. 



1971. Mass culture of the rotifer Brachionus plicatilis and 

 its evaluation as food for larval anchovies. Mar. Biol. 

 (Berl.) 10:183-188. 

 Thomas, J C 



1968. Management of the white seabass (Cynoscion no- 

 bilis ) in California waters. Calif Dep. Fish Game, Fish. 

 Bull. 142, p. 1-34. 

 Vernet, M , J R Hunter, and R. D. Vetter 



1988. Accumulation of age pigments in two cold-water 

 fishes. Fish. Bull., U.S. 86:401-407. 



M M. Mullin 

 E. R. Brooks 



Institute of Marine Resources 

 Scripps Institution of Oceanography 

 University of California, San Diego 

 La Jolla, CA 92093-0218 



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