RNA, DNA and protein concentrations in fed and starved herring Clupea harengus larvae

Herring Clupea harengus larvae were hatched and reared for 66 d in the laboratory to test hypotheses concerning correlations between nucleic acid concentrations and growth rates.A modified absorbance method is introduced which allowed RNA, DNA and protein to be measured on individual larvae.The amounts of RNA, DNA and protein increased per larva but no significant correlation was found between protein growth rates and RNA concentration, RNA:DNA or RNA:protein.After 7 d of starvation there was a significant loss of RNA, DNA and protein only in larvae 65 d old.It is concluded that nucleic acid ratios, except perhaps protein to DNA ratios, are not valuable for estimating growth rates of wild larvae.