Length adjustment of larval and early-juvenile cod (Gadus morhua) after up to 3 years of preservation in alcohol

Comparison of live Baltic cod larvae lengths and early-juveniles with corresponding lengths after preservation in 95% ethyl alcohol for periods of one to 3 years resulted in an average shrinkage of 0.70 mm for the entire size range of 4–40 mm standard length cod. Although the relative shrinkage depended on fish size and varied from 2 to 20% of the fresh length, the absolute shrinkage values were not size dependent and did not change during the observed preservation period. Thus a general additive correction value of +0.7 mm can be used to calculate live lengths from measured standard lengths of alcohol-preserved material.