USE OF CARBON RATHER THAN DRY-WEIGHT TO ASSESS THE DNA CONTENT AND NUTRITIONAL CONDITION INDEX OF SOLE LARVAE

A new biochemical index has been proposed, based on the DNA amount in the larva related to dry weight, to estimate the nutritional condition of marine fish larvae. Starvation induces a strong and fast increase of this index, which can be assessed al the individual level. Weighing very small quantities of dry matter is difficult. It is suggested tha t carbon content should be used, which can be quantified by accurate s tandard techniques, Results of a preliminary calibration experiment on sole larvae fed in captivity at three temperatures show a strong corr elation between dry weight and carbon. DNA/C values are not the same f or the early development stages (symmetrical larva) or the later ones (metamorphosing larva), both levels being quite independent of the rea ring temperatures despite great differences in growth rates. DNA/C sho uld provide a convenient and accurate tool for assessing the nutrition al condition of field-caught specimens. (C) 1997 International Council for the Exploration of the Sea.