Variation of relative organic matter in Mytilus edulis L. larvae and postlarvae

Abstract The variations in relative organic matter (ROM: organic matter/total dry weight) were studied in larval cultures of Mytilus edulis L. reared at 15°C and at 20°C, using single and mixed algal diets. A characteristic inverted peak is observed prior to metamorphosis, with higher minimum values in cultures reared at 20°C and fed a mixed algal diet. The shape of the ROM curve appears to reflect major physiological events in M. edulis larvae and is thus appropriate as a convenient condition index from the first larval stages to the post-larval phase.