Chemical changes during growth and starvation of larval Pleuronectes platessa

Plaice (Pleuronectes platessa L.) were sampled during periods of growth and starvation, from the end of the yolk-sac stage through metamorphosis, for changes in water, triglyceride, carbohydrate, total nitrogen, total carbon, and ash. The percentage of water in larvae decreased continuously during development. During post-hatching growth (up to late Stage 2) nitrogen and carbohydrate were laid down faster than triglyceride. The pattern changed during later larval development. The early deposition of protein in preference to neutral fat suggests that conversion of food during growth, without simultaneously laying down fatty energy stores, may be advantageous to pelagic marine fish larvae. During starvation the percentage of water in plaice larvae increased. Triglyceride, carbohydrate, nitrogen and carbon (as a percentage of the dry body weight) decreased during starvation, but ash increased sharply. The continuous use of nitrogen during starvation may be a catabolic adaptation to the marine environment.