Some physiological and biochemical considerations of larval development in the American lobster, Homarus Americanus Milne Edwards

Abstract

The weight-specific respiration rates of fed and starved lobsters and the ammonia excretion rates of fed lobsters increased with each larval stage (I through IV) and decreased with the first postlarval stage (V). The rate of change in metabolic rates was greater than the rate of change of body size of the larval stages, indicating an increased energy demand of the later larval stages. There was no significant difference in the O: N ratio for the first three larval stages but a reduction was observed in stage IV and V lobsters, reflecting an increased dependence on protein catabolism for energy. Protein was the principal biochemical constituent of all lobster stages. Significant decreases in lipid content and increases in ash and chitin content of the last larval (IV) and first postlarval (V) stages were detected.