Glycolytic capacities depend on developmental stage in the clownfish Amphiprion ocellaris

Abstract

Detailed knowledge about basic metabolism in the early life stages of fishes helps increase our understanding of energetically important life phases. However, little is known about metabolic capacities during ontogenetic development of anemone fishes before and after settlement. This study established activities of 3 key metabolic enzymes—citrate synthase (CS), pyruvate kinase (PK) and lactate dehydrogenase (LDH)—to establish oxidative and glycolytic capacities in eggs, larvae and juveniles of false clownfish Amphiprion ocellaris before and after hatch, and during ontogenetic metamorphosis from the pelagic to sedentary mode of life (settlement stage). Oxidative capacity significantly increased after hatching and remained constant throughout development. Compared to just-hatched larvae (1-2 d old), the glycolytic and fermentative capacities on the contrary were about 2.5- and 2.1-fold higher in pre-settlement (7-8 d old) larvae, respectively, and decreased significantly in post-settlement (15 d old) juveniles. Thus, relative glycolytic enzyme activity ratios verified that settlement-stage anemone fish larvae mostly rely on glycolytic capacities for the burst-swimming capabilities needed during settlement before entering into the benthic mode of life. Intraspecific variances in enzyme activities due to ontogenetic transition should be considered when using key metabolic enzymes as biomarkers for analysing larval physiological status.