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 glyco lytic 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.

Evolution, Development and Ecology of Anemonefishes

“…In the natural environment, metamorphosis is associated with an environmental change; anemonefish larvae actively swimming in the open ocean adopt a sedentary lifestyle when they settle in their sea anemone host. This change of behavior seems associated with metabolic changes as observed by Paul and Kunzmann (2019) who noticed changes in the enzymatic activities of aerobic and anaerobic metabolism during A. ocellaris metamorphosis which could be explained by this change in swimming activities. Such metabolic changes often occur during teleost metamorphosis (Darias et al 2008;Ferraresso et al 2013).…”