Application of a stoichiometric bioenergetic approach and whole-body protein synthesis to the nutritional assessment of juvenile Thenus australiensis

• Published in: Scientific reports Vol. 13; no. 1; p. 14378
• Main Authors: Williamson, Andrea, Carter, Chris G., Basseer Codabaccus, M., Fitzgibbon, Quinn P., Smith, Gregory G.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-09-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 631/443/1784; 631/443/319; 631/601/1737; Bioenergetics; Carbohydrates; Crustaceans; Decapoda; Dissolved inorganic carbon; Energy metabolism; Energy resources; Feeding; Humanities and Social Sciences; Lipids; Metabolism; multidisciplinary; Nutrition assessment; Oxygen; Oxygen consumption; Oxygen uptake; Protein biosynthesis; Protein synthesis; Protein turnover; Proteins; Science; Science (multidisciplinary); Shellfish; Stochastic models; Stochasticity; Thenus
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-41070-z

The present study successfully combined a stoichiometric bioenergetic approach with an endpoint stochastic model to simultaneously determine specific dynamic action, metabolic substrate use and whole-body protein synthesis in juvenile slipper lobster
Thenus australiensis
. Juvenile lobsters were fasted for 48 h to investigate routine metabolism before receiving a single meal of formulated feed containing 1%
15
N-labeled Spirulina. Postprandial oxygen consumption rate, dissolved inorganic carbon, and total nitrogen excretion returned to the pre-feeding level within 24 h. The rate of whole-body protein synthesis was 0.76 ± 0.15 mg CP g
−1
day
−1
, with a significant reduction from 24 to 48 h post-feeding. The postprandial increase in whole-body protein synthesis accounted for 13–19% of total oxygen uptake. Protein was the primary energy substrate for 48 h fasted (45% oxygen consumption) and post-feeding lobster (44%), suggesting that dietary protein was not efficiently used for growth. The secondary energy substrate differed between carbohydrates in 48 h fasted and lipids in post-feeding lobsters. The present study recommends integrating protein synthesis into protein requirement experiments of marine ectotherms to acquire a more comprehensive picture of protein and energy metabolism and nutritional physiology crucial for formulating cost-effective aquafeeds.