Asian sea bass or barramundi (Lates calcarifer) performs optimally over a wide temperature range and also maintains high levels of growth performance outside of its optimum range. Limiting environmental conditions, particularly those imposed by sub-optimum temperatures test the adequacy of nutrient supply and the efficiency of growth. Consequently, Asian sea bass provides a model species with which to study how environmental factors affect growth processes. Protein metabolism was investigated in detail: protein synthesis was modeled in relation to temperature and nutritional factors such as time after feeding, dietary protein content and protein source. Daily rates of protein synthesis were related to changes in protein degradation, investigation of autophagic-lysosomal and ubiquitin-proteasome protein degradation pathways showed a significant increased gene expression of Cathepsin D but no other significant changes. Combining data from a series of experiments highlight mechanisms underlying changes in growth performance at extreme temperatures and suggested an increase in the use of dietary amino acids for energy and increased metabolism via deamination and excretion. The use of model species to study nutritional physiology and implications for understanding possible impacts of climate change will be discussed further.

Item Type:	Conference Extract
Research Division:	Agricultural, Veterinary and Food Sciences
Research Group:	Fisheries sciences
Research Field:	Aquaculture
Objective Division:	Animal Production and Animal Primary Products
Objective Group:	Fisheries - aquaculture
Objective Field:	Aquaculture fin fish (excl. tuna)
UTAS Author:	Carter, CG (Professor Chris Carter)
UTAS Author:	Bridle, AR (Associate Professor Andrew Bridle)
UTAS Author:	Katersky, RS (Dr Robin Katersky Barnes)
ID Code:	53331
Year Published:	2008
Deposited By:	NC Marine Conservation and Resource Sustainability
Deposited On:	2008-11-26
Last Modified:	2008-12-16
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