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Thermal physiology of tropical rock lobster (Panulirus ornatus); defining physiological constraints to high temperature tolerance

Citation

Uy, T and Fitzgibbon, QP and Codabaccus, BM and Smith, GG, Thermal physiology of tropical rock lobster (Panulirus ornatus); defining physiological constraints to high temperature tolerance, Aquaculture, 569 Article 739357. ISSN 0044-8486 (2023) [Refereed Article]

Copyright Statement

2023 Published by Elsevier B.V.

DOI: doi:10.1016/j.aquaculture.2023.739357

Abstract

This study investigated the effect of chronic temperature acclimation (24, 26, 28, 30, and 32C) on growth, aerobic metabolism, feeding, and gut evacuation rate of early juvenile spiny lobster, Panulirus ornatus (initial weight=0.480. 03g) to determine thermal optima for growth and identify physiological constraints at high temperatures for this emerging aquaculture species. Groups of 7 juvenile lobsters were communally cultured (n=4) for 45days post-acclimation and solely fed on a formulated feed. Lobster specific growth rate (SGR), apparent feed intake (AFI), and specific feed consumption (SFC) displayed unimodal response to temperature peaking at 28.0, 27.9, and 26.2C, respectively. Similarly, survival had a significant quadratic relationship with temperature; however, it displayed an inverse relationship to SGR, AFI, and SFC where the lowest survival was found at 29.1C. Continuous exponential increases in lobster standard, routine and maximum metabolic rates, and aerobic scope were observed up to a maximum non-lethal temperature of 32C. Gastrointestinal evacuation rate (GIER) (>96%) increased minimally between 24 and 30C from 2.5h to 2.9h and substantially rose to 5.1h at 32C. While the feed conversion ratio improved with increasing temperature, the temperature optimum for metabolic feeding efficiency closely matched specific growth rate and apparent feed intake. These findings show that optimum temperature for growth performance of juvenile P. ornatus does not align with maximum aerobic scope, rather growth was limited by prolonged GIER (up to 5.1h) at high temperatures 32C which constrained food consumption. These findings contribute to the growing body of literature debating the universality of aerobic scope to define physiological thermal boundaries of aquatic ectotherms suggesting thermal performance of lobsters under sub-lethal temperatures to be regulated by feed intake and driven by digestive processes such as GIER. Future research should focus on lobster feed formulation and its influence on digestive processes such as GIER, foregut evacuation, and digestibility which may influence the thermal tolerance of spiny lobsters in culture.

Item Details

Item Type:Refereed Article
Keywords:thermal tolerance, tropical rock lobster, lobster aquaculture, metabolic rates, aerobic scope, gastrointestinal evacuation
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 rock lobster
UTAS Author:Uy, T (Mr Theodore Uy)
UTAS Author:Fitzgibbon, QP (Associate Professor Quinn Fitzgibbon)
UTAS Author:Codabaccus, BM (Dr Basseer Codabaccus)
UTAS Author:Smith, GG (Professor Gregory Smith)
ID Code:155496
Year Published:2023
Deposited By:Fisheries and Aquaculture
Deposited On:2023-02-23
Last Modified:2023-03-22
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