Evaluating the Impact of Acute Thermal Stress in GIFT Tilapia Using a Custom-Designed Portable Thermal Aquarium Setup

Abstract

A portable thermal aquarium was custom-designed in this study to assess the physiological response of Genetically Improved Farmed Tilapia (GIFT) to acute thermal stress. The design included a modified aquarium heater and temperature controller unit, equipped with an external temperature sensor. A total of 144 fish (average weight: 27.13 ± 0.19 g) were assigned to three groups, viz., Control (28 °C), and two acute thermal stress exposed group (34 °C and 36 °C), with exposure durations of two and twelve hours (n=4 replicates/group) in temperature-controlled aquariums. The impact of acute thermal stress was assessed by measuring liver metabolism, stress hormones, and enzyme activities. Results revealed significant alterations (p < 0.05) in serum cortisol, T3, and T4 levels in fish exposed to thermal stress. Similarly, liver enzyme activities including SOD, CAT, GPx, GST, and GR, along with the brain AChE activity, were markedly elevated under thermal stress. The portable thermal aquarium designed for this study proved to be cost-effective, versatile, and adaptable to tanks of varying volumes. This study also highlights the importance of simulation studies to understand thermal stress-related perturbations in fish. The use of portable thermal aquariums offers a means to replicate warming scenarios in aquaculture systems.