EFFECT OF THERMAL STRESS IN GILLS AND MUSCLE OF BLACK CUSK-EEL Genypterus maculatus JUVENILE

The Genypterus genus contains native species of economic relevance with high potential to aquaculture diversification, including the black cusk-eel (Genypterus maculatus), which is distributed on the south Pacific coast of Chile and Peru. Environmental factors such as temperature can generate stress in the native and commercial population, affecting the performance of fish. The objective of this work was to study the effect of heat stress in gills and muscle of black-cusk-eel juveniles.

Black cusk-eel juveniles were collected from CIMARQ and separated in control and stress groups. The stress group was subjected to high-temperature stress (18,5°C) while the control group was maintained at 13°C for five days. At the end of the experiment, fish were euthanized, sampling plasma, gills and skeletal muscle for cortisol level, DNA damage and relative gene expression evaluation through RT-qPCR.

High temperature produces a significant increase in cortisol levels in the stress group (Fig. 1A), generating DNA damage in gills, observed by an increase in the AP sites (Fig. 1B). Additionally, the stressed group presents an up-regulation of heat shock proteins (Fig. 1C y D), oxidative stress (Fig. 1E, F y G) and related to autophagy (Fig. 1H). This study showed that thermal stress can affect different key tissues generating damage and modulating the expression of relevant processes that can affect the performance of black cusk-eel, information that should be considered in a climate change world scenario. Funding: CONICYT FONDECYT Postdoctorado 3180283.