Abstract

The aquaculture industry has many problems associated with bacteria, viruses, and parasites, and the stress caused by these infections can modulate the physiological response in fish. In Chile, the sea lice Caligus rogercresseyi constitutes a major problem affecting the Chilean salmonid industry, having a strong negative effect on salmon production. For this reason, the aim of this study was to investigate the neuroendocrine and stress response of the most commonly cultured salmonid species in Chile, the Atlantic salmon (Salmo salar) and the Coho salmon (Oncorynchus kisutch), which were experimentally infested with the sea lice Caligus rogercresseyi. We analyzed the monoamine response in the telencephalon, optic tectum, and hypothalamus, as well as cortisol levels in plasma. In the liver and muscle we analyzed the cellular response by measuring heat shock proteins (60, 70, 90) and glucocorticoid mRNA transcription. After 14 days post infection C. rogercresseyi infestation modified the neuroendocrine and stress response in Atlantic and Coho salmon, with Coho salmon presenting a faster and higher response than the Atlantic salmon.