&lt;b&gt;Dietary lipid sources affect freshwater catfish jundiá, &lt;i&gt;Rhamdia quelen&lt;/i&gt;, survival, when challenged with&lt;i&gt; Aeromonas hydrophila&lt;/i&gt;&lt;/b&gt; - doi: 10.4025/actascianimsci.v35i4.19617

Rodrigo Javier Vargas,José Luiz Mouriño,Geovana Dotta,Débora Machado Fracalossi,Bruno Correia Da Silva

doi:10.4025/actascianimsci.v35i4.19617

Dietary lipid sources affect freshwater catfish jundiá, Rhamdia quelen, survival, when challenged with Aeromonas hydrophila - doi: 10.4025/actascianimsci.v35i4.19617

Rodrigo Javier Vargas, José Luiz Mouriño + Show 3 more

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https://doi.org/10.4025/actascianimsci.v35i4.19617

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Abstract

The immune modulatory activity of diet long chain polyunsaturated fatty acids in fish has been previously demonstrated, although results for freshwater species are controversial. This study evaluates the effect of different dietary lipids on freshwater catfish jundia, Rhamdia quelen, survival and its non-specific response (phagocytosis) after being inoculated with the pathogen Aeromonas hydrophila. Five diets were offered to jundia fingerlings during 150 days prior to challenge: cod liver oil (FO), sunflower oil (SO), linseed oil (LO), canola oil (CO) and coconut oil (CNO). Accumulated mortality was significantly lower in fish fed FO and CNO diets and higher in fish fed LO. In spite of the highest values observed for phagocytotic activity in CNO-fed fish (50.0 + 12.7%) and in FO-fed fish (45.0 + 10.5%) when compared to those fed other diets, no significant differences in phagocytosis were reported. Results show the relevance of a balanced dietary lipid source with adequate concentrations of n-3 and n-6 series of fatty acids to prevent mortality after pathogen challenge.

Highlights

Teleost fishes occupy a key evolutionary position in the development of innate and adaptive immune responses since they are the earliest class of vertebrates with innate and adaptive immunity (WHYTE, 2007)
This study evaluates jundiá survival and a non-specific immune response to dietary lipid sources after being inoculated with A. hydrophila
Phagocytotic and un-phagocytotic leukocytes were counted under the microscope and phagocytosis percentage was calculated by the equation below: Diets and liver of three fish per experimental unit were pooled for lipid and fatty acid analyses

Summary

Introduction

Teleost fishes occupy a key evolutionary position in the development of innate and adaptive immune responses since they are the earliest class of vertebrates with innate and adaptive immunity (WHYTE, 2007). The stimulation or inhibition of the immune system by dietary fatty acids in freshwater fish depends directly on the quantity and quality of the dietary fatty acids and on their ratio, such as EPA: ARA ratio (LIN; SHIAU, 2003). This fact complicates mechanism elucidation and generates contradictory results since they depend on which fatty acids or fatty acid ratios are to be taken into account and which immune responses are to be measured. This study evaluates jundiá survival and a non-specific immune response to dietary lipid sources after being inoculated with A. hydrophila

Material and methods

Results and discussion

Conclusion