Endogenous and environmental factors can influence the lipid contents of fishes among which, in the Amazon River, seasonal dynamics influences stand out. Herein, nine most consumed Amazonian fish species had their lipid composition evaluated in terms of effects of tissue, season and eating habits. Higher amounts of lipids were obtained from fish livers than dorsal muscles. Statistical analysis has shown that Amazonian fishes presented different lipid profiles according to their eating habits, which mainly comprised saturated fatty acids to distinguish detritivorous livers, and linolenic acid, cholesterol, polar lipids for carnivorous and piscivorous fish muscles. Furthermore, in Amazonian fish, some very important lipids for human nutrition were found, such as w-3 and w-6 fatty acids whose availability depended on the tissue metabolism and fishes’ eating habit along with the seasonal periods. For example, our findings indicated that the piscivorous fish C. monoculus presented higher levels of linoleic acid for livers than linolenic acid and the opposite occurred for muscles. The w-6 and w-3 fatty acids ratio was influenced by the season dynamic of the Amazon River and availability of food according to each specific eating habit, pointing mainly to the piscivorous fishes as the healthiest fish for human consumption.

Endogenous and environmental factors can influence the lipid contents of fishes among which, in the Amazon River, seasonal dynamics influences stand out. Herein, nine most consumed Amazonian fish species had their lipid composition evaluated in terms of effects of tissue, season and eating habits. Higher amounts of lipids were obtained from fish livers than dorsal muscles. Statistical analysis has shown that Amazonian fishes presented different lipid profiles according to their eating habits, which mainly comprised saturated fatty acids to distinguish detritivorous livers, and linolenic acid, cholesterol, polar lipids for carnivorous and piscivorous fish muscles. Furthermore, in Amazonian fish, some very important lipids for human nutrition were found, such as w-3 and w-6 fatty acids whose availability depended on the tissue metabolism and fishes’ eating habit along with the seasonal periods. For example, our findings indicated that the piscivorous fish C. monoculus presented higher levels of linoleic acid for livers than linolenic acid and the opposite occurred for muscles. The w-6 and w-3 fatty acids ratio was influenced by the season dynamic of the Amazon River and availability of food according to each specific eating habit, pointing mainly to the piscivorous fishes as the healthiest fish for human consumption.

Hypoptopoma incognitum is a fish of the fifth most species-rich family of vertebrates and abundant in rivers from the Brazilian Amazon. Only two species of Loricariidae fish have their complete mitogenomes sequence deposited in the Genbank. An innovative RNA-based approach was used to assemble the complete mitogenome of H. incognitum with an average coverage depth of 5292×. The typical vertebrate mitochondrial features were found; 22 tRNA genes, two rRNA genes, 13 protein-coding genes, and a non-coding control region. Moreover, the use of this approach allowed the measurement of mtRNA expression levels, the punctuation pattern of editing, and the detection of heteroplasmies.

Hypoptopoma incognitum is a fish of the fifth most species-rich family of vertebrates and abundant in rivers from the Brazilian Amazon. Only two species of Loricariidae fish have their complete mitogenomes sequence deposited in the Genbank. An innovative RNA-based approach was used to assemble the complete mitogenome of H. incognitum with an average coverage depth of 5292×. The typical vertebrate mitochondrial features were found; 22 tRNA genes, two rRNA genes, 13 protein-coding genes, and a non-coding control region. Moreover, the use of this approach allowed the measurement of mtRNA expression levels, the punctuation pattern of editing, and the detection of heteroplasmies.