title: Fatty Acid Composition of Tropical Fish Depends on Reservoir Trophic Status and Fish Feeding Habit.
abstract: Eutrophication results in a deficiency of n-3 LC-PUFA (long-chain polyunsaturated fatty acids) in aquatic food chains, affecting fish nutrition and physiology. The trophic transfer of FA (fatty acids) to fish species of different feeding habits was investigated in two reservoirs in southeast Brazil-the mesotrophic Ponte Nova Reservoir (PN) and the hypereutrophic Billings Reservoir (Bil). Total FA profile of stomach contents and adipose tissue, triacylglycerols (TAG), and phospholipids (PL) from liver and muscle of the omnivorous Astyanax fasciatus and the carnivorous Hoplias malabaricus were analyzed by gas chromatography. A prevalence of n-6PUFA, as 18:2n-6 (linoleic acid) and 20:4n-6 (arachidonic acid, ARA) was observed in the stomach contents and in the tissues of A. fasciatus from the PN reservoir. In contrast, n-3 LC-PUFA, as 20:5n-3 (eicosapentaenoic acid, EPA) was accumulated in fish tissues from Bil, resulting in higher n3/n6 and EPA/ARA ratios, compared to fish from PN. This differential FA accumulation was also observed for H. malabaricus, but differences were slightly minor, and no changes were observed in the EPA/ARA ratios between fish from both reservoirs. Regardless reservoir, FA profiles of TAG resembled that of their diet, whereas FA profiles of PL were more conservative and mainly comprised by LC-PUFA. We conclude that reservoir trophic status affected the FA composition of food resources available to these fish species, resulting in differential allocation of n-3 and n-6 FA. As expected, FA profile of the investigated fish species also reflected their feeding habit and physiological demands.
authors.affiliation: Departamento de Fisiologia do Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Trav. 14, 321, São Paulo, SP, 05508-090, Brazil. eniladal@gmail.com.
authors.forename: Aline D
authors.initials: AD
authors.lastname: Gomes
authors.affiliation: Departamento de Fisiologia do Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Trav. 14, 321, São Paulo, SP, 05508-090, Brazil.
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Tolussi
authors.affiliation: Departamento de Geociências, Universidade Federal de São João Del Rei, São João Del Rei, MG, Brazil.
authors.forename: Iola G
authors.initials: IG
authors.lastname: Boëchat
authors.affiliation: Departamento de Ecologia do Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Marcelo L M
authors.initials: MLM
authors.lastname: Pompêo
authors.affiliation: Departamento de Ecologia do Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Maíra P T
authors.initials: MPT
authors.lastname: Cortez
authors.affiliation: Departamento de Fisiologia do Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Trav. 14, 321, São Paulo, SP, 05508-090, Brazil.
authors.forename: Renato M
authors.initials: RM
authors.lastname: Honji
authors.affiliation: Departamento de Fisiologia do Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Trav. 14, 321, São Paulo, SP, 05508-090, Brazil.
authors.forename: Renata G
authors.initials: RG
authors.lastname: Moreira
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry; D000818:Animals; D001938:Brazil; D060125:Characiformes / Q000378:metabolism / Q000502:physiology*; D017753:Ecosystem; D005227:Fatty Acids / Q000032:analysis*; D005247:Feeding Behavior; D005398:Fisheries; D005766:Gastrointestinal Contents / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D018482:Muscle, Skeletal / Q000378:metabolism
chemical_list: D005227:Fatty Acids
keywords: Eutrophication; Feeding habit; Food chain; Polyunsaturated fatty acids