Cichla kelberi no reservatório de jupiá-sp: dieta, bromatologia e aspectos parasitológicos
Data
2020-02-28
Autores
Silva, Bruno da
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Universidade Estadual Paulista (Unesp)
Resumo
Cichla kelberi é uma espécie de peixe nativa da bacia hidrográfica do rio Amazonas e Tocantins-Araguaia e introduzida no reservatório de Jupiá, alto rio Paraná, Brasil. Sua introdução proporcionou a pesca esportiva e comercial da espécie nesse reservatório, pois apresenta tecido muscular com características organoléticas (odor, sabor, textura e cor) apreciadas pela população, tornando-se um importante recurso pesqueiro nessa região. Cichla kelberi é considerada uma espécie carnívora/piscívora na maioria dos reservatórios em que ocorre, porém, também é caracterizada por apresentar plasticidade alimentar, uma característica peculiar a um animal topo de cadeia alimentar, o que pode ser acentuada com as variações sazonais, contribuindo com seu sucesso nos reservatórios. Diante das possíveis alterações na dieta, C. kelberi pode sofrer modificações metabólicas em períodos específicos do ano, e ter sua composição bromatológica e perfil de ácidos graxos (FAs) teciduais (fígado e músculo) alterados. Além disso, aspectos parasitários também são fortemente importantes para sanidade do pescado e qualidade alimentar. Assim, investigamos as seguintes hipóteses: 1) C. kelberi apresenta plasticidade alimentar no reservatório de Jupiá, alto rio Paraná, Brasil, a qual influencia o perfil de FA no tecido hepático nos períodos chuvoso e seco; 2) há diferença na qualidade química (composição bromatológica e perfil de FAs) e parasitológica do tecido muscular de C. kelberi, entre os períodos chuvoso e seco, sendo considerado adequado para o consumo humano. A dieta de 25 espécimes por coleta (estação seca e chuvosa) foi analisada pelo método gravimétrico, sendo observadas diferenças significativas entre os períodos chuvoso e seco (Permanova one-way), para amplitude de nicho trófico e variabilidade individual (PERMDISP). Os itens mais importantes para tais diferenças foram Macrobrachium sp. e fragmentos de peixe, com maior variedade de itens alimentares observada no período chuvoso, sugerindo que a espécie seja carnívora/carcinófaga. Foram analisados por cromatografia gasosa o perfil de ácidos graxos dos tecidos hepático e muscular, do conteúdo estomacal e de Macrobrachium sp.. A alteração na dieta entre os períodos pode ter causado à diferenciação do perfil de ácidos graxos hepático e muscular, com grande contribuição de C22:6n3 (DHA, ácido docosahexaenoico), C20:5n3 (EPA, ácido eicosapentaenoico) e C20:4n6 (ARA, ácido araquidônico), com a participação de ácidos graxos de origem vegetal, como C18:2n6 e C18:3n3. Foi caracterizada a composição bromatológica do tecido muscular, não sendo observada diferença significativa entre períodos de coleta, com composição bromatológica esperada para espécies carnívoras. A inspeção realizada por meio de mesa transparente com luz para visualização de cistos parasitários não encontrou larvas encistadas no tecido muscular, concluindo que a espécie apresenta qualidade química e é segura para o consumo humano do ponto de vista parasitológico no reservatório de Jupiá, alto rio Paraná, Brasil. Além disso, os resultados aqui apresentados demonstram que C. kelberi consegue se manter estável m e que a plasticidade alimentar pode ser essencial para seu sucesso nos reservatórios.
Cichla kelberi is a native fish to the basin of the Amazon River and Tocantins-Araguaia and was introduced in the Jupiá Reservoir, upper Paraná River, Brazil. The introduction provided sport and commercial fishing of the species in this reservoir, because of organoleptic characteristics, including flavor, texture and color present on the muscular tissue that is appreciable by the population, becoming an important fishing resource in this region. Cichla kelberi is considered a carnivorous/piscivorous species in most of the reservoirs in which it occurs. However, it is characterized by presenting food plasticity, a characteristic peculiar to a carnivorous animal in the food chain, which can be accentuated with seasonal variations, contributing to its success in the reservoirs. According to possible changes in the diet, C. kelberi may undergo metabolic changes at specific season year and have its chemical composition and tissue fatty acid (FA) profile (liver and muscle) altered. Furthermore, parasitic aspects are also important for fish health and food quality. Thus, we investigate the following hypotheses: 1) C. kelberi presents food plasticity in the Jupiá Reservoir, upper Paraná River, Brazil, which influences the FA profile in liver tissue in the rainy and dry periods; 2) There is a difference in the chemical quality (chemical composition and FA profile) and parasitological quality of the muscle tissue of C. kelberi, between the rainy and dry periods, being appropriated for human consumption. The diet of 25 specimens per collection (rainy and dry season) was analyzed by the gravimetric method, with significant difference between rainy and dry periods (Permanova one-way), for trophic niche amplitude and individual variability (PERMDISP). The most important items for such differences were Macrobrachium sp. and fish fragments, with a greater variety of food items observed in the rainy season, suggesting that the species is carnivorous/carcinophagous. The fatty acid profile of the liver and muscle tissues, stomach contents and Macrobrachium sp. were analyzed by gas chromatography. The change in diet between periods may cause differentiation on the liver and muscle fatty acid profile, with large contribution of C22:6n3 (DHA, docosahexaenoic acid), C20:5n3 (EPA, eicosapentaenoic acid) and C20:4n6 (ARA, arachidonic acid), with participation of fatty acids of vegetable origin, such as C18:2n6 and C18:3n3. The chemical composition of muscle tissue was characterized, with no significant difference between periods, with expected chemical composition for carnivorous species. The inspection carried out by means of a transparent table with light to view parasitic cysts did not find larvae encysted in the muscle tissue, concluding that the species has chemical quality and is safe for human consumption from the parasitological viewpoint in the Jupiá Reservoir. In addition, the results presented here demonstrate that C. kelberi is endogenously stable and that food plasticity may be essential for success in reservoirs.
Cichla kelberi is a native fish to the basin of the Amazon River and Tocantins-Araguaia and was introduced in the Jupiá Reservoir, upper Paraná River, Brazil. The introduction provided sport and commercial fishing of the species in this reservoir, because of organoleptic characteristics, including flavor, texture and color present on the muscular tissue that is appreciable by the population, becoming an important fishing resource in this region. Cichla kelberi is considered a carnivorous/piscivorous species in most of the reservoirs in which it occurs. However, it is characterized by presenting food plasticity, a characteristic peculiar to a carnivorous animal in the food chain, which can be accentuated with seasonal variations, contributing to its success in the reservoirs. According to possible changes in the diet, C. kelberi may undergo metabolic changes at specific season year and have its chemical composition and tissue fatty acid (FA) profile (liver and muscle) altered. Furthermore, parasitic aspects are also important for fish health and food quality. Thus, we investigate the following hypotheses: 1) C. kelberi presents food plasticity in the Jupiá Reservoir, upper Paraná River, Brazil, which influences the FA profile in liver tissue in the rainy and dry periods; 2) There is a difference in the chemical quality (chemical composition and FA profile) and parasitological quality of the muscle tissue of C. kelberi, between the rainy and dry periods, being appropriated for human consumption. The diet of 25 specimens per collection (rainy and dry season) was analyzed by the gravimetric method, with significant difference between rainy and dry periods (Permanova one-way), for trophic niche amplitude and individual variability (PERMDISP). The most important items for such differences were Macrobrachium sp. and fish fragments, with a greater variety of food items observed in the rainy season, suggesting that the species is carnivorous/carcinophagous. The fatty acid profile of the liver and muscle tissues, stomach contents and Macrobrachium sp. were analyzed by gas chromatography. The change in diet between periods may cause differentiation on the liver and muscle fatty acid profile, with large contribution of C22:6n3 (DHA, docosahexaenoic acid), C20:5n3 (EPA, eicosapentaenoic acid) and C20:4n6 (ARA, arachidonic acid), with participation of fatty acids of vegetable origin, such as C18:2n6 and C18:3n3. The chemical composition of muscle tissue was characterized, with no significant difference between periods, with expected chemical composition for carnivorous species. The inspection carried out by means of a transparent table with light to view parasitic cysts did not find larvae encysted in the muscle tissue, concluding that the species has chemical quality and is safe for human consumption from the parasitological viewpoint in the Jupiá Reservoir. In addition, the results presented here demonstrate that C. kelberi is endogenously stable and that food plasticity may be essential for success in reservoirs.
Descrição
Palavras-chave
Influência sazonal, Plasticidade alimentar, Qualidade de tecido muscular, Transferência trófica, Perfil de ácidos graxos, Tucunaré amarelo, Seasonal influence, Food plasticity, Muscle tissue quality, Trophic transfer, Fatty acid profile, Yellow peacock bass