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| Author(s): |
Bruno da Silva
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Botucatu. 2020-03-31. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu |
| Defense date: | 2020-02-28 |
| Advisor: | Igor Paiva Ramos; Cristiéle da Silva Ribeiro |
| Abstract | |
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. (AU) | |
| FAPESP's process: | 18/00281-3 - Cichla kelberi in the Jupiá-SP reservoir: diet, bromatology and parasitological aspects |
| Grantee: | Bruno da Silva |
| Support Opportunities: | Scholarships in Brazil - Master |