The objective of this study was to evaluate meat yield and centesimal composition of the Amazonian fish species, A. ocellatus, P. castelnaeana, and L. friderici, in the dry and flood seasonal cycles of rivers. In each seasonal cycle (flood and dry), a total of 60 fish were collected, comprising 20 specimens of each of the following species: A. ocellatus, P. castelnaeana, and L. friderici. Were evaluated the meat yield, cuts yield and centesimal composition of the fish samples. Meat yield in the clean body cuts and skinless filet varied between species and hydrological period. The results showed that seasonal variation influenced the centesimal composition and yield of the species studied, with significant differences between the cuts produced during processing. These findings highlight the need to apply a variety of technological processes to ensure efficient use of these species throughout the year. The total waste represented more than 50% of the whole fish, and the head size was directly proportional to the amount of waste generated. These results underscore the importance of waste utilization for animal and/or human nutrition.

Fish processing provides waste of around 50.0% to 70.0% of the animal's initial weight, especially the skin. Thus, this residue contains the by-product that allows biopolymers to be obtained, highlighting collagen, which can be widely used in different areas. The present study aimed to evaluate the yield of collagen extracted from peacock bass Cichla monoculus skin and to characterize them physicochemically. Twenty-five peacock bass with an average weight of 646 ± 175 g were used. The skin samples were removed by manual filleting and weighed, with an average yield of 3.7%. Subsequently, such models were analyzed for chemical composition, showing 61.8% for moisture, 29.3% for crude protein, 1.5% for ash, 6.3% for total lipids, and 1.2% for non-nitrogenous extract (NNE). Acid-soluble collagen (ASC) presented an average yield of 8.2%, presenting in its analysis of centesimal composition 12.5% ​​of moisture, 82.6% of crude protein, 1.1% of ash, 2.6% of total lipids, and 1.2% NNE. The skin and collagen extracted from the tucunaré skin have technological potential for use in the preparation of products, adding value to these by-products from fish processing.

The tambaqui Colossoma macropomum is the main species of edible fish originating from fish farming in the Amazon region. This study aimed to determine and compare the hematological and biochemical parameters of tambaqui from fish farms in municipalities in the Metropolitan Region of Manaus, Amazonas, Brazil. Two fish farms were sampled in a semi-excavated pond-type breeding system in each of the five towns investigated (Presidente Figueiredo, Manaus, Iranduba, Manacapuru and Novo Airão), totaling ten breeders. On each farm, ten specimens were captured, totaling 100 animals. Blood was collected by caudal puncture, and hematological and biochemical parameters were determined using the methodology described for teleosts fish. For the erythrogram in the variables of hematocrit, hemoglobin concentration and erythrocytes, significant differences were observed in Iranduba and Novo Airão, demonstrating indications of anemic processes and dehydration. For plasma biochemistry, low levels were observed in fish from Iranduba and Novo Airão. High values in lipid compounds were found in tambaqui from Manacapuru. High intraspecific variation was found in the leukogram and thrombogram, which determined similarities between tambaqui from different farms and municipalities. On the other hand, fish from Manacapuru have an inappropriate diet, indicated by the high levels of cholesterol and triglycerides found in the blood.

A elevada diversidade de peixes amazônicos, aliada à crescente demanda por aproveitamento integral dos recursos pesqueiros e redução de resíduos, reforça a necessidade de estudos que subsidiem o uso sustentável dessas espécies. Nesse contexto, o presente estudo avaliou os rendimentos cárneos e de subprodutos de 14 espécies de peixes Siluriformes comercializadas no Estado do Amazonas, considerando a influência da sazonalidade (cheia e seca). O delineamento experimental foi inteiramente casualizado, em esquema fatorial (14×2), com 10 repetições por tratamento, totalizando 280 espécimes. Observou-se efeito significativo (p<0,05) da estação sobre o peso médio, sendo superior na cheia. A Pirarara destacou-se como a espécie mais pesada na cheia, enquanto a Dourada apresentou maior peso na seca. Os rendimentos de peixe eviscerado foram superiores (p<0,05) para Babão, Piracatinga e Caparari na cheia, e para Babão, Piracatinga e Bagre zebra na seca. De modo geral, a maioria das espécies apresentou maior (p0,05) os rendimentos sem pele. A Pirarara apresentou maiores (p<0,05) proporções de cabeça e vísceras, principalmente na cheia. De forma geral, espécies como Jaú, Jandiá e Mapará apresentaram maiores rendimentos de carcaça na estação seca. Os resultados evidenciam a influência dos ciclos hidrológicos sobre a composição corporal e o aproveitamento industrial dessas espécies, contribuindo para estratégias de processamento mais eficientes e sustentáveis na cadeia produtiva do pescado amazônico.