Jackson Pantoja-Lima

Aquaculture faces challenges in reducing feed costs while promoting sustainable use of by-products. This study aimed to evaluate the effects of totally replacing soybean oil (SBO) with fish by-product oil (FBO) in the diet of Colossoma macropomum, focusing on growth performance, physiological and hepatic responses, meat composition, and economic viability. A total of 360 juveniles (9.1 ± 0.59) were distributed in a randomized design with six treatments (0–100% SBO replacement) and six replicates each, and fed to apparent satiation for 91 days. Growth performance did not differ significantly among treatments (p > 0.05), although fish receiving 40% FBO achieved the best feed conversion ratio among treatments. Hematological and biochemical analyses indicated that higher FBO levels (particularly 100%) indicating subtle yet adaptive physiological adjustments, such as moderate modulations in lipid metabolism and erythropoietic activity. Liver weight and hepatosomatic index decreased linearly with increasing FBO levels. In meat composition, FBO inclusion enhanced protein and reduced lipid contents. Although economic indicators were not statistically different (p > 0.05), offered the most favorable trade-off between biological performance and economic efficiency. These findings demonstrate that partial replacement of SBO with FBO, particularly at 40%, represents a sustainable and economically viable alternative for C. macropomum farming.

A aquicultura cresceu significativamente nas últimas décadas e a profissionalização da atividade demanda maior precisão no planejamento e monitoramento das áreas produtivas. Nesse contexto, as geotecnologias tornam-se ferramentas fundamentais, proporcionando dados geoespaciais precisos para o licenciamento ambiental e a gestão eficiente dos empreendimentos. Esta revisão apresenta os principais equipamentos e tecnologias utilizados na medição e no georreferenciamento em aquicultura, como GPS (Global Positioning System), receptores GNSS RTK (Global Navigation Satellite System - Real-Time Kinematic), estações totais, drones e aplicativos móveis. A evolução das técnicas de medição é abordada, destacando sua relevância desde as civilizações antigas até as inovações atuais. Dos equipamentos atuais, o GNSS RTK é recomendado por profissionais pela precisão do posicionamento por satélite de metros para centímetros, permitindo a realização de trabalhos de alta exatidão em tempo real. As aplicações práticas e os benefícios dessas tecnologias são discutidos, bem como suas limitações e perspectivas futuras. Por fim, conclui-se que a integração de geotecnologias com sistemas digitais, inteligência artificial e sensoriamento remoto podem promover o avanço da aquicultura sustentável, possibilitando maior controle, eficiência e tomada de decisão baseada em dados precisos.

A 52-day experiment was conducted to determine the effect of varying dietary protein levels on juvenile matrinxã Brycon amazonicus, and to evaluate their resulting growth performance, hematological parameters and enzymatic activities. Sixty fish (29.03 ± 1.16g) were distributed in 12 tanks (310 L) with a completely randomized design, and maintained at four dietary crude protein levels (270, 320, 350, 390 g.kg-1 ). The results revealed that the fish fed diet 390 g.kg-1 CP had the best final weight, weight gain, feed conversion ratio, specific growth rate, protein efficiency ratio and lipid retention rate. The same could be stated for hematocrit, number of circulating erythrocytes, triglycerides and total proteins of the hematological profile (p0.05). In short, our findings suggest that 390 g/kg-1 CP in diet increases zootechnical performance indices in juvenile matrinxã.

The objective of this study was to evaluate the zootechnical performance of tambaqui (Colossoma macropomum) for fattening (> 2 kg) under three management strategies on nine fish farms, which were equally distributed as follows: Low Productive Efficiency (LPE) – 6-8 tons year^-1 without aeration; Medium Productive Efficiency (MPE) – 9-14 tons year^-1 with emergency aeration and High Productive Efficiency (HPE) – 15-22 tons year^-1 with supplemental aeration. Tank management data were collected and water quality parameters were monitored. Performance indices were evaluated through monthly biometrics until the end of the cycle; growth curves (von Bertalanffy) and instantaneous growth rate (IGR) were also calculated for comparison. Analysis of variance was applied to test the effect of the productive efficiency of the models on zootechnical performance. There was a difference (p-1), pH (6.51-6.77), temperature (31.12-33.81 °C), conductivity (43.37-55.63 µS cm^-1), transparency (23.04-26.92 cm), nitrite (0.06-0.08 mg L^-1) and nitrate (0.36-0.42 mg L^-1) were within the cultivation standards. Phosphorus (0.37-0.48 mg L^-1) and TSS (65.85-91.12 mg L^-1) parameters suggest higher nutrient loads promoted by high densities. Differences between systems (pHPE in final weight (2,726.53 ± 136.99 g), weight gain (2,719.98 ± 133.84 g) and apparent feed conversion (1.82 ± 0.02). The growth curves and IGR revealed differences in performances, indicating that production strategies alter the way fish grow. Systems with higher productivity demonstrate, based on their better results, greater care in the management.

The environmental impacts caused by fish farming can lead to changes in aquatic ecosystems, especially in fish communities. In this study, we investigated possible changes in water quality, in the number of species and individuals of the same species caused by the construction of fish nurseries in dammed Amazonian streams. For this purpose, four streams located in the municipalities of Novo Airão and Presidente Figueiredo were selected. Samples were collected in streams without fish farming and in streams with stretches used for fish farming, where collections took place both downstream and upstream. The fish were captured, identified, quantified and the water was collected for physical and chemical analyses, in addition to the environmental characterization that was carried out. Comparisons were made using fish richness and abundance indices between the sampled points and correspondence analysis of the species identified at the collection sites, using the Mantel test and principal component analysis (PCA) for the environmental characteristics of the water and variables physical and chemical, and permutational multivariate analysis of variance (PERMANOVA) to verify the possible effects of species composition on the sampled conditions and on the analyzed environmental variables. In total, 2,302 fish belonging to 53 species, 15 families and six orders were found. We conclude that the Amazonian streams dammed for fish farming, under the analyzed conditions, can be characterized as environments with different and specific levels of richness and abundance, however, the data set analyzed in this study did not show that these characteristics are directly related to productive activity. We recommend that further studies be carried out following the current research.

Context: Waterfalls and rapids of Amazon basin have been suggested as causing the speciation and genetic structure of many freshwater species, including turtles. The species behavior affects the way waterfalls and rapids limit gene flow. The Yellow-spotted River Turtle ( Podocnemis unifilis ), a widely distributed and endangered Amazonian turtle, does not show the habit to migrate long distances for breeding or eating, but has a complex geographic pattern of genetic variation. Objectives: Here, we investigate isolation by distance and by resistance of P. unifilis . We analyzed if the species ecological niche and waterfalls explain the genetic distance in Brazilian Amazonia. Methods: We evaluated the P. unifilis spatial distribution of genetic variability and diversity using the control region of mitochondrial DNA. We tested the hypotheses of isolation either by distance and resistance through an integrative approach using genetic, geographic, and ecological data. We created a resistance matrix using species niche modeling. We compared the explanation power of geographical distance (both linear and in-water distance) and resistance distance on genetic distance (ΦST fixation index) using multiple regressions and Mantel tests. Results: We found a high genetic diversity and pattern of genetic structure proved to be geographically complex. The population structure followed some watersheds but also showed structuring within different rivers. We found that landscape resistance better explains genetic distance than linear and in-water distance. Conclusions: The resistance of the landscape influences the displacement of individuals by aquatic, vegetational, biological, and geomorphological variables, and efforts to species conservation need to be applied throughout its distribution considering landscape genetics.

The present study objectified to evaluate the trophic relationships and the possible aggressive mimicry involving Carnegiella strigata, Carnegiella marthae and Gnathocharax steindachneri, in lowland forest streams. Samplings occurred in November 2002, March and August 2003 in Amanã Sustainable Development Reserve (ASDR). The total of 943 fish was caught, being 79.43% of C. marthae, 3.18% of C. strigata and 17.39% of G. steindachneri. Stomach contents, degree of stomach repletion, relative volume and frequency of occurrence of food items were evaluated. Thirteen food items were identified, and the presence of terrestrial and aquatic insects indicates the high dependence of these species and the flooded forest. Low feeding overlap was observed between Carnegiella strigata and C. marthae compared to Gnathocharax steindachneri. However, the overlap between the two Carnegiella species was relatively high, which could explain the low frequency of syntopic occurrence among these species, suggesting a possible case of competitive exclusion.

Lysine effect on the characterization of fillet, by-products, residues, and morphometry of tambaqui Colossoma macropomum (Cuvier, 1818)

Background: The capture of ornamental fish is one of the main economic activities of riverine families in the Amazon. However, studies regarding the local ecological knowledge of workers in this activity are still incipient. In view of this, we have studied and explored the local ecological knowledge of artisanal fishers who specialize in the capture of fish for the aquarium trade in the middle part of the Negro River basin and investigated issues related to the ecological aspects of the fish species that are targeted by this trade in the region. Methods: Therefore, we conducted semi-structured interviews and applied questionnaires to artisanal fishers of ornamental fish (N = 89), from the municipality of Barcelos, from January to April 2016. Results: In total, 41 popular names were cited, which correspond to four ethnocategories and 10 families. The main species were Paracheirodon axelrodi (12.5%), Hemigrammus bleheri (8.3%), Ancistrus dolichopterus (6.4%), Symphysodon discus (5.3%), and Potamotrygon motoro (3.8%). According to the fishers, the species of fish known in the region as “piabas” have a preference for living in clusters (28.9%) and carry out migratory movements (26.1%). The diet of local fish species reported by fisheries is diverse, though mainly based on periphyton (42.2%), and the reproductive cycle directly influenced by the period of flooding of rivers in the region (37.6%) Conclusion: Our study revealed that the fishers possess information on the ecological aspects of local ornamental fish species, many of which are consistent with scientific literature. The information presented may assist in the decision-making process for the management of local fishery resources and contribute to the resumption of growth and sustainability in the capture of ornamental fish.