The nursery phase in tilapia using biofloc technology is important as it increases the predictability of production. However, none studies evaluating the stocking densities of tilapia focused only on the use of an inorganic carbon source to promote the nitrification process as the main way to control nitrogen in the system. This study aimed to evaluate the effect of varied nursery stocking densities, in a chemoautotrophic biofloc system, on water quality, zootechnical parameters, and health of Nile tilapia (Oreochromis niloticus). Fifteen tanks (100 L capacity) containing heaters (28 ±1°C) inoculated with mature bioflocs were used. Seven hundred and fifty tilapia fingerlings (weighing 0.66 ±0.17 g) were distributed in the tanks, in triplicate, so that the densities in the tanks reached 200, 350, 500, 650, and 800 fish m-3. Dissolved oxygen and tilapia growth showed a negative linear relationship with fish density. A positive linear relationship with density was observed for nitrogen compounds, alkalinity, suspended solids, yield, and feed conversion. However, the water quality parameters were appropriate for tilapia and allowed good zootechnical performance irrespective of the fish density. Hematological parameters, fish survival, and uniformity in growth did not alter with densities. Total suspended solids produced by fish biomass showed a quadratic relationship with density, with the highest efficiency of the tanks stocked with 406 fish m-3. It is possible to construct a tilapia nursery in chemoautotrophic biofloc systems with densities reaching up to 800 fish m-3 and yield exceeding 12 kg m-3. But the density of 406 fish m-3 had a better efficiency in solid production by biomass.

Nile tilapia (Oreochromis niloticus) has an opportunistic omnivorous feeding behavior and studies have demonstrated the consumption of microorganisms by the species from bioflocs, especially in the early phases of life. One may thus assume that when reared in biofloc systems, there may be a reduction in the feeding rates in the Nile tilapia nursery system when compared to the ponds. This study evaluated the effects of different feeding management options in Nile tilapia nurseries in a biofloc system. A total of 700 fingerlings (2.37 ± 0.55 g) were stocked in 20 experimental units (100 L) and inoculated with mature biofloc for the evaluation of five different feeding management options. After 49 days, it was observed that the higher feed rates caused an increase in nitrogen compounds and solids in the water, worsening the feed conversion rate. Furthermore, the excess feed supplied to the tilapia in the biofloc caused a reduction in the utilization of protein nitrogen, an increase in the liver and visceral fat, in addition to an increase in the production of solids and consumption of alkalinizer by fish biomass. On the other hand, low feeding rates cause a decrease in the growth and uniformity of the tilapia juveniles. Taking the results into consideration, it is recommended to use the feed management option proposed in treatment TC (26% below the highest feed rate) in the tilapia nursery in the biofloc system.

This study evaluated the technical and economic feasibility of the biofloc technology (BFT) system during the fry rearing phase of Nile tilapia (Oreochromis niloticus), focusing on suspended solids management, stocking density, and economic performance at a pilot scale. Three trials were conducted. The first assessed the effects of four total suspended solids (TSS) ranges (0–200, 200–400, 400–600, and 600–800 mg·L⁻¹) on larval performance and water quality. TSS levels between 200 and 600 mg·L⁻¹ promoted improved water quality and zootechnical performance. The second trial tested five stocking densities (2, 4, 6, 8, and 10 larvae·L⁻¹), evaluating their impact on water quality, survival, and size uniformity. Higher densities negatively affected survival (R² = 0.84) and final weight (R² = 0.92), while also increasing solids and nitrogenous compounds, thus impairing performance (p < 0.05). The third trial monitored six production cycles at pilot scale, evaluating zootechnical parameters, sex reversal efficiency, and economic indicators. All cycles showed survival rates above 85%, sex reversal close to 100%, and positive net margins (18.5 to 41.9%), demonstrating the viability of BFT for commercial fry operations. The results emphasize the importance of controlling suspended solids and stocking density to maintain water quality and optimize larval performance. Furthermore, the system proved economically viable, with good feed conversion rates and profitability, even without water exchange. These findings support BFT as a sustainable and efficient alternative for tilapia fry production, offering significant water savings and promising economic returns when properly managed.

This study evaluated the zootechnical performance, cost per kilogram of fish produced and hematological parameters of yellowtail lambari (A. bimaculatus) fed different diets. The diets comprised four treatments: formulated powdered diet with premix (A); formulated powdered diet without premix (B); commercial powdered diet (C) and commercial powdered diet until the fish reached an average weight of 3 g, after which a 1.5 mm extruded commercial diet was fed (D). The fish were fed for 54 days. Diet D resulted in fish with a higher average final weight, weight gain and yield, with a reduction in apparent feed conversion. There was no difference between the treatments in terms of survival before and after purification, carcass yield and hematological parameters of the lambari. However, the cost of the diet per kilo of fish for diet D was higher (R$2.57 per kg) than for diet B (R$1.77 per kg). According to the data obtained in this study, it is possible to provide a formulated diet without harming the growth of the species; however, it may be interesting to combine it with the provision of an extruded diet for fish of at least 3g, to reduce rearing time in excavated ponds.

O expressivo crescimento da tilapicultura tem sido observado nos últimos anos, e isto só é possível com aumento da produção de alevinos, que é a base da cadeia produtiva. As metodologias de manejo reprodutivo e produção de alevinos de tilápia são variadas, com diferentes níveis de adoção de tecnologias e, consequentemente, diferentes eficiências produtivas. Esse estudo objetivou mostrar um panorama da produção de alevinos de tilápia-do-nilo em Santa Catarina, por meio de questionário realizado com produtores de formas jovens. Pretendeu-se detectar gargalos e possibilidades de melhorias na produção catarinense de alevinos desta espécie. A produção de alevinos de tilápia em Santa Catarina cresceu 62,7% entre as safras de 2018/19 a 2020/21, concentrando-se nas regiões do Médio e Alto Vale do Itajaí. Observou-se contudo ampla dispersão em eficiência produtiva (alevinos produzidos por área e por fêmea) entre os piscicultores. Os pontos importantes que podem ser melhorados incluem a utilização de métodos mais eficientes para obtenção de larvas, o uso de tecnologias como aeradores associado ao monitoramento da qualidade de água, o uso de estufas na reprodução e alevinagem, o monitoramento da masculinização, além da reposição periódica de matrizes em centrais de seleção.

O gasto com a alimentação dos peixes é o principal custo de produção na piscicultura, e desta forma o manejo alimentar deve ser realizado de maneira precisa, evitando desperdícios. Uma forma de obter maior controle é através da automatização. Este estudo objetivou avaliar diferentes tipos de alimentadores automáticos de eixo helicoidal, dois comerciais (AC1 e AC2) e um protótipo desenvolvido pela Epagri. Para cada modelo foram realizados testes avaliando quatro granulometrias de rações (1,3mm; 2,5mm; 4-5mm, e 6-8mm), com diferentes níveis de enchimento do silo (cheio, médio e vazio), e com tempos de fornecimento de 1, 3, 5, 10, 20 e 30s. O parâmetro avaliado foi a acurácia no fornecimento de ração (g), representado pelo erro médio observado (K). O protótipo foi eficaz no fornecimento de todas as rações, já o alimentador comercial AC1 não foi adequado para dietas de 1,3mm, e o alimentador AC2 funcionou apenas para as granulometrias de 4-5mm e 6-8mm. Os resultados dos ensaios possibilitam concluir que o protótipo desenvolvido pela Epagri apresentou uma boa acurácia, assim como os modelos comerciais avaliados, além de ser eficaz para todas as granulometrias avaliadas.