Agroecology-based aquaculture emerges as a particularly interesting production alternative for rural family farmers. In such systems, it is desirable to use means for enhancing the zootechnical performance and improving fish immune responses from natural products. Thus, the present study aimed to evaluate the effect of organic diet supplementation with oregano essential oil, Origanum vulgare, on zootechnical performance, hematological parameters, and resistance to the ectoparasite Ichthyophthirius multifiliis (ich) in silver catfish juveniles, Rhamdia sp. A completely randomized design with five treatments (concentrations 0, 0.5, 1.0, 1.5, and 2.0 g oregano essential oil kg-1 diet) and four replicates was adopted. Groups of 20 silver catfish juveniles (initial weight 12.5 ± 0.5g) were stocked in 20 polyethylene tanks (54 L usable volume) connected to a water recirculation system with individual aeration. The diets were prepared with certified organic ingredients and offered for 89 days in two meals a day. At the end of the experimental period, survival, zootechnical performance, hematological parameters, and fish body composition were evaluated. After the final biometry, an experimental challenge with ich infection was performed. Dietary concentrations of oregano essential oil had no effects on growth, hematology, and body composition of silver catfish juveniles (p > 0.05). Neither was there any influence on the level of infection and accumulated mortality of the fish under challenge with ich. Supplementation with oregano essential oil did not prove to be an effective dietary additive in improving the performance or increasing resistance against ich in silver catfish juveniles. However, in view of the importance of the topic, further studies should be carried out to increase knowledge about the effect of this and other natural additives in silver catfish, including at other stages of development.

Understanding the embryogenesis of a species is a useful tool for locating areas for spawning and for the study of growth of the species in their natural environment. This study was conducted at the Panamá Fish Hatchery in Santa Catarina, Brazil, to characterize the embryonic development of the piavuçu Leporinus macrocephalus (Characiformes, Anostomidae). Description was based on the analysis of embryos collected at 10-minute intervals during the first three hours after fertilization, and later at 30-minute intervals until larva hatching. Piavuçu eggs are detached, transparent, small, spherical, with a large perivitelline space. Hatching takes place 11 hours and 30 minutes after fertilization at an average temperature of 28.2°C. Total length and weight of recently hatched larva were 2.39 ± 0.12 mm, and 0.5 ± 0.1mg respectively.

O trabalho teve por objetivo diagnosticar e quantificar a geração de resíduos sólidos domésticos (RSD) na terra indígena Rio das Cobras, Nova Laranjeiras, PR. Foi obtida uma média de 0,09 kg.habitante-1.dia-1. Embora a produção de RSD seja pequena, é relevante destacar a importância de políticas públicas e ações de educação ambiental que possibilitem minimizar os impactos dos resíduos no meio ambiente e o bem-estar físico e cultural dos povos indígenas.

A criação de organismos aquáticos tem crescido devido a uma maior demanda por pescado e as fontes naturais possuírem estoques limitados com tendência ao esgotamento. A comercialização, no entanto, é um dos obstáculos para que a atividade se consolide e gere maiores rendimentos aos produtores. No município de Laranjeiras do Sul, no Estado do Paraná este aspecto se agrava devido à falta de informação de produção e comercialização. Neste sentido, o objetivo deste trabalho foi gerar e analisar informações referentes à venda e criação de pescado em Laranjeiras do Sul para subsidiar as políticas de expansão da piscicultura local. Por meio do mapeamento dos canais de comercialização através de entrevistas mensais com os diferentes comerciantes de pescado e por meio de pesquisas junto aos dados das instituições responsáveis (Emater, Seab, Ibge) foi possível constatar que, exceto o pescado comercializado na feira do peixe vivo e nos pesque-pague, o comercializado em supermercados ou mercados, restaurantes ou lanchonetes, peixaria, ou por intermediários é oriundo de outros municípios, estados e até países. Também foi constatado que na região centro-sul do Paraná não existem abatedouros ou frigoríficos de peixes, tornando-se este um entrave para o aumento da produção, comercialização e consumo do pescado. Foram identificadas 32 espécies comercializadas sendo 30 nos mercados, 16 nos restaurantes e 10 em pesque-pague. A espécie mais comercializada em todos os estabelecimentos é a tilápia (34 toneladas), representando mais de 75% das espécies comercializadas durante o período pesquisado, com preço médio do filé em R$ 33,97 kg-1. Os resultados obtidos demonstram a necessidade de maior ampliação dos canais de comercialização e políticas públicas para fomentar a atividade no município e região.

The demand for food from organic aquaculture has been growing worldwide. Certification and labeling are means adopted to differentiate these products from conventional ones. However, mutual recognition and equivalence between national standards for organic aquaculture represent an obstacle for the sector. Thus, the aim of this study was to verify the equivalence and harmonization, for organic fish production, of the norm which regulates Brazilian organic aquaculture, and four international public standards (European Union, Canada, China and Australia). The comparison was made using the tool "EquiTool", an international guide for checking equivalence between standards. It was found that the Brazilian standard has greater equivalence with the Chinese standard. The main non-conformities occurred between the Brazilian and European, followed by the Australian and Canadian standards, respectively. The greater differences were found in the delimitation of the conversion periods to the organic system, in food and in the use of chemosynthetic products to treat animal diseases.