ABSTRACT. Diet of Anostomidae species (Teleostei, Characiformes) in the influence area of Manso Reservoir, Mato Grosso, Brazil. The diet of four species of Anostomidae (Leporinus friderici Bloch, 1794, L. striatus Kner, 1858, L. elongatus Valenciennes, 1849 and Leporinus sp.) were investigated in the Manso Reservoir, Mato Grosso State, Brazil. Fish were sampled in three sites: upriver, in the main body of the reservoir, and below the dam. Were analized 276 stomachs. The diet was evaluated using the frequency of ocorrence and volumetric methods. Leporinus friderici showed tendency to herbivory, mainly in the upriver site. In the reservoir and below the dam, it consumed large quantities of fish; Isoptera only in the reservoir. Leporinus striatus and L. elongatus have similar diets, consuming Chironomidae larvae (Diptera), whereas Leporinus sp. was more generalist, feeding similar proportions of vegetable, detritus and insect (Chironomidae and Ephemeroptera). INTRODUÇÃOA flexibilidade de hábito alimentar é uma característica adaptativa do comportamento animal, uma vez que ambientes naturais variam espacial e temporalmente, sendo que os peixes respondem à baixa disponibilidade alimentar alterando seu comportamento. Em reservatórios recém-formados, alterações no comportamento alimentar dos peixes são esperadas, principalmente em função da incorporação de material terrestre ao sistema aquático (AGOSTINHO et al., 1999) e do incremento da produção em todos os níveis tróficos (O'BRIEN, 1990), que pode alterar temporariamente a disponibilidade dos recursos alimentares. Espera-se que espécies estreitamente relacionadas apresentem, no mínimo, estratégias e táticas comportamentais diferenciadas que permitam a co-existência. Em relação à partilha de recursos alimentares, espécies de peixes congenéricas ou mesmo simpátricas têm mostrado, além de diferenças comportamentais (AGOSTINHO et al

ABSTRACT. Feeding ecology ofTo express diet results, were used occurrence and volumetric methods. The individuals consumed expressive amount of Chironomidae and Ephemeroptera larvae, in both bays and periods (dry and wet). Ontogenetic analysis showed that small individuals (Standard length = 1.6 to 7.2 cm) ate mainly Chironomidae, whereas larger ones (Standard length = 13.0 to 18.6 cm) consumed mainly Ephemeroptera. Then it is possible to infer that P. bonariensis is benthic-feeding fish with specialized diet. This characteristic was attributed because its narrow niche breadth allied with position and form of its mouth adapted to feed on the bottom. KEYWORDS.Feeding, fishes, bays, Pantanal. A dieta foi composta essencialmente por larvas bentônicas de Chironomidae e Ephemeroptera, independente do local e período (seca e cheia) analisados. Entretanto, nota-se marcante diferença na composição alimentar de acordo com o tamanho do peixe. Os menores exemplares (comprimento padrão = 1,6 a 7,2 cm) consumiram preferencialmente Chironomidae e os maiores (comprimento padrão = 13,0 a 18,6 cm) Ephemeroptera. Conclui-se que P. bonariensis tem hábito alimentar bentívoro e especializado, devido principalmente ao restrito espectro alimentar aliado à posição e forma da boca adaptada a explorar o substrato. RESUMO. Foi investigada a dieta de Pachyurus bonariensis

The study sought to evaluate the potential of the aquatic macrophyte Pontederia parviflora Alexander in the absorption of copper (Cu) and possible variations in its tissues after 21 days of exposure to this metal. The concentration of Cu was analyzed in the solution and in the vegetal tissues (stem, root and leaves). The experiment was set up in triplicates with weekly measurements of pH, temperature and DO. The results indicated that P. parviflora reduced 96% of Cu in the solution and the root was the vegetal tissue, which accumulated more Cu. Values of pH, DO and temperature were in accordance with the metabolic activities of the plants. In the anatomic analyses, dark spots were identified in the vascular bundles and in the epidermis of the aerial parts, highlighting the variation resulting from the presence of this substance. However, these variations were not sufficient to damage the development of the individuals. P. parviflora showed high capacity of extraction and storage of the metal, being a good alternative to aquatic environments with high concentrations of Cu.