ABSTRACT. Food used by two sympatric species of Moenkhausia (Characiformes, Characidae), in a stream of centerwestern Brazil. This study evaluated the seasonality in the diet of Moenkhausia dichroura (Kner, 1858) and M. sanctaefilomenae (Steindachner, 1907), sympatric species of the Cancela stream, state of Mato Grosso, Brazil. Regardless of the seasonal period, allochthonous food source predominated in the diet of both species (>50% of all items consumed) and among these terrestrial insects were the dominant resource. However, aquatic insects were important in the diet of M. dichroura as well. Hymenoptera (Formicidae) was the dominant item to both species, thus they were characterized as terrestrial insectivorous. The restricted diet of these species is confirmed by the trophic niche breadth, whose values were in general low: Ba=0.26 to M. dichroura in both periods and Ba=0.41 and 0.38 in the dry and rainy period, respectively, to M. sanctaefilomenae. The feeding overlap was high in the rainy period (O jk =0.75) and intermediate in the dry period (O jk =0.41), showing that the food partitioning between species was larger in this period. KEYWORDS. Diet, Moenkhausia dichroura, M. sanctaefilomenae, coexistence.RESUMO. Esse estudo avaliou sazonalmente a dieta de Moenkhausia dichroura (Kner, 1858) e M. sanctaefilomenae (Steindachner, 1907), coletadas em simpatria no riacho Cancela, Mato Grosso, Brasil. Independente do período hidrológico, alimentos de origem alóctone predominaram na dieta de ambas as espécies (>50% do total de itens consumidos), sendo insetos terrestres o recurso principal, embora, para M. dichroura insetos aquáticos tenham contribuído na dieta também. Hymenoptera (Formicidae) foi o alimento mais consumido, sendo ambas as espécies caracterizadas como insetívoras terrestres. A dieta restrita dessas espécies é confirmada pelos baixos valores de amplitude de nicho trófico: Ba=0,26 para M. dichroura em ambos os períodos e Ba=0,41 no período de seca e 0,38 no período de chuva, para M. sanctaefilomenae. A sobreposição alimentar foi elevada no período de chuva (O jk =0,75) e apresentou valor intermediário no período de seca (O jk =0,41), evidenciando maior partilha do alimento entre as espécies neste período. PALAVRAS-CHAVE.Dieta, Moenkhausia dichroura, M. sanctaefilomenae, coexistência.

This study evaluated the diet and feeding selectivity of the catfish Imparfinis mirini in streams with different degrees of urbanization and the effect of rainfall on the availability of prey. The diet was based especially on Chironomidae and Trichoptera. Significant spatial differences in diet were found between the streams; the diet of the fish was similar in the rural and peri-urban streams, and differed from that in the urban stream. Seasonality was an unimportant factor affecting the species' diet, which did not differ significantly between the rainy and dry periods in any of the streams. Fish from the urban stream fed more according to what was available in the environment, while fish from the peri-urban and rural streams showed higher degrees of selectivity. The results indicate that environmental conditions influenced the diet and prey selection of this species in response to the differences in diversity and abundance of the food organisms. They indicate that trophic studies of benthivorous fishes, such as I. mirini, may represent an alternative way to assess human effects on streams.

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ABSTRACT. This study investigated the diet of four characids [Hyphessobrycon eques (Steindachner, 1882), Odontostilbe pequira (Steindachner, 1882), Psellogrammus kennedyi (Eigenmann, 1903) and Serrapinnus calliurus (Boulenger, 1900)] coexisting in two lagoons and checked for possible spatial diff erences and the infl uence on population fi tness. The main goal was check if these species show better fi tness according to the nutritional value of the food resource consumed. In this way, it is expected that the species show improved nutritional conditions (evidenced by the relative condition factor) when foraging for items of animal origin, and the reverse is expected when consuming items of plant origin and detritus. Sampling was conducted in August 2011. The diet was evaluated by analyzing contents and calculating the relative condition factor for each sampled individual, obtaining a mean value for each population. Species exhibited high food plasticity; H. eques and P. kennedyi altered most their diets from a lagoon to another. Despite these variations, the condition factor showed no signifi cant spatial variation for any species. The results indicated that these species have physiological adaptations that allow them to obtain the maximum energy from food, even if it has low nutritional value, or that fi sh can compensate for the consumption of low nutritional food by increasing the consumption rate. Thus, regardless of the type of resources consumed, these have met the metabolic needs of the fi sh in the studied lagoons.KEYWORDS. Fishes, diet, condition factor, Pantanal, lagoons.RESUMO. Infl uência da plasticidade alimentar no fi tness de pequenos caracídeos neotropicais. Este estudo investigou a dieta de quatro caracídeos [Hyphessobrycon eques (Steindachner, 1882), Odontostilbe pequira (Steindachner, 1882), Psellogrammus kennedyi (Eigenmann, 1903) e Serrapinnus calliurus (Boulenger, 1900)], que coexistem em duas lagoas, e verifi caram-se possíveis diferenças espaciais no fi tness dessas populações. O objetivo principal foi analisar se essas espécies demonstram melhor fi tness de acordo com o valor nutricional do recurso consumido. Desta forma, espera-se que as espécies demonstrem melhores condições nutricionais (demonstrado pelo fator de condição relativo) durante o forrageamento de itens de origem animal, assim como o contrario é esperado ao consumir itens de origem vegetal e detritos. A amostragem foi realizada em agosto de 2011. A dieta foi avaliada através da análise do conteúdo estomacal e o fator de condição relativo foi calculado para cada indivíduo amostrado, obtendo-se um valor médio para cada população. As espécies exibiram elevada plasticidade alimentar; H. eques e P. kennedyi alteraram a maioria dos itens alimentares de suas dietas entre as lagoas estudadas. Apesar destas variações, o fator de condição não variou espacialmente para qualquer espécie. Os resultados indicam que estas espécies possuem adaptações fi siológicas que lhes permitem obter o máximo de energia a partir do alimento, mesmo que...

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The Devonian Escarpment (DEEPA), located in the south of Brazil, represents an important area of environmental preservation composed by grasslands, gallery forests, as well as rock outcrops and archaeological sites. A law project (LP 527/2016), which suggests a reduction of the DEEPA area in approximately 70% of its original area (from 393,579 to 125,895 ha), is currently being processed in the Paraná State House of Representatives. Such reduction seems to be related to economic interests (mainly agriculture and mining) in the state of Paraná. If approved, LP 527/2016 will allow farmers to deliberately expand their activities, with the suppression of natural forest as main consequence. Additionally, loss of faunal diversity, contamination of water and soils, and alteration in nutrient cycles are expected, due the intensive use of agrochemicals. In addition to the direct environmental consequences, we expect the disappearance of areas of high geological interest, reducing local geodiversity, as well as substantial economic losses with ecotourism. Brazil is a signatory to the United Nations Convention on Biological Diversity, where it undertakes to develop strategies to prevent biodiversity loss and ecosystem degradation by 2020. An approval of the LP would be contradictory, considering that there are few natural vegetation areas in this region of the country. We emphasize that the proposal of such projects goes against the sustainability in the country and disregard the scientific knowledge generated until then. Thus, it is necessary to develop regional and federal political objectives that guarantee economic development in a balanced way, considering the local bio and geodiversity, not the proposal of mechanisms that destroy them.