ICB - Artigos publicados em periódicos

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Navegando ICB - Artigos publicados em periódicos por Autor "Agostinho, Karla Danielle Gaspar da Luz"

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    Food spectrum and trophic structure of the ichthyofauna of Corumbá reservoir, Paraná river Basin, Brazil
    (Sociedade Brasileira de Ictiologia, 2006-03) Agostinho, Karla Danielle Gaspar da Luz; Bini, Luis Mauricio; Fugi, Rosemara; Agostinho, Angelo Antonio; Júlio Júnior, Horácio Ferreira
    In this paper we evaluate plasticity of fish concerning diet. We expect that sampling over a large temporal and spatial scale, including environmental changes such as impoundments, will allow us to cover most of the diet plasticity. We also evaluate the efficacy of ordination method in discriminating trophic groups based on fish species diet. Data were obtained from 17 sampling stations sampled monthly from March/96 to February/99 in the Corumbá river drainage, before and after the formation of the Corumba reservoir. Diet was determined analysing 9,177 stomach contents from 64 fish species. Trophic categories were discriminated by a non-hierarchic grouping analysis named k-means, applied to diet data. Most of the species presented great trophic plasticity, eating a great variety of food items. Resources availability, estimated from all fish stomach contents, was similar among environments, except in creeks, where it varied more with a large importance of terrestrial insects. K-means present satisfactory results, identifying nine trophic groups (detritivores, herbivore-piscivores, insectivore-herbivores, omnivores, invertivores, aquatic insectivores, piscivore-insectivores, piscivores and herbivores).
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    Similarities in correlates of native and introduced fish species richness distribution in Brazilian reservoirs
    (2018) Gonçalves Ortega, Jean Carlo; Agostinho, Angelo Antonio; Santos, Natália Carneiro Lacerda dos; Agostinho, Karla Danielle Gaspar da Luz; Oda, Fabrício Hiroiuki; Severi, William; Bini, Luis Mauricio
    We assessed the relationships among native and introduced fish species richness and a set of explanatory variables, including area, altitude, reservoir age, temperature, human influence index and fish abundance. We expected to find different relationships based on species origin (i.e., native or introduced). Based on compiled data from Brazilian reservoirs, we modeled the variation in the number of native and introduced fish species by generalized linear mixed models with different spatial autocorrelation structures. Reservoirs located in warmer regions and with higher fish abundance showed higher species richness of both native and introduced fish. Reservoir age tended to be negatively correlated with native species richness. Our results suggest that reservoir communities in warmer regions may be more resistant to local extinctions caused by impoundments, but they are more susceptible to species introductions. Our results also highlight that an extinction debt can be expected for native species because older reservoirs showed lower native species richness.