The impact of a biomanipulation experiment on the ichthyofauna diet from a neotropical reservoir in Brazilian semiarid

• Published in: Acta limnológica brasiliensia 2018, Vol.30, p.1-11
• Main Authors: Moura, Cristiane de Carvalho Ferreira Lima, Oliveira, Jônnata Fernandes, Novaes, José Luís Costa, Costa, Rodrigo Silva da, Araújo, Darlan Dantas Alves de, Peretti, Danielle
• Format: Article
• Language: English
• Subjects: Astyanax bimaculatus; Biology; Biomanipulation; Composition; Diet; Eating behavior; Ecology; Ecosystem biology; Ecosystems; Environmental changes; Experiments; Feeding; Fish; Fisheries management; fishes; Fishing; Food; Foods; Freshwater fishes; Hoplias; Hypostomus; Ichthyofauna; Introduced species; Leporinus piau; LIMNOLOGY; Multidimensional scaling; Native species; Oreochromis niloticus; Prochilodus brevis; Removal; Reservoirs; Scaling; semiarid; Similarity; Species classification; Tilapia
• ISSN: 0102-6712; 2179-975X; 2179-975X
• DOI: 10.1590/s2179-975x2817

Abstract Aim To evaluate the impact of a biomanipulation experiment on the feeding of fish species from a neotropical semiarid reservoir, before and after the removal of the exotic species Oreochromis niloticus. Methods The values of Food Index were analyzed for six species: Oreochromis niloticus , Prochilodus brevis Steindachner,1875, Hypostomus cf. paparie Fowler,1941, Hoplias gr. malabaricus Bloch,1794, Astyanax bimaculatus Linnaeus,1758 and Leporinus piau Fowler,194. All data were obtained in two periods, before of the removal O. niloticus (May 2012 to January 2013) and after its removal (April 2013 to November 2013). The Morisita-Horn index was used to evaluate the feeding similarity among the six species and determine trophic categories (insectivorous, omnivorous, iliophaga and piscivora). To establish the probable variations due the presence of O. niloticus species, the Food Index of the six species was used in a Bray-Curtis similarity matrix. Through the Non-metric Multidimensional Scaling (NMDS) we could not observe any differences among items consumed by different species. The Canonical Correspondence Analysis (CCA) was used to assay the influence of environmental variables on the dietary, from the Food Index data. Results All species were classified in four trophic categories that do not shown any variation among the formed groups during studied periods. After the removal of Nile tilapia some species showed changes in food items, according to NMDS. The CCA indicated low association among the monthly Food Index of species and the environmental changes. Conclusion The process of biomanipulation on the Ecological Station from Serra Negra reservoir, which compares the dietaries from five local species before and after removal of exotic species Oreochromis niloticus, resulted in modification of dietary composition from three of five studied species. Resumo Objetivo Avaliar o impacto de um experimento de biomanipulação na alimentação das espécies da ictiofauna de um reservatório do semiárido neotropical, antes e após a remoção da espécie exótica Oreochromis niloticus. Métodos Os dados foram amostrados em dois períodos, antes da remoção da espécie (maio de 2012 a janeiro de 2013) e após a remoção (abril de 2013 a novembro de 2013). Foram analisadas os valores do Índice Alimentar de seis espécies: Oreochromis niloticus, Prochilodus brevis Steindachner,1875, Hypostomus cf. paparie Fowler,1941, Hoplias gr. malabaricus Bloch,1794, Astyanax bimaculatus Linn