The invertebrate colonization during decomposition of Eichhornia azurea was observed in a lateral lake in the mouth zone of Paranapanema River into Jurumirim Reservoir in two periods of the year. The litter bags method was used for measuring the decomposition rate as well as to evaluate the invertebrates colonization. Forty-two litter bags, measuring 15 × 20 cm in size and 2 mm mesh net, were incubated "in situ". Six litter bags (three for colonization and three for decomposition measurements) were removed after the 1 st , 3 rd , 7 th , 14 th , 28 th , 56 th and 72 nd days of incubation. After each day, the material was carefully cleaned for detritus removal and invertebrate sampling. The biological material was fixed with 4% formaline and then sorted and identified. The remaining plant material was dried in an oven (at 60 o C) and weighed. A fast material loss occurred during the first 24 hours and the decomposition rate was higher during the rainy season than in the dry season. A peak on invertebrate density (110 ind.g.DW -1 ) on the remaining detritus of Eichhornia azurea was recorded in the 56 th day of dry season, when the polyphenol concentration of plant detritus was 0.57 UDO.g.DW -1 . In the rainy season, higher density was found in the 28 th day of incubation, when the polyphenol concentration was 4.36 UDO.g.DW -1 . Apparently, the reduction in the polyphenol concentration was followed by an increase in invertebrate densities. The majority of the species observed in the detritus belongs to the collector group that was dominant after the 7 th and 14 th days in the rainy and dry seasons, respectively.Key words: decomposition, colonization, invertebrate, Eichhornia azurea, lake. RESUMO Decomposição de Eichhornia azurea e colonização por invertebradosA colonização por invertebrados durante o processo de decomposição de Eichhornia azurea foi examinada em duas épocas do ano na zona de desembocadura do Rio Paranapanema,
ResumoA etnoictiologia, baseando-se em parâmetros da ecologia, pode ser uma ferramenta bastante útil no estudo das mudanças ambientais provocadas por ações humanas, pois tais mudanças são percebidas pelos sujeitos que exercem atividades pesqueiras de subsistência e/ou recreativas nos ambientes impactados. O objetivo do presente trabalho foi investigar as percepções dos pescadores artesanais do município de Carmo do Rio Claro, Minas Gerais, acerca das alterações decorrentes de ações antropogênicas. Os dados foram obtidos de agosto de 2009 a janeiro de 2010 por meio de entrevistas abertas e semi-estruturadas, recorrendo-se às técnicas usuais de registro etnográfi co. Foram entrevistados 50 pescadores profi ssionais registrados, sendo 49 homens e apenas uma mulher. Os resultados revelam que esses pescadores têm observado a diminuição dos recursos pesqueiros, o desaparecimento e/ou escassez de algumas espécies e a introdução de espécies. Torna-se necessário procurar as melhores formas de recuperação e conservação das espécies nativas do reservatório de Furnas, além de um melhor monitoramento das espécies introduzidas. Unitermos: Carmo do Rio Claro, etnoictiologia, etnozoologia, impactos antrópicos, pescadores artesanais, recursos pesqueiros, reservatório de Furnas AbstractConception of the artisanal fi sherfolk who use Furnas Reservoir, Minas Gerais State, about fi shing stocks: an ethnoichthyological study. Ethnoichthyology, based on ecological parameters, can be a very useful tool to study man-made environmental changes. These changes are perceived by individuals who fi sh for a living and/or recreational activities in the impacted environs. The objective of this study was to investigate how the artisanal fi sherfolk of the municipality of Carmo do Rio Claro, Minas Gerais, perceive the environmental changes caused by anthropogenic actions. The data were collected from August 2009 to January 2010 by means of openended interviews according to usual ethnographical techniques. Fifty professional fi sherfolk were interviewed, forty-nine men and one woman. The results showed that they had experienced a reduction of fi shing resources, Biotemas, 23 (4): 135-145, dezembro de 2010
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