Navegando por Assunto "Peixe - Rio Guamá (PA)"

Agora exibindo 1 - 5 de 5

Acesso aberto (Open Access)
Abordagem multicriterial e indicadores ecológicos e econômicos utilizados na identificação de áreas prioritárias para a conservação da ictiofauna no Estuário Amazônico, Brasil
(Universidade Federal do Pará, 2012) MOURÃO, Keila Renata Moreira; FRÉDOU, Flávia Lucena; http://lattes.cnpq.br/4779271407117528
This study was divided into three steps: (1) description of spatial and temporal distribution of fish fauna in the area of transition from marine and freshwater environments (Chapter 1), (b) use of descriptors of community as a way to determine the community structure and use of the habitat for fish fauna (Chapter 2) and (3) use of community descriptors studied in Chapters 1 and 2, as a criteria to development indicators (integrated in GIS environment) to define priority areas and scenarios for the conservation of the fish fauna (Chapter 3). The collections of the fish fauna in the main channel and tidal creek occurred from 2004 to 2011 during the dry period (July- December) and rainy period (January-June), using gill net, trawl and block net as fishing gears, and in three important areas of the Amazon estuary: the bays of Guajará and Marajó and Guamá River. A total of 41,516 specimens of 136 species, 38 families and 12 orders were captured. The spatial and temporal distribution of fish fauna in the area of transition from mesohaline and freshwater environments showed that species richness increases from the Guamá River towards the Marajó Bay, along with the increasing salinity. In relation to trophic functional groups, piscivores (PV) and zoobentívoros (ZB) were dominant in all areas. The community descriptors obtained in the main channel, showed the highest values of biomass and relative abundance in number in Marajó Bay. In relation to the tidal channel, the abundance of biomass was greater in Guajará Bay. The main channel is used for breeding and nursery, and 90% of the individuals were immature. The indicators of diversity of the environment (DA), habitat use (UH), relative abundance (CPUE), environmental health (SA) and relation to fisheries (PR), showed conservation priorities considered medium and high, along the area study. This trend was also observed considering the ecological and economic scenarios, that showed medium-high and high-very high priority for conservation of the fish fauna in the northern portion Marajó Bay in the dry period, respectively. The methodologies used determined the ecological importance of the study area, emphasizing the heterogeneity between them and therefore cannot be considered as a single environment. The multicriteral approach adopted has no precedent for the Amazon estuary. This methodology proved to be effective in providing, through the different scenarios, a range of options that allows the decision maker to explore the issue as best as possible or use it as part of a process of decision making.
Acesso aberto (Open Access)
Acute toxicity and histopathology in ornamental fish amazon bluespotted corydora (Corydoras melanistius) exposed to formalin
(2012-12) SANTOS, Rudã Fernandes Brandão; DIAS, Henrique Malta; FUJIMOTO, Rodrigo Yudi
The objective of this work was to evaluate the acute toxicity of formalin and histopathological effects on the Amazon ornamental fish, bluespotted coridora (Corydoras melanistius). A randomized design was used, with ten concentrations of formalin (40%) (0, 3, 6, 12, 25, 50, 100, 150, 200 and 250mg.L-1) with four replicates and five fish per container (3L) in static system for 96 hours. The moribund fish were killed and fixed in 10% formalin to proceed the histopathological analysis of gill, liver and kidney. At the end of this experiment the following mortality rates (%) were obtained in increasing order of exposure: 0, 0, 0, 0, 0, 65, 85, 100, 100 and 100%. The lethal concentration 50% (LC50-96h (I)) estimated was 50.76 mg.L-1 with regression of y = 0.51x, and r² = 0.80. Further, in higher concentrations morphological changes as gill hyperplasia, with filling of interlamellar spaces, disorganization of liver arrangement, and necrosis in kidney were observed. In this study, the formalin can be considered slightly toxic to bluespotted corydora, and cause morphological changes when exposed to high concentrations. The use of formalin to treat of ornamental fish in the inner river of capture with wrong concentration can provoke negative environmental and biological effects.
Acesso aberto (Open Access)
Composition of functional ecological guilds of the fish fauna of the internal sector of the Amazon Estuary, Pará, Brazil
(2014-12) MOURÃO, Keila Renata Moreira; FERREIRA, Valdimere; FRÉDOU, Flávia Lucena
The present study describes the spatial and temporal structure of the estuarine fish community in the internal sector of the Amazon Estuary. Samples were obtained in the main channels and tidal creeks of Guajará and Marajó Bays and Guamá River. A total of 41,516 fish specimens were collected, representing 136 taxa, 38 families and 12 orders. In the dry season, the mean salinity of the main channel increased along a limnicmarine gradient, between the Guamá River and the Marajó Bay. Species richness was lowest in the mouth of the Guamá River and in the right margin of the Guajará Bay. Fish species composition and environmental guilds differed markedly among areas: Migrants and Freshwater Stragglers were dominant in the Guamá River and the Guajará Bay, while Estuarine, Marine Stragglers and Migrants predominated in the Marajó Bay. However, the trophic guilds were still relatively well balanced, in functional terms. Piscivores and Zoobenthivores were the dominant feeding functional groups in all the studied areas. In this study, the assessment of the community and the use of the guild approach were efficient to describe the structure and functioning of the assemblages of estuarine fish also helping to assess the anthropogenic pressures in the area.
Acesso aberto (Open Access)
Distribuição e assinatura isotópica de Pb em sedimentos de fundo da Foz do Rio Guamá e da Baía do Guajará (Belém - Pará)
(2012) SANTOS, Suziane Nascimento; LAFON, Jean Michel; CORRÊA, José Augusto Martins; BABINSKI, Marly; DIAS, Fabiana Ferrari; TADDEI, Maria Helena Tirolo
Lead analyses in bottom sediments from the hydrographic system of Belem (Para) indicated low contents of this metal for the sediments from the Guama river, with no significant anthropogenic contribution. A concentration of 18.1 ± 1.5 mg kg-1 and 206Pb/207Pb isotopic signature of 1.196 ± 0.002 are assigned for Pb from natural sources. On the other hand, the significant increase of Pb contents in the sediments from the Guajará bay, together with the decrease of 206Pb/207 ratios (1.172 < 206Pb/207 < 1.188) point to an anthropogenic lead contribution, originated by the industrial and urban activities of the city of Belem.
Acesso aberto (Open Access)
Raphidascaris (Sprentascaris) lanfrediae sp. nov. (Nematoda: Anisakidae) from the fish Satanoperca jurupari (Osteichthyes: Cichlidae)
(2011-08) MELO, Marly de Fátima Carvalho de; SANTOS, Jeannie Nascimento dos; GIESE, Elane Guerreiro; SANTOS, Everton Gustavo Nunes dos; SANTOS, Cláudia Portes
Raphidascaris (Sprentascaris) lanfrediae sp. nov. is described from the intestine of the freshwater fish Satanoperca jurupari (Heckel) (Cichlidae) from the Guamá River, state of Pará, Brazil. The prevalence in fish (n = 59) was 27% with intensity of one-124 (mean 16) nematodes per fish. The new species is characterized mainly by the markedly larger size of ventricular appendix in relation to the oesophagus, presence of short male caudal alae, 14-16 subventral pairs of preanal papillae and six pairs of postanal papillae.