Navegando por Autor "GIARRIZZO, Tommaso"

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Acesso aberto (Open Access)
Biometric relationships between body size and otolith size in 15 demersal marine fish species from the northern Brazilian coast
(Instituto Nacional de Pesquisas da Amazônia, 2019-12) OLIVEIRA, Rory Romero de Sena; ANDRADE, Marcelo Costa; MACHADO, Fabiola Seabra; CUNHA, Élida Jesana Santana; FREITAS, Flaviane Souto de; KLAUTAU, Alex Garcia Cavalleiro de Macedo; GIARRIZZO, Tommaso; SAINT-PAUL, Ulrich
The relationships between fish size and sagitta otolith measurements were calculated for the first time for 15 species belonging to six families from the northern Brazilian coast. A total of 220 fish were sampled from the bycatch landed by the bottom-trawl industrial shrimp-fishing fleet between August and September 2016. All species had strong relationships between otolith measurements and fish total length with the coefficient of determination (r 2) ranging between 0.71 and 0.99. The variable most strongly related to fish total length was found to be the sagittal otolith length (OL) with 98% of the variability. These relationships are a useful tool to estimate length and mass of preyed fish from otoliths found in stomach contents of marine predators.
Acesso aberto (Open Access)
Effect of seasonal flooding cycle on litterfall production in alluvial rainforest on the middle Xingu River (Amazon basin, Brazil)
(Universidade Federal do Pará, 2015-08) CAMARGO-ZORRO, Mauricio; GIARRIZZO, Tommaso; JESUS, Allan Jamesson Silva de
The assumption for this study was that litterfall in floodplain environments of the middle Xingu river follows a pattern of seasonal variation. According to this view, litterfall production (total and fractions) was estimated in four alluvial rainforest sites on the middle Xingu River over an annual cycle, and examined the effect of seasonal flooding cycle. The sites included two marginal flooded forests of insular lakes (Ilha Grande and Pimentel) and two flooded forests on the banks of the Xingu itself (Boa Esperança and Arroz Cru). Total litterfall correlated with rainfall and river levels, but whereas the leaf and fruit fractions followed this general pattern, the flower fraction presented an inverse pattern, peaking in the dry season. The litterfall patterns recorded in the present study were consistent with those recorded at other Amazonian sites, and in some other tropical ecosystems.
Acesso aberto (Open Access)
Effect of waterfalls and the flood pulse on the structure of fish assemblages of the middle Xingu River in the eastern Amazon basin
(Instituto Internacional de Ecologia, 2015-08) BARBOSA, Thiago Augusto Pedroso; BENONE, Naraiana Loureiro; RUFFEIL, Tiago Octavio Begot; GONÇALVES, Alany Pedrosa; SOUSA, Leandro Melo de; GIARRIZZO, Tommaso; JUEN, Leandro; MONTAG, Luciano Fogaça de Assis
The structure of fish assemblages in Neotropical rivers is influenced by a series of environmental, spatial and/or temporal factors, given that different species will occupy the habitats that present the most favourable conditions to their survival. The present study aims to identify the principal factors responsible for the structuring of the fish assemblages found in the middle Xingu River, examining the influence of environmental, spatial, and temporal factors, in addition to the presence of natural barriers (waterfalls). For this, data were collected every three months between July 2012 and April 2013, using gillnets of different sizes and meshes. In addition to biotic data, 17 environmental variables were measured. A total of 8,485 fish specimens were collected during the study, representing 188 species. Total dissolved solids, conductivity, total suspended matter, and dissolved oxygen concentrations were the variables that had the greatest influence on the characteristics of the fish fauna of the middle Xingu. Only the barriers and hydrological periods played a significant deterministic role, resulting in both longitudinal and lateral gradients. This emphasizes the role of the connectivity of the different habitats found within the study area in the structuring of its fish assemblages.
Acesso aberto (Open Access)
Feeding ecology of juvenile dog snapper Lutjanus jocu (Bloch and Shneider, 1801) (Lutjanidae) in intertidal mangrove creeks in Curuçá estuary (Northern Brazil)
(2009-12) MONTEIRO, Dijane Pantoja; GIARRIZZO, Tommaso; ISAAC, Victoria Judith
The diet and feeding ecology of juvenile dog snapper (Lutjanus jocu) were investigated in 92 specimens collected in four intertidal mangrove creeks of Curuçá estuary, Northern Brazil, between September 2003 and July 2004. No significant differences in total length were found between the sampling months. Feeding intensity was high as indicated by high stomach fullness index and low vacuity index. The most important prey was Penaeidae, followed by Grapsidae and Porcellanidae. The diet of juvenile dog snapper showed clear seasonal differences. Specimens from dry season (September and November) and dry / wet season transition (January), were specialists feeding exclusively on Penaeidae. However, the specimens from wet season (March and May) and wet /dry season transition (July) that consumed mainly Grapsidae, Penaeidae and Porcellanidae were generalist. These seasonal changes in diet could be related to variations in food availability.
Acesso aberto (Open Access)
Food consumption as an indicator of the conservation of natural resources in riverine communities of the Brazilian Amazon
(Universidade Federal do Pará, 2015-12) NAHUM, Victoria Judith Isaac; ALMEIDA, Morgana Carvalho de; GIARRIZZO, Tommaso; DEUS, Cláudia Pereira de; VALE, Rozeilza; KLEIN, Gilmar Nicolau; BEGOSSI, Alpina
The present study analyzed and compared the daily consumption of foods of animal origin in eleven communities of the Lower Amazon, Trombetas and Purus Rivers, representing three different management systems and levels of conservation in the Brazilian Amazon. All food items of animal origin were weighed by at least 10% of the families in the study communities during a week in each period of the flood cycle between 2006 and 2008. Fish was the most important food, and was consumed during six days of the week, with an average rate of 169 kg.person-1.year-1. Game was second in importance, with 37 kg.person-1.year-1. This yearly rate of fish consumption is one of the highest in the world and is almost double the minimum recommended by the World Health Organization. The dietary patterns reflect both the isolation of the communities from large urban centers and the better preservation of the local environments due to the existence of protected areas. Environmental degradation may thus have effects on the health and food security of local populations. The study emphasizes the need for the implementation of public policies and participative management initiatives.
Acesso aberto (Open Access)
Length-weight relationships and condition factor of the eaglebeak pacu Ossubtus xinguense Jégu, 1992 (Characiformes, Serrasalmidae), an endangered species from Rio Xingu rapids, northern Brazil
(Universidade Federal do Pará, 2015-08) ANDRADE, Marcelo Costa; JESUS, Allan Jamesson Silva de; GIARRIZZO, Tommaso
This study reports on the length-weight relationships and condition factor for the endangered rheophilic fish Ossubtus xinguense Jégu from Rio Xingu rapids. This species is threatened by construction of the third largest hydroelectric in the world, the Belo Monte dam close to the city of Altamira, northern Brazil. Specimens were collected in the dry season between July 2012 and September 2012. Male specimens have body length larger than females, atypical in serrasalmid fishes, and different length-weight relationships were found between adult and juvenile specimens. This study presents the first biological characteristics for O. xinguense.
Acesso aberto (Open Access)
Mercury concentration in different tissues of Podocnemis unifilis (Troschel, 1848) (Podocnemididae: Testudines) from the lower Xingu River – Amazonian, Brazil
(Universidade Federal do Pará, 2015-08) ARAUJO, Juliana de Souza; GIARRIZZO, Tommaso; LIMA, Marcelo de Oliveira
Studies using chelonians as biosentinels of environment quality or health risks associated with turtle consumption are very rare, especially in the Amazon basin. This study aims to measure Mercury levels (Hg) in muscle, liver, fat and blood of Podocnemis unifilis from the lower Xingu River, assessing the possible difference in concentration between sexes and also evaluating the potential bioaccumulation along different body sizes. Samples were collected during the dry season (October 2012) and Mercury (Hg) concentrations were analysed by Cold Vapor Atomic Absorption Spectrometry (CVAAS). A total of 29 specimens of P. unifilis of different sizes showed low levels lower than 0.2 mg/Kg). Higher Hg concentrations were found in the liver, and significant correlations between Hg concentrations in the different tissues were also detected. There was no difference between males and females and a negative correlation was found between Hg concentration and body size.
Acesso aberto (Open Access)
Mercury in fish and sediment of Purus River, Acre State, Amazon
(Universidade Federal do Pará, 2016-09) CASTRO, Nathália Santos Serrão de; BRAGA, Camila Margalho; TRINDADE, Paulo Arthur de Abreu; GIARRIZZO, Tommaso; LIMA, Marcelo de Oliveira
Core subject: To quantify the Hg content of sediment and fish collected along the Purus River (Acre State, Amazon) in order to identify if those samples could be a potential route of Hg exposure to the population of Manoel Urbano (a riverside community). Methods: The total mercury (THg) was quantified using the Cold Vapor Atomic Absorption technique. Results: We collected 06 samples of sediment and 264 samples of fish. The Hg in sediments ranged between 0.038 and 0.065 µg.g–1.The results indicate that sediment is in agreement with “uncontaminated” Amazonian rivers. The carnivorous species presented the highest level of Hg on muscle (mean 0.927 µg/g–1), followed by piscivorous (mean 0.873 µg.g–1), planktophagus (mean 0.566 µg.g–1), omnivorous (mean 0.533 µg.g–1) and detritivorous (mean 0.176 µg/g–1). Fourty four percent (44%) of the total species collected presented mean levels of THg on muscle, a percentage greater than the threshold recommended by WHO. Conclusion: Some species may be a route for Hg exposure. The sediment is within the normality. The authors suggest that other factors, such as culture and society, should be considered for future researches in order to promote the population healths.
Acesso aberto (Open Access)
Population and biological parameters of selected fish species from the middle Xingu River, Amazon Basin
(Universidade Federal do Pará, 2015-08) CAMARGO-ZORRO, Mauricio; GIARRIZZO, Tommaso; NAHUM, Victoria Judith Isaac
This study estimates the main biological parameters, including growth rates, asymptotic length, mortality, consumption by biomass, biological yield, and biomass, for the most abundant fish species found on the middle Xingu River, prior to the construction of the Belo Monte Dam. The specimens collected in experimental catches were analysed with empirical equations and length-based FISAT methods. For the 63 fish species studied, high growth rates (K) and high natural mortality (M) were related to early sexual maturation and low longevity. The predominance of species with short life cycles and a reduced number of age classes, determines high rates of stock turnover, which indicates high productivity for fisheries, and a low risk of overfishing.
Acesso aberto (Open Access)
Temporal patterns in the occurrence of selected tropical fishes in mangrove creeks: implications for the fisheries management in north Brazil
(2009-06) GIARRIZZO, Tommaso; KRUMME, Uwe
To examine the temporal patterns in the occurrence of a tropical ichthyofauna, fisheries-independent samples were collected between September 2003 and July 2004 from intertidal mangrove creeks in the Curuçá estuary, Pará, north Brazil. Juveniles occurred year-round with the most intense occurrence during the wet/dry transition season (Anchovia clupeoides, Cetengraulis edentulus, Rhinosardinia amazonica, Mugil sp.). The occurrence of Colomesus psittacus and Anchoa hepsetus was continuous. Sciades herzbergii displayed two peaks (wet and dry season) while Cathorops sp. peaked only in the wet season. The continuous presence of juveniles in the tropical mangroves suggested that the fisheries management should be based on large no-take areas rather than closed seasons.
Acesso aberto (Open Access)
Tometes camunani (Characiformes: Serrasalmidae), a new species of phytophagous fish from the Guiana Shield, rio Trombetas basin, Brazil
(2013-06) ANDRADE, Marcelo Costa; GIARRIZZO, Tommaso; JÉGU, Michel Louis Arthur Marie Ange François
A new species of Serrasalmidae, Tometes camunani, is described from the upper drainages of the rio Trombetas basin, Pará State, Brazil. The new species is distinguished from its congeners by having neurocranium with a slight concavity at the level of the frontal bone (vs. concavity absent, dorsal profile of neurocranium straight). It can be further distinguished from its congeners by having teeth with central cusp taller and acute (vs. central cusp shorter and with rounded edge in T. trilobatus), a terminal mouth (vs. upturned mouth in T. lebaili), and 12-26 prepelvic spines (vs. 0-9 in T. makue). The new species is strictly rheophilic like other species of Tometes, and occurs exclusively in the rapids of shield rivers, complex and fragile biotopes that are threatened by anthropogenic activities. An identification key to the species of the Myleus group is provided.