Navegando por Assunto "Ictiofauna"

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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)
Alimentação, distribuição espacial e sazonal das espécies de Arius (Siluriformes : Ariidae) do Estuário amazônico
(Universidade Federal do Pará, 1999-08-30) MENDES, Fabrício Lemos de Siqueira; BARTHEM, Ronaldo Borges; http://lattes.cnpq.br/4192105831997326
The Family Ariidae (Order Siluriformes) contains marine and estuarine catfishes distributed along the coasts of ali the continents, inhabiting tropical and subtropical shores where they live in shallow waters with sandy or muddy bottoms. In the Amazon River estuary in Pará State, Brazil, there are seven species belonging to the genus Anus (A. couma, A. parkeri, A. rugispinis, A. quadriscutis, A. grandicassis, A. phrygiatus e A. proops). The aim of this study is to identify feeding preference, feeding overlap, spatial distribution and seasonal distribution of the species of genus Anus (Siluriformes, Ariidae) of the Annazon stuary. Collections were made from August to October 1996, and February to April and August to October 1997. Specimens were captured with bottom nets without escape doors belonging to the piramutaba fishing fleet of the Amazon estuary. There are two species groups in the genus Anus: those that feed on crustaceans (A. rugispinis, A. quadriscutis, A. grandicassis, A. phtygiatus e A. proops), and those that feed on fish (A. couma, A. parken). In relation to feeding overlap, ali the species demonstrated a certain degree of feeding overlap, as well as spatial overlap. A. couma and A. phrygiatus. are the most abundant in the 5-10 m depth range and A. rugispinis, A. quadriscutis, A grandicassis and A. parkeri e A. proops in the 10-20 m range. A. phrygiatus is the only species that has a greater abundance during the rainy season, and the other species are present both in the dry as well as the rainy season.
Acesso aberto (Open Access)
Analysis of fish assemblages in sectors along a salinity gradient based on species, families and functional groups
(2013-12) PASSOS, Ana Carolina dos; CONTENTE, Riguel Feltrin; ABBATEPAULO, Felippe Veneziani; SPACH, Henry Louis; VILA, Ciro Colodetti; JOYEUX, Jean Christophe; CARTAGENA, Beatriz Fernanda Chinchilla; FÁVARO, Luis Fernando
Here we test the effects of the east-west salinity gradient in the subtropical Paranaguá Bay Estuarine Complex (PEC) on the structure of shallow water fish fauna, determined according to taxonomic (families and species) and functional composition metrics. A total of 152 species were observed. The families with the largest number of species were the Sciaenidae, Carangidae, Haemulidae and Gobiidae. The most abundant species were Atherinella brasiliensis, Harengula clupeola, Anchoa januaria and Anchoa tricolor. Marine stragglers dominated in number of species, followed by marine migrants and estuarine species. Most species were zoobenthivores, followed by piscivores and zooplanktivores. Families and species more frequently associated with estuarine conditions dominated in the mesohaline sector, and those more frequently associated with marine conditions dominated in the euhaline sector. The fish assemblages along the estuarine salinity gradient were found to be better characterized by taxonomic metrics than by functional ones. This is most likely because individuals of all functional groups inhabit all salinity sectors, and thus these metrics are not useful for differentiating assemblages along salinity gradients. Our results differ from those of other studies in tropical and subtropical estuaries, which have emphasized the importance of functional groups in determining fish assemblages along salinity gradients.
Acesso aberto (Open Access)
Caracterização da atividade pesqueira em Vila do Conde (Barcarena, Pará), no estuário amazônico
(2011-08) PAZ, Alexsandra Câmara; FRÉDOU, Flávia Lucena; FRÉDOU, Thierry
Vila do Conde is an important industrial complex in the south of the Marajó Bay. Despite the important fishery activity and the vulnerability in terms of environmental impacts, no relevant scientific study on fishery and ichthyofauna has been carried out in the area. This study aimed to describe the fishing activity by monitoring commercial landings of the main site (Praia do Conde) of the region between December 2005 and November 2006. The relative abundance index, catch-per-unit-of-effort (CPUE in kg/fishing trip), was used to identify the harvest season, species and fleet most relevant in the region. Forty-three boats were monitored, mainly small wooden boats. The main fishing gear was the long-line. The main local species were Brachyplatystoma rousseauxii (dourada catfish), Plagioscion squamosissimus (South American silver croaker), Pellona flavipinnis (yellowfin river pellona), P. castelnaeana (Amazon pellona) e B. filamentosum (filhote). Fleets caught an average of 19 kg/trip. Motorised boats were more productive than non-motorised. Two maximum harvest periods were observed: in January and September/October. The gross revenue of the fishery was over R$ 100,000.00. Wooden small boats contributed to 36% of the total catch.
Acesso aberto (Open Access)
Caracterização da ictiofauna durante o período seco, na Baía do Guajará e Baía do Marajó
(Universidade Federal do Pará, 2009) MELO, Ylana Priscila da Costa; FRÉDOU, Thierry; http://lattes.cnpq.br/8119220407894290
The Bay of Guajará and Bay of Marajó coverage area of search and inserted into the context of the estuary Paraense, are characterized by receiving the majority of freshwater discharge and submit macrotidal area. The fishing in this region is of great importance to the economy of several municipalities in the state of Pará, including the capture of several species and different fishing gear and two fleets and technologically distinct (artisanal and industrial). As part of the research study in the Bay of Guajará and Bay of Marajó, it was necessary to contribute with important information related to biology and ecology of the environment, where such information was used to perform the characterization of the fish fauna of the area during the dry period in order to survey the local diversity, since the majority of fish landed in Bethlehem is from these areas through fishing. The study included areas belonging to the state of Pará, covering the port terminals Bay of Guajará and Bay of Marajó. An extra collection was performed in the area of the island of Mosqueiro. The data available so far do not show differentiation in the composition of the fauna of the areas studied. It was estimated a total of 37 fish species, accounting for 4379 individuals in the Bay of Guajará Bay of Marajó and Mosqueiro island, where the family was more representative Scianidade grouping species that contributed the most, which were: Hake (Plagioscion squamosissimus) and Curuca (Stellifer rastrifer) (assumed to be constant, ie, effectively making up the fish fauna of the place in the bay of Guajará, as in the bay of Marajó and the island of Mosqueiro). Among the 37 species, 4 were considered constant, 26 were occasional white and 7 catches. Hake (Plagioscion squamossisimus) and Curuca (Stellifer microps) were the most important species for fisheries in terms of catch per unit effort (CPUE), frequency of occurrence, and relative contribution of Simper analysis (multivariate). Being only the island of Mosqueiro that stood out: Mackerel (Pellona flavipinis), because of marine influence in this area is higher, which thus characterizes the local biota and distinguish it from other regions. Overall diversity was low with greater variations, and the evenness remained free of major difference between the areas. The area had low species diversity compared to other estuaries, mainly explained by the high hydrodynamic of the area and high flow vessels, making the environment inhospitable to the emergence of some species. More emphasis has earned the bay of Guajará has great ecological importance because it is considered as the nursery, and therefore economical, as there are commercial species that spend part of their life cycle there.
Acesso aberto (Open Access)
Composição, abundância e pesca da ictiofauna como indicadores do estado de conservação de dois lagos de várzea no baixo Rio Amazonas (Brasil)
(Universidade Federal do Pará, 2010) ALMEIDA, Morgana Carvalho de; ISAAC, Victoria Judith; http://lattes.cnpq.br/3696530797888724
The Amazon floodplain has a rich biodiversity and its characteristics influence the economically and ecologically important natural aquatic resources for the people. On the basis of these information, the objective of this research was to characterize the composition and abundance of ichthyofauna in two floodplain lakes in the Santarem region, and to understand the use I buy fishers in the Piracãoera and Campos fishing communities, in the Urucurituba region, and Barreira and Correio communities in the Tapará region. Samples were taken in the Aramanaí and Curiquara lakes considering the four hydrological periods (rising, flood, low, dry) for the period between July of 2006 and April of 2007. For the fish sampling were used set gillnets batteries. To collect data on catches of fishermen, forms were used that contained information about the characteristics of the fisheries. We caught 10,146 fish, which were distributed in 156 species, 27 families and 8 orders. The most abundant families in number of individuals were Sciaenidae and Loricariidae. In Aramanaí Lake, the Loricaria sp, was the species with the highest CPUAn with 0.02 individuals per m². hour. In terms of CPUAp featured species Potamotrygon motoro, with 0.13 g.m ². hour and Pterygoplichthys pardalis with 0.11 g. m². hour. In Curiquara Lake, the main catch in number of individuals was represented by the Pachypops fourcroi with 0,001 individuals per m² of gillnet. Curiquara and Aramanaí lakes 9 trophic guilds were identified and for both lakes fish piscivores and detritivores showed the largest catch by weight. The average length of individuals caught in the lakes was 20.27 ± 7.53 cm. The highest mean length of individuals was in the flood and lower in the low period. When fishing is practiced by fishermen used a variety of fishing gear devices highlighting the gill netting. The use of gear depends on the environment exploited, target species, and in addition to the season, and there may be combinations of more than one gear during the catch. The average yield of the fisheries in the two regions was 10 kg.fishermen.dia-1. In Urucurituba region the CPUE average was 16kg.fishermen.dia-1, in Tapará was 4.5 kg.fishermen.dia-1. The Urucurituba’s fishermen showed the higher catch volume and fish marketing. These communities are partially fulfilling the rules of the fisheries agreements.
Acesso aberto (Open Access)
A comunidade ictica e suas interrelacões tróficas como indicadores de integridade biológica na área de influencia do projeto hidrelétrico Belo Monte-Rio Xingu, PA
(Universidade Federal do Pará, 2004-04) CAMARGO-ZORRO, Mauricio; ISAAC, Victoria Judith; http://lattes.cnpq.br/3696530797888724
This study presents applied methodologies to better understand the dynamics of mechanisms characterizing a portion of the Xingu River, with respect to fish communities living in that environment. Through the study of the ichthyofauna it is aimed to verify various environmental standard patterns, in order to assess the current conservation state of a part of the Xingu River. Based on surveys of the local ichthyofauna conducted over seasonal variations, analyses were conducted at the specieS, population and trophic guild levels. With regards to the ecological population level, study of biological parameters such as individual growth rates, asymptotic body length, mortality rates and size at first maturity were good indicators for a better understanding of the life history of those fish groups. Therefore a trend was observed in which species of relatively small body size to followed a "r" type strategy, whilw species of larger body sizes would follow the "k" strategy tactics. From a functional point of view, it was verified that guild community structure is not only a good indicator of convergence patterns to similar ecosystems as like the Xingu River studied stretch, but also a tool to assess its conservation status. A steady- state ecosystem model for the medium Xingu River sector indicated that it is a system highly instable, and simultaneusly look like a mature seasonal system. An apparent seasonal restriction of food availability observed in the studied river section could imply optimum use efficiency and transfer of the trophic resources. A biogeographic study was undertaken based on species occurrence in order to conceptualise the River stretch comprised between the confluences of the Iriri and Xingu Rivers up to the vicinity of of the village Senador José Porfirio, in the Xingu basin. By means of this analysis, it was possible to demonstrate that the medium upstream of waterfalls) and lower (downstream) courses of the Xingu River are parts of two endemic areas. The low affinity of species composition observed in these two sectors is attributed to geographic variations in the landscape. Therefore, the boundaries of the waterfalls around the village of Belomonte and the influence of the Amazon River in the lower Xingu course could trigger differences in ichthyofaunal composition and species abundance when compared to the medium course of that river. Finally, the importance of maintaining all hydrologic connectivity is pointed out in order to maintan the unity of the system, from the headwaters to the mouth. Impacts on environmental processes and fish populations in the medium course of the Xingu River as a result of the eventual construction of the Belemonte hydroelectric dam are discussed.
Acesso aberto (Open Access)
Descrição cariotípica de peixes dos gêneros Baryancistrus, Parancistrus, Peckoltia e Ancistrus (Ancistrinae, Loricariidae) da Bacia Amazônica
(Universidade Federal do Pará, 2003-06-13) SOUZA, Augusto Cesar Paes de; PIECZARKA, Julio Cesar; http://lattes.cnpq.br/6644368250823351
The subfamily Ancistrinae is one of the most diversified among Loricariidae fish, including approximately 200 species, distributed in 26 genera. These fish are easily recognized by the presence of bony plates arranged in series along the body, and by the antero-ventral position of the mouth. Their common names are acaris, bodós, cascudos and sucker-mouth. Species of the subfamily Ancistrinae comprise an important social-economic resource, constituting one of the most important commercial activities in Altamira-PA. In this study, the karyotype of nine species of fish belonging to four different genera (Baryancystrus, Parancistrus, Peckoltia and Ancistru,$) of the subfamily Ancistrinae were analyzed through conventional (Giemsa, C-band and Ag-NORs) and fluorochrome (Chromomycin A3) techniques. The species of the genus Baryancistrus showed a diploid number 2n= 52, and FN=104. NORs were found in an interstitial position of the short arm of a biarmed chromosome. The species B. aff niveatus had large blocks of constitutive heterochromatin, rich in G-C. This character was considered apomorphic. Hence, the karyotype of this species was considered the most derived among the species of this genus. Genus Parancistrus includes species with a karyotypic structure very similar to the one found in Baryancistrus, and the position of NORs could be considered as a possible apomorphy shared by these two genera. The species of the genus Peckoltia showed a diploid number with 52 chromosomes, and FN=102, with large heterochromatic blocks in ali the species. These blocks comprised almost ali the long arras of some submetacentric and subtelocentric chromosome pairs, which could be considered as a possible apomorphy shared by the species of this group. NORs were found in the long arm of a submetacentric pair in P. vittata, and in the maximum of three chromosomes in Peckoltia spl and Peckoltia sp2. Ancistrus ranunculus showed the most derived karyotype among all the species analyzed in this study. This karyotype had 48 chromosomes and FN=80. Cytogenetic analyses so far suggest that inversions were the most important rearrangement that occurred during the chromosomal diversification of Ancistrinae, except in Ancistrus ranunculus, in which Robertsonian rearrangements were also observed.
Acesso aberto (Open Access)
Distribuição espaço-temporal da ictiofauna de poças de maré de um estuário amazônico: interação de fatores
(Universidade Federal do Pará, 2012-02-28) OLIVEIRA, Rory Romero de Sena; GIARRIZZO, Tommaso; http://lattes.cnpq.br/5889416127858884
The intertidal rockpool ichthyofauna has been studied for several years in temperate and tropical regions at the Pacific Coast, however, in Brazil, the knowledge about it is still incipient. The aim of the present study was to investigate the fish assemblages in tidepools located in three different habitats: rocky outcrop, mangrove forest and salt marsh, at Areuá Island, Curuçá river estuary, North Brazil. Samples were taken quarterly from February 2009 to November 2009, during the spring tide, following a standardized methodology. The physicochemical parameters changed along a topographic gradient and were responsible for the spatio-temporal distribution of fish fauna at rocky outcrop tidepools. Salinty, mean depth and substrate heterogeneity were the parameters that more explained the variations in fish fauna distribution A clear segregation of fish assemblages was found between the tidepools of rocky outcrop and vegetated habitats (tideools in mangrove forest and saltmarsh). These findings suggest that the fish fauna has preferences for some habitats influenced by environmental variables and substrate heterogeneity. However, more researches should be conducted taking into account inter-and intra-specific relationships.
Acesso aberto (Open Access)
Diversidade e densidade ictiofaunística em lagos de várzea da Reserva de Desenvolvimento Sustentável Mamirauá, Amazonas, Brasil
(Universidade Federal do Pará, 2006) CHAVES, Rose Cristine Queiroz; QUEIROZ, Helder Lima de; http://lattes.cnpq.br/3131281054700225
The structure of the fish community in amazonian várzea lakes is determined by the flood pulse and seasonal and daily variations in the physico-chemical parameters of the water. The objective of this work was to characterize the fish community structure of four lakes in different stages of the seasonal cycle. Fish samples were taken bimonthly along one year in four lakes at Mamirauá Sustainable Development Reserve, state of Amazonas, Brazil. The richness of species and the fish biomass were analyzed, in order to investigate how much the community patterns were regulated by the environmental variables. A total of 6,058 individual fish were collected, representing 6 orders, 21 families, 76 genera and 116 species. The orders Characiformes and Siluriformes presented the largest variety of families and species, reaching together around 90% of the captured specimens. The fish fauna varied between different periods and lakes, and the highest richness and biomass values were found in the water level dropping season, except in Taracoá Lake with greater richness in the flooding season. The species Potamorhina latior, Potamorhina altamazonica, Mylossoma duriventre, Amblydoras hancokii, Amblydoras sp., Liposarcus pardalis, Psectrogaster amazonica and Osteoglossum bicirrhosum showed the highest number of individuals. Oxydoras niger, Colossoma macropomum, Cichla monoculus, Osteoglossum bicirrhosum, Arapaima gigas and Pseudoplatystoma tigrinum were the dominant species in biomass. The analysis of the physico-chemical parameters indicates that the changes along the year and the flood pulse influence determine the fish community structure, and the set of parameters composed by dissolved oxygen, pH and water temperature seemingly explains the fish community pattern. Similarity Analysis indicates that the fish fauna composition in the same time of the flood pulse in consecutive years are much alike. Therefore, it is probable that the fish community composition is re-established every cycle, with the connection of the different water bodies during the flood.
Acesso aberto (Open Access)
Diversidade e variabilidade espaço-temporal da ictiofauna da região estuarina do rio Curuçá município de Curuçá, Pará Brasil
(Universidade Federal do Pará, 2006) HERCOS, Alexandre Pucci; ISAAC, Victoria Judith; http://lattes.cnpq.br/3696530797888724
The study of estuarine fish communities has called researchers’ attention due to the fact that these ecosystems present a great variety and abundance of fish, many of which have commercial importance. Such studies have become fundamental in the evaluation of fish stocks, and also contributed to the conservation of coastal and estuarine environments. Rio Curuçá’s estuary is located at the coastline in the northern part of the state of Para, although fishing is the main economic activity in towns of the region, there are a few studies on local ictiofauna. The main objective of this study was to characterize the demersal ictiofauna of the main channels in the Curuçá River estuary, identifying annual and spatial variations in the composition, density and biomass of ictiofauna, as well as non-biotic factors that influence these variations. In order to this, data collection trips were carried out once every two months, using trawl net, in two of the main estuary channels. At the end of the study, 18.989 individuals of 73 species were captured. Ophichthus cylindroideus, Hippocampus reidi, Sygnathus pelagicus and Butis koilomatodon had not yet been registered in the state’s north coastline. Sciaenidae, Engraulidae and Ariidae families were the most representative in number of species, density and biomass. 20 species, classified as estuarine, were majority, and presented leading densities and biomass in all months and capture stations. Average density (0,12 ind/m²) was significantly greater during the rainy season, but biomass (1,11 g/m²) did not present significant changes during the months of capture. The Curuçá area has presented greater richness of species, density and biomass. This difference is related mainly to a greater heterogeneity of substrat in the area, and thus a greater availability of microhabitats. Physical and chemical composition of water was homogeneous in capture stations, and had little influence on the spatial distribution of ictiofauna. The registration of new species for the region enforces the importance of other studies for a greater comprehension of local ictiofauna, which is an important economic resource to the local human population.
Acesso aberto (Open Access)
Diversidade, distribuição e estrutura da comunidade de peixes na Estação Científica Ferreira Pena: Amazônia Oriental
(Universidade Federal do Pará, 2001-11-20) MONTAG, Luciano Fogaça de Assis; BARTHEM, Ronaldo Borges; http://lattes.cnpq.br/4192105831997326
The conservation of the biodiversity in aquatic ecosystems is one of the most important and difficult challenges in the current world. According to available information, the biodiversity of aquatic ecosystems is poorly understood in comparison with tropical terrestrial ecosystems. Thus, systematic and taxonomic analyses, the understanding of phylogenetic, biogeographical and ecological relationships represent items that need to be investigated. The first question addressed is the characterization of the ecosystem. We observed that the environmental features, mainly wideness and depth, ranges spatially along the rivers and possess the inferior zone with strong characteristics of river—lake transitional areas. The following question was to estimates fishes richness of in the Ferreira Penna Scientific Station. In order to answer this question, we used protocol techniques and obtained 130 species, of these 39 were separated by morphospecies. This fact indicates that approximately 30% of the fauna might be new or there is no available bibliography for identification. The species collected in the inventory are considered to represent a reasonable set of the ichythyofauna of the region. Lastly, we aimed to characterize fish communities and expose the patterns of distribution of species concerning the investigated habitats. As a result, we observed that the com position of species in the communities followed the substitution and addition pattern. The greatest diversity of species was observed for the final zones of the rivers. The increase in the water volume and area in some habitats of the rivers makes possible their exploitation by a larger number of individuals or new species.
Acesso aberto (Open Access)
Ecologia da ictiofauna do estuário do rio Paciência, Ilha do Maranhão - Brasil
(Universidade Federal do Pará, 2012-02-23) SILVA JÚNIOR, Milton Gonçalves da; CASTRO, Antonio Carlos Leal de; http://lattes.cnpq.br/9450410023114396; SAINT-PAUL, Ulrich; http://lattes.cnpq.br/5897104750785224
Estuarine systems constitute an important habitat for different species of fish. From the ecological standpoint, the ichthyofauna plays an important role in the energy balance between trophic levels in estuarine ecosystems. Thus, the following were aims of the present study: determine the spatiotemporal distribution of the ichtyofauna; explain behavioral and ecological characteristics; compare the composition of relative biomass, ecological and functional guilds in different estuarine systems in northern Brazil; investigate the influence of biotic and abiotic variables and correlations with the biological patterns of the ichthyofauna; and identify changes in the biotic integrity of the tidal creeks studied. Data were acquired through bimonthly sampling in the Iguaiba, Grande and Cristovao tidal creeks between January 2006 and September 2007, using gillnets and block nets. Samples were also taken of the surface water for the determination of physicochemical parameters and dissolved inorganic nutrients. Diversity, evenness and richness indices were employed for the ecological characterization of the species. The biotic integrity index was used to assess the effects of possible environmental changes on the ichthyofauna. Univariate (ANOVA, Kruskall-Wallis) and multivariate (Cluster, nMDS, SIMPER, COIA and ABC curves) statistical methods were used to compare species and capture sites. A total of 12,219 individuals distributed among 55 species and 27 families were caught. The families Sciaenidae, Ariidae, Carangidae, Engraulidae and Mugilidae had the greatest species richness. Ariopsis bonillai and Cetengraulis edentulus made the greatest contribution to the formation of similar groups. Stellifer naso and Cynoscion acoupa were responsible for the dissimilarity between the groups formed. Approximately 66% of the fish caught were juveniles, thereby confirming the use of estuarine systems as nurseries. The records between the Marajoara and Maranhao Gulfs indicate the occurrence of 140 species. Marine occasional visitors and freshwater species occurred occasionally. Marine estuarine-opportunists and estuarine dependents species made the largest contribution to the Maranhão Gulf, whereas estuarine residents species had high biomass values in all estuarine systems investigated. Detritivores occurred mainly in the state of Para and zoobenthivores were found mainly in the state of Maranhao. The occurrence of piscivores was inversely proportional to the abundance of juveniles. The co-structure formed between environment-fish parameters was significant. Salinity, pH, silicate, ammonium, phosphate and nitrate exerted an influence over the structure of the fish community. No species were associated with environments with high concentrations of inorganic nutrients. The ABC curves revealed that the estuarine environment is moderately disturbed and the integrity index characterized the environmental quality of the tidal creeks as very poor to fair. The presence of juveniles demonstrates the importance of tidal creeks to fish development. The ichthyofauna analyzed in the present study exhibits seasonality with regard to hydrological periods. The fish community in tidal creeks can serve as an indicator of the quality of ecosystems submitted to tidal pulses. Therefore, the protection of tidal creeks in mangroves is essential to the management of fishery resources, considering the strong association between ichthyofauna abundance and the structural composition of the habitat.
Acesso aberto (Open Access)
Ecologia da ictiofauna e análise ecossistêmica das áreas de influência direta da UHE Coaracy Nunes, Ferreira Gomes - AP
(Universidade Federal do Pará, 2012-04-25) OLIVEIRA, Júlio Cesár Sá de; NAHUM, Victoria Judith Isaac; http://lattes.cnpq.br/3696530797888724
The reservoir of UHE Coaracy Nunes in Araguari is located between the cities of Porto Grande and Ferreira Gomes in the state of Amapá, Brazil, lying 200 km from the Atlantic Ocean. The Coaracy Nunes was the first dam to be built in the Brazilian Amazon, with its works started in 1967. The Araguari river is the main of the state of Amapá and represents a source of income generation through fishing, farming activities in their floodplain, navigation, mining, power generation and recreation. The present study aimed to assess the changes imposed by the construction of the reservoir of UHE Coaracy Nunes, through the fish assemblages of four areas of direct influence of this plant. For this, from May 2009 to July 2010, fish collections were made bimonthly, with standardized mesh networks ranging from 1.0 to 10.0 cm between knots and other technical aids. From these collections, in the Chapter 1 was investigates the composition, abundance (CPUEn) and biomass (CPUEp) on the fish fauna, sampling efficiency (collector curve, rarefaction curves and Jacknife) and descriptors of ecological communities (richness, diversity, evenness and dominance) of the assemblages of the four areas. We conducted analyzes of variance (ANOVA: factorial), Kruskal-Wallis, t-test and Mann-Whitney test to see if there were significant differences between the descriptors of the areas and seasons. These analyzes were corroborated by multivariate analysis of grouping (cluster), spatial (MDS) and ANOSIM Simper. In chapter 2, the ecological status of the four areas were verified using as indicators: species abundance curves, curves and Kdominance curves ABC, as well as species-abundance models geometric series, log series, log normal and broken stick, and regression model linear size spectra. In chapter 3, the trophic structure was estimated from the categorization of species in each area five guilds: piscivorous, omnivorous, detritivorous, carnivorous and herbivorous. The abundance, biomass and ecological indexes of these guilds were estimated and verified their spatial and temporal variations, by analysis of variance (ANOVA: factorial and Kruskal-Wallis) and Student t test. In chapter 4, the diet of most abundant species assemblage of each area was checked and their spatial and temporal variations detected by analysis of variance (ANOVA: factorial and Kruskal-Wallis). Also estimated the breadth and niche overlap of the most abundant species, as well as the existence of competition between species through modeling zero. In chapter 5 was evaluated four areas of the ecosystem through flow models of biomass in the ecosystem food web, using as a tool for modeling software Ecopath. These analyzes were designed to describe the changes in ecological attributes that quantify the properties of maturity, stability and resilience ecosystem that could reflect the ecological status of these areas. The model included functional compartments from primary producers to top predators. In general, all analyzes indicated significant changes in fish fauna attributed to the implementation of UHE Coaracy Nunes, reflected in the three organizational levels: ecosystem, community (assembly) and guild. The results indicated the capture of 1977 fish divided into two classes, 9 orders, 23 families, 73 genera and 108 species. The species accumulation curves and rarefaction curves showed that samples areas were sufficient to Reservoir and Lacustrine areas. The results showed that the area downstream was more rich, diverse and equitable in relation to other areas and did not influence the seasonal variation in these rates. The relative abundance (CPUEn) was higher in areas Reservoir and Lacustrine and relative biomass (CPUEb) was higher in the downstream, with no seasonal differences for these descriptors in all areas. The cluster analysis (cluster) and spatial (MDS) of the fish fauna permitted to identify the formation of three distinct assemblies: Downstream, Upstream and an assembly comprising Reservoir and Lacustrine areas, confirming the similarity of these two areas. The results of the curves whitake-plot, ABC and K-dominance, as well as the satisfactory adjustment of the broken stick model and the patterns of currvas spectrum size to the assembly area downstream indicate that this area was the most balanced in terms of ecology. Reservoir and Lacustrine areas, the results of both the model adjust geometric series, as the results of the curves whitake-plot, ABC and K-spectrum dominance and size as well as the results of the curves and adjustments to the model spectrum and lower logserie size for the assembly of the reservoir area, reflect that fish these areas, most of them are little guys with high dominance and low evenness, featuring typical of communities impacted areas. The trophic structure of fish assemblages in areas dammed (Reservoir and Lacustrine) formatted according to the bus of the river, which was isolated and fragmented environment, determining their physical modification, requiring the establishment of a fish fauna species pre-adapted to environmental conditions impoundment, different, in part, the structure of the pre-river ichthyofauna bus, highlighting the piscivores, omnivores and detritivores that were the richest and most abundant in the availability in the two areas of food resources of your choice. The results showed that the diets of the assemblies of all areas were similar to the prevalence of consumption of fish and debris, followed by allochthonous plant food, revealing a pattern with a few large clusters and a higher concentration of species with narrower niches. However, the pattern of low amplitude was evidenced by trophic guild dominance of piscivores, added to the detritivore and herbivore guilds. Seasonality little influence on the supply of most species in all areas. The comparative patterns of diet among the areas upstream and downstream to the Reservoir and Lacustrine areas indicate that most species of impoundment areas belonged to guilds piscivorous, omnivorous and detritivorous bus before the river, which colonized these environments, influenced mainly by abundance of food resources on their preferences and physical conditions are favorable. Competitive interactions were evidenced by the null model, suggesting that competition was also an important factor in structuring assemblages. Ecossistemicamente, the four flow models represent ecosystems with high biomass production primári coming from the riparian forest and filamentous algae, which are partially used. The detritus-based food chain had to be more important than that is based on primary aprodução Reservoir and Lacustrine areas. Most flow occurs in compartments lower trophic levels. The properties area downstream ecosystem indicate that this environment is further developed and couple, characterized by a high resilience and entropy. The area presented Reservoir ecosystem attribute features that conferred less resilient and more stable, but less than the couple areas of the river. The Lacustrine area presented attributes characterizing an environment of intermediate resilience, stable immature and at the same time. The Upstream area showed a pattern intermediate amount of resilience, stability and maturity.
Acesso aberto (Open Access)
Efeito da alteração do hábitat sobre assembleias de peixes em igarapés afogados da Amazônia oriental
(Universidade Federal do Pará, 2014-02-26) SOUSA, Híngara Leão; FERREIRA, Cristiane de Paula; http://lattes.cnpq.br/7804816854015308; MONTAG, Luciano Fogaça de Assis; http://lattes.cnpq.br/4936237097107099
The natural aquatic ecosystems are complex systems that are exposed to a variety of disturbances. In the Amazon region, for instance, land use and occupation have altered the physical structure of aquatic environments, especially regarding the small streams, influencing their communit structure and composition. This has led to research development and evaluation programs to see how the changes that are occurring in these environments affect biotic communities, through habitat characteristics that are more sensitive to disturbance. Thus, this study aimed to describe and measure physical attributes of drowned out streams and evaluate how fish assemblages respond to different levels of streams physical integrity. Our hypothesis is that structurally intact environments endure a more diverse ichthyofauna than altered environments, since their decreased environmental complexity limits the potential ecosystem, because they presented a decrease in environmental complexity. The study was conducted in 34 streams, 17 located within the territory of Caxiuanã National Forest, and 17 in its surroundings, located close to Portel and Melgaço cities (PA). The process of urbanization is expanding in the region, reaching areas of forests and streams that are still preserved. There is also an intense logging, because the area is included in the main timber pole of the estuary in the state of Pará. The physical habitat was evaluated according to a standardized protocol of stream environmental assessment. The samplings were conducted with hand nets passed along 150 meter long reaches during six hours (divided among segments and collectors). Although a set of metrics which responded to the local impact gradient has been detected these were not sufficient to reduce or increase the number of species across different levels of preservation, maintaining substantially constant the wealth and abundance for all three groups (altered, intermediate and preserved). However, the difference was significant for the composition, with eleven exclusive exclusive species of altered habitats and eight preserved environments. The degradation of the physical environment, even at smaller scales favors the occurrence and abundance of most tolerant species and phenotypic plasticity, in addition to the population increase of opportunistic species. Different effects can be exerted on the groups of species that make up a community, since they have different biological and ecological attributes that include your answers to the same ecological variables. Therefore, the possible deconstruction of community groups of species (taxonomic, functional, etc.) may show different responses to the changes of habitat, being a promising strategy for linking environmental standards of richness characteristics displayed by these communities. Assessment of biotic integrity is also an alternative to identify effects of habitat alteration on species, especially considering the region’s peculiarity and the lack of information about the local ichthyofauna.
Acesso aberto (Open Access)
Efeito da monocultura de dendezeiro (Elaeis guineensis JACQ.) na integridade física e nas assembleias de peixes de igarapés da Amazônia Oriental
(Universidade Federal do Pará, 2014-02-25) FERREIRA, Márcio Cunha; JUEN, Leandro; http://lattes.cnpq.br/1369357248133029; MONTAG, Luciano Fogaça de Assis; http://lattes.cnpq.br/4936237097107099
The aim of the present study is to evaluate the effect of palm oil farming Elaeis guineenses JACQ. in the integrity of physical habitat and in the assemblages of fishes in upland streams of Eastern Amazonia. The sampling sites were established in sections (150 m) of 23 streams in the Acará-Mirim basin, northeastern of Pará state. According to the results of the index of physical integrity, all streams (n = 8) that drain forest areas were classified as preserved (IPI = 5.00 to 4.00), whereas the 15 streams that drain oil palm plantations have been classified as changed (IIF = 3.67 to 2.67). 9,734 specimens of fish belonging to six orders, 24 families, over 64 species were collected. The most abundant species during the study were Microcharacidium weitzmani, Apistogramma gr. regain, Trichomycterus hasemani, Hyphessobrycon heterorhabdus and Copella arnoldi. The richness observed in streams that drain plantations was higher (S = 61) than found in the streams in forest fragments (S = 42). The results of PERMANOVA show that exist differences between sites (GL = 22; pseud – F = 2.44; P = 0.01), however the ordering produced by NMDS shows that this difference is subtle (stress = 0.19). a similar result was obtained using functional trophic groups abundance (stress = 0.18). the results of TITAN indicates that some species are adapted to persist in certain environmental conditions, such as Aequidens tetramerus, Apistogramma agassizii and Microcharacidium weitzmani are associated with lower physical habitat integrity (P < 0.05; purity > 0.95; reliability > 0.95), while the species Hyphessobrycon heterorhabdus and Helogenes marmoratus shown to be indicative of more intact habitats (P < 0.05; purity > 0.95; reliability > 0.95). There was no correlation between the species richness and the index of physical integrity, while the only functional trophic groups that correlated with the index were the diggers and collectors browsers. These groups are composed by Cichlid fishes that have tolerant and generalist behaviors that may have explained his great contribution in the fish assemblage even in places where sedimentation was high compared to places with the nearest natural setting. This shows that even species richness was higher in altered streams there are strong evidences of loss of environmental quality in streams draining plantations generated by the cultivation of oil palm.
Acesso aberto (Open Access)
Efeito de bacias e de variáveis ambientais na estrutura de comunidades de peixes de igarapés na região do interflúvio Madeira-Purus
(Universidade Federal do Pará, 2008) BARROS, Daniela de França; ZUANON, Jansen Alfredo Sampaio; http://lattes.cnpq.br/0161925591909696; ALBERNAZ, Ana Luisa Kerti Mangabeira; http://lattes.cnpq.br/1220240487835422
The main objective of this study was to investigate the richness and composition of the fish fauna in headwaters of streams in the Madeira-Purus interfluvial region, and if they are related to environmental variables and / or watersheds. Data was collected along two field campaigns, lasting approximately 20 days each, between the months of April and July 2007. A total of 22 streams were sampled, belonging to five different watersheds. Fish were captured with hand nets and small seine nets. Information on the structural characteristics of the streams and physical-chemical of water was also obtained. A total of 5509 fish were captured, belonging to 86 species, 22 families and six orders. Characiformes was the most diversified taxonomic group, followed by Gymnotiformes and Siluriformes. The species composition was influenced mostly by the width and depth of the channel, discharge and substrate. The presence of different environments around creeks has also contributed to the differences in fish species composition. The watersheds had strong effect on communities of fish. However, the results cannot allow to assert with certainty if differences in fish composition among watersheds are reflecting historical effects or environmental conditions.
Acesso aberto (Open Access)
Efeitos do espaço e do ambiente sobre assembleias de peixes de igarapés da Amazônia oriental
(Universidade Federal do Pará, 2012) BENONE, Naraiana Loureiro; MONTAG, Luciano Fogaça de Assis; http://lattes.cnpq.br/4936237097107099
The amazon streams have harsh environmental characteristics for several fish species due to their oligotrophic conditions. In spite of that, these watercourses possess a rich and diversified ichthyofauna, resulting from the various microhabitats found in streams. In ria lake systems, the rivers and streams suffer a natural impoundment, which provokes a lowering on current velocity values. This could homogenize the environment, since current velocity affects many of the streams features. Thereby, distance between streams could have its importance emphasized as a structural factor of stream fish assemblages. This study aimed to analyze the influence of space and environment on the structure of fish assemblages in drowned streams of Caxiuanã, in Eastern Amazon. The fishes were caught during the period of drought of 2010, including 34 transects of drowned streams. Eight abiotic factors were measured to test the effect of the environment. To analyze the effect of the space, space filters were calculated based on the geographical coordinates, as well as the distance among the streams following the watercourse. The analyses showed that the environment was the only factor to influence the beta diversity, refuting the hypothesis of the space as a structuring factor and reinforcing the paper of the ecological niche in the distribution of species. Nevertheless, the abiotic factors explained a low percentage of the variation in the fish composition, what shows that other variables can affect these assemblages.
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)
Estradas, alagados antrópicos, peixes e a fragmentação de redes fluviais em uma paisagem agrícola do Nordeste do Pará
(Universidade Federal do Pará, 2011-04-18) BREJÃO, Gabriel Lourenço; GERHARD, Pedro; http://lattes.cnpq.br/5621269098705408
Badly planned roads crossing streams can generate small impoundments in channel segments upstream these crossings, turning lotic environments into lentic ones. The aim of this work was to study the diversity and functional structure of fish communities in anthropic impoundments in northeastern Pará state. These impoundments are formed due to roads construction on the riverine network, with large or small impacts on the hydrological connectivity, subject that is largely ignored for Neotropical lotic systems. Eighteen reaches were sampled in seven streams: six crossed by roads, and one not crossed by roads, used as a reference. Five streams are located in the cities of Igarapé-Açu and Marapanim in an agricultural landscape, and two in the city of São Francisco do Pará in a forest matrix. Five of six streams crossed by roads showed the formation of large impounded areas. In these locations three reaches were selected to sample fish: one upstream, one inside, and another one downstream the impoundment. In the not impounded stream only two reaches, upstream and downstream the road crossing the channel, were selected. The selected environments were sampled once between June and November, 2010, using visual census techniques (ad libitum and linear transect) in 200 m extension reaches. Seventy three species distributed in six orders, 26 families and 63 genera were registered. Characiformes (38.4%) and Siluriformes (31.5%) were the most representative orders in species number. Characidae, with 15 species (20.5%), e Cichlidae, with 10 (13.7%), were the most representative families in species number. These species were organized in 18 functional trophic groups (FTG) formed according to the most frequency observed feeding tactics to and its observed spatial distribution during the diving sessions. The impoundments enforced modifications in the streams biotic (assemblage taxonomic and functional structure) and physical structure of the streams. These environments showed lower species richness, higher abundance and lower FTG diversity in relation to the upstream and downstream reaches. The impoundments showed larger width, depth and high temperature besides less average speed and dissolved oxygen when compared to the upstream and downstream reaches. The use of functional trophic groups approach allowed to understand how the riverine network fragmentation process interfere in the studied fish assemblage structure.