ABSTRACT
METHODS: Sampling was performed at three sites in the Tapajós River mouth, Pará State, Brazil, and an aliquot of blood was collected from each turtle by post-occipital dorsal vein puncture. The aliquots were used for the determination of hematological parameters and for the study of hemoparasites in the blood samples. RESULTS: A total of 37 turtles were sampled: 21 Podocnemis expansa, three P. sextuberculata, nine P. unifilis, and four P. erythrocephala. Parasitological analyses showed inclusions in erythrocytes compatible with Haemogregarina sp., representing an overall prevalence of parasitized animals of 64.8% with an average of 94,789 parasites/ml of blood. In this study, the evolutionary forms of Haemogregarina spp. from trophozoites, pre-meronts, meronts, and mature and immature gamonts were observed in three species of freshwater turtle species, and one morphotype of the parasite with high similarity to Haemogregarina podocnemis has been observed. CONCLUSION: Despite recent research on freshwater turtles, this study provides new information on the intensity of blood parasite infection and hematological parameters of free-living animals, highlighting the need for studies on infected and uninfected animals from the same population.
Subject(s)
Turtles , Animals , Turtles/parasitology , Turtles/blood , Brazil/epidemiology , Fresh Water , Erythrocytes/parasitology , Rivers , PrevalenceABSTRACT
Abstract Introduction: Chemical pollution represents a great concern to aquatic organisms, especially fish. Metals enter the aquatic environment from a variety of sources, including natural biogeochemical cycles and anthropogenic sources such as industrial and residential effluents, mining and atmospheric sources. Objective: To describe the Eustrongylides sp. larvae and the interaction with their fish hosts as indicators of mercury (Hg) contamination in the Brazilian Amazon, and the distribution of Hg in the internal organs of fish species Hoplias malabaricus and Pygocentrus nattereri collected in oxbow lakes on the Tapajós River, in the municipality of Santarém, in the state of Pará. Methods: Total Hg was analyzed using the Direct Hg Analyzer - DMA-80. Concentrations of Hg in Eustrongylides sp. were compared with those found in the tissues/organs of the hosts H. malabaricus and P. nattereri. Hg concentrations in the host/parasite system were statistically compared using Principal Component Analysis. The bioconcentration factor (BCF) was calculated to assess the bioaccumulation capacity of metals in Eustrongylides sp. larvae, comparing the concentration of Hg in the parasite with that accumulated in the musculature of infected hosts. Results: Hg concentrations in all tissues/organs analyzed were higher in the parasitic species Eustrongylides sp. larvae when compared with those found in tissues/organs of H. malabaricus and P. nattereri. There was an inversely proportional relationship, showing that when Eustrongylides sp. larvae are present, the concentration in the parasite is higher than in the musculature of host fish H. malabaricus and P. nattereri. The BCF of Hg was found by comparing Eustrongylides sp. larvae/H. malabaricus muscle and was observed during a flood (BCF Hg = 15 364). Conclusions: The results confirm the greater bioaccumulative capacity of Eustrongylides sp. compared to its host. The data indicated the viability of using Eustrongylides sp. larvae in biomonitoring programs. It is worth mentioning that fish samples for Hg analysis must be free of parasites since their presence can alter the results.
Resumen Introducción: La contaminación química del hábitat acuático representa un gran peligro para organismos acuáticos, especialmente para peces. Los metales ingresan al ambiente acuático desde una variedad de fuentes, incluidos los ciclos biogeoquímicos naturales y fuentes antropogénicas, como efluentes industriales y residenciales, minería y fuentes atmosféricas. Objetivo: Describir las especies de Eustrongylides sp. y la interacción con sus peces hospederos como indicadores de contaminación por mercurio en la Amazonía brasileña, y la distribución en los órganos internos de las especies de peces Hoplias malabaricus y Pygocentrus nattereri recolectadas en cochas del Río Tapajós, en el municipio de Santarém, del estado de Pará. Métodos: El Hg total se analizó utilizando el Direct Hg Analyzer - DMA-80. Las concentraciones de Eustrongylides sp. se compararon con las encontrados en los tejidos/órganos de los hospederos H. malabaricus y P. nattereri. Las concentraciones en el sistema hospedero/parásito se compararon estadísticamente utilizando el análisis de componentes principales. Se calculó el factor de bioconcentración (BCF) para evaluar la capacidad de bioacumulación de metales en larvas de Eustrongylides sp., comparando la concentración en el parásito con la acumulada en la musculatura de los hospederos infectados. Resultados: Las concentraciones de Hg en todos los tejidos/órganos analizados fueron mayores en las larvas de la especie parasitaria Eustrongylides sp. en comparación con las encontradas en los tejidos/órganos de H. malabaricus y P. nattereri. Hubo una relación inversamente proporcional, mostrando que cuando las larvas de Eustrongylides sp. están presentes, la concentración en el parásito es mayor que en la musculatura de los peces hospederos H. malabaricus y P. nattereri. El BCF de Hg se encontró comparando Eustrongylides sp. larvas/ músculo H. malabaricus y se observó durante una inundación (BCF Hg = 15 364). Conclusiones: Los resultados confirman la mayor capacidad bioacumulativa de Eustrongylides sp. en comparación con su hospedero. Los datos indicaron la viabilidad de utilizar larvas de Eustrongylides sp. en programas de biomonitoreo. Cabe mencionar que las muestras de pescado para análisis de Hg deben estar libres de parásitos ya que su presencia puede alterar los resultados.
Subject(s)
Animals , Mercury/analysis , Nematoda/microbiology , Brazil , River Pollution , Amazonian Ecosystem , Fishes/microbiologyABSTRACT
Small-scale fisheries provide income and food security to local peoples around the world. In the Brazilian Amazon, the pescada (Plagioscion squamosissimus) is among the fishes that contributes most to catches in small-scale fisheries. Our main goal was to evaluate the abundance, size, relevance to small-scale fisheries and trophic ecology of P. squamosissimus in the Tapajós and Tocantins rivers, in the Brazilian Amazon. We combined data from fishers' local ecological knowledge (LEK) and fish sampling. We expected that fishers in the Tapajós River, less altered by anthropic changes, would cite a higher abundance, larger size and more prey and predators of P. squamosissimus. We interviewed 61 and 33 fishers and sampled fish in nine and five sites in the Tapajós and Tocantins rivers, respectively. The comparison between fishers' citations and fish sampled indicated a higher relevance of P. squamosissimus to fishers in the Tapajós River, where this fish had an average larger size and where the fishers mentioned more food items. This pattern could be partially related to the history of anthropogenic changes in the Tocantins River. These results indicated that P. squamosissimus is a generalist fish, which could be resilient to fishing and environmental pressures.(AU)
A pesca de pequena escala fornece renda e segurança alimentar para as populações locais em todo o mundo. Na Amazônia brasileira, a pescada (Plagioscion squamosissimus) está entre os peixes que mais contribuem para as capturas em pescarias de pequena escala. Nosso objetivo principal foi avaliar a abundância, tamanho, relevância para a pesca artesanal e ecologia trófica de P. squamosissimus nos rios Tapajós e Tocantins, na Amazônia brasileira. Combinamos dados do conhecimento ecológico local dos pescadores (CEL) e amostragem de peixes. Esperávamos que os pescadores do rio Tapajós, menos alterado por mudanças antrópicas, citassem maior abundância, maior tamanho e mais presas e predadores de P. squamosissimus. Entrevistamos 61 e 33 pescadores e amostramos peixes em nove e cinco locais nos rios Tapajós e Tocantins, respectivamente. A comparação entre as citações dos pescadores e os peixes amostrados indicou uma maior relevância de P. squamosissimus para os pescadores do rio Tapajós, onde este peixe teve um tamanho médio maior e onde os pescadores mencionaram mais itens alimentares. Esse padrão pode estar parcialmente relacionado ao histórico de mudanças antrópicas no rio Tocantins. Esses resultados indicaram que P. squamosissimus é um peixe generalista, que pode ser resiliente à pesca e às pressões ambientais.(AU)
Subject(s)
Animals , Perciformes , Hunting , Brazil , Amazonian Ecosystem , Knowledge , Trophic LevelsABSTRACT
The pelagic shrimp, Acetes paraguayensis Hansen, 1919, is an ecologically important species with an enormous socioeconomic value for the human populations in the regions where it occurs. This species also has considerable potential for shrimp farming, although few details are known of its biology. This study investigated the artisanal exploitation of A. paraguayensis stocks in the northern Brazilian municipality of Santarém over 16 months, focusing on the types of equipment most used to harvest of this shrimp, the fishing dynamics, and production patterns. The matapi trap was the principal method used of harvesting A. paraguayensis in the study region, conforming to a typically artisanal, small-scale fishing production system. This study results provide an essential research tool for developing conservation and management strategies and the eventual establishment of farming protocols.
O camarão pelágico, Acetes paraguayensis Hansen, 1919, é uma espécie ecologicamente importante, de enorme valor socioeconômico para as populações humanas localizadas nas regiões produtoras. Essa espécie tem também um potencial considerável para o cultivo, embora poucas informações sejam conhecidas da sua biologia. Assim o presente estudo investigou a exploração artesanal das po-pulações de A. paraguayensis no município paraense de Santarém, no Norte do Brasil, por 16 meses, concentrando-se nos tipos de equipamento mais utilizados para sua captura, na dinâmica pesqueira e nos padrões de produção. O matapi foi o principal método utilizado, configurando-se como um sistema de produção pesqueira tipicamente artesanal de pequena escala. Os resultados do presente estudo constituem importante instrumento de investigação para o desenvolvimento de estratégias de conservação e gestão e o eventual estabelecimento de protocolos de cultivo.
Subject(s)
Animals , Decapoda , Hunting , Brazil , RiversABSTRACT
Abstract: Larvae of non-biting midges in the family Chironomidae can be found in association with several species of fish in the family Loricariidae. In this study, we describe the first record of phoretic interaction between larvae of Ichthyocladius sp. and the fish Hisonotus chromodontus in streams in the Amazon basin. Between July 2010 and March 2019, fish were collected from three streams of the Teles Pires River basin in the state of Mato Grosso, Brazil. We investigated the attachment site of chironomid larvae on the body of fish and the frequency of attachment. A total of 1.241 specimens of H. chromodontus were collected, among which nine hosts were found carrying in the ventral region a single Ichthyocladius sp. specimen. All Ichthyocladius sp. were attached to a spicule of fish between the pectoral and pelvic fins, in which they were observed at the fourth developmental stage at the beginning of the cocoon construction (1.50 mm). In addition, a pre-pupa larva (2.60 mm) and an empty cocoon (2.50 mm) were reported. The Loanda stream had the highest occurrence of this type of association (of 12 fish examined, three had larvae). The other two streams reported a lower occurrence: the Baixada Morena stream had three fish associated with larvae amongst 1105 fish examined, whereas the Selma stream had three out of 124 fish infested by larvae. The occurrence of only one larva per host can be related to the small body area of the host fish (average standard length = 26.60 mm and average weight = 0.31 g). We observed that the larvae prefer fixation sites in the vicinity of the pectoral and pelvic fin of the fish, which is presumably associated with the fact that chironomids feed on algae and debris suspended by the movement of loricariids. These streams differ with respect to the presence of riparian forests, which may affect resource availability and thereby influence ecological interactions between the species.
Resumo: Larvas de mosquitos da família Chironomidae podem ser encontradas em associação com várias espécies de peixes da família Loricariidae. Neste estudo, descrevemos o primeiro registro de interação forética entre larvas de Ichthyocladius sp. e o Hisonotus chromodontus em riachos da bacia amazônica. Entre julho de 2010 e março de 2019, foram coletados peixes em três riachos da bacia do rio Teles Pires, no estado de Mato Grosso, Brasil. Nós investigamos o local de fixação das larvas de quironomídeos no corpo dos peixes e a frequência da fixação. Um total de 1.241 espécimes de H. chromodontus foram coletados, entre os quais nove hospedeiros foram encontrados carregando, na região ventral, um único espécime de Ichthyocladius sp. Todos os Ichthyocladius estavam aderidos a uma espícula do peixe entre as nadadeiras peitoral e pélvica, onde foram observados no quarto estágio de desenvolvimento, no início da construção do casulo (1,50 mm), além de uma pré-pupa (2,60 mm) e um casulo vazio (2,50 mm). O riacho Loanda apresentou a maior ocorrência de hospedeiros na associação (de 12 peixes examinados, três estavam com larvas) e o menor registro foi para o riacho Selma (dos 1105 peixes examinados, três estavam infestados). A ocorrência de apenas uma larva por hospedeiro pode estar relacionada à pequena área corporal do peixe hospedeiro (comprimento padrão médio = 26,60 mm e peso médio = 0,31 g). Observamos que as larvas preferem locais de fixação nas proximidades da nadadeira peitoral e pélvica dos peixes, o que está presumivelmente associado ao fato dos quironomídeos se alimentarem de algas e detritos suspensos pelo movimento dos loricarídeos. Os riachos diferem com relação à presença de matas ciliares, que podem afetar a disponibilidade de recursos e, assim, influenciar as interações ecológicas entre as espécies.
ABSTRACT
Artisanal and small-scale gold mining (ASGM) flourishes along many tropical rivers, and it still requires proper documentation in many countries, as well as interpretation in terms of rational resource exploitation and wildlife preservation. In this study we used remote sensing techniques to analyze two representative examples of ASGM: one along the Marupa River in Brazil (Tapajós Domain) and another one along the Kahayan River in Indonesia (Central Kalimantan). The documented spatial extent of ASGM is ~9175 km2 along the Marupa River and ~30,427 km2 along the Kahayan River. It was established these activities change rapidly (2-3 years) in space. Although active and inactive sites occur in both areas, a great number of inactive sites distinguish the Marupa River. It is very crucial that ASGM along the Marupa and Kahayan rivers link strongly to watercourse meanders, but also changes river valley morphology. This is an interesting evidence of coupled fluvial-anthropic morphodynamics of meandering river valleys. Geological phenomena represented in the study areas include gold resource exploitation (economic phenomenon), landforms and their dynamics (geomorphological phenomenon), and mercury environmental pollution (geochemical phenomenon). Due to remarkable spatial extent and evident interconnection, these phenomena seem to be unique and, thus, constituting geological heritage. Identification of the latter means that ASGM sites add value to the local environment. A paradox is that illegal and mercury-releasing ASGM needs termination, but such an action will result in the loss of the noted geological heritage value. Solution to this paradox requires careful development of plans for local management. However, it is clear that the presence of the noted heritage requires turning more attention to ASGM and their natural (river valley) context.
ABSTRACT
This study compared the monogeneans community in C. monoculus from the Tapajós River (state of Pará) and Jari River (state of Amapá), northern Brazil. A total of 2188 monogeneans belonging to eight taxa were collected from the gills of fish: Gussevia arilla, Gussevia longihaptor, Gussevia tucunarense, Gussevia undulata, Sciadicleithrum ergensi, Sciadicleithrum umbilicum, Sciadicleithrum uncinatum and Tucunarella cichlae. Gussevia arilla was the dominant species for C. monoculus from the Tapajós River basin, while S. umbilicum predominated among the hosts from the Jari River basin. For the two populations of C. monoculus, the prevalence, mean intensity and mean abundance of monogeneans were different and the of parasites community had a high qualitative similarity (87.5 %). The monogeneans community of C. monoculus was characterized by high species richness, with infection values varying from low to moderate. The geographic distance and differences in environmental characteristics arising from the same did not influence the richness of species of monogeneans infesting C. monoculus in the Tapajós and Jari rivers, but appear to have been determinants in the differences observed in the structure of the monogenean communities in each region.
ABSTRACT
Although the Atlantic Forest marmosets (Callithrix spp.) are among the best studied Neotropical primates, the Amazonian marmosets (Callibella humilis, Cebuella spp. and Mico spp.) are much less well-known. Even species diversity and distributions are yet to be properly determined because field data and materials currently available in scientific collections do not allow comprehensive taxonomic studies of Amazonian marmosets. From 2015 to 2018, we conducted 10 expeditions in key-areas within southern Amazonia where little or no information on marmosets was available. In one such region-the Tapajós-Jamanxim interfluve-we recorded marmosets with a distinctive pelage pigmentation pattern suggesting they could represent a new species. We tested this hypothesis using an integrative taxonomic framework that included phylogenomic data (ddRAD sequences), pelage pigmentation characters, and distribution records. We found that the marmosets of the northern Tapajós-Jamanxim interfluve have unique states in pelage pigmentation characters, form a clade (100% support) in our Bayesian and Maximum-Likelihood phylogenies, and occur in an area isolated from other taxa by rivers. The integration of these lines of evidence leads us to describe a new marmoset species in the genus Mico, named after the Munduruku Amerindians of the Tapajós-Jamanxim interfluve, southwest of Pará State, Brazil.
ABSTRACT
Specimens of the Cichla pinima are of ecological and economic importance in the Amazon region and are a good bioindicator species of Hg bioaccumulation. Adult specimens of Cichla pinima were obtained by fisheries in the Tapajós river region's impacted gold mining area. Tissues such as muscle, liver, skin, and gill were submitted for total mercury (THg) analysis. For hepatic bioavailability, assays were carried out in the whole liver and in the sub-cellular hepatic fraction. The weight-length relationship showed an equation of W = 2E - 06L3.3002 (R2 = 0.856) indicating an allometric growth. The mean THg values found in the muscle tissue of 676 ± 258 µg kg-1 were below the maximum limit established for human consumption, but were similar to Cichla fish from other areas impacted by Hg in the Amazon region. The trends of levels in the tissues were as follows: liver>muscle>gonads>skin>gill, with no significant differences between the gills and skin. A significant and positive correlation as rs = 0.65 was obtained between the THg contents in cytosolic fraction and the total hepatic THg (liver homogenate). However, only 7% of the THg were found and were available to the sub-cellular hepatic fraction. This profile can be an indicative of a hepatic cellular transference in fish exposed to high Hg levels in the Amazon region now that low concentrations of Hg have been found in the sub-cellular fraction. However, data of differential THg partition in the subcellular compartments should be considered, since others' hepatic fractions can act in the Hg linkage into the cell.
Subject(s)
Dietary Exposure/statistics & numerical data , Environmental Monitoring , Fishes/metabolism , Mercury/metabolism , Water Pollutants, Chemical/metabolism , Animals , Brazil , Cichlids , Ecology , Gold/analysis , Humans , Mercury/analysis , Mining , Muscles/chemistry , Rivers , Seafood/analysis , Water Pollutants, Chemical/analysisABSTRACT
The Amazon basin includes 1000s of bodies of water, that are sorted according to their color in three types: blackwater, clearwater, and whitewater, which significantly differ in terms of their physicochemical parameters. More than 3,000 species of fish live in the rivers of the Amazon, among them, the sardine, Triportheus albus, which is one of the few species that inhabit all three types of water. The purpose of our study was to analyze if the gene expression of T. albus is determined by the different types of water, that is, if the species presents phenotypic plasticity to live in blackwater, clearwater, and whitewater. Gills of T. albus were collected at well-characterized sites for each type of water. Nine cDNA libraries were constructed, three biological replicates of each condition and the RNA was sequenced (RNA-Seq) on the MiSeq® Platform (Illumina®). A total of 51.6 million of paired-end reads, and 285,456 transcripts were assembled. Considering the FDR ≤ 0.05 and fold change ≥ 2, 13,754 differentially expressed genes were detected in the three water types. Two mechanisms related to homeostasis were detected in T. albus that live in blackwater, when compared to the ones in clearwater and whitewater. The acidic blackwater is a challenging environment for many types of aquatic organisms. The first mechanism is related to the decrease in cellular permeability, highlighting the genes coding for claudin proteins, actn4, itgb3b, DSP, Gap junction protein, and Ca2+-ATPase. The second with ionic and acid-base regulation [rhcg1, slc9a6a (NHE), ATP6V0A2, Na+/K+-ATPase, slc26a4 (pedrin) and slc4a4b]. We suggest T. albus is a good species of fish for future studies involving the ionic and acid-base regulation of Amazonian species. We also concluded that, T. albus, shows well defined phenotypic plasticity for each water type in the Amazon basin.
ABSTRACT
The fish fauna of freshwater streams in the Tapajos National Forest was surveyed and a list of species is presented. The sampling was conducted from 2012 to 2013 during the dry season. Fish were collected with dip nets and seine nets in 22 streams of 1(st) to 3(rd) order. Sampling resulted in 3035 specimens belonging to 117 species, 27 families and six orders. The most abundant species were Bryconops aff. melanurus, Hemigrammus belottii, and Hemigrammus analis. Four undescribed species were recognized, one of which is known only from the area of this study. A significant dissimilarity was observed in fish species composition among drainage systems. This is the first survey of the stream ichthyofauna in the Tapajós National Forest, and it presents relevant information for future studies and decision-making in the management and conservation of fish fauna in this conservation unit.
ResumoA ictiofauna de riachos na Floresta Nacional do Tapajós foi inventariada e uma lista de espécies é apresentada. As amostragens foram realizadas de 2012 a 2013 durante o período de águas baixas. Os peixes foram coletados com redes de arrasto e peneiras em 22 riachos de 1ª a 3ª ordem. As amostragens resultaram em 3035 espécimes pertencentes a 117 espécies, 27 famílias e seis ordens. As espécies mais abundantes foram Bryconops aff. melanurus, Hemigrammus belottii and Hemigrammus analis. Quatro espécies novas foram reconhecidas, sendo uma conhecida apenas da área de estudo até o presente momento. Foi observada uma dissimilaridade significativa na composição de espécies de peixes entre os sistemas de drenagem. Esse é o primeiro inventário da ictiofauna de riachos na Floresta Nacional do Tapajós e apresenta informações relevantes para subsidiar estudos futuros e a tomada de decisões no gerenciamento da ictiofauna nessa Unidade de Conservação.
ABSTRACT
The Teles Pires River basin is located in an area of the Southern Amazon where discharge of tannery effluents and intense agricultural activity occurs. These activities increase the risk of contamination by runoff and leaching of pesticides and heavy metals. This study presents the concentration and bioaccumulation of heavy metals copper (Cu) and total chromium (Cr) in matrinxã (Brycon falcatus), a species of fish highly consumed in the region. Liver and muscle tissue was analyzed from 41 samples of B. falcatus collected during the dry season in 2013 from the Teles Pires River basin. Considering that bioaccumulation is the progressive increase in the amount of a substance in an organism or part of an organism, copper bioaccumulation in liver samples from B. falcatus was verified. Cr and Cu concentrations were higher in the liver than in the muscle tissue of fish collected in all rivers. The highest concentrations of Cr in the liver were observed in fish collected from the Teles Pires River (1.87 µgâ¢g -1) and the Celeste River (1.06 µgâ¢g -1). The highest concentrations of Cu in the liver were observed in fish collected from the Cristalino River (44.20 µgâ¢g-1) and the Teles Pires River (34.77 µgâ¢g-1). The high concentration of Cu in the livers of fish collected from the Teles Pires river basin reflects the economic activities of mining and agriculture in the surrounding areas of this basin.
Na Amazônia Meridional a bacia do rio Teles Pires está numa área onde existe despejo de efluentes de curtumes e intensa atividade agrícola, aumentando o risco de lixiviação e escoamento de defensivos agrícolas e metais pesados. Este estudo apresenta a concentração e bioacumulação de metais pesados, cobre (Cu) e cromo (Cr) total no matrinxã, Brycon falcatus, uma espécie de peixe muito consumida regionalmente. Analisamos o fígado e tecido muscular de 41 exemplares de B. falcatus coletados durante a estação seca de 2013 na bacia do rio Teles Pires. Considerando que bioacumulação é o aumento progressivo na quantidade de uma substância em um organismo ou parte deste, verificamos bioacumulação de cobre nas amostras de fígado de B. falcatus. As concentrações de Cr e Cu foram maiores no fígados do que no músculo dos peixes nos rios coletados. As maiores concentrações de Cr no fígado foram observadas nos peixes coletados no rio Teles Pires (1,87 µgâ¢g-1) e no rio Celeste (1,06 µ gâ¢g-1). As maiores concentrações de Cu no fígado foram observadas nos peixes coletados no rio Cristalino (44,20 µgâ¢g-1) e no rio Teles Pires (34,77 µ gâ¢g -1). As altas concentrações de Cu no fígado dos peixes coletados na bacia do rio Teles Pires refletem as atividades econômicas do garimpo e agricultura no entorno desta bacia.
Subject(s)
Animals , Metals, Heavy , Hydrographic Basins , Chromium , Amazonian Ecosystem , CopperABSTRACT
The study present evaluated the levels of mercury (Hg) and methylmercury (MeHg) in hair samples of people from Barreiras community, riverside inhabitants of the Tapajós River (Pará, Brazil), an area impacted by clandestine gold mining, as well as we analyzed the levels of Hg and Se (selenium) in nine fish species (carnivores and non-carnivorous) from the Tapajós River, which stand out as the main species consumed by riverside inhabitants, to evaluate a relationship between frequency of fish consumption and Hg concentration, and also to evaluate possible mechanisms of fish protection (or non-protection) to Hg exposure by Se. Furthermore we analyze the water quality to evaluate the environmental trophic state, fact responsible by creating conditions that can potentiate the effects of toxic mercury. Concentrations of Hg and MeHg were analyzed in hair samples of 141 volunteers in different age band. Of those, 84.40% of samples present values above the threshold for biological tolerance, which is 6.00µgg(-1) of total Hg in hair. Total Hg, in men there was a variation of 2.07-24.93µgg(-1), while for women the variation was 4.84-27.02µgg(-1). Consequently, the level of MeHg in men presented a variation of 1.49-19.57µgg(-1), with an average of 11.68µgg(-1), while with women the variation was from 3.73 to 22.35µgg(-1), with an average of 10.38µgg(-1). In fish species, Hg concentrations in carnivorous species had an average of 0.66µgg(-1), higher than that permitted by current legislation, ranging from 0.30 to 0.98µgg(-1), while the non-carnivorous species have values below the recommended by the legislation averaging 0.09µgg(-1), ranging between 0.02 and 0.44µgg(-1). For Se in fish, show that among carnivores, the contents of Se ranged between 0.18 and 0.54µgg(-1) with a mean of 0.34µgg(-1), while for non-carnivores these values were of the order of 0.16-0.56µgg(-1), with an average of 0.32µgg(-1). In surface water quality variables at the sampling points all showed values in accordance with the range established by current legislation. In this regard, the results provided by this study, while not conclusive, are strong indicators that despite not having been shown the relationship between the concentration of mercury in hair and feeding habits along the Tapajós River basin communities showed that a plausible correlation exists between levels of mercury and selenium in fish. This fact may serve as a subsidy to research human health, because in the Amazon, there is still a lot to examine with regards to the full understanding of the Se cycle.
Subject(s)
Environmental Monitoring/methods , Hair/chemistry , Mercury/analysis , Rivers , Seafood/analysis , Adolescent , Adult , Animals , Brazil , Child , Child, Preschool , Enterobacteriaceae/isolation & purification , Female , Fishes , Humans , Infant , Infant, Newborn , Linear Models , Male , Methylmercury Compounds/analysis , Middle Aged , Mining , Risk Factors , Selenium/analysis , Water Pollutants, Chemical/analysis , Water Quality , Young AdultABSTRACT
Two new species Ancistrus are described: A. verecundus from the upper rio Madeira basin and A. parecis from the upper rio Juruena, rio Tapajós basin, Brazil. The two species differ from all congeners except A. jataiensis, A. reisi, and A. tombador in the absence of an adipose fin which is replaced by a series of median platelets forming a low postdorsal ridge. Ancistrus verecundus is further distinguished from these species, except A. tombador by the broad naked margin of the snout and reduced tentacle development. Ancistrus verecundus differs from A. tombador in various morphometric features, and in having the base of the first anal-fin pterygiophore covered by skin (vs. base of the first anal-fin pterygiophore exposed and forming a platelet-like element). Ancistrus verecundus and A. tombador have two or more dermal plates of the dorsal plate series between the end of the postdorsal ridge and the origin of the first plate-like procurrent caudal-fin ray, whereas the other species of the genus that lack an adipose fin, including A. parecis, have one or none. Ancistrus parecis is further distinguished from A. tombador and A. verecundus by the presence of tentacles in adults. It also differs from A. tombador in morphometric and meristic features and from A. jataiensis and A. reisi in the length of the mandibular tooth row, the number of teeth on dentary and premaxillary, and the caudal-peduncle depth. A key is provided for the identification of species of Ancistrus lacking an adipose fin.
Duas novas espécies de Ancistrus são descritas: A. verecundus das cabeceiras do rio Madeira e A. parecis das cabeceiras do rio Juruena, bacia do rio Tapajós, Brasil. As duas novas espécies diferem de todos congêneres, exceto de A. jataiensis, A. reisi e A. tombador, pela ausência da nadadeira adiposa, a qual é substituída por uma série de placas medianas, formando uma pequena e baixa crista postero-dorsal. Ancistrus verecundus é facilmente distinguido dessas espécies, exceto de A. tombador, por apresentar a margem nua do focinho larga e os tentáculos reduzidos. Ancistrus verecundus difere de A. tombador por vários caracteres morfométricos e por apresentar a base do primeiro pterigióforo da nadadeira anal coberto por pele (vs. base do primeiro pterigióforo da nadadeira anal exposto e formando uma placa pré-anal). Ancistrus verecundus and A. tombador apresentam duas ou mais placas dérmicas na série dorsal de placas entre a crista postero-dorsal e a origem do primeiro raio prócorrente da nadadeira caudal, enquanto que as outras espécies do gênero sem nadadeira adiposa, incluindo A. parecis, apresentam menos que duas. Ancistrus parecis é distinguido de A. tombador e A. verecundus pela presença de tentáculos em adultos. Ele também difere de A. tombador por caracteres morfométricos e merísticos, e de A. jataiensis e A. reisi pelo comprimento do ramo mandibular, número de dentes no dentário e na pré-maxila, e altura do pedúnculo caudal. É fornecida uma chave de identificação para as espécies de Ancistrus sem nadadeira adiposa.
ABSTRACT
Two new species Ancistrus are described: A. verecundus from the upper rio Madeira basin and A. parecis from the upper rio Juruena, rio Tapajós basin, Brazil. The two species differ from all congeners except A. jataiensis, A. reisi, and A. tombador in the absence of an adipose fin which is replaced by a series of median platelets forming a low postdorsal ridge. Ancistrus verecundus is further distinguished from these species, except A. tombador by the broad naked margin of the snout and reduced tentacle development. Ancistrus verecundus differs from A. tombador in various morphometric features, and in having the base of the first anal-fin pterygiophore covered by skin (vs. base of the first anal-fin pterygiophore exposed and forming a platelet-like element). Ancistrus verecundus and A. tombador have two or more dermal plates of the dorsal plate series between the end of the postdorsal ridge and the origin of the first plate-like procurrent caudal-fin ray, whereas the other species of the genus that lack an adipose fin, including A. parecis, have one or none. Ancistrus parecis is further distinguished from A. tombador and A. verecundus by the presence of tentacles in adults. It also differs from A. tombador in morphometric and meristic features and from A. jataiensis and A. reisi in the length of the mandibular tooth row, the number of teeth on dentary and premaxillary, and the caudal-peduncle depth. A key is provided for the identification of species of Ancistrus lacking an adipose fin.
Duas novas espécies de Ancistrus são descritas: A. verecundus das cabeceiras do rio Madeira e A. parecis das cabeceiras do rio Juruena, bacia do rio Tapajós, Brasil. As duas novas espécies diferem de todos congêneres, exceto de A. jataiensis, A. reisi e A. tombador, pela ausência da nadadeira adiposa, a qual é substituída por uma série de placas medianas, formando uma pequena e baixa crista postero-dorsal. Ancistrus verecundus é facilmente distinguido dessas espécies, exceto de A. tombador, por apresentar a margem nua do focinho larga e os tentáculos reduzidos. Ancistrus verecundus difere de A. tombador por vários caracteres morfométricos e por apresentar a base do primeiro pterigióforo da nadadeira anal coberto por pele (vs. base do primeiro pterigióforo da nadadeira anal exposto e formando uma placa pré-anal). Ancistrus verecundus and A. tombador apresentam duas ou mais placas dérmicas na série dorsal de placas entre a crista postero-dorsal e a origem do primeiro raio prócorrente da nadadeira caudal, enquanto que as outras espécies do gênero sem nadadeira adiposa, incluindo A. parecis, apresentam menos que duas. Ancistrus parecis é distinguido de A. tombador e A. verecundus pela presença de tentáculos em adultos. Ele também difere de A. tombador por caracteres morfométricos e merísticos, e de A. jataiensis e A. reisi pelo comprimento do ramo mandibular, número de dentes no dentário e na pré-maxila, e altura do pedúnculo caudal. É fornecida uma chave de identificação para as espécies de Ancistrus sem nadadeira adiposa.