COMPOSIÇÃO DE MICROFITOPLÂNCTON DE UM ESTUÁRIO DO RIO AMAZONAS, PARÁ, BRASIL

This work aims to describe the composition, relative abundance and frequency of occurrence of microphytoplankton in the Arienga River, determined from the analysis of ten samples collected in the rainy and dry seasons (May and September 2009 respectively), during five stations, using a plankton net with a mesh size of 20mm. In the period studied, the rainfall showed an atypical behavior, compared to the average of the last ten years for the region, as pH and temperature did not undergone changes. A total of 128 species were identified, belonging to divisions: Dinophyta (0.78%), Chrysophyta (0.78%), Cyanobacterium (12.50%), Chlorophyta (26.56%), and Bacillariophyta (59.38%). Of Genres found, 17 had 100% of representativeness at in both fenods. It was possible to confirm two large groups, suggesting that the rainfall regime was the main controller factor of phytoplankton composition and spatial variation of species along the Arienga River. The phytoplankton diversity was considered characteristic of the Amazon region; therefore, it is considered that the human action did not affect the phytoplankton community of the Arienga River to date.Keywords: phytoplankton; estuary; Amazon; Bacillariophyta; Polymyxus coronalis.Este trabalho teve como objetivo descrever a composição, abundância relativa e frequência de ocorrência do microfitoplâncton do rio Arienga, a partir da análise qualitativa de 10 amostras coletadas no período chuvoso e seco (respectivamente maio e setembro de 2009), em cinco estações, utilizando-se uma rede cônico-cilíndrica de plâncton com abertura de malha de 20mm. No período estudado a precipitação pluviométrica apresentou um comportamento atípico, comparado à média dos últimos 10 anos para a região, o pH e a temperatura não sofreram variações. Foram identificadas 128 espécies pertencentes às divisões: Dinophyta (0,78%), Chrysophyta (0,78%), Cyanobactéria (12,50%), Chlorophyta (26,56%) e Bacillariophyta (59,38%). Dos gêneros encontrados, 17 apresentaram 100% de representatividade, nos períodos de coleta. Foi possível constatar dois grandes grupos, sugerindo que o regime pluviométrico foi o principal fator controlador da composição fitoplanctônica e da variação espacial de espécies do rio Arienga. A diversidade fitoplanctônica foi considerada característica para a região amazônica.Palavras-chave: fitoplâncton, estuário, Amazônia, Bacillariophyta, Polymyxus coronalis

Detection of mitochondrial DNA heteroplasmy suggests a doubly uniparental inheritance pattern in the mussel Mytella charruana

The unusual type of mitochondrial DNA (mtDNA) transmission in which females pass on their mtDNA F to both sons and daughters, and males pass on their mtDNA M to their sons, is termed Doubly Uniparental Inheritance (DUI) and has been observed in several bivalve mollusk families, including the Mytilidae. The present study found mitochondrial heteroplasmy in Mytella charruana, a tropical estuarine mytilid, which is most likely due to the occurrence of DUI. Cytochrome oxidase c subunit I (COI) sequences provide evidence for the presence of mtDNA M in the gonad and adductor muscle of male M. charruana. Intraspecific COI mtDNA F and mtDNA M mitotype divergence (p-distances) in M. charruana ranged from 20.5% to 20.8%. COI phylogenetic trees suggest that mtDNA M arose before M. charruana, Perna perna and Mytella guyanensis split, though independently of the DUI event that occurred in the genera Mytilus and Brachidontes. The comparison of COI gene products of mtDNA M among M. charruana and other bivalves, including mytilids, has shown that they all have important differences, suggesting independent evolutionary changes in their male COI lineages.(Detecção de heteroplasmia no DNA mitocondrial sugere um padrão de herança dupla uniparental em mexilhões Mytella charruana). Um tipo de transmissão não usual de herança do DNA mitocondrial (mtDNA), na qual as fêmeas passam os seus mtDNA F aos filhos e às filhas e os machos passam os seus mtDNA M para os seus filhos machos, é conhecido por herança dupla-uniparental e tem sido observada em várias famílias de moluscos bivalves, incluindo a Mytilidae. O presente estudo mostrou a ocorrência de heteroplasmia mitocondrial em Mytella charruana, um mitilídeo estuarino tropical, provavelmente devido a herança dupla uniparental. Sequências da citocromo oxidase c subunidade I (COI) mostraram que o mtDNA M está presente nas gônadas e nos músculos adutores dos machos de M. charruana. As divergências intraespecíficas (distância-p) entre as sequências de COI dos mitótipos mitocondriais mtDNA F e mtDNA M em M. charruana variaram de 20.5% a 20.8%. As árvores filogenéticas baseadas em COI sugerem que o mtDNA M surgiu antes da separação das espécies M. charruana, Perna perna e Mytella guyanensis, independentemente do evento DUI que ocorreu nos gêneros Mytilus e Brachidontes. A comparação dos produtos do gene mtDNA M de M. charruana e de outros bivalves, incluindo mitilídeos, mostrou que eles têm importantes diferenças, sugerindo mudanças evolucionárias independentes em suas linhagens masculinas de COI

AVALIAÇÃO HISTOPATOLÓGICA DO FÍGADO DE Brachyplatystoma rousseauxii (CASTELNAU, 1855) DA BAÍA DO GUAJARÁ, BELÉM, PARÁ

The species Brachyplatystoma rousseauxii is one of the most important economic resources of the Amazon region. The objective of the present work was to analyze the histopathology of the liver of B. rousseauxii and to indicate this species as a biomonitor of the environmental quality of the Guajará Bay. Samples were collected in four areas: a control area and three areas identified as discharge sites of solid and liquid wastes. Sampling was carried out in four season periods: dry/wet season, wet season, wet/dry season and dry season. The number of collected specimens was 36. The fishes were submitted to biometry after catching. They presented mean total length of 33.45 cm (±7.72), total weight of 239.21 g (±135.24), and liver weight of 1.22 g (±0.56). Liver fragments were processed for light microscopy analysis. Histopathologic analysis demonstrated that 70% of the fish presented hepatitis, inflammation, fatty degeneration, and congestion, and that 30% presented well-organized liver structures, and they were considered healthy. The hepatic changes observed and the number of specimens collected suggest that the environmental quality of the Guajará Bay is affected and that the species B. rousseauxii  is probably adapted to the areas where there are waste discharges. KEY WORDS: Amazonian biome, biomonitor, liver, histopathology, fish

Os conhecimentos ecológicos dos pescadores Xikrin-Mẽbêngôkre, Terra Indígena Trincheira Bacajá, Pará, Brasil

The ecological knowledge of the Xikrin-Mẽbêngôkre and its praxis in aquatic environments of Indigenous Trincheira Bacajá (ILTB) are relevant to improving the use of fisheries resources. The fish were aquatic resources most cited as a supply of food needs of Xikrin. Fishermen consider switching this seasonal cycle creates different etnohabitats conducive to a spatiotemporal ichthyodiversity associated with subsistence and commercial fishing. The experts were able to identify the types of landforms associated with Basin of Bacajá river, facilitating orientation in the ways and paths traversed during fishing trips. It is noteworthy that in the description of the occurrence and distribution of fish in the ethnohabitats ILTB there are important specifics beyond the seasonal periods, such as those related to fishing intrinsic and inherent to fish (size, weight, eating behavior and ethno-ecological aspects). The details in the categorization of aquatic ethnohabitats and biodiversity associated with these sites highlights the relationship of Xikrin with their area of usage as well as the agreed divisions of space between the villages, which must be kept, not only for survival and strengthening communities, but also the intrinsic value of belonging and being Xikrin.Os conhecimentos ecológicos dos pescadores Xikrin-Mẽbêngôkre e sua práxis nos ambientes aquáticos da TITB foram estudados visando obter informações relacionadas à percepção local sobre a dinâmica espaço-temporal dos peixes no rio Bacajá. Os dados foram obtidos por meio de entrevistas; observações diretas e excursões guiadas. Os peixes foram os recursos aquáticos mais citados como suprimento das necessidades alimentares dos Xikrin. Os pescadores consideram que a alternância entre o ciclo sazonal cria diferentes etnohabitats propícios a uma ictiodiversidade espaço-temporal, associada à pesca de subsistência e comercial. Destaca-se que na descrição de ocorrência e de distribuição dos peixes nos etnohabitats da TITB há especificidades importantes além dos períodos sazonais, tais como aqueles relacionados intrínsecos à pesca e os inerentes aos peixes (tamanho, peso, comportamento alimentar e aspectos ecológicos). O detalhamento na categorização dos etnohabitats aquáticos e na biodiversidade associado a estes locais ressalta a existência de uma ampla relação dos Xikrin com sua área de uso, bem como as acordadas divisões do espaço entre as aldeias, que devem ser mantidos, não apenas para sobrevivência e fortalecimento das comunidades, mas também pelo próprio valor intrínseco de pertencimento e ser Xikrin

Grau de adesão ao tratamento com anti-retrovirais entre indivíduos HIV positivos atendidos no Hospital Universitário de Santa Maria

This qualitative study evaluated, during six months, the adherence to antiretroviral therapy among 898 patients who were more than 15 years old and have received the medications to the control of the infection by the Human Immunodeficiency Virus (HIV) at the University Hospital of Santa Maria (HUSM) pharmacy. The age of the participants was between 30 and 49 years old, being 517 male (58%) and 381 (42%) female. The majority of the patients (72%) showed a good level of adherence. Only 7% of the individuals abandoned the treatment. One concludes that it is needed a constant monitoring for keeping adequate adhesion to the treatment for a long time. The pharmaceutical and clinical attention in the accompaniment and treatment of the infection by the HIV had increased the expectation and improved the quality of life of the evaluated individuals.Este estudo qualitativo avaliou, por um período de seis meses, o grau de adesão a terapia anti-retroviral, entre 898 indivíduos maiores de 15 anos, que recebem medicamentos para o controle da infecção pelo vírus da Imunodeficiência Humana (HIV), junto a farmácia de doenças infectocontagiosas, no Hospital Universitário de Santa Maria (HUSM).  A faixa etária mais prevalente da população estudada foi a de 30 - 49 anos, sendo 517 do sexo masculino (58%) e 381 do sexo feminino (42%). A maioria dos pacientes (72%) apresentou bom nível de adesão. Apenas 7% dos indivíduos abandonaram o tratamento. Conclui-se que manter uma adequada adesão ao tratamento por longo prazo, é um trabalho que necessita constante vigilância. A atenção farmacêutica e clínica no acompanhamento e tratamento da infecção pelo HIV aumentaram a expectativa e melhorou a qualidade de vida dos indivíduos avaliados

Environmental predictors of the life history of the flag tetra Hyphessobrycon heterorhabdus (Characiformes: Characidae) in streams of the Eastern Amazon

Abstract This study aimed to characterize the reproductive biology of Hyphessobrycon heterorhabdus, and its response to environmental variations in the Eastern Amazon streams. We sampled specimens every two months, between March 2019 and January 2020. The population was evaluated for sex ratio, reproductive activity, growth pattern, condition factor, size at the first sexual maturation, spawning type, and fecundity. We analyzed 180 specimens, which showed a sex ratio of 1.6 males for each female across the whole period, with 2.3 males for each female during the period of greatest reproductive activity. The peak of reproductive activity coincided with higher precipitation periods and was partially predicted by factors such as water temperature, stream discharge, dissolved oxygen, substrate complexity, and electrical conductivity. The length where 50% and 100% of population to reach sexual maturity was 18.0 and 22.0 mm for males and 19.7 and 27.0 mm for females. The oocyte diameters showed a bimodal frequency, with at least two batches of oocytes. The average fecundity of 197 oocytes. The results indicate that this species presents an opportunistic strategy, and the tactics that make up this strategy depend on variations in both the physical structure of the habitat and physicochemical aspects of the water

Physiological responses associated with capture and crowding stress in matrinxã Brycon cephalus (Gunther, 1869)

The dynamics of plasma cortisol, blood glucose, plasma chloride and liver glycogen were investigated in matrinxã (Brycon cephalus) submitted to capture and various periods of crowding. A total of 400 fish (700 ± 22 g weight) were distributed in four ponds divided into four 50-m2 squares (25 fish/square, 350 gL-1), where they were acclimated for 30 days. On the sampling day, after 24 h without food, all fish from three squares were transferred to the fourth square. Six fish were sampled before the procedure (control group, zero time) and 1, 3, 6 and 24 h after the capture and crowding. Each sampling was performed in a different pond to prevent additional stress. Fish were anaesthetized and blood and liver collected for biochemical analysis. Water temperature, pH, dissolved oxygen, alkalinity, ammonia and nitrite levels were within acceptable levels for matrinxã rearing. Slight but not significant increases were verified in plasma cortisol and blood glucose levels, as were decreases in plasma chloride and liver glycogen levels. The results suggest that matrinxã is highly tolerant to the procedures of capture and short-term crowding