Capim River Research Articles

The loss of riparian vegetation along streams causes morphological divergences in functional traits of semiaquatic insects (Heteropteran: Gerromorpha) in the eastern Amazon.

Understanding the effects of mining activities on Amazonian streams and their impact on aquatic communities is of paramount importance in the current context of resource overexploitation in society. In this study, we assessed the significance of the environment and interspecific interactions on the organization patterns of semiaquatic insect species in a mineral extraction region in the eastern Amazon. We utilized the morpho functional characteristics of 22 species from the suborder Gerromorpha (Heteropteran), considering both the abundance and sexual dimorphism of these species. Additionally, we quantified the density of riparian vegetation surrounding each stream to categorize sampling points and evaluate whether there are differences in species distribution patterns among categories. We sampled 16 sites, categorized into two treatments based on the percentage of riparian vegetation in forested and deforested areas located in the Capim River Basin. We did not find the action of environmental filters on the total assembly; however, we found significant morphological divergence for all the traits analyzed. On the other hand, the separation of streams into treatments with different portions of riparian vegetation showed that there are significant differences between them regarding species distribution patterns. Forested streams within a 500-m radius have species distributed over a larger area, indicating that these streams have greater resource availability or that species can use these resources more efficiently. Our results demonstrate the importance of riparian vegetation for the studied communities, as well as for mitigating the impacts caused by mining activities.

New species of Batrochoglanis Gill (Siluriformes: Pseudopimelodidae) from the Capim River basin, State of Pará, Brazil

Batrochoglanis labrosus new species, is described from the Capim River Basin, State of Pará, Brazil. The new species differs from congeners by the stout, inferior mandible, hypertrophied lips on the lateral of the mouth, a broad dark brown band extending dorsoventrally from the beginning of the trunk to the posterior third of the adipose fin followed by a second dark brown band on the caudal peduncle, dark brown pelvic fin, and caudal fin hyaline with a concentration of dark brown spots on the posterior margin, sometimes forming an irregular band. The morphometric variables of B. labrosus are similar in B. villosus and B. castaneus, forming a B. villosus species group. The B. villosus group is distinct from other group formed by B. acanthochiroides and B. transmontanus in the third axis of the Principal Components Analysis. The variables with higher positive loadings in the B. villosus group, representing larger measurements, were adipose-fin base length, eye diameter, maxillary barbel length, head depth, and mouth width; the higher negative loadings representing shorter measurements were pelvic fin to anal fin distance and pectoral-fin spine length. The species is known only from the Capim River basin, where it is possibly endemic.

LENGTH-WEIGHT RELATIONSHIPS OF THREE FRESHWATER MUSSEL SPECIES FROM THE AMAZON (UNIONIDA, HYRIIDAE)

Length-weight relationships of three freshwater mussel species (Hyriidae), Eastern Amazon: the length-weight relationships allow important biological estimates for the fisheries management of species. Through this relationship, it is possible to estimate the weight of the individuals by their lengths, from which the biomass of the studied population can be determined. In addition, it gathers important data to assess the ecological patterns of different populations. The aim of this study was to analyze the length-weight relationships and their respective meat yields of three species of freshwater mussels: Castalia ambigua, Triplodon corrugatus and Paxyodon syrmatophorus from Capim River Bay, Pará, Brazil. For this, the total length, visceral weight, and total weight of 1,057 individuals were determined. All three relationships were considered strong, with determination coefficients greater than 0.9. The species C. ambigua showed negative allometric growth, while the other species P. syrmatophorus and T. corrugatus showed isometric growth. The species with the highest meat yield was P. syrmatophorus with 14.8%. The study presents the first parameter record of weight-length relationships for these three freshwater mussel species.

Intertextuality and knowledge translation in travel reports: the Capim River and its inhabitants in the narratives of Alfred Russel Wallace (1849), João Barbosa Rodrigues (1874–1875) and Emil Goeldi (1897)

Abstract The article analyzes the narratives of three travels along the Capim River, in the state of Pará, Brazil, between 1849 and 1897: those of Alfred Russel Wallace (1823–1913), João Barbosa Rodrigues (1842–1909) and Emil Goeldi (1859 –1917), who traveled with another scientist, Jacques Huber (1867–1914). These are considered the first scientists to explore the river and publish work on it. We highlight the intertextuality of their reports and also the process of knowledge translation between travelers and their interlocutors, an approach that we consider necessary and unavoidable for the development of this field of investigation. Our main sources are published narratives, sometimes associated with manuscripts and iconography.

Provenance and Paleoenvironmental Studies of Cretaceous African and South American Kaolins: Similarities and Differences

The African and South American continents are of great interest in continental drift studies. Hence, this study assesses the possible correlations in the provenance and paleoenvironment of selected Cretaceous Nigerian and Cameroonian (in Africa), and Argentine and Brazilian (in South America) kaolins through an analysis of their mineralogical and geochemical characteristics. On the basis of their mineralogical composition, the Nigerian Lakiri and Brazilian soft Capim River kaolins are predominantly characterised as pure kaolins, whereas the kaolins from Cameroon (except for Yatchika) and Argentina are mainly considered as sandy kaolins. The present study revealed that the Brazilian soft Capim River kaolin had the highest kaolinite structural order, whilst the Argentine Santa Cruz kaolin had the least. The kaolins from Nigeria, Cameroon, and Argentina were dominated by subhedral to anhedral kaolinite crystals relative to the Brazilian kaolin, which possess more euhedral kaolinite crystals. The kaolins were formed by the intense weathering of intermediate to felsic rocks under anoxic conditions, which is consistent with the structural framework of the basins. The average paleotemperatures obtained for the kaolins (except for the one from Santa Cruz) indicates that the paleoweathering took place under tropical climates.

Suscetibilidade à erosão hídrica do solo: bacia hidrográfica do rio Capim (MA-PA)

The objective of this study was to analyze the sustainability to water erosion in the Capim river/PA-MA. Acquired precipitation (GPCC), slope (TOPODATA project), land use and land cover data (MapBiomas) and pedology (Brazilian Soil Classification System) were obtained. Based on these variables, in a Geographic Information System environment, the product representing the sustainability to soil water erosion was generated. A sustainability gradient for soil water erosion was observed in the SE-NW direction, where it was higher near the mouth of the Capim River. The other variables were: clinical component presenting predominance of stability and high sustainability in the south of the basin; land use influences the entire axis of the basin, indicating instability in the medium-low Capim and in the extreme southeast. It was observed that the sustainability to erosion in the Capim watershed is motivated by intensified land use near the mouth. The zoning carried out in the basin is a warning sign for the municipalities of São Domingos do Capim, Rondon do Pará and Goianésia do Pará.

Unraveling the role of environmental factors and dispersal capacity in a metacommunity of Amazonian stream fishes

Separating species in terms of dispersal capacity can be useful to understand how local and regional factors affect the distribution of organisms in metacommunities. In this study, we sought to unravel how the characteristics of local habitats and spatial distances structure fish communities in Amazonian streams. We hypothesized that fishes classified with high dispersal capacity are mainly structured by mass effects and respond to environmental and spatial variables in the same proportion, while fishes classified with low dispersal capacity are mainly structured by species sorting, responding mainly to local environmental variables. We collected fish from 36 well-preserved streams in the Capim river basin in northern Brazil during the dry season. In general, the community composition was structured by characteristics of the local habitat. Spatial variables influenced each group at different intensities, agreeing with the models of species sorting and mass effects and corroborating our hypotheses. Thus, our findings suggest that the dispersal mode affects how metacommunities are structured. The differences in the patterns observed between the groups compared can help in the management and conservation of species, such as those with greater environmental requirements and more susceptible to habitat changes. We emphasize the need to maintain habitat integrity and connectivity in headwater streams to conserve species in their habitats.

Hepatic coccidiosis in Serrasalmus rhombeus Linnaeus, 1766 from the Amazon basin: morphological and histopathological aspects.

Calyptospora species are coccids that commonly cause liver infections in fish all around the world. This paper describes the morphology and histopathological characteristics of liver infection caused by Calyptospora sp. in black piranha Serrasalmus rhombeus, from the Capim River, in the municipality of Ipixuna do Pará, state of Pará (Brazil). Specimens were collected, analyzed and necropsied and tissue fragments containing parasites were prepared for histology and scanning electron microscopy. Parasitism was detected in 33.0% of the analyzed specimens, which had spherical oocysts in the liver, with four pyriform sporocysts presenting sporozoites internally. A histological examination revealed oocysts positioned close to blood vessels, causing necrosis and degeneration of hepatic parenchyma, while the presence of mononuclear cell infiltrate and melanomacrophages indicated the onset of an inflammatory process. This is the first record of the genus Calyptospora in fish from the Capim River.

Salmonellosis in a young Amazonian manatee (Trichechus inunguis)

ABSTRACT: The objective of this study was to describe a case of salmonellosis in an Amazonian manatee (Trichechus inunguis). The animal was rescued from a tributary of the Capim River, in the municipality of Goianésia do Pará, Pará, Brazil, kept in a pool, and died approximately five months after being rescued. The main changes observed at necropsy were that the cecum and colon had serosal hyperemia, wall edema, thickened mucosa with ulcerated areas and covered by a thin layer of fibrin, and a yellowish liquid content. Histologically, there was moderate multifocal fibrinonecrotic typhlocolitis associated with intense bacterial colonization. Salmonella enterica subsp. enterica (rough) was isolated in cecum and colon fragments. This is the first report of salmonellosis in an Amazonian manatee.

Length‐weight relationships of eleven fish species captured in 18 streams of the Capim River basin, Brazil

The length-weight relationship is important for the study of populational dynamics. This study aimed to describe the length-weight relationships (LWR) of 11 fish species sampled on 18 streams of the Capim river basin on eastern Amazon. Specimens were captured in 2014, 2015 and 2017, using sieve nets with 2 mm of mesh size. Fixed specimens were fixed in 10% formalin and conserved in alcohol 70%, measured for standard length (SL, 0.1 cm) and total weight (W, 0.01 g). The 11 species analysed were: Hemigrammus bellottii, Hemigrammus ocellifer, Hyphessobrycon heterorhabdus, Iguanodectes rachovii, Copella arnoldi, Nannostomus trifasciatus, Apistogramma regani, Apistogramma agassizii, Gymnorhamphichthys rondoni, Hypopygus lepturus, Anablepsoides urophthalmus.

Renal myxoboliosis of Metynnis hypsauchen in the Brazilian Amazon: morphological and histopathological aspects

In their natural habitat, fish are constantly threatened by icthyoparasites, notably those from the Phylum Cnidaria, Hatschek, 1888, represented by species of the Myxozoa, responsible for infections in fish that cause complications to their health that can lead to death. Among these parasites, the genus Myxobolus Butschli, 1882 is responsible for the largest number of infections described in fishes from the Americas. This study describes the morphological and histopathological aspects of parasitism by Myxobolus sp. in specimens of Metynnis hypsauchen, obtained from the Capim river, in the municipality of Ipixuna do Pará, Pará, Brazil. During the months of August and March, 2018, 20 animals were captured, euthanized and autopsied. With the aid of a stereomicroscope an external and internal investigation was performed on the animals for the purpose of finding lesions or parasitic cysts, followed by confirmation of infection in Light Microscopy (ML). Cysts and Fragments from parasitized tissues were processed using techniques for histology and Scanning Electron Microscopy (SEM). For histology they were stained with Hematoxylin-Eosin (H-E) and Ziehl-Neelsen and for SEM Micrographs were captured, using equipment from the Museu Paraense Emílio Goeldi. The prevalence of parasitism was 60% (12/20) of the specimens, and the cysts were in the epithelium and lumen of the renal tubules, causing histopathological changes. The characteristics of the parasite spores are those associated with the genus Myxobolus, with an ellipsoid format, two polar capsules and a sporoplasm region. It was possible to confirm a high parasite load of Myxobolus, with compromised renal functions. This study is the first to describe Myxospore in Metynnis hypsauchen.

Ecological uniqueness of fish communities from streams in modified landscapes of Eastern Amazonia

Abstract Ecological uniqueness is one aspect of beta (β) diversity that shows the relative contribution of sites (local contribution to beta diversity – LCBD) and taxa (species contribution to beta diversity – SCBD) in the formation of a unique environment in terms of species composition, and may be directly related to habitat quality. Our objective was to evaluate the uniqueness of fish communities from streams in modified areas of the Amazon, and to investigate the main environmental predictors at local and landscape scale. We sampled 58 streams in the Capim river basin (Para, Brazil) located within areas of preserved forest, reduced-impact logging, conventional logging and pasture. We found greater β diversity and higher LCBD in the pasture areas, making this land use the largest contributor to β diversity in the study area. At local scale, this high contribution was primarily influenced by environmental heterogeneity, thalweg depth, percentage of land use and cover (all positively), and volume of large woody debris in the riverbed (negatively). This indicates that the β diversity of fish is highly affected by streams with greater thalweg depth, possibly due to the reduced amount of large woody structures entering streams within pasture areas. These streams also showed greater environmental heterogeneity due to the large variation in disturbance levels of this area, which renders their sites suitable for potential occupation by different species, making them high contributors (high LCBD) and also leading them to present high β diversity. On the other hand, areas with a higher percentage of forest at landscape scale (including preserved forest, reduced-impact logging and conventional logging) were the main contributors, while pasture areas had a higher percentage of exposed soil. We did not find any association between SCBD values and the habit of the species, as the taxa that contributed most to β diversity can be classified as having reduced niches (specialists) as well as broader niches (generalists). We conclude that modified areas may contribute substantially to β diversity because they have a distinct species combination, however different patterns can be observed at local and landscape scales.

Henneguyosis in gills of Metynnis hypsauchen: an Amazon freshwater fish.

This study describes aspects of infection caused by Myxozoa of the genus Henneguya sp. in gills of fish belonging to the species Metynnis hypsauchen. Two sampling were made in the Capim river, close to the Ribeira community, in the municipality of Ipixuna do Pará, State of Pará, Brazil, during the months of August 2018 and March 2019. The animals were captured and transported live to the Laboratório de Pesquisa Carlos Azevedo, at the Universidade Federal Rural da Amazônia (UFRA), in Belém, Pará, Brazil.The animals were examined, and after parasitism was confirmed, Differential Interference Contrast Microscopes were used, to evaluate the parasite spores. Ziehl-Neelsen stain techniques were used in histology. Necroscopic analyses of Metynnis hypsauchen specimens found parasites in 80% of the hosts (16/20), with whitish-colored cysts in the branchial filaments, containing mature spores of the genus Henneguya. The histopathological analysis indicated large areas with cystic lesions with associated ischemic necrosis. The descriptions from this study indicate that the parasite drastically compromises the host's respiratory system. Additionally, it is worth noting that parasite fauna studies of fishes in the Capim river are still a vast topic for research; this is the first record of infection by Henneguya sp. in Metynnis hypsauchen, captured in the Capim river in Ipixuna do Pará.

Simulation of Flow in the Capim River (PA) using the SWAT Model

Simulation of Flow in the Capim River (PA) using the SWAT Model

Reducing the deleterious effects of logging on Ephemeroptera communities through reduced impact management

Reduced impact logging has emerged as one alternative to reduce the effects of timber harvesting. However, the effects of this method on aquatic ecosystems still need to be tested. We studied the effects of logging (reduced-impact logging—RIL and conventional logging methods—CL) on the chemical water quality and physical habitat conditions of streams in eastern Amazonia, as well as on Ephemeroptera diversity. Were analyzed control streams (without logging—CONTROL), streams with RIL and streams with CL, located in the Capim River Basin. Specimens were collected using a dipnet, following a standard protocol and abiotic data were measured with a multiparameter probe. Conventional logging in proximity to streams increased the conductivity and pH of the water, reduced dissolved oxygen and canopy cover of the stream’s channel, altering the composition of Ephemeroptera when compared with CONTROL and RIL areas. We verified that specialist Ephemeroptera species within control environments were replaced by species more tolerant to changes in the natural habitat conditions. In contrast, there was species similarity between RIL and CONTROL streams.

Análise do Programa de Controle da Tuberculose no estado do Pará, Brasil, de 2005 a 2014

OBJECTIVE: To analyze the indicators of the Brazilian National Tuberculosis Control Program in the Integration Regions of Para State, from 2005 to 2014. MATERIALS AND METHODS: Ecological study using 31,372 cases of pulmonary tuberculosis (TB) in people aged 20 years and older, registered in the Notifiable Diseases Information System. RESULTS: The average incidence in all State was 71.7/10,000 inhabitants. Regiao Metropolitana recorded 49.6% (15,572) of the cases and incidence of 114.7/10,000 inhabitants, with increasing trend in the period (22.3%). The greatest reduction in the number of cases occurred in Regiao Xingu (41.9%). In Para, 70.8% of cases were discharged by cure, with the highest proportion in Regiao Guama (77.9%). Only 72.6% of the cases had laboratory confirmation. The rate of discharge by cure, in confirmed cases, decreased from 73.1% in 2005 to 67.3% in 2014, with the highest rate (85.4%) in 2006, in Regiao Rio Caete; and the lowest rate (48.9%) in 2014, in Regiao Tapajos, with a tendency to increase in Araguaia, Carajas, Lago de Tucurui, and Tocantins Regions. In five Regions, the discontinuing treatment was higher than the State average (13.0%), and, in the period, it increased in Xingu, Tapajos, Marajo, Tocantins, Carajas, Guama, Capim River, and Caete Rivers Regions. The highest mortality occurred in Regiao Metropolitana in 2011; and the lowest, in Regiao Guama in the years 2009 and 2010. CONCLUSION: In the period studied, Para State was far from reaching the indicators proposed for the elimination of TB, contributing to the maintenance of endemic in Brazil.

Ichthyological Overview and Remarks on Freshwater Fishes from Capim River, Lower Amazon Basin, Brazil

The Capim River drainage should be considered small and thin by comparison with large Amazonian rivers. It rises by confluence of the Surubiú and Ararandeua rivers near 400 m high and their headwaters would be comfortably included in the Dry Emerged Lowland (terra firme) forest area of Sternberg’s Amazonian concept. Because of this reason the freshwater fish fauna of Capim River is comprised mainly by Amazonian fish families found in tributaries also with origin in terra firme areas. The ichthyofauna from the main channel of the poorly sampled Capim River, in the stretch between its confluence with Tauarí River and its mouth at Guamá River, is herein reported by way of rapid assessment. Also broad comparisons were made among freshwater fishes of the Capim with that from Tocantins and Guamá rivers. Two rapid access research surveys of collecting ichthyological material were performed in dry and humid periods of the year 1998 comprising the regional hydrologic cycle. The ichthyological diversity showed by the 461 studied specimens includes 79 species probably derived from Guamá and Tocantins rivers. These species are distributed between two situations: 1) downstream Capim River, at confluence with Guamá River, where is under tidal waters influence and periodically flooded, and 2) upriver Capim that is less humid and with water rapids, independent from sea hydrologic influence. This fish fauna includes local species common at high areas of the Amazonian Dry Emerged Lowland that are in part shared with that from Tocantins River. In view of these observations, we assume that the Capim River freshwater ichthyofauna may reflect diverse origin from the simple transfer of populations from Guamá River, but originate through a more complex process including the past ichthyofauna of the earlier drainages of terra firme forest and their reorganization.

Tide distortion and attenuation in an Amazonian tidal river

The present study seeks to evaluate tidal propagation in the Guamá-Capim river system, in the Amazonian region, considering hydrodynamic and geomorphological aspects. Available data sets on fluvial discharge and water level variations were considered, besides several methods of measuring the tides (currents, water levels and discharges) recorded at different stations and in different periods. The main point argued is that fluvial discharge is the key-factor in tidal distortion and tidal bore formation in the system investigated, whereas the low relief of the area would be the main factor contributing to landward tidal incursion. The results show an impressive upward tidal incursion of more than 200 km, including substantial distortion -increasing upstream -of the tidal wave, of which the ebb phase lasts up to 5 hours longer than the flood, including higher flood current velocities as far as 161 km upstream. Generally, only hyposynchronous tidal response was observed. Seasonally, the fluvial discharge varies about 10 times in the Guamá and 4 times in the Capim River. The increase of the fluvial discharge results in an increasing distortion of the tide, besides a weak increase of the attenuation. During high fluvial discharge periods in conjunction with equinoctial tides (e.g. March-April), a tidal bore occurs in the system, also increased by the generally low relief. Therefore, the conclusions include: low relief and the distortion related to high fluvial discharges are the main factors controlling tidal propagation along the system and tidal bore formation. Furthermore, the system could be classified as a tidal river, in which massive regional fresh water input results in virtually non-existent salinity throughout the Guamá-Capim system.

Quantification of Hematite and Goethite Concentrations in Kaolin Using Diffuse Reflectance Spectroscopy: A New Approach To Kubelka-Munk Theory

AbstractKaolin ores are usually contaminated by some Fe-bearing minerals, the strong colors of which degrade the quality of the final product. A spectroscopic technique is sought to quantify the content of hematite and goethite, the main contaminant minerals in the kaolin from Capim River in Brazil, was the focus of this study. The total Fe content obtained through X-ray fluorescence showed a poor correlation with the brightness of kaolin, due to the inability to differentiate between the Fe contained in the (oxyhydr)oxides and the Fe present in the crystalline structure of kaolinite, especially when the Fe-bearing minerals occur in small quantities. Here, a new generic technique to quantify Fe (oxyhydr)oxides in kaolin, based on the Kubelka-Munk theory, is presented. A new interpretation of the theory was made that enables its use without the need to measure thin layers of material. The results with synthetic goethite and hematite were very positive (R2pred ≈ 0.99) and experiments with contaminants from the mine are already underway.

Characterization of kaolin from the Capim River region — Brazil

Kaolin has been intensively used as an industrial mineral, mainly in the paper industry, as coating or filler material. In order to achieve the market requirements for this kind of use, there are several beneficiation processes that kaolin should pass, such as grain size classification, chemical bleaching and magnetic separation. In this work, mineralogical, chemical and physical characterizations were carried out in kaolin samples from the mined ore in Capim 1 deposit being commercially exploited by Pará Pigmentos S/A, before and after different steps of the industrial beneficiation processes. X-ray fluorescence and brightness measurement results indicate that all kaolin samples are typified by low iron content and high brightness grade. X-ray diffraction and scanning electron microscopy data exhibit kaolinite as the main mineral phase with minor amounts of quartz. The Hinckley index (> 1.06) as determined with XRD shows that all samples exhibit high structural order. From electron spin resonance and 57Fe Mössbauer spectroscopy data we obtained essential information about the chemical nature of iron impurities. Results reveal that the highest improvement in kaolin properties is obtained when previous magnetic separation is included in the beneficiation.