An inventory of the ferns and lycophytes of the Lower Tapajós River Basin in the Brazilian Amazon reveals collecting biases, sampling gaps, and previously undocumented diversity

While possessing a remarkable diversity in the acidic and oligotrophic waters of the Amazon basin, the genus Pinnularia appears underdescribed in the region. In this study, we present light and scanning electron microscopical observations on Pinnularia caprichosa sp. nov. from Tupé Lake, a dendritic lake located on the floodplain of the Negro River basin. This new taxon has a large axial area and transapical striae that are slightly radiate to parallel and longer in the middle portion of the valve. The species was compared with Pinnularia elliptica, P. instabilis, P. lacunarum, P. montana, P. permontana and P. subflexuosa, all of which closely resemble P. caprichosa but differ from the new species in specific details of size, striae density and valve shape.

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Selenium Levels in the Whole Blood of Children and Teenagers from Two Riparian Communities at the Madeira River Basin in the Western Brazilian Amazon

Biological Trace Element Research ◽

10.1007/s12011-016-0741-0 ◽

2016 ◽

Vol 175 (1) ◽

pp. 87-97 ◽

Cited By ~ 5

Author(s):

Claudia M. Vega ◽

José M. Godoy ◽

Paulo R. G. Barrocas ◽

Rodrigo A. Gonçalves ◽

Beatriz F. A. De Oliveira ◽

...

Keyword(s):

River Basin ◽

Whole Blood ◽

Brazilian Amazon ◽

Madeira River ◽

Madeira River Basin ◽

Riparian Communities

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Total and methyl mercury distribution in water, sediment, plankton and fish along the Tapajós River basin in the Brazilian Amazon

Chemosphere ◽

10.1016/j.chemosphere.2019.06.212 ◽

2019 ◽

Vol 235 ◽

pp. 690-700 ◽

Cited By ~ 20

Author(s):

A.S. Lino ◽

D. Kasper ◽

Y.S. Guida ◽

J.R. Thomaz ◽

O. Malm

Keyword(s):

River Basin ◽

Methyl Mercury ◽

Brazilian Amazon ◽

Mercury Distribution

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A new Planothidium species (Achnanthidiaceae, Bacillariophyceae) from Xingu Ria, Amazon River basin, Brazil

Phytotaxa ◽

10.11646/phytotaxa.477.2.4 ◽

2020 ◽

Vol 477 (2) ◽

pp. 194-204

Author(s):

KRYSNA S. MORAIS ◽

LÍVIA F. COSTA ◽

CARLOS E. DE M. BICUDO ◽

LUC ECTOR ◽

CARLOS E. WETZEL

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

New Species ◽

River Basin ◽

Brazilian Amazon ◽

Diatom Species ◽

Amazon River Basin ◽

Sediment Samples ◽

Xingu River ◽

Scanning Electron

A new Planothidium species was found in sediment samples (~4,000 yr BP) from the Xingu Ria (Xingu River), Brazilian Amazon. The new species morphology was analyzed using light and scanning electron microscopy. Planothidium xinguense sp. nov., is mainly characterized by its elliptical, slightly asymmetrical valves, with strongly marked short rostrate ends in the small specimens, while long and strongly rostrate apices are observable in the larger valves. The taxon belongs to the group of species bearing a cavum on the rapheless valves around the name “Planothidium rostratum sensu lato”. Morphology and ecology of the new species is compared with that of morphologically related taxa. Information of core chronology and the co-occurrence of other diatom species in the sample is also provided.

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THE EFECTS OF SETTLEMENT ON THE PREVALENCE OF AscarisINFECTION IN TWO AMERINDIAN POPULATIONS OF THE BRAZILIAN AMAZON

Acta Amazonica ◽

10.1590/1809-43921993231035 ◽

1993 ◽

Vol 23 (1) ◽

pp. 25-35 ◽

Cited By ~ 3

Author(s):

Janet M. CHERNELA ◽

Vernon E. THATCHER

Keyword(s):

River Basin ◽

Ascaris Lumbricoides ◽

Environmental Contamination ◽

Close Contact ◽

Intestinal Parasites ◽

Nematode Species ◽

Brazilian Amazon ◽

Necator Americanus ◽

Fishing Villages ◽

The Third

Studies were made of the intestinal parasites of Amerindian populations of the Uaupes River basin of Brazil. Three groups were sampled: 1) Tukano fisher-agriculturalists who live in permanent riverine villages; 2) Maku hunter-horticulturalists who live in close contact with the Tukano fishing villages; and 3) Maku who inhabit the forest interior and have little contact with permanent settlements. Fecal samples were collected from 498 individuals of which 220 were from the first group, 135 from de second and 143 from the third. The samples were analyzed by means of microflotation and centrifugal sedimentation. A total of 18 protozoan and helminth species were recorded based on the presence of cysts or eggs. These included five nematode species that could not be identified. The three common pathogenic nematodes were found to be prevalent: the hookworm, Necator americanus(96%); the whipworm, Trichuris trichiura(77%) and the large roundworm, Ascaris lumbricoides(75%). The prevalence of Ascarisamong the villages was found to vary from 56 to 100%. Individuals living in, or associated with, permanent settlements had higher prevalence and intensity rates than those living in the nomadic hunter-gatherer way. This is shown to be directly related to fecal contamination of the environment in and around permanent settlements. The prevalence of Ascarisin a population can be used as an indicator of such environmental contamination.

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