scholarly journals Subfossil and periphytic diatoms from the upper Paraná river, Brazil: last ~1000 years of a transition period

Hoehnea ◽  
2018 ◽  
Vol 45 (3) ◽  
pp. 431-449
Author(s):  
Daiane Trevisan Ruwer ◽  
Liliana Rodrigues

ABSTRACT Considering the lack of knowledge regarding the paleolimnology and the diatom flora from the sediment in Brazilian aquatic environments, this study aimed to provide information about diatom biodiversity and autoecology in an environment located in the upper Paraná river floodplain. Sediment and periphytic samples were collected from a swamp located in an island of the upper Paraná river floodplain. Sediment samples were obtained by collecting a core of ~2 m with a calibrated date of 726 to 903 cal yr BP near the base. The core was sliced into layers of 2.5 cm, totaling 41 samples. Periphytic diatom samples were obtained by scraping macrophytes' petioles, totaling two samples. The community was represented by 31 species belonging to 15 genera. All of the taxa were found in the sediment record, and 15 were present in the periphyton. The three new records (Eunotia longicamelus, Planothidium bagualensis and Luticola hustedtii) reinforce the importance of paleolimnological and periphytic studies to increase information about the aquatic biodiversity.

Hoehnea ◽  
2018 ◽  
Vol 45 (4) ◽  
pp. 560-590 ◽  
Author(s):  
Bárbara Dunck ◽  
Maria Gabriela Junqueira ◽  
Andressa Bichoff ◽  
Matheus Vieira da Silva ◽  
Alfonso Pineda ◽  
...  

ABSTRACT The upper Paraná river floodplain is a strategic area for the Brazilian biological and environmental patrimony and contains several conservation units. We aimed to record the occurrence and the geographic distribution of microalgae in this floodplain during 30 years of research carried out by the Center for Research in Limnology, Ichthyology and Aquaculture - State University of Maringá. We consulted 80 publications (national and international journals and books published from 1986 to 2016). We considered only published works that referenced algae at the generic and infrageneric levels. The results indicated 938 species of algae (562 periphytic, 482 planktonic), which 103 co-occur in the two habitats. Cosmarium was the richest genera for periphyton and Traquelomonas for phytoplankton. This study increased the knowledge of microalgae biodiversity in Brazil and provided data for future ecological and biogeographic studies.


2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 735-745 ◽  
Author(s):  
MC. Souza ◽  
K. Kawakita ◽  
SR. Slusarski ◽  
GF. Pereira

The purpose of this study was to update the floristic inventory found in the Upper Paraná River floodplain. Floristic surveys were performed from February 2000 through March 2008, as part of the Brazilian Long-Term Ecological Research Program (PELD/CNPq -Site 6). The material collected was identified from 774 species, 442 genera, and 116 families. The ten families with high species richness were Leguminosae, Poaceae, Rubiaceae, Asteraceae, Euphorbiaceae, Myrtaceae, Cyperaceae, Solanaceae, Sapindaceae, and Orchidaceae, which contributed to 46.1% of the total number of species. Genera with high richness were Solanum, Cyperus, Panicum, Eugenia, Tillandsia, Serjania, Casearia, and Polygonum, which together contributed to 10.2% of the total number of species. These data, combined with information published in 1997, recorded 955 species, 575 genera, and 128 families. These organisms were from several riparian environments and were distributed as herbs, shrubs, trees, climbers and epiphytes. Panicum maximum, Pennisetum purpureum, Ricinus communis, and Urochloa decumbens are considered weeds due to the wide distributions determined for these species. The results presented herein suggest the need to further investigate the control of these potential weed species.


2010 ◽  
Vol 8 (2) ◽  
pp. 321-327 ◽  
Author(s):  
Daniela Aparecida Garcia ◽  
Evanilde Benedito

The present study described the variations in energy density from skeletal muscles of Loricariichthys platymetopon in relation to body size, sex, gonadal development stages, sampling site and habitat type (lotic, semi-lotic and lotic). Samplings were performed between June 2002 and August 2006 in points located in the upper Paraná River floodplain, Rosana Reservoir and Diamante Stream. The energy density from each muscle sample of 212 specimens was determined using an adiabatic calorimeter. The correlations between the variables 'muscle energy density' and 'specimen standard length' were not significant. Only in the Rosana Reservoir there was a significant difference in energetic means between 'sex'. Otherwise, due to the gonadal development stage, a significant difference between energetic means was recorded only for males from the upper Paraná River floodplain and for both sexes in Rosana Reservoir. The density of muscle energy ranged from 4,170 to 5,540 cal/g DW (dry weight), with the means (± standard deviation) of 5,140± 0.06 cal/g DW in the Reservoir, 4,950±0.25 cal/g DW in the stream and 4,920 ±0.18 cal/g DW in the floodplain. Furthermore, we also detected a significant difference between the energy means from the different sampled sites, but the same was not registered among the analyzed habitats. In conclusion, the variation in muscle energy density from L. platymetopon may occur. The occurrence of variation between the sexes depends on the site, and the density variation among the stages depends on both the site and 'sex'. In summary, the spatial variation in muscle energy density from this species strengthens the idea that this factor is not a constant parameter, so it should not be applied in bioenergetics modeling and in the quantification of energetic balance as an unique value.


2015 ◽  
Vol 66 (1) ◽  
pp. 33 ◽  
Author(s):  
Luis A. Espínola ◽  
Carolina V. Minte-Vera ◽  
Horacio F. Júlio Junior ◽  
Luciano N. Santos ◽  
Kirk O. Winemiller

Invasion by Cichla ocellaris was studied in the Upper Paraná River floodplain. Generalised linear models and the Akaike Information Criterion (AIC) were applied to standardised gill-net catch data (CPUE), with years, rivers, secchi depth, and their respective interactions. Generalised additive models and AIC were used to evaluate relationships of CPUE for C. ocellaris with standard length, sampling year and secchi depth. C. ocellaris was first recorded in 1992 in the Paraná and Ivinheima Rivers. Nevertheless, the CPUE of individuals was very low in the latter until 2000, and the species was not recorded from the Baía River until 2000. In 2001, CPUE of C. ocellaris greatly increased (from 20 to 140) in all three rivers, and this coincided with changes in hydrology and suspended sediment. Greater secchi depth is thought to benefit foraging by these visually oriented, diurnal piscivores. The estimated annual growth rate for local populations was 21% for the Paraná, 42% for the Ivinheima, and 73% for the Baía Rivers. Consequently, relative to other populations, C. ocellaris of the Baía River and, to a lesser degree, the Ivinheima River, appear to be less influenced by density-dependent factors given their more recent invasions of those areas.


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