The Poorly KnownRiggia acuticaudata(Crustacea: Isopoda) ParasitizingAncistrussp. (Siluriformes: Loricariidae) from the Paraguay River Basin, Brazil, with Comments on its Reproductive Biology

2015 ◽  
Vol 82 (1) ◽  
pp. 25-28 ◽  
Author(s):  
Fabrício H. Oda ◽  
Rodrigo J. da Graça ◽  
Luiz Fernando C. Tencatt ◽  
Luiz Eduardo R. Tavares ◽  
Otávio Froehlich ◽  
...  
Author(s):  
M. J. Pereira ◽  
L. F. Viana ◽  
M. H. B. Sais ◽  
Y. R. Súarez

Abstract This work aimed to describe the reproductive biology of Hypoptopoma inexspectatum in southern Pantanal. A total of 538 individuals were sampled and analyzed from February 2009 through January 2011 in southern Pantanal. We did not observe differences in sex-ratio, and both sexes presented positive allometric length/weight relationship (LWR). Reproduction occurs mainly from January to February. Females reached first maturation (L50) with 37.80 mm and males with 45.80 mm. Absolute fecundity is estimated in mean=177.43 (sd±127.06) oocytes and relative fecundity in 3.12 (sd±2.23) oocytes/mg. Fecundity is positively correlated with standard length (Spearman r= 0.43; p=0.013), and total spawning is a used spawning strategy for H. inexspectatum.


2014 ◽  
Vol 14 (3) ◽  
Author(s):  
Lívia Medeiros Cordeiro ◽  
Rodrigo Borghezan ◽  
Eleonora Trajano

We present herein a synthesis of faunistic data from caves in the Serra da Bodoquena karst area, middle Paraguay River basin, Mato Grosso do Sul State. Those include phreatic, submerged and dry caves. Emphasis is given to troglobites (exclusively subterranean species), potentially threatened due to their morphological, physiological and behavioral specializations, associated to generally small distributions. The Bodoquena karst area distinguishes as a spot of high diversity of troglobites, such as trichomycterid and heptapterid catfishes, aquatic planarians and gastropods, arachnids (Eusarcus opilionids, ctenid spiders), Polydesmida diplopods, several collembolans, some insects, and Peracarida crustaceans, which include interesting phylogenetic relicts as spelaeogriphaceans. Four geographic compartments corresponding to microbasins, seemingly with biogeographic importance for the subterranean fauna, are recognized. Phreatobic troglobites (Trichomycterus catfishes, aquatic peracarids, planarians) distribute widely across these compartments and some well beyond (the spelaeogriphacean Potiicoara brasiliensis reaches Mato Grosso state), while those living in base-level streams (Rhamdia and Ancistrus catfishes) and the terrestrial ones, that live in the vadose (aerated zone) are generally restricted to one compartment. Many subterranean ecosystems in Mato Grosso do Sul are endangered by several threats described here and urgent actions for effective protection are required to guarantee a sustainable use of the land and the karst aquifers.


2007 ◽  
Vol 5 (4) ◽  
pp. 479-484 ◽  
Author(s):  
Andréa L. Neuberger ◽  
Elineide E. Marques ◽  
Carlos S. Agostinho ◽  
Rafael J. de Oliveira

In order to evaluate aspects of the reproductive biology of Rhaphiodon vulpinus in the Upper and Middle Tocantins River, samples were taken monthly from October, 1999 through September, 2001, by means of gill nets. Males, which were more abundant than females (chi2 146.87: df=1: p<0.05), matured at a smaller size. The reproductive period of the species extended essentially from November through January, with a peak of activity in November. Fecundity, with an estimated mean value of 98,185 oocytes, varied from 38,177 to 215,841 oocytes, and it did not correlate with the length of the individual female analyzed (r=0.4663: p=0.206). Relative fecundity was 130.6 oocytes/g total weight. Mature oocytes had a mean diameter of 0.98 mm, corresponding to a volume of 0.50 mm³.


2019 ◽  
Vol 46 (3) ◽  
pp. 176
Author(s):  
Camila Calazans Da Silva Luz ◽  
Alexander Webber Perlandim Ramos ◽  
Gessica De Jesus Oliveira Silva

The disorderly use of land is currently one of the main causes of environmental problems. From this perspective, the objective of this study was to determine the natural and environmental vulnerability of the Jauru river basin in the Brazilian state of Mato Grosso. This goal was made from the perspective that the results generated contribute to environmental planning and management, considering that the Jauru river is tributary of the Paraguay river, responsible for the flooding of the Pantanal plain and, that possible impacts caused by the basin may compromise the dynamic equilibrium of the Pantanal's flood pulse. The model of assessment of natural and environmental vulnerability was adopted, with the identification of the following environmental characteristics: geology, slope, agricultural aptitude and vegetation cover and land use. Data were related through Geographic Information Systems to generate natural and environmental vulnerability maps. It was verified, through the data obtained, that in both vulnerabilities studied there was a predominance of the middle class, mainly resulting from the presence of fragile soils. Also, the predominance of the classes of agricultural aptitude found in the basin, as well as the suppression of the natural vegetation to expand the pasture areas. It was concluded that the areas covered by natural vegetation and/or pastures, in the Jauru river basin, present average natural vulnerability and state of medium to high environmental vulnerability, evidencing that livestock, the main activity regional economic development, has been developed in disagreement with environmental aptitude, contributing to the elevation of the state of environmental vulnerability in the basin.


2018 ◽  
Vol 6 (2) ◽  
pp. 1
Author(s):  
Felix Koffi KONAN ◽  
Charles Koffi BOUSSOU ◽  
Yves Kotchi BONY ◽  
Mexmin Koffi KONAN ◽  
Edia Oi EDIA ◽  
...  

Malapterurus teugelsi Norris, 2002, an endemic electric catfishes of the Kogon River Basin in Guinea, is assessed as Near Threatened due to its restricted distribution area, fishing pressure, mining activities, loss of habitats and aquatic pollution. This fish has a high cultural representation in the folklore of the local population. Moreover, in addition to its very limited distribution, very little information exists on its reproductive biology and its food ecology. Therefore, singular care must be paid to it for its conservation.


2007 ◽  
Vol 67 (4 suppl) ◽  
pp. 889-895 ◽  
Author(s):  
A Sanches ◽  
PM. Galetti Jr

Brycon hilarii is a migratory fish widely distributed throughout the Paraguay River Basin. It is appreciated in sport fishing and for its superior meat quality. It is also the main species for tourist attraction in the Bonito region (State of Mato Grosso do Sul, Brazil). Considering the lack of information on the genetic structure of the fish of this species, the aim of the present study was to detect the genetic variability of Brycon hilarii through RAPD markers. A total of eighty specimens collected in different seasons at four sites of the Miranda River sub-basin (Paraguay River Basin, Brazil) were used for analysis. The results of genetic similarity, Shannon diversity, and AMOVA revealed differences between the sampling sites. Through AMOVA, differences between populations were more evident among the animals collected during the non-reproductive season, corresponding to a time of less movement of these fish. A population structuring model in which B. hilarii appears organized into genetically differentiated reproductive units that coexist and co-migrate through the studied system was suggested, contrasting the currently accepted idea that freshwater migratory fish form large panmictic populations in a determined hydrographic system. Despite the lack of a complete picture regarding the distribution of B. hilarii in the studied region, this initial idea on its population genetic structure could be an important contribution to providing aid for management and conservation programs of these fish.


2019 ◽  
Vol 687 ◽  
pp. 917-928
Author(s):  
Larissa Richter ◽  
Amauris Hechavarría Hernández ◽  
Gustavo S. Pessôa ◽  
Marco Aurelio Zezzi Arruda ◽  
Ary T. Rezende-Filho ◽  
...  
Keyword(s):  

2020 ◽  
Vol 27 (1) ◽  
Author(s):  
Getulio Rincon ◽  
Kerly Pereira ◽  
Carlos Eduardo Santos ◽  
Natascha Wosnick ◽  
Ana Rita Nunes ◽  
...  

The Brazilian Amazonian coast, extending from Amapá to Maranhão states, is drained by a series of small to medium sized rivers of the Amazon basin. The Pindaré-Mearim is an isolated basin formed by the junction of the Pindaré and Mearim rivers at its lower portion. Along the Pindaré and Mearim rivers there is a single reported species of freshwater stingray identified as Potamotrygon motoro. Although specimens have been deposited in research institutions, most of these specimens have been captured on the Amazon basin and its direct tributaries or along the Panará-Paraguay river basin. Hence, there is a severe lack of information on the P. motoro of the Pindaré- Mearim river basin. Here we present new data regarding P. motoro general morphology, emphasizing the color variation, sexual dimorphism and notes on its biological aspects. 


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