Perazzo G.,Federal University of Paraná |
Noleto R.B.,Faculdade Estadual de Filosofia |
Vicari M.R.,State University of Ponta Grossa |
Machado P.C.,Grande Rio University |
And 2 more authors.
Reviews in Fish Biology and Fisheries | Year: 2011
Fishes of the family Cichlidae generally show low karyotype variability. Nevertheless, karyotype variants have been identified within some genera, providing information about their evolutionary history. In the present study, karyotype characteristics of Crenicichla lepidota and Australoheros facetus, two sympatric species found in the São Gonçalo-Mangueira basin, were studied. Besides conventional procedures, double fluorochromes staining chromomycin A 3/DAPI and fluorescent in situ hybridization (FISH) with rDNA probes were also used. Both species presented 2n = 48 chromosomes, but karyotypes were differentiated by fundamental number, which was equal to 70 in A. facetus and 56 in C. lepidota. Similar heterochromatin distribution patterns were also observed on the pericentromeric region of most chromosomes, although C. lepidota presented an additional heterochromatic block in the first pair. The Ag-NORs, 18S rDNA probe and CMA 3/DAPI were coincident in location on the first and second pairs of C. lepidota and A. facetus, respectively. The minor rDNA loci (5S rDNA) were found in four sites located on two distinct chromosomal pairs in C. lepidota. Although the data obtained here to C. lepidota and to A. facetus show chromosomal characteristics considered ancestral to the family, new data are presented to both species. Additionally, this study corroborates the hypothesis in which evolutionary processes like non-Robertsonian rearrangements are involved in the diversification of the major groups of Neotropical Cichlidae. Thus, the karyotype diversification observed in A. facetus have the high fundamental number pathway while C. lepidota has others evolutionary chromosomal mechanisms. © 2010 Springer Science+Business Media B.V.
Schwarz K.K.,State University of Maringá |
Furuya W.M.,State University of Maringá |
Natali M.R.M.,State University of Maringá |
Gaudezi M.C.,Faculdade Estadual de Filosofia |
de Lima P.A.G.,Faculdade Estadual de Filosofia
Revista Brasileira de Zootecnia | Year: 2011
This experiment was conducted to evaluate increasing levels of mannanoligosaccharides (MOS) in the diet of Nile tilapia larvae (Supreme®) at the sex reversal stage for 30 days. Nile tilapia larvae (n = 1500, p = 0.01 ± 0.001 g), were randomly distributed in 30 tanks of 100 liters each, for 30 days. The fish were distributed in a randomized design with six treatments and five replicates. The control diet (no MOS) was elaborated to contain approximately 35% of crude protein and 3,100 kcal DE/kg. Mannanoligosaccharides were included in the other diets, replacing corn, at levels of 0, 0.15, 0.30, 0.45, 0.60 or 0.75%. Linear increase in the intestine length, intestinal villous height and villi density was observed with the dietary MOS increase. No differences in body composition, weight gain, final weight, final length, condition factor, survival rate or number of goblet cells of the gut of the larvae were observed. A quadratic effect on feed conversion ratio was observed with the MOS inclusion and the best value was estimated with 0.34%. Dietary MOS inclusion at 0.34% improves feed conversion and increases intestine length, villi height and density of intestinal villi in diets for Nile tilapia larvae. © 2011 Sociedade Brasileira de Zootecnia.
Vogel H.F.,State University of Maringá |
Zawadzki C.H.,State University of Maringá |
Metri R.,Faculdade Estadual de Filosofia
Biota Neotropica | Year: 2012
Seasonal segregation among syntopic species can be viewed as one of the available strategies for coexistence, reducing competitive process. The present work therefore aimed to interpret the assemblage structures comprising birds of the genus Turdus (Turdidae), through the analysis of seasonal variation in the species occurrence in a forest remnant located in the southcenter State of Paraná. Mist-netting was employed twice a month for capturing birds, totalling an annual effort of 7488 h.m2. The frequency of occurrence, constancy and class of species dominance was determined, together with the parameters generally used in studies of ecological communities (richness, abundance, diversity and evenness). A total of 162 individuals were captured, representing five species. Turdus rufiventris was the most constant and frequent species. Turdus amaurochalinus and Turdus leucomelas were captured with variable constancies and frequencies along the seasons. Turdus amaurochalinus was also very common and may present an overlapping process between migrant and non-migrant individuals during spring. Turdus albicolis was considered accessory, whereas Turdus subalaris was only registered during the reproductive period. Hence, it was possible to observe that seasonal modifications occurred both in the frequency of occurrence and in the constancy and dominance of species. These results indicated the possibility of a lower use of the environment during the breeding season, as well as the presence of a higher number of individuals in summer and increased abundance of Turdus rufiventris and T. leucomelas during autumn and winter.
Dias J.,State University Londrina |
da Fonte M.A.M.A.,State University Londrina |
Baptista R.,State University Londrina |
Mantoani M.C.,State University Londrina |
And 2 more authors.
Natureza a Conservacao | Year: 2013
Recent papers about invasive plants in Brazil have highlighted the scarcity of criteria for determining invasiveness status. Here, we reviewed papers published in academic journals before March 2012, together with undergraduate monographs, theses and dissertations and abstracts from meetings in ecology, botany and related fields, in order to list plants reported as invasive and verify the criteria used. A total of 124 works were listed, of which 45.9% reported quantitative samples and 35% dealt with Atlantic Forest, 18.5% with Cerrado and 17.8% with Caatinga, the most affected vegetation domains. Invasive behavior was supported by field data for only 54 alien species. Actual figures could be larger; however, the need for further research cannot be used as a justification for inaction in terms of public policy, and the precautionary principle should be employed in implementing temporary solutions in order to avoid irreversible damage. © 2013 ABECO.
Linearization of the titration curves for determination of buffering capacity of feed fiber in a wide pH range [Linearização de curvas de titulação para determinação da capacidade tamponante da fibra de alimentos em ampla faixa de pH]
De Oliveira Junior J.M.,Faculdade Estadual de Filosofia |
Bockor L.,Federal University of Paraná |
Eggers M.,University of Kiel |
Gierus M.,University of Kiel |
And 2 more authors.
Acta Scientiarum - Animal Sciences | Year: 2010
A method for linearization of titration curves and its application to determine the buffering capacity (BC) of neutral detergent fiber (NDF) from 13 feeds and their mixtures was evaluated. Individual data from 2 essays, including samples of white oat, black oat, ryegrass, red clover and white clover (essay 1), and samples of corn, soybean meal, wheat straw and mixtures of these five feeds (essay 2). Titration was performed just to the pH 2.0. The titratable acidity was measured as the amount of HCl needed (mEq g-1 NDF) to reduce the initial pH of the solution down to 4.0, 3.0 and 2.0, and the linear buffer (LB) measure were determined as the inverse of the slope of the linear regression between linearized pH, calculated as EXP (1 pH-1), and the accumulated HCl in each interval. The transformation presented satisfactory fitting to linear regression for all materials evaluated, with r2 higher than 0.85 and standard error residual lower than 0.059. A positive correlation between TA and LB evaluated in the different ranges of pH was obtained. Unlike TA, the LB method makes it possible to obtain the BC as a single linear ratio, valuable for every pH interval from 8.0 to 2.0.