Notas sobre a ocorr\ueancia de Tityus serrulatus Lutz & Mello, 1922 (Scorpiones, Buthidae) no oeste do Rio Grande do Sul, Brasil

O escorpião amarelo Tityus serrulatus é registrado pela primeira vez para oeste do Rio Grande do Sul. Foram coletados dois espécimes no município de Uruguaiana (29° 45' 23'' S e 57° 05' 37'' W) em junho de 2006. A ocorrência dos espécimes de T. serrulatus no Rio Grande Sul representa um aumento de 2.127 km em sua área de distribuição conhecida

Fator de condição gonadal, índice hepatossomático e recrutamento como indicadores do período de reprodução de Loricariichthys platymetopon (Osteichthyes, Loricariidae), bacia do rio Uruguai médio, sul do Brasil

The recruitment period of Locariichthys platymetopon (Isbrucker & Nijssen, 1979) was investigated. It has been found out, through the data analysis, that the gonadal condition factor is a good indicator of the reproductive period and that the hepatossomatic index is probably related to the storage of reservation for the winter period. The recruitment occurred in November coinciding with the reproductive activity of May

Fator de condição gonadal, índice hepatossomático e recrutamento como indicadores do período de reprodução de Loricariichthys platymetopon (Osteichthyes, Loricariidae), bacia do rio Uruguai médio, sul do Brasil Gonadal condition factor, hepatossomatic index and recruitment as indicators of reproductive period of Loricariichthys platymetopon (Osteichthyes, Loricariidae), Medium Uruguay river basin, South of Brazil

The recruitment period of Locariichthys platymetopon (Isbrucker & Nijssen, 1979) was investigated. It has been found out, through the data analysis, that the gonadal condition factor is a good indicator of the reproductive period and that the hepatossomatic index is probably related to the storage of reservation for the winter period. The recruitment occurred in November coinciding with the reproductive activity of May

Biological and ecological aspects of Palaemonetes argentinus (Nobili, 1901)(Crustacea, Decapoda, Palaemonidae), in the Felizardo arroyo, medium Uruguai River, Uruguaiana, Rio Grande do Sul, Brazil

This work presents aspects of density, biomass, reproduction and growth of Palaemonetes argentinus. Captures were made seasonally in the period between July 2001 and May 2002, in three distinct spots of the Felizardo stream, an affluent of the medium Uruguai River, through the electric fishing technique. The results obtained refer to the four seasons of the year, throughout which a total of 551 individuals were captured out of an expected 604. The period of higher density and biomass was the Spring season with 5,982 ind./ha and 2,057 g/ha, respectively. The weight-length relation obtained for the P. argentinus population was Wt= 0.145252*L2.679. The fecundity (NO) length relation obtained for the same population was NO= exp. (1.64908 + 0.528255)* Lt and the fecundity (NO) weight relation was Wt= exp. (-1.95674 + 0.0311)*NO. The curve determined for the growth in length of Palaemonetes argentinus indicated Lt= 5.7 (1-e -0.373082 (T -0.400498)) and Wt= 1.608 (1- e -0.172389 (W -1.052659)). The reproductive period occurs with greater intensity in the spring and proceeds in a reduced manner in summer, having a rest period in the autumn and winter. The number of eggs in the spawnings varied between 18 and 84, with an average of 39.88 eggs per egged female

Bivalve molluscs of São Marcos locality, Medium Uruguay River Basin, Brazil

To verification of quali-quantitative it has been accomplished collected of bivalve molluscs during the period of twelve months, together with analysis of some abiotic variables in the middle care of Uruguay river, situated in São Marcos, Uruguaiana municipality. The place where the collects has been accomplished, were divided in three distinct spots, considerating the substract type predominant; sand, rock and mud. The individuals were collected using hands and with. The selection screen aid, of 0.8mm size net and were conserved in a dry environment. They had been collected a total of 1,022 units of bivalves, wich belong to 12 taxa, being that of these only specimens Cyanocyclas limosa and Diplodon parallelopipedon had been captured alive (tanatocenosis). It had great quantitative predominance of Corbicula fluminea and Diplodon uruguayensis. With exception of bivalves invading, the too much species had been collected only in the slimy substratum. Other species occurrence were Mycetopoda siliquosa and Anodontites trigonus, there two species a vulnerable to extinction in Rio Grande do Sul

<b>Cd, Cu, and Mn from Uruguay River Basin in Uruguaiana, RS, Brazil, and their toxicological potential for human leukocyte

This study assessed the limnology from the Medium Uruguay River Basin in Uruguaiana, Brazil, with a focus on the concentration of heavy metals (Cd, Cu, and Mn), to assess the toxicological potential (cytotoxicity and genotoxicity) for humans using as biological matrix of study human leukocyte cells. The conductivity, resistivity, and dissolved O2 levels exceeded the limits recommended by the National Environmental Council (Conselho Nacional do Meio Ambiente - CONAMA). The percentage of non-viable human leukocyte cells exposed to water samples was approximately 20% higher than that of the negative control (<3%), but similar to the positive control. The DNA damage index was high for all heavy metal concentrations assayed when compared to the negative control 12±2.96, p < 0.0001, with a range of 155.66±23.89 to 194.33±23.23, but similar to the positive control (210.62±27.48). Moreover, the leukocyte degeneration index was higher in all samples containing heavy metals than in the negative control (4%), which demonstrates to be due the presence of Cu (11.8-12.5%), Cd (13-15.6%), and Mn (15.6-22.5%). Taken together, our results show that the quality from water samples analyzed is below than recommended by CONAMA and offers risk of contamination by heavy metals for the general population.

Ichthyofauna of the Quarai-Chico creek, Uruguai river middle basin, Espinilho State Park, Rio Grande do Sul, Brazil

With the aim of identifying the composition of the ichthyofauna from Quarai-Chico creek (a tributary of the middle Uruguai river located in the municipality of Barra do Quarai), seasonal samplings were taken over the period of one year, from April 1997 to March 1998. Captures were made by means of electrical fishing techniques. A total of 3,564 specimens were captured, distributed in 37 species, 27 genders and 14 families. The Characidae family demonstrated the highest representivity, with 12 species captured, while the Anostomidae, Gymnotidae, Heptapteridae, Pimelodidae, Poecillidae, Synbranchidae and Sternopygidae families each produced evidence of only a single species. In general teams, the results obtained demonstrated a higher ichthyic diversity than the other creeks in the region of the Western frontier of Rio Grande do Sul