Entity

Time filter

Source Type

Santa Fe de la Vera Cruz, Argentina

Oliveira-Filho E.C.,Laboratory of Environmental Toxicology | Oliveira-Filho E.C.,Laboratory of Ecotoxicology | Geraldino B.R.,Laboratory of Environmental Toxicology | Coelho D.R.,Laboratory of Environmental Toxicology | And 2 more authors.
Chemosphere | Year: 2010

Plant molluscicides have been regarded as possible alternatives to the costly and environmentally hazardous molluscicides currently available. This study was undertaken to compare the developmental toxicity of a plant molluscicide (Euphorbia milii latex, LAT) with that of three synthetic molluscicidal compounds. Biomphalaria glabrata egg masses (0-15h after spawning) were exposed to molluscicides for 96h and thereafter examined up to the 14th day after spawning. Embryo deaths, abnormal embryo development (malformations) and the day of hatching were recorded. Although exhibiting a weak ovicidal effect, LAT markedly impaired the development of snail embryos at concentrations ≥1000μgL-1 and produced anomalies (EC50=2040μgL-1) such as abnormal shells, hydropic embryos, cephalic and non-specific malformations. Embryolethal potencies of molluscicides were as follows: triphenyltin hydroxide (TPTH; LC50=0.30μgL-1)>niclosamide (NCL; LC50=70μgL-1)>copper sulphate (CuSO4; LC50=2190μgL-1) ⋙ LAT (LC50=34030μgL-1). A few malformations were recorded in embryos exposed to concentrations of TPTH within the range of lethal concentrations, while almost no anomalies were noted among those treated with NCL or CuSO4. A hatching delay (hatching on day 10 after spawning or later) was observed among LAT-exposed embryos. The effects of NCL, TPTH and CuSO4 on hatching were to some extent masked by their marked embryolethality. The no-observed effect concentrations (NOEC) for embryotoxicity were as follows: TPTH, 0.1μgL-1; NCL, 25.0μgL-1; CuSO4, 500.0μgL-1 and LAT, 500.0μgL-1. Results from this study suggest that, although LAT was not acutely embryolethal after a short-term exposure, it markedly disrupted snail development. The marked embryotoxicity of E. milii possibly contributes to its effectiveness as a molluscicide. © 2010 Elsevier Ltd. Source


Perez-Garcia C.,University of Vigo | Perez-Garcia C.,Laboratory of Ecotoxicology | Hurtado N.S.,University of Vigo | Moran P.,University of Vigo | Pasantes J.J.,University of Vigo
BioMed Research International | Year: 2014

The chromosomal changes accompanying bivalve evolution are an area about which few reports have been published. To improve our understanding on chromosome evolution in Veneridae, ribosomal RNA gene clusters were mapped by fluorescent in situ hybridization (FISH) to chromosomes of five species of venerid clams (Venerupis corrugata, Ruditapes philippinarum, Ruditapes decussatus, Dosinia exoleta, and Venus verrucosa). The results were anchored to the most comprehensive molecular phylogenetic tree currently available for Veneridae. While a single major rDNA cluster was found in each of the five species, the number of 5S rDNA clusters showed high interspecies variation. Major rDNA was either subterminal to the short arms or intercalary to the long arms of metacentric or submetacentric chromosomes, whereas minor rDNA signals showed higher variability. Major and minor rDNAs map to different chromosome pairs in all species, but in R. decussatus one of the minor rDNA gene clusters and the major rDNA cluster were located in the same position on a single chromosome pair. This interspersion of both sequences was confirmed by fiber FISH. Telomeric signals appeared at both ends of every chromosome in all species. FISH mapping data are discussed in relation to the molecular phylogenetic trees currently available for Veneridae. © 2014 Concepción Pérez-García et al. Source


Machado C.K.,Rua Paulo Malschitzki | Pinto L.H.,Rua Paulo Malschitzki | Ciampo L.F.D.,Inovaparq | Lorenzi L.,Rua Paulo Malschitzki | And 3 more authors.
Ecotoxicology and Environmental Safety | Year: 2014

Understanding the toxicity of certain potentially toxic compounds on various aquatic organisms allows to assess the impact that these pollutants on the aquatic biota. One source of pollution is the wastewater from hemodialysis. The process of sewage treatment is inefficient in inhibition and removal of pathogenic bacteria resistant to antibiotics in this wastewater. In many countries, such as Brazil, during emergencies, sewage and effluents from hospitals are often dumped directly into waterways without any previous treatment. The objective of this study was to characterize the effluents generated by hemodialysis and to assess the degree of acute and chronic environmental toxicity. The effluents of hemodialysis showed high concentrations of nitrites, phosphates, sulfates, ammonia, and total nitrogen, as well as elevated conductivity, turbidity, salinity, biochemical and chemical oxygen demand, exceeding the thresholds defined in the CONAMA Resolution 430. The samples showed acute toxicity to the green flagellate Euglena gracilis affecting different physiological parameters used as endpoints in an automatic bioassay such as motility, precision of gravitational orientation (r-value), compactness, upward movement, and alignment, with mean EC50 values of recalculate as 76.90 percent (±4.68 percent) of the undiluted effluents. In tests with Daphnia magna, the acute toxicity EC50 was 86.91 percent (±0.39 percent) and a NOEC value of 72.97 percent and a LEOC value 94.66 percent. © 2014 Elsevier Inc. Source


Attademo A.M.,Laboratory of Ecotoxicology | Attademo A.M.,CONICET | Cabagna-Zenklusen M.,Laboratory of Ecotoxicology | Lajmanovich R.C.,Laboratory of Ecotoxicology | And 6 more authors.
Ecotoxicology | Year: 2011

Activity of B-esterases (BChE: butyrylcholinesterase and CbE: carboxylesterase using two model substrates: α-naphthyl acetate and 4-nitrophenyl valerate) in a native frog, Leptodactylus chaquensis from rice fields (RF1: methamidophos and RF2: cypermethrin and endosulfan sprayed by aircraft) and non-contaminated area (pristine forest) was measured. The ability of pyridine-2-aldoxime methochloride (2-PAM) to reactivate BChE levels was also explored. In addition, changes in blood cell morphology and parasite infection were determined. Mean values of plasma BChE activities were lower in samples from the two rice fields than in those from the reference site. CbE (4-nitrophenyl valerate) levels varied in the three sites studied, being highest in RF1. Frog plasma from RF1 showed positive reactivation of BChE activity after incubation with 2-PAM. Blood parameters of frogs from RF2 revealed morphological alterations (anisochromasia and immature erythrocytes frequency). Moreover, a major infection of protozoan Trypanosoma sp. in individuals from the two rice fields was detected. We suggest that integrated use of several biomarkers (BChE and CBEs, chemical reactivation of plasma with 2-PAM, and blood cell parameters) may be a promising procedure for use in biomonitoring programmes to diagnose pesticide exposure of wild populations of this frog and other native anuran species in Argentina. © 2010 Springer Science+Business Media, LLC. Source


Attademo A.M.,Laboratory of Ecotoxicology | Attademo A.M.,CONICET | Peltzer P.M.,Laboratory of Ecotoxicology | Peltzer P.M.,CONICET | And 6 more authors.
Journal of Zoo and Wildlife Medicine | Year: 2012

Trombiculid mites are known to parasitize a variety of amphibian species; however, few comparisons of mite parasitism among sites have been made. Here, Hannemania sp. parasitism in frogs (Leptodactylus chaquensis) inhabiting agroecosystems from mideastern Argentina was described. A total of 40 adult frogs (22 females and 18 males) were analyzed to detect ectoparasite Hannemania spp. larvae. Prevalence and mean abundance of Hannemania sp. were consistently higher in frogs from the agroecosystems (rice and soybean fields) than from two reference sites. Leptodactylus chaquensis might be considered an important host species of Hannemania sp., particularly in agricultural areas. Copyright © 2012 by American Association of Zoo Veterinarians. Source

Discover hidden collaborations