Bibliografìa Argentina del género Prochilodus (Pisces: Curimatidae)

Fil: López, Hugo Luis. División Zoología Vertebrados, Museo de La Plata, UNLPFil: Bonetto, Argentino A.. Museo Argentino de Ciencias Naturales Bernardino Rivadavia; Buenos AiresFil: Gómez, Sergio E.. División Zoología Vertebrados, Museo de La Plata, UNLPFil: Protogino, Lucila Cristina. División Zoología Vertebrados, Museo de La Plata, UNL

Some haematological parameters in Prochilodus lineatus (Pisces, Curimatidae)

Les valeurs des indices hématologiques ont été mesurées chez 56 adultes de #Prochilodus lineatus$ ("sabalo") capturés dans les plaines d'inodation du Salado (Argentine). Le sang a été collecté dans les vaisseaux de la partie caudale des poissons. Les valeurs des paramètres hématologiques ont été mesurées en utilisant les méthodes classiquement utilisées en hématologie humaine. Les résultats obtenus ont ensuite été normalisés pour servir de standard à cette espèce. En ce qui concerne les globules rouges les valeurs moyennes suivantes ont été obtenues : nombre de globules rouges = 1 580 000/mm3 (870 000 - 2 610 000) ; hématocrite = 32,85 % (20,80 - 47,20) ; concentration en hémoglobine = 8,3 g/100 ml (5,2 - 11,9). Le sexe ou le stade de maturation ne paraissent pas affecter les paramètres sanguins, toutefois il semble exister des corrélations significatives entre les différents indices hématologiques. (Résumé d'auteur

Implications of differences between temperate and tropical freshwater ecosystems for the ecological risk assessment of pesticides

Despite considerable increased pesticide use over the past decades, little research has been done into their fate and effects in surface waters in tropical regions. In the present review, possible differences in response between temperate and tropical freshwaters to pesticide stress are discussed. Three underlying mechanisms for these differences are distinguished: (1) climate related parameters, (2) ecosystem sensitivity, and (3) agricultural practices. Pesticide dissipation rates and vulnerability of freshwaters appear not to be consistently higher or lower in tropical regions compared to their temperate counterparts. However, differences in fate and effects may occur for individual pesticides and taxa. Furthermore, intensive agricultural practices in tropical countries lead to a higher input of pesticides and spread of contamination over watersheds. Field studies in tropical farms on pesticide fate in the enclosed and surrounding waterways are recommended, which should ultimately lead to the development of surface water scenarios for tropical countries like developed by the Forum for the co-ordination of pesticide fate models and their use for temperate regions. Future tropical effect assessment studies should evaluate whether specific tropical taxa, not represented by the current standard test species in use, are at risk. If so, tropical model ecosystem studies evaluating pesticide concentration ranges need to be conducted to validate whether selected surrogate indigenous test species are representative for local tropical freshwater ecosystems

Toxic effects of ammonia exposure on growth performance, hematological parameters, and plasma components in rockfish, Sebastes schlegelii, during thermal stress

Abstract Rockfish, Sebastes schlegelii (mean length 14.53 ± 1.14 cm and mean weight 38.36 ± 3.45 g), were exposed for 4 weeks with the different levels of ammonia in the concentrations of 0, 0.1, 0.5, and 1.0 mg/L at 19 and 24 °C. The indicators of growth performance such as daily length gain, daily weight gain, condition factor, and hematosomatic index were significantly reduced by the ammonia exposure and high temperature. The ammonia exposure induced a significant decrease in hematological parameters, such as red blood cell (RBC) count, white blood cell (WBC) count, hemoglobin (Hb), and hematocrit (Ht), whose trend was more remarkable at 24 °C. Mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were also notably decreased by the ammonia exposure. Blood ammonia concentration was considerably increased by the ammonia concentration exposure. In the serum components, the glucose, glutamic oxalate transaminase (GOT), and glutamic pyruvate transaminase (GPT) were substantially increased by the ammonia exposure, whereas total protein was significantly decreased. But, the calcium and magnesium were not considerably changed

Descrição das larvas das principais espécies de peixes utilizadas pela pesca, no Pantanal.

Elaborou-se uma chave ilustrada, baseando-se na comparacao de caracteristicas morfologicas e morfometricas dos estadios iniciais, quando as larvas ainda sao encontradas no plancton, a deriva no rio. A chave possui a descricao das cinco principais especies utilizadas economicamente no Pantanal: pacu (Piaractus mesopotamicus), curimbata (Prochilodus lineatus), dourado (Salminus maxillosus), piavucu (Leporinus macrocephalus). As especies pintado (Pseudoplatystoma corruscans) e cachara (Pseudoplatystoma fasciatum), por nao apresentarem nenhuma diferenca nas caracteristicas utilizadas nas descricoes, foram incluidas em Pseudoplatystoma sp. As descricoes foram feitas a partir de amostras obtidas em condicoes artificiais.bitstream/item/37433/1/BP19.pd

Phylogenetic signal in amphibian sensitivity to copper sulfate relative to experimental temperature

The release of large quantities of chemicals into the environment represents a major source of environmental disturbance. In recent years, the focus of ecotoxicology has shifted from describing the effects of chemical contaminants on individual species to developing more integrated approaches for predicting and evaluating long term effects of chemicals across species and ecosystems. Traditional ecotoxicology is typically based on data of sensitivity of a few surrogate species to a contaminant and often considers little variability in chemical sensitivity within and among taxonomic groups. This approach assumes that evolutionary history and phylogenetic relatedness among species have little or no impact on species’ sensitivity to chemical compounds. Few studies have tested this assumption. Using phylogenetic comparative methods and published data for amphibians, we show that sensitivity to copper sulfate, a commonly used pesticide, exhibits a strong phylogenetic signal when controlling for experimental temperature. Our results indicate that evolutionary history needs to be accounted for to make accurate predictions of amphibian sensitivity to this contaminant under different temperature scenarios. Since physiological and metabolic traits showing high phylogenetic signal likely underlie variation in species sensitivity to chemical stressors, future studies should evaluate and predict species vulnerability to pollutants using evolutionarily informed approaches

Analyses of the sediment toxicity of Monjolinho River, São Carlos, São Paulo State, Brazil, using survey, growth and gill morphology of two fish species (Danio rerio and Poecilia reticulata)

The objective of this work was to evaluate the toxicity of the sediments of the Monjolinho River (São Carlos - São Paulo/Brazil), through partial chronic toxicity bioassays with juveniles of D. rerio and P. reticulata. Histological analyses of the gills and biometric measurements were conducted to detect the possible deleterious effects that caused the death. In all points the sampled the alterations were found in the gills (hyperplasia, fusion of secondary lamellas and dilation of blood vessels), with the most intense lesions (second stage) occurring at the point two. The biometric analysis pointed to inadequate conditions for the growth of the test-organisms when exposed to the sediment samples. These results showed that the conditions of these environments were not suitable for the survival and growth of these fishes.Este trabalho teve como objetivo avaliar a toxicidade dos sedimentos do rio Monjolinho (São Carlos - São Paulo/Brasil), por meio de bioensaios de toxicidade crônicos parciais com juvenis de D. rerio e P. reticulata. Foram realizadas análises histológicas das brânquias dos organismos para detectar possíveis efeitos deletérios que antecedam a mortalidade. Em todos os pontos amostrados, foram verificadas alterações nas brânquias (hiperplasia, fusão de lamelas secundárias e dilatação de vasos sanguíneos), sendo no ponto dois foram encontradas lesões mais acentuadas (segundo estágio). A análise biométrica dos indivíduos expostos em amostras de sedimento demonstrou condições inadequadas para o crescimento e desenvolvimentos dos organismos-teste em todo o ambiente estudado. Os sedimentos apresentaram maior toxicidade no período chuvoso, sendo estes resultados confirmados por meio das análises histológicas das brânquias dos organismos expostos, as quais demonstraram lesões mais acentuadas no mesmo período. Tal situação possivelmente decorre dos impactos antrópicos os quais o sistema está suscetível (efluentes domésticos, industriais e agrícolas), que foram constatados pelas análises físicas e químicas dos sedimentos.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Toxicity and effects of copper sulfate on parasitic control and hematological response of tambaqui Colossoma macropomum.

The purpose of this work was to determine the mean lethal concentration (LC50-96h) of copper sulfate (CuSO4) for juveniles Colossoma macropomum (Characidae), to evaluate the effectiveness of different concentrations of CuSO4 on elimination of parasites, as well as to study the effects of CuSO4 on blood parameters after short-term exposure. After determination of the LC50-96h from 17.5 mg L-1 of CuSO4, it was investigated the effects of exposure for 48 h to 1.75, 4.37 and 8.75 mg L-1 of CuSO4, on parasites and blood parameters. In gills and skin, concentrations of 4.37 and 8.75 mg L-1 of CuSO4 eliminated Monogenoidea Anacanthorus spathulatus. In fish exposed to different concentrations of CuSO4, plasma total protein, chloride, potassium, glucose and copper levels, hemoglobin and hematocrit were similar to controls, whereas sodium levels presented decrease in fish exposed to 1.75 and 4.37 mg L-1. Red blood cell counts decreased in fish exposed to different three concentrations of CuSO4, while the Mean Corpuscular Volume (MCV) increased. However, exposure to 8.75 mg L-1 of CuSO4 caused decrease on total leukocytes, lymphocytes, neutrophils and PAS-positive granular leukocytes (PAS-GL) number when compared to control fish