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The aims of this research were to evaluate the efficacy of copper oxychloride (CuCl2.3Cu(OH)2), copper hydroxide (Cu(OH)2) and diquat (1.1′-ethylene-2.2′-bipyridyldiylium dibromide), isolated and in association with 0.1% of both copper sources, in the control of the unicellular algaeAnkistrodesmus gracilisand the filamentous algaePithophora kewesis, and to determine the acute toxicity of the tested chemicals inHyphressobrycon eques, Pomacea canaliculata, Lemna minorandAzolla caroliniana.The efficacy was estimated by the methods of chlorophyllaand pheophytinareadings, changed into growth inhibition percentage. Both algae were exposed to the following concentrations: 0.2; 0.4; 0.8; 1.2 mg L−1of diquat and its association with the copper sources; and 0.1; 0.3; 0.5; 0.7; 1.0 and 1.5 mg L−1in the isolated applications of copper hydroxide and copper oxychloride. An untreated control was kept. The acute toxicity was estimatedby 50% lethal concentration (LC50). The copper sources were effective forA. graciliscontrol, at rates as high as 0.1 mg L−1(>95% efficacy). Isolated diquat and its association with copper hydroxide were both effective at rates as high as 0.4 mg L−1, with 95 and 88% control efficacy, respectively. The copper oxychloride was effective at 0.2 mg L−1, with 93% efficacy. None of the tested chemicals and associations was effective onP. kewesiscontrol. The most sensitive non target organism to the tested chemicals wasL. minor; the less sensitive wasH. eques. [ABSTRACT FROM PUBLISHER]

This trial was conducted in order to determine the 50% lethal concentration (LC (I) 50-96h) of the aqueous extract of dried leaves of Terminalia catappa, a plant with antifungal, antibacterial and antiparasitic activity. Due to the increasing use of herbal medicines in aquaculture, its use is an option for controlling diseases in fish. Toxicity tests are important before recommending any treatment, since some products have therapeutic concentration close to lethal. To conduct the study used 135 fish species Guarus (Phalloceros caudimaculatus), exposed to increasing concentrations of: 0.0, 50.0, 100.0, 150.0, 200.0, 250.0, 300.0 mL of stock solution per liter of water. The results were calculated by the method Trimmed Spearman Karbo, demonstrating that the 50% lethal concentration (LC (I) 50-96h) estimated was 208.52 mL / L, with lower limit of 187.79 mL / L and higher 231.54 mL / L. Observed changes in behavior of the test organisms at concentrations above 250 mL / L decrease in the levels of dissolved oxygen and pH. Concentrations below 250 mL /L result in mortality rate near zero, so the aqueous extract shown low toxicity. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the efficacy of imazamox for control of S. molesta and to assess the effects of plant decomposition on environmental indicators after application of this herbicide in microcosm conditions. The following rates were used: 600, 700, 800 and 900 g ai ha−1 and spray volume 50 L ha−1. Control efficacy was determined as the percentage (from 0 to 100%) of visible injury symptoms in the plants, biochemical and chemical oxygen demand (BOD5 and COD), water quality variables, chlorophyll a and pheophytin a at 0, 7, 15, 30, 45 and 60 days after application (DAA) and fresh and dry biomass at 60 DAA. Imazamox was effective in controlling 94% of S. molesta with 900 g ai ha−1; it reduced 95% of fresh weight and 92% of dry weight of plant at 60 DAA, and reduced chlorophyll a of the plants for all rates. For BOD5, there was an increase for all rates at 15, 30 and 45 DAA with restoration of the parameters at 60 DAA, and for COD, there was an increase at 60 DAA with 700 and 900 g ai ha−1. For temperature, pH, dissolved oxygen and electrical conductivity, there was no significant effect after spraying. Imazamox was effective in controlling S. molesta with 900 g ai ha−1 without causing significant effects on the physical-chemical parameters of water quality. [ABSTRACT FROM AUTHOR]

This study aimed to assess, in a microcosm condition, the efficacy of electrostatic spraying of herbicide imazamox in the control of Salvinia molesta and the effects of decomposition of plant material on water quality. The herbicide rates used were 600, 700, 800, and 900 g ai ha−1 and spray volume of 50 L ha−1 in electrostatic application. Control effectiveness was assessed at 7, 15, 30, 45, and 60 days after application (DAA), expressed in percentage (0–100%) of visible injury symptoms in the plants, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), chlorophyll a and pheophytin a contents at 0, 7, 15, 30, 45, and 60 DAA, and fresh and dry biomass at 60 DAA. Imazamox was effective in controlling 63% of S. molesta with 900 g ai ha−1 in 45 DAA and 30% with 800 g ai ha−1 in 30 DAA, and reduced 82.3% and 17.5% of fresh weight and 62.6% and 9.3% of dry weight of plant at 60 DAA, respectively. The imazamox spray reduced chlorophyll a with all doses applied and increased BOD5 in 45 DAA with 900 g ai ha−1 and COD in all assessment periods, but for temperature, dissolved oxygen, electrical conductivity, and pH, there was no significant effect after spraying. The herbicide imazamox reduced S. molesta plants with 900 g ai ha−1, without causing significant effects on environmental indicators of water quality. Electrostatic spraying of herbicide can be used in management strategies of aquatic plants to reduce plant density in water bodies and maintain the colonization of plants at a level not harmful to the aquatic biota. [ABSTRACT FROM AUTHOR]

The knowledge of fish mineral requirements, such as selenium, is important to promote the growth and health status for fish in captivity, but excess or deficiency must be avoided. Therefore, this study evaluated the growth performance, hematology and the parasite load of Nile tilapia (Oreochromis niloticus) supplemented with organic selenium (0.0; 0.25; 0.5; 1.0 and 1.5 mg/Kg). The increased levels of selenium did not affect significantly (p<0.05) the growth performance of tilapia. However, the increases of thrombocytes and parasite load are proportional to the increases of selenium levels. Unlike expected, supplemented diets with selenium did not benefit growth performance and supplementation of 1.5 mg/kg caused deleterious effects on the health of tilapia. [ABSTRACT FROM AUTHOR]

In this study we describe the anti- Trichodina effects of teflubenzuron (TFB) for Oreochromis niloticus and for Piaractus mesopotamicus . We also evaluated the acute toxicity, for both species, by using TFB in the concentrations of 700.0, 800.0, 900.0 and 1000.0 mg L −1 and a control, without the drug. To assess the efficacy of TFB against Trichodina spp., we used the concentrations of 30.0 or 50.0 mg L −1 for one hour exposure in tilapia, and the concentration of 30.0, 50.0 and 80.0 mg L −1 for one hour and 50 mg L −1 for two hours exposures in pacu. Teflubenzuron did not present significant toxicity in either species, with LC50;48h > 1000.0 mg L −1 . The drug effectiveness was observed against four identified Trichodina species: T. magna, T. heterodentata , T. compacta and T. centrostrigeata , with 87.9% parasite reduction with one hour exposure to 50.0 mg L −1 TFB on O. niloticus and 96.1% with two hours exposure to 50.0 mg L −1 TFB on P. mesopotamicus . Teflubenzuron is a drug with potential to be used in Brazilian aquaculture; it attends to important requirements, such as low toxicity and high efficacy in controlling Trichodina spp. infection in O. niloticus and P. mesopotamicus . [ABSTRACT FROM AUTHOR]

The use of drugs in aquaculture is necessary to combat pathogens responsible for causing the high rate of mortality in fish farming, such as infection by ectoparasites. The aim of this research was to evaluate the efficacy: (A) of toltrazuril (TOL) treatment against Ichthyophthirius multifiliis, Trichodina heterodentata and Anacanthorus penilabiatus; (B) of thiamethoxam (TH), in treating fish infected by A. penilabiatus and (C) of enrofloxacin (ENR) and florfenicol (FFC) against Aeromonas sp. and Streptococcus sp. The drugs TOL and TH were administered in therapeutic baths while ENR and FFC were mixed with the fish food. The drug concentrations were adjusted according to the experimental conditions (laboratory, microcosm or mesocosm). The drug TOL presented a treatment efficacy rate of 100% against I. multifiliis in microcosm and T. heterodentata in mesocosm. Moreover, ENR presented an efficacy rate of 100% in treating fish infected by Aeromonas sp. and Streptococcus sp. in mesocosm. Finally, TH efficacy rate in controlling A. penilabiatus infection was 81.86% in mesocosm and FFC decreased the overall bacterial load in infected fish. Aeromonas sp. and Streptococcus sp. strains were found in the samples collected for microbiological analysis. In conclusion, TH presented a high efficacy in treating fish against A. penilabiatus infection while TOL was better in controlling T. heterodentata. The antibiotics used in mecoscosm condition presented potential to be used against bacterial infection in aquaculture. [ABSTRACT FROM AUTHOR]

Uncaria tomentosa is a medicinal plant used in folk medicine by Amazon tribes. In this study the constituents of aqueous extract of U. tomentosa bark were quantified by chromatographic technique and its lethal concentration 50 (48h) in Hyphessobrycon eques was determined. The chromatography showed high levels of oxindole alkaloids, quinovic acid glycosides, and low molecular weight polyphenols. The CL50 48h was 1816 mg/L. Fish showed behavior changes at concentrations above 2000 mg/L, accompanied by a significant decrease of dissolved oxygen. At the highest concentration 100% mortality was observed attributed to oxygen reduction by the amount of oxindole alkaloids, polyphenols accumulation of the extract in the gills, and the interaction of these compounds with dopamine. In conclusion, the aqueous extract of U. tomentosa did not alter the chemical components and it was shown that U. tomentosa has low toxicity to H. eques; therefore, it can be used safely in this species. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to determine the acute toxicity of Roundup® Ready (RR) in Piaractus mesopotamicus, and evaluate the effects on the morphology of the gills and liver of exposed surviving fish. Fish were exposed to 3.0, 3.5, 4.0 and 4.5mgL−1 of glyphosate, and the LC50;48h was estimated at 3.74±0.2mgL−1. Gill histopathology was rare, and the activity of Na+/K+-ATPase enzyme did not change, suggesting normal function. However, the damage to the liver was classified as moderate to severe. Cytoplasmic vacuolization, lipid accumulation, nuclear and cellular membrane alterations and glycogen depletion were found in the liver, suggesting a reduction in the liver function. The glyphosate in the RR formulation was classified as moderately toxic for P. mesopotamicus, and the severe damage in the liver may affect the detoxification and/or tissue repair process and contribute to fish death. [Copyright &y& Elsevier]

The surface epithelium of the vas deferens of Agouti paca, a wild and large South American rodent, was basically formed by principal and basal cells being only the principal cells related to endocytosis processes and also secretion taking base on their cytoplasmic ultrastructural features. Principal cell of vas deferens epithelium were characterized mainly by presence of vesicles with several shapes, sizes and internalized content at their apical cytoplasm occurring smaller pits and pale small vesicles seen next to the apical brush border of microvillus. Moreover, coated vesicles, smooth surface vesicles and great vesicles; multivesicular bodies, endosomes and lysosomes were seen. Presence of an apocrine secretory apparatus was also viewed, showing apical cytoplasmic expansions protruding into the vas deferens luminal compartment. The basal flattened cells, without luminal surface contact, occurred next to the basement membrane of the ductus, and did no exhibit special ultrastructural features. [ABSTRACT FROM AUTHOR]