Chemical management of aquatic macrophytes under simulated floodplain condition in mesocosms.

Floating natives (Eichhornia crassipes and Pistia stratiotes) and emergent exotic invasives (Hedychium coronarium and Urochloa arrecta) macrophytes grow as aquatic weeds in both natural and artificial floodplain areas in Brazil, where the chemical control should be researched. The herbicides glyphosate and saflufenacil, alone or mixed, were tested for weed control under simulated floodplain condition in mesocosms. Glyphosate (1,440 g ha-1), saflufenacil (120 g ha-1), or glyphosate (1,440 g ha-1) + saflufenacil (42, 84, and 168 g ha-1) were applied firstly; and 75 days after treatment (DAT), glyphosate (1,680 g ha-1) was applied as a follow-up treatment to control plant regrowth. An herbicide-free check was also used. Echhinornia crassipes was the species most susceptible to the different herbicides. Saflufenacil alone presented the lowest control on the macrophytes (≤45%) from 7 to 75 DAT, and in most cases they presented high regrowth rates, i.e., this herbicide was the least effective treatment in reducing the dry mass production of the macrophyte community. Glyphosate alone presented low efficacy to control H. coronarium (30-65%), but for the other macrophytes, it presented control peaks ≥90%, maintaining control levels ≥50% until 75 DAT. Glyphosate + saflufenacil, regardless rate of saflufenacil, caused similar damage to glyphosate in E. crassipes and P. stratiotes; however, in U. arrecta it caused 20-30% less injury. In contrast, these treatments provided the best control of H. coronarium. The complementary application of glyphosate was essential to improve the level of control of the first application, after plant regrowth.

Control of Salvinia molesta with imazamox and analysis of environmental indicators in microcosms.

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.

Electrostatic spraying of imazamox to control the floating aquatic plant Salvinia molesta and its effects on environmental indicators of water quality.

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.

Detection of anti-cancer drugs and metabolites in the effluents from a large Brazilian cancer hospital and an evaluation of ecotoxicology.

The use of chemotherapy agents has been growing worldwide, due to the increase number of cancer cases. In several countries, mainly in Europe countries, these drugs have been detected in hospitals and municipal wastewaters. In Brazil this issue is poorly explored. The main goal of this study was to assess the presence of three anti-cancer drugs, 5-fluorouracil (5-FU), gemcitabine (GEM) and cyclophosphamide (CP), and two metabolites, alpha-fluoro-beta-alanine (3-NH2-F) and 2'-deoxy-2',2'-difluorouridine (2-DOH-DiF), in effluents from a large cancer hospital, in the municipal wastewater treatment plant (WWTP) influent and effluent, and also to evaluate toxicity of the mixtures of these compounds by ecotoxicological testing in zebrafish. The sample collections were performed in Barretos Cancer Hospital of the large cancer center in Brazil. After each collection, the samples were filtered for subsequent Liquid Chromatography Mass Spectrometry analysis. The presence of CP, GEM, and both metabolites (3-NH2-F and 2-DOH-DiF) were detected in the hospital wastewater and the WWTP influent. Three drugs, GEM, 2-DOH-DiF and CP, were detected in the WWTP effluent. Two drugs were detected below the limit of quantification, 2-DOH-DiF:

Isolation of Saprolegnia aenigmatica oomycetes and protocol for experimental infection of pacu (Piaractus mesopotamicus) / Isolamento do oomiceto Saprolegnia aenigmatica e protocolo de infecção experimental em pacu (Piaractus mesopotamicus)

Successful disease treatment depends on molecular studies under indoor conditions with experimental infection protocols that facilitate understanding the disease and the drug`s efficacy. The internal transcribed spacer (ITS) region was sequenced from three isolates, which were identified as Saprolegnia aenigmatica. Subsequently, healthy fish were immunosuppressed with dexamethasone (1.2 mg kg-1) and descaled to the skin using a sharp scalpel. These individuals were isolated in individual aquariums maintained at 22°C. Individuals in one group were subcutaneously inoculated with 9,000 zoospores (DDZ treatment), a second group was exposed to oomycetes in water with three colonized baits (DDB), a third group was maintained in water without zoospores (DD), and a control group (C) consisted of healthy animals. After 48 and 96 hours, two animals from each group were euthanized for fungal reisolation. The fish from groups DD and C did not show clinical signs, and no oomycetes were isolated. The animals from the DDZ and DDB groups showed cotton-wool-like masses on the skin, and S. aenigmatica was re-isolated. Thus, for infection using zoospores or baits parasitized by S. aenigmatica, an immunosuppressor (dexamethasone) and a sharp scalpel can be used effectively to establish an experimental infection in P. mesopotamicus.

O sucesso do tratamento de uma enfermidade depende do estudo de moléculas em condições de laboratório por meio de protocolos de infecção experimental que viabilizam a compreensão da doença e da eficácia dos fármacos. Pela sequência ITS foram identificadas três cepas de Saprolegnia aenigmatica. Dessa forma, pacus sadios foram submetidos à imunossupressão com dexametasona (1,2 mg kg-1), esfoliados com auxílio de bisturi e distribuídos em aquários a 22ºC. Após este procedimento, um grupo de animais foi inoculado com 9.000 zoósporos/peixe subcutâneo (DEZ), a outro foram adicionadas três iscas colonizadas com o oomiceto na água (DEI), um terceiro grupo foi mantido sem contato com o oomiceto (DE) e um quarto grupo, de animais sadios, representaram o controle (C). Após 48 e 96h deste procedimento, foram eutanaziados animais de cada grupo para reisolamento. Os animais do grupo DE e C não apresentaram sinais clínicos e não foi reisolado o oomiceto. Porém, tanto os animais do grupo DEZ quanto como os animais do grupo DEI apresentaram micélio branco na pele e foi reisolado Saprolegnia aenigmatica. Assim, a infecção com zoósporos ou com iscas colonizadas por S. aenigmatica, com o uso de dexametasona e abrasivo epitelial são formas eficazes de infecção experimental em P. mesopotamicus.

Sensitivity of aquatic organisms to ethanol and its potential use as bioindicators / Sensibilidade de organismos aquaticos ao etanol e seu potencial uso como bioindicadores

The aim of this research was to evaluate the feasibility for the use of the organisms Lemna minor, Azolla caroliniana, Hyphessobrycon eques, Pomacea canaliculata and Daphnia magna as exposure bioindicators for ethanol (lethal and effective concentration 50% - LC50(I)/EC50(I)). Thus, the following concentrations were used 5.0; 10.0; 20.0; 30.0; 40.0 and 50.0 mg L-1 ethanol on L. minor; 25.0; 50.0; 75.0; 100.0; 150.0 and 200.0 mg L-1 on A. caroliniana; 0.3; 0.5; 1.0; 2.0 and 3.0 mg L-1 on H. eques; 0.05; 0.10; 0.20; 0.40 and 0.80 mg L-1 on P. canaliculata; and 40.0; 60.0; 80.0; 100.0; 120.0 and 140.0 mg L-1 on D. magna. An untreated control was also kept for all organisms, with three repetitions. The increase in the ethanol concentration elevated the electrical conductivity and decreased the water dissolved oxygen and pH. The ethanol LC50 for L. minor and A. caroliniana were 12.78 and 73.11 mg L-1, respectively, and was classified as slightly toxic; 1.22 mg L-1 for H. eques (moderately toxic); 0.39 mg L-1 for P. canaliculata (highly toxic) and 98.85 mg L-1 for D. magna (slightly toxic). Thus, H. eques and P. canaliculata have showed good potential for the use as ethanol exposure bioindicators on water bodies.

O objetivo deste estudo foi avaliar a viabilidade do uso dos organismos teste Lemna minor, Azolla caroliniana, Hyphessobrycon eques, Pomacea canaliculata e Daphnia magna como bioindicadores de exposição ao etanol (concentração letal e efetiva 50% - CL50(I)/CE50(I)). Assim, foram utilizadas as seguintes concentrações: 5,0; 10,0; 20,0; 30,0; 40,0 e 50,0 mg L-1 de etanol para L. minor; 25,0; 50,0; 75,0; 100,0; 150,0 e 200,0 mg L- 1 (A. caroliniana); 0,3; 0,5; 1,0; 2,0 e 3,0 mg L-1 (H. eques); 0,05; 0,10; 0,20; 0,40 e 0,80 mg L-1 (P. canaliculata ) e 40,0; 60,0; 80,0; 100,0; 120,0 e 140,0 mg L-1 para D. magna, todos com controle em triplicata. O aumento da concentração do etanol elevou a condutividade elétrica e diminuiu o oxigênio dissolvido e o pH da água. A CL50 do etanol para as macrófitas L. minor e A. caroliniana foi 12,78 e 73,11 mg L-1, respectivamente, sendo classificado como ligeiramente tóxico; para o H. eques, foi de 1,22 mg L-1 (moderadamente tóxico); 0,39 mg L-1 para o P. canaliculata (altamente tóxico) e 98,85 mg L-1 para D. magna (ligeiramente tóxico). Assim, o H. eques e o P. canaliculata apresentaram potencial para uso como organismos bioindicadores de exposição do etanol em corpos hídricos.

Análise histoquímica das glândulas anexas do aparelho reprodutor do macho de paca (Cuniculus paca) / Histochemical analysis of the accessory glands of male paca (Cuniculus paca)

A paca (Cuniculus paca) é um roedor típico de regiões tropicais. Com a finalidade de estudar esta espécie selvagem para manejo adequado e sua preservação, objetivou-se neste trabalho caracterizar a histoquímica das glândulas anexas do trato reprodutor do macho da paca. Para este fim, cortes histológicos dessas glândulas foram submetidas às reações histoquímicas com Ácido Periódico de Schiff (PAS), Alcian blue (AB), PAS. + AB. e PAS + Amilase. Na glândula bulbouretral foi constatado que o epitélio produz secreção rica em glicoproteínas neutras e ácidas, glicosaminoglicanas, e em algumas regiões produz mais de um tipo de secreção. Não foi observada a presença de glicogênio no epitélio. Na glândula vesicular, seu epitélio em borda em escova corou-se por glicoproteínas neutras e também por substância de composição desconhecida, não contendo glicoproteínas ácidas, glicogênio ou glicosaminoglicanas. Verificou-se presença de pequena quantidade de glicoproteínas ácidas e neutras na próstata, em especial na mucosa, além de glicoproteínas ácidas carboxiladas e sulfatadas em pequena quantidade no tecido conjuntivo da lâmina própria dessa glândula. Por fim, a glândula coaguladora apresentou pequena quantidade de glicoproteínas neutras na borda em escova de seu epitélio e substância de composição desconhecida, sendo ausente o glicogênio. Conclui-se que as glândulas anexas do trato reprodutor da paca apresentam características histoquímicas que compartilham certa similaridade com outras espécies da ordem Rodentia, com a presença de glicoproteínas neutras e ácidas em algumas glândulas, principalmente no epitélio da glândula bulbouretal e na borda em escova do epitélio das demais glândulas.(AU)

Paca is a wild rodent typical of the tropical region. In order to study this species with focus on the proper management and preservation, this study aims to characterize the histochemistry of the accessory glands of the reproductive tract of the male paca. For this purpose, histological sections were stained with Periodic Acid-Schiff (PAS), Alcian Blue (AB), PAS + AB e PAS + Amilase. In the histochemical reaction of the bulbouretral gland was found that the epithelium produces secretion rich in neutral and acid glycoproteins, glycosaminoglycans, and in some regions produces more than one type of secretion. The epithelium did not contain any glycogen. In the vesicular gland the epithelium had bush border stained by neutral glycoproteins, but no acid glycoproteins, glycogen or glycosaminoglycan. The coagulating gland showed small amount of neutral glycoproteins in the brush border of the epithelium, without glycogen. It is concludes that the accessory glands of paca have histochemical characteristics that share some similarity with other species of the Order Rodentia, with some glands with neutral and acid glycoproteins, mainly in the epithelium of the bulbouretral gland and in the brush border of the other glands.(AU)

Análise histoquímica das glândulas anexas do aparelho reprodutor do macho de paca (Cuniculus paca) / Histochemical analysis of the accessory glands of male paca (Cuniculus paca)

Paca is a wild rodent typical of the tropical region. In order to study this species with focus on the proper management and preservation, this study aims to characterize the histochemistry of the accessory glands of the reproductive tract of the male paca. For this purpose, histological sections were stained with Periodic Acid-Schiff (PAS), Alcian Blue (AB), PAS + AB e PAS + Amilase. In the histochemical reaction of the bulbouretral gland was found that the epithelium produces secretion rich in neutral and acid glycoproteins, glycosaminoglycans, and in some regions produces more than one type of secretion. The epithelium did not contain any glycogen. In the vesicular gland the epithelium had bush border stained by neutral glycoproteins, but no acid glycoproteins, glycogen or glycosaminoglycan. The coagulating gland showed small amount of neutral glycoproteins in the brush border of the epithelium, without glycogen. It is concludes that the accessory glands of paca have histochemical characteristics that share some similarity with other species of the Order Rodentia, with some glands with neutral and acid glycoproteins, mainly in the epithelium of the bulbouretral gland and in the brush border of the other glands.

A paca (Cuniculus paca) é um roedor típico de regiões tropicais. Com a finalidade de estudar esta espécie selvagem para manejo adequado e sua preservação, objetivou-se neste trabalho caracterizar a histoquímica das glândulas anexas do trato reprodutor do macho da paca. Para este fim, cortes histológicos dessas glândulas foram submetidas às reações histoquímicas com Ácido Periódico de Schiff (PAS), Alcian blue (AB), PAS. + AB. e PAS + Amilase. Na glândula bulbouretral foi constatado que o epitélio produz secreção rica em glicoproteínas neutras e ácidas, glicosaminoglicanas, e em algumas regiões produz mais de um tipo de secreção. Não foi observada a presença de glicogênio no epitélio. Na glândula vesicular, seu epitélio em borda em escova corou-se por glicoproteínas neutras e também por substância de composição desconhecida, não contendo glicoproteínas ácidas, glicogênio ou glicosaminoglicanas. Verificou-se presença de pequena quantidade de glicoproteínas ácidas e neutras na próstata, em especial na mucosa, além de glicoproteínas ácidas carboxiladas e sulfatadas em pequena quantidade no tecido conjuntivo da lâmina própria dessa glândula. Por fim, a glândula coaguladora apresentou pequena quantidade de glicoproteínas neutras na borda em escova de seu epitélio e substância de composição desconhecida, sendo ausente o glicogênio. Conclui-se que as glândulas anexas do trato reprodutor da paca apresentam características histoquímicas que compartilham certa similaridade com outras espécies da ordem Rodentia, com a presença de glicoproteínas neutras e ácidas em algumas glândulas, principalmente no epitélio da glândula bulbouretal e na borda em escova do epitélio das demais glândulas.

Diquat associated with copper sources for algae control: Efficacy and ecotoxicology.

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 algae Ankistrodesmus gracilis and the filamentous algae Pithophora kewesis, and to determine the acute toxicity of the tested chemicals in Hyphressobrycon eques, Pomacea canaliculata, Lemna minor and Azolla caroliniana. The efficacy was estimated by the methods of chlorophyll a and pheophytin a readings, changed into growth inhibition percentage. Both algae were exposed to the following concentrations: 0.2; 0.4; 0.8; 1.2 mg L(-1) of diquat and its association with the copper sources; and 0.1; 0.3; 0.5; 0.7; 1.0 and 1.5 mg L(-1) in 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 for A. gracilis control, 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 on P. kewesis control. The most sensitive non target organism to the tested chemicals was L. minor; the less sensitive was H. eques.

Teflubenzuron as a tool for control of trichodinids in freshwater fish: Acute toxicity and in vivo efficacy.

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.

Atrazine levels in the Jaboticabal water stream (São Paulo State, Brazil) and its toxicological effects on the pacu fish Piaractus mesopotamicus.

The aim of this study was to determine the environmental concentration of atrazine (ATZ) in five streams located in the north of São Paulo state (Brazil) and evaluate its toxicological impact on young specimens of the pacu fish Piaractus mesopotamicus. Samples of water were collected on three occasions between 2010 and 2011, corresponding to periods signifying the beginning, middle, and end of rain season. ATZ levels were estimated by a high-performance liquid chromatography coupled with a mass spectrometry (HPLC-MS/MS) triple quadrupole. Later, the quotient of environmental risk (QR) was determined based on the medium lethal concentration (LC50 48 h), non-observable effect concentration (NOEC), and the estimated environmental concentration (EEC) of ATZ detected in the environment. Histological changes in gills and liver were also studied, along with the brain activity of the enzyme acetylcholinesterase (AChE). The highest concentration of ATZ measured was 10.4 µg L(-1). The ATZ LC50 (48 h) for young P. mesopotamicus was 24.46 mg L(-1) and the QR was classified as "safe". Although the QR indicated that ATZ could be safe for the tested species, it caused many histological alterations in the liver and gills of the exposed specimens, and an increase in the AChE levels.

Metabolic effects of trichlorfon (Masoten®) on the neotropical freshwater fish pacu (Piaractus mesopotamicus).

Fish parasites are among the crucial limiting factors in aquaculture. The organophosphorous pesticide trichlorfon is widely used as an insecticide and against fish parasites worldwide. In this study, the effects of environmental trichlorfon on biochemical and physiological parameters were investigated in Piaractus mesopotamicus (pacu), a widely farmed fish in South America, through sublethal exposure (8 µg L(-1), 10 % of the LC50; 96 h) and recovery. The activity of brain acetylcholinesterase (AChE) was reduced after exposure (15.5 %) and remained decreased during the recovery (21.5 %). In white muscle, AChE activity decreased 31 % only after recovery. Alkaline phosphatase (ALP) and acid phosphatase (ACP) activities of the liver, muscle and plasma were steady during exposure. However, after the recovery period, ALP activity was increased in the liver and muscle and decreased in plasma, while ACP was increased in the liver and decreased in muscle. Intermediary metabolism was also affected by trichlorfon, depicting increase of energetic demand (hypoglycemia, neoglucogenesis and lipid catabolism), which remained even after recovery. These results indicate that P. mesopotamicus is adversely affected by sublethal concentrations of trichlorfon and are useful for assessing the impact as well as the pros and cons of its use in controlling fish parasites in aquaculture.

Histologia do fígado de tilápia do Nilo (Oreochromis niloticus) alimentados com dietas contendo silagem biológica de pescado / Histology liver in Nile tilapia (Oreochromis niloticus) fed diets with fish silage

Este estudo teve como objetivo avaliar as possíveis alterações histopatológicas hepática de tilápias do Nilo alimentadas com dietas contendo silagem biológica de pescado com diferentes concentrações protéicas. Foram utilizados 180 juvenis alimentados com dietas contendo três níveis de proteína (20, 24 and 28% PB), e duas proporções de silagem biológica (» e ½) durante 75 dias. Os fragementos de fígado foram fixados em Bouin e inclusos em Histosec®. Posteriorente foram cortados em microtomo com espessura de 2 a 5µm. O método utilizado para coloração foi hematoxilina/eosina e PAS. Os cortes histológicos foram analisados em microscopio de luz. O desarranjo na morfologia do fígado dos peixes alimentados com silagem biológica foi influenciado pelos altos níveis protéicos, e pelo aumento ½ de proporções de proteínas de origem animal das dietas. Foi observado que a variação dos hepatócitos está diretamente ligada com o tipo da dieta fornecida para os peixes. Nos peixes alimentados com as dietas contendo 28% PB, o fígado apresentou desarranjo da estrutura cordonal dos hepatócitos, pontos de necrose e deslocamento do núcleo para periferia. Níveis elevados de silagem biológica de pescado provoca alterações deletérias no fígado. O nível de proteína adequado para manter o desenvolvimento associado à saúde do peixe é de 24%PB.(AU)

This study aimed to evaluate possible histopathological liver of tilapia fed diets containing fish silage and level protein. Sample of 180 fed with tilapia fingerlings fed with diets containing three protein levels (20, 24 and 28% CP), and Proportions residue fermented silage of tilapia (» and ½) of were analyzed during 75 days. The tissue fragments were fixed in Bouin and included in Histosec®. After that, between 2 to 5µm slices were done in a rotation microtome. The methods used for tissue analysis were hematoxilin/eosin and PAS. The histological slices were examined under light microscope (Olympus BX-50). The disarray in the morphology of the liver of fish fed biological silage was influenced by high protein levels, and increased proportions of ½ of animal protein diets. It was observed that the variation of hepatocytes is directly related to the type of diet for fish. In fish fed diets containing 28% CP, the liver showed disruption of the structure cordon of hepatocytes, necrosis and shifting points of the core to the periphery. Elevated levels of biological fish silage cause deleterious changes in the liver. The level of protein required to maintain the health of the associated development fish is 24% crude protein.(AU)

Copper sulfate acute ecotoxicity and environmental risk for tropical fish / Ecotoxicidade aguda e risco ambiental do sultado de cobre para peixes tropicais

The aim of this study was to estimate copper sulfate acute toxicity and to determine death percentage and environmental risk on guppy fish (Phallocerus caudimaculatus), zebrafish (Brachydanio rerio), mato grosso (Hyphessobrycon eques), and pacu (Piaractus mesopotamicus). Fish were exposed to 0.01, 0.03, 0.05, 0.07, 0.10, and 0.30 mg L-1 (guppy), 0.05, 0.07, 0.10, and 0.30 mg L-1 (zebrafish), 0.07, 0.10, 0.20, and 0.30 mg L-1 (mato grosso) and 9.5, 10.0, 10.5, 11.0, 11.5, and 12.0 mg L-1 (pacu) of copper sulfate, with triplicate control. The estimated 50% average lethal concentrations (LC50; 96 hours) were 0.05 (guppy), 0.13 (zebrafish); 0.16 (mato grosso) and 10.36 mg L-1 (pacu). Copper sulfate was extremely toxic for guppy, highly toxic for zebrafish and mato grosso and lightly toxic for pacu and presents environmental risk of high adverse effects on the guppy, zebrafish and mato grosso and moderate adverse effect to the pacu. Therefore, the guppy fish, zebrafish, and mato grosso are important alternatives for copper sulfate toxicity evaluation in waterbodies.

O objetivo deste estudo foi estimar a toxicidade aguda, determinar a porcentagem de mortalidade e o risco ambiental do sulfato de cobre para o peixe guaru (Phallocerus caudimaculatus), zebrafish (Brachydanio rerio), mato grosso (Hyphessobryconeques) e pacu (Piaractus mesopotamicus). Para realização dos ensaios com sulfato de cobre foram utilizados: 0,01; 0,03; 0,05; 0,07; 0,10 e 0,30 mg L-1 (guaru), 0,05; 0,07; 0,10 e 0,30 mg L-1 (paulistinha), 0,07; 0,10; 0,20 e 0,30 mg L-1 (mato grosso) e 9,5; 10,0; 10,5; 11,0; 11,5 e 12,0 mg L-1 (pacu) como controle em triplicata. A concentração letal média 50% (CL50; 96h) estimada para o guaru foi de 0,05, para o paulistinha foi de 0,13 para o mato grosso foi de 0,16 e para o pacu foi de 10,36 mg L-1. O sulfato de cobre foi classificado como extremamente tóxico para o guaru, altamente tóxico para o paulistinha e mato grosso e ligeiramente tóxico para o pacu e apresenta risco ambiental de elevado efeito adverso para o guaru, paulistinha e mato grosso e moderado efeito adverso para o pacu. Assim, conclui-se que o guaru, paulistinha e mato grosso são importantes alternativas para avaliação da toxicidade do sulfato de cobre em corpos hídricos.

Histopathological evaluation of seven Amazon species of freshwater ornamental armored catfish / Avaliação histopatológica em sete especies de cascudos ornamentais amazônicos

Fish commonly known as acaris or plecos are freshwater armored catfish economically important as a food resource and as ornamental fish. Most of these species are captured in the Amazon region. However, despite its economic importance, there is a lack of knowledge about their biological aspects. Thus, this study aimed to characterize and evaluate the histopathological aspects of important organs as gills, liver, integument and kidney of seven species of armored freshwater ornamental catfish from Guamá River, Pará State, Brazil. All organs showed typical characteristics of organs of other teleosts. In some species, gills and liver showed slight histopathological changes: telangiectasis, edema and morphological changes related to the presence of parasites (Monogenea and Digenea) in the gills, and changes in the arrangement of hepatocytes rows, and vacuolation of hepatocytes in the liver. Thus, the knowledge of the normal structure of organs and changes found can be used as tools for environmental and health monitoring of animals.

Os peixes conhecidos como Acaris ou Cascudos são siluriformes de água doce com o corpo revestido por placas ósseas, economicamente importantes como fonte de alimento e peixes ornamentais. A maioria destas espécies é capturada na região amazônica. Contudo, apesar de sua importância econômica, há desconhecimento sobre os aspectos biológicos desses peixes. Assim, o objetivo deste trabalho foi caracterizar e avaliar histologicamente órgãos importantes (brânquias, fígado, rim e tegumento) de sete espécies de peixes ornamentais de água doce do rio Guamá, Pará, Brasil. Todos os órgãos observados apresentaram as características típicas dos órgãos de teleósteos. Em algumas espécies, as brânquias e o fígado mostraram pequenas alterações histopatológicas: edema, telangiectasias e alterações morfológicas relacionadas com a presença de parasitas (Monogenea e Digenea) nas brânquias, e modificações no arranjo de linhas de cordões de hepatócitos e vacuolização destas células foram também observadas. Assim, o conhecimento da estrutura dos órgãos e as alterações encontradas podem ser utilizados como ferramentas para o monitoramento ambiental e sanitário dos animais.

Acute Toxicity and Determination of the Active Constituents of Aqueous Extract of Uncaria tomentosa Bark in Hyphessobrycon eques.

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 (48 h) in Hyphessobrycon eques was determined. The chromatography showed high levels of oxindole alkaloids, quinovic acid glycosides, and low molecular weight polyphenols. The CL50 48 h 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.

Morphology of accessory genital glands of spotted paca (Agouti paca Linnaeus, 1766).

The spotted paca is the second largest rodent in Brazil, where it is of great economic interest in impoverished regions in view of its prominence as a low-cost source of protein. Little is known about the morphology of the accessory genital glands of this species. Thus, we studied the position and morphology of the genitals in ten adult male spotted pacas. The animals were divided into two groups, five animals were used for fixing of samples in 10% aqueous formaldehyde for macroscopic studies and the other five animals were designated for microscopic analysis. These were arranged in pairs and had the vesicular, prostate, coagulating and bulbourethral glands identified, being structured as mucous glands, which lead into the pelvic urethra. It was concluded that the accessory genital glands found in the paca are the same as those found in most rodents, showing similar histological aspects.

Acute toxicity by water containing hexavalent or trivalent chromium in native Brazilian fish, Piaractus mesopotamicus: anatomopathological alterations and mortality.

This study evaluated the toxicity of hexavalent and trivalent compounds of chromium to the pacu, Piaractus mesopotamicus, in acute exposures of 96 h through mortality and histopathological responses. Hexavalent potassium dichromate was more toxic than trivalent compounds of chromium chloride, chromium oxide and chromium carbochelate. Sufficient mortalities occurred only with potassium dichromate to yield an LC50 value at 124.2 mg L(-1). Hexavalent chromium caused reversible and irreversible lesions, which may affect organ functionality. Histopathological evaluation showed that trivalent chromium caused lesions of lower severity. Pacu subjected to different concentrations of chromium carbochelate showed no histopathological changes in the kidneys, liver, skin and gills, being similar to those of the control fish. Among the three sources of Cr(3+), only chromium chloride at 200 mg L(-1) resulted in mortality, which reached 100 % within the first 18 h. These findings confirm that trivalent chromium, when administered within recommended levels, may be used safely in aquaculture.

Light microscope observations on the epididymis of paca (Agouti paca).

The features of paca epididymis, based on its appearance in light microscope, is described in this paper. The cellular population of the epithelial lining comprises principal cells, basal cells, apical cells, narrows cells, and hallo cells. The epididymis is divided in five distinct and continuous regions, Zone I, or initial segment, and zone II, are both localized into the head. Zone III comprises the distal head and all the body. Zones IV and V are restricted to the tail, in the proximal and distal cauda epididymis respectively. Each zone can be readily distinguished on the basis of morphological characteristics. The height of epididymal epithelium is greater in zone I. There is a progressive increase in the diameter of the tubular lumen through the different areas, with the maximum in the zone V. The presence of a high epithelium, and the virtual absence of sperm in zone I suggest fast transit of spermatozoa in this region. Zone V comprises the distal tail, has smaller epithelial lining, greater luminal diameter, shorter stereocilia than the other zones, and contains spermatozoa packed inside the lumen, that characterizes this zone as a place of sperm storage. The findings are compared with other reports in rodents and other domestic animals, to contribute to the understanding of epididymal morphophysiology.

Acute toxicity and environmental risk of teflubenzuron to Daphnia magna, Poecilia reticulata and Lemna minor in the absence and presence of sediment.

This study aimed to estimate the acute toxicity of teflubenzuron (1-(3,5-dichloro-2,4-difluorophenyl)-3-(2,6-difluorobenzoyl)urea) (TFB) for Daphnia magna, Lemna minor and Poecilia reticulata, in the absence and presence of sediment; evaluate the effect of sediment on the TFB bioavailability; and to classify this insecticide according to its environmental poisoning risk for agricultural and aquaculture uses. The tests of TFB acute toxicity were conducted in static system in a completely randomized design with increasing TFB concentrations, and a control group. The TFB has been classified according to the estimated values of EC50 and LC50 by its acute toxicity and environmental risk. The sediment significantly reduced toxicity and bioavailability of TFB in water column. Therefore, the insecticide can be classified as being highly toxic to Daphnia magna, which means the agricultural and aquacultural uses of TFB pose a high risk of environmental toxicity to non-target organisms. However, it was practically non-toxic to L. minor and P. reticulata.