The role of habitat complexity in the survival rates of migratory (native) and sedentary (non-native) species of fish larvae

The increasing losses of original features of many riverine environments and the consequent decline of native aquatic species are now a widely recognized problem. The main river basins of South America have been undergoing constant changes in their communities of fish, with native migratory species disappearing and the rising of sedentary exotic ones. However, few studies report experiments that qualify and/or quantify this correlation. Three experiments were conducted to evaluate the predation mortality of two species of fish larvae (native and non-native) regarding their habitat features. The hypothesis that natural features of habitat (aquatic vegetation and water turbidity) controls the survival rates of fish larvae was tested. The experiments highlight the importance of community structure on population dynamics. The native fish larvae showed to be more adapted than the non-native to using the aquatic plants for refuge. The habitat complexity can be closely related to the persistence of native migratory fish species.(AU)

Evaluation of the use of Ancistrus brevipinnis (Loricariidae) as a bioindicator of water quality in the Ilha river, RS, Brazil

The use of fish as bioindicators of the effect of contaminants in the aquatic environment is usual. However, detritivorous species are less used for environmental monitoring. Thus, the aim of this study was to evaluate the use of Ancistrus brevipinnis as a potential bioindicator of water quality of the Ilha River, RS (southern Brazil) and compared to the result obtained for a routine species (Bryconamericus iheringii). For this purpose, the condition factor (CF), the presence of morphological changes in the gills and the quantification of metals in different tissues of the specimens collected in three sites of the Ilha River were evaluated. A homogeneity in the distribution of data was observed in the CF for the species B. iheringii, whereas the specimens of A. brevipinnis showed an oscillation in the distribution of data of the CF. Histological analysis showed greater sensitivity of B. iheringii in reproducing characteristics of the environment in its gill lamellae, which was not observed in A. brevipinnis. Conversely, Cr quantification was higher in the intestine samples of A. brevipinnis at all sites and in all collections due to its feeding behavior. The data reinforce the use of water column species as Bryconamericus iheringii for environmental monitoring, even if they do not reflect the whole aquatic ecosystem. Further studies evaluating other tissues and biomarkers, such as the gastrointestinal tract, may assist in describing the use of species more related to sediment.(AU)

Ecological aspects of Rhinoclemmys punctularia punctularia (Testudines: Geoemydidae) in two localities in northern Brazil / Aspectos ecológicos de Rhinoclemmys punctularia punctularia (Testudines: Geoemydidae) em duas localidades no norte do Brasil

Rhinoclemmys punctularia punctularia is the only turtle of the family Geoemydidae with part of its range in Brazil. The species is semi-aquatic and widely distributed across the Amazon basin but is still poorly studied. We evaluated aspects of the population structure, habitat use, seasonal activity, and diet of the species during one year, from the beginning of the rainy season to the end of the dry season, in two headwater localities in the Tocantins and Tapajós river basins, in the state of Pará, Brazil. We captured 45 individuals, 14 in the Tocantins basin and 31 in the Tapajós basin. The size-class frequency distributions of captured individuals did not differ between the two samples. The turtles were most frequently captured in first-order streams, followed by lentic (third-order dammed streams) and second-order streams. The capture rate did not vary significantly between sampling periods (start and peak of the rainy season; start and end of the dry season). The trapping effort to capture a single individual was much higher in the Tapajós basin (1,215 trap-hours) than in the Tocantins basin (136 trap-hours). Overall, the low capture rates confirm the secretive nature of the species in Amazonia and its apparent rarity. The individuals analyzed in this study consumed mainly plants.(AU)

Rhinoclemmys punctularia punctularia é o único quelônio da família Geoemydidae com parte de sua distribuição no Brasil. A espécie é semi-aquática e amplamente distribuída na bacia amazônica, mas ainda é pouco estudada. Avaliamos aspectos da estrutura populacional, uso do habitat, atividade sazonal e dieta da espécie ao longo de um ano, desde o início da estação chuvosa até o final da estação seca, em duas localidades de cabeceira nas bacias dos rios Tocantins e Tapajós, no estado do Pará, Brasil. Capturamos 45 indivíduos: 14 na bacia do Tocantins e 31 na bacia do Tapajós. A distribuição de frequências por classe de tamanho dos indivíduos capturados não diferiu entre as duas amostras. Os quelônios foram mais frequentemente capturados em riachos de primeira ordem, seguidos por riachos lênticos (riachos de terceira ordem represados) e de segunda ordem. A taxa de captura não variou significativamente entre os períodos de amostragem (início e pico da estação chuvosa; início e fim da estação seca). O esforço de armadilhagem para capturar um único indivíduo foi muito maior na bacia do Tapajós (1.215 horas-armadilha) do que na bacia do Tocantins (136 horas-armadilha). No geral, as baixas taxas de captura confirmam a natureza discreta da espécie na Amazônia e sua aparente raridade. Os indivíduos analisados neste estudo consumiram principalmente plantas.(AU)

Pitiose cutânea em equino no sertão do Ceará / Skin pythiosis in horse in the backwoods of the Ceará State

A pitiose é uma infecção invasiva ulcerativa piogranulomatosa causada pelo oomiceto Pythium insidiosum, parasita de plantas aquáticas em águas estagnadas. Apesar de não serem raros os relatos de pitiose nas espécies domésticas, a espécie equina é a mais afetada. A enfermidade pode ser adquirida através da colonização de lesões traumáticas e do folículo piloso. Em casos dessa infecção, pode-se encontrar hifas recobertas por células necróticas, formando massas branco-amareladas semelhantes a corais, denominadas de kunkers. As lesões são localizadas prioritariamente nas extremidades distais dos membros e na porção ventral da parede tóraco-abdominal. O diagnóstico da pitiose está relacionado a um prognóstico reservado dependendo do grau de comprometimento anatômico que a enfermidade se encontra. Diante do exposto, este trabalho teve como objetivo relatar um caso de pitiose cutânea em um equino, fêmea da raça Mangalarga Machador. O animal apresentava lesões ulcerativas no membro torácico esquerdo e no membro pélvico esquerdo. O tratamento escolhido foi o cirúrgico e imunoterápico, com intuito de remover todo o tecido lesionado e, posteriormente, coletar material para realização do exame histopatológico. O equino foi submetido a um protocolo pós-operatório com a terapia antitetânica por via intramuscular. A antibioticoterapia sistêmica foi realizada com penicilina benzatina, anti-inflamatório esteroidal, dexametasona foi realizada uma vez ao dia, durante cinco dias. Posteriormente, optou-se pelo uso do anti-inflamatório não esteroidal maxicam uma vez ao dia, durante cinco dias. O animal recebeu quatro doses do imunoterápico PITIUM-VAC por via subcutânea, com intervalo de 14 dias entre uma e outra aplicação, apresentando uma resposta satisfatória ao tratamento.

Pythiosis is an invasive ulcerative pyogranulomatous infection caused by the Oomycete Pythium insidiosum, a parasite of aquatic plants in standing water. Although reports of pythiosis in domestic species are not uncommon, equine species are the most affected. The disease can be acquired through the colonization of traumatic lesions and hair follicles. Hyphae covered by necrotic cells, forming yellowish-white coral-like masses called "kunkers" can be found. The lesions are located primarily on the distal extremities of the limbs and on the ventral portion of the thoracoabdominal wall. The diagnosis of pythiosis is linked to a poor prognosis, depending on the degree of anatomical involvement of the disease. Thus, this work aimed to report a case of cutaneous pythiosis in a female Mangalarga Machador equine. The animal presented ulcerative lesions on the left thoracic limb and the left pelvic limb. The chosen treatment was surgery and immunotherapy to remove all the injured tissue and, later, collect the material for histopathological examination. The horse was submitted to a post-operative protocol with intramuscular anti-tetanus therapy. Systemic antibiotic therapy with benzathine penicillin, steroidal anti-inflammatory, dexamethasone was performed once a day for five days. Subsequently, it was decided to use the non-steroidal anti-inflammatory maxicam once a day for five days. The animal received four doses of the immunotherapy PITIUM-VAC subcutaneously, with an interval of 14 days between applications, presenting a satisfactory response to the treatment.

A checklist of aquatic macrophytes of the Guaraguaçu river basin reveals a target for conservation in the Atlantic rainforest

Describing and understanding distribution of species in natural ecosystems is the first step to establish conservation efforts. In aquatic habitats, macrophytes play a central role in promoting biodiversity and ecosystem functioning. This study aimed to create the first checklist of aquatic macrophyte species occurring in the Guaraguaçu river, the largest river in Paraná State coast, Brazil. Species herborized, identified and incorporated into the Herbarium collection of the Universidade Federal do Paraná. A total of 47 species were registered corresponding to 37 genera and 29 botanical families; Cyperaceae and Poaceae were the most representative families. In addition, the wide invasion of the non-native species Urochloa arrecta (Hack. ex T. Durand & Schinz) Morrone & Zuloaga was registered and the presence of the floating-leaved non-native species Nymphaea caerulea Savugny was recorded. Even so, the inventory shows a noteworthy richness of aquatic macrophytes species in the Guaraguaçu river, and it is clear macrophyte species reflect a gradient of anthropic impact and salinity in this tidal estuarine river. Our study contributes to the creation of public policies to aid in the protection of this river that represents a central site for biological conservation efforts, yet is constantly threatened by anthropic activities.

A checklist of aquatic macrophytes of the Guaraguaçu river basin reveals a target for conservation in the Atlantic rainforest

Describing and understanding distribution of species in natural ecosystems is the first step to establish conservation efforts. In aquatic habitats, macrophytes play a central role in promoting biodiversity and ecosystem functioning. This study aimed to create the first checklist of aquatic macrophyte species occurring in the Guaraguaçu river, the largest river in Paraná State coast, Brazil. Species herborized, identified and incorporated into the Herbarium collection of the Universidade Federal do Paraná. A total of 47 species were registered corresponding to 37 genera and 29 botanical families; Cyperaceae and Poaceae were the most representative families. In addition, the wide invasion of the non-native species Urochloa arrecta (Hack. ex T. Durand & Schinz) Morrone & Zuloaga was registered and the presence of the floating-leaved non-native species Nymphaea caerulea Savugny was recorded. Even so, the inventory shows a noteworthy richness of aquatic macrophytes species in the Guaraguaçu river, and it is clear macrophyte species reflect a gradient of anthropic impact and salinity in this tidal estuarine river. Our study contributes to the creation of public policies to aid in the protection of this river that represents a central site for biological conservation efforts, yet is constantly threatened by anthropic activities.(AU)

Temperature influences swine wastewater treatment by aquatic plants

Studies show that aquatic plants are an efficient alternative to minimize the harmful effects of wastewater. Two species of aquatic macrophytes (Pistia stratiotes and Eichhornia crassipes) were chosen to evaluate the temperature effect on the performance of these macrophytes species in a post-treatment system of swine wastewater. The experiment was carried out in the municipality of Toledo, Paraná State, Brazil. For the experimental system, 24 concrete tanks with 80 L capacity were used, each measuring approximately 1.5 m in length, 0.25 m in width and 0.16 m deep. Wastewater characteristics and variables hydrogen potential (pH), electrical conductivity (EC), and dissolved oxygen (DO) were measured weekly. After, we analyzed the aquatic macrophytes and centesimal composition. The use of aquatic macrophytes was efficient for final swine wastewater polishing. Nitrogen removal showed higher efficiency in the summer period for both species studied. The abiotic variables (pH and EC) presented better results during the winter for both species evaluated. Air and wastewater low temperatures did not influence these variables. Dissolved oxygen presented better results in the summer period for E. crassipes species. There was a significant increase in N and P contents in the plant tissue. This fact proves that the use of aquatic macrophytes is an interesting alternative for swine wastewater treatment.

Temperature influences swine wastewater treatment by aquatic plants

Studies show that aquatic plants are an efficient alternative to minimize the harmful effects of wastewater. Two species of aquatic macrophytes (Pistia stratiotes and Eichhornia crassipes) were chosen to evaluate the temperature effect on the performance of these macrophytes species in a post-treatment system of swine wastewater. The experiment was carried out in the municipality of Toledo, Paraná State, Brazil. For the experimental system, 24 concrete tanks with 80 L capacity were used, each measuring approximately 1.5 m in length, 0.25 m in width and 0.16 m deep. Wastewater characteristics and variables hydrogen potential (pH), electrical conductivity (EC), and dissolved oxygen (DO) were measured weekly. After, we analyzed the aquatic macrophytes and centesimal composition. The use of aquatic macrophytes was efficient for final swine wastewater polishing. Nitrogen removal showed higher efficiency in the summer period for both species studied. The abiotic variables (pH and EC) presented better results during the winter for both species evaluated. Air and wastewater low temperatures did not influence these variables. Dissolved oxygen presented better results in the summer period for E. crassipes species. There was a significant increase in N and P contents in the plant tissue. This fact proves that the use of aquatic macrophytes is an interesting alternative for swine wastewater treatment.(AU)

Growth of Microcystisstrains isolated from environments with the presence and absence of submerged macrophytes in coexistence with Ceratophyllum demersum

Cyanobacterial blooms can cause severe ecological and health problems in drinking water reservoirs. To alleviate this problem, allelopathically active submerged macrophytes can be used to reduce cyanobacterial growth. Accordingly, this study aimed to evaluate the sensitivity of strains of the Microcystis aeruginosacomplex isolated from reservoirs with the presence and absence of submerged macrophytes to the allelochemicals of Ceratophyllum demersum.A coexistence experiment was carried out between the submerged macrophyte C. demersum and four Microcystisstrains, with two treatments for each strain, one in coexistence with the submerged macrophyte (7 g L-1) and control (in the absence of the macrophyte). Two strains of M. aeruginosa(BMIUFRPE-06 and BMIUFRPE-07) and two of M. panniformis(BMIUFRPE-08 and BMIUFRPE-09) were used, which were isolated from Cajueiro (with submerged macrophytes) and Tapacurá (without submerged macrophytes) reservoirs, respectively. The biomass of Microcystisstrains from the reservoir without macrophytes (BMIUFRPE-08 and BMIUFRPE-09) was significantly inhibited in 96% (T-test: p 0.05; growth rate -ANOVA: p > 0.05). These results suggest that strains isolated from environments with submerged macrophytes are less sensitive to allelochemicals of these plants,as these strains may be adapted to the coexistence with submerged macrophytes.

Metastatic calcification and granulomatous grastroenteritis associated to Pythium insidiosum in a dog

Pythiosis is a granulomatous process of which the oomycete Pythium insidiosum is its etiological agent. It can affect animals and humans alike and its infection occurs when free zoospores in the water get in contact with the target tissues and encyst. The disease often occurs in tropical places with abundance of water and aquatic plants that host the fungus. Dogs infection is predominantly gastric with granuloma formations in the stomach and intestine with progressive signs of vomiting, weight loss and diarrhea. In this case report, we described clinical, surgical, necroscopic and histopathological findings of a one year and two months old, male boxer that presented clinical signs of anorexia and persistent vomiting. It was noticed on ultrasound examination an increase in stomach and intestine thickness. Laparotomy confirmed a mass affecting the gastric wall which, an incision biopsy, showed an abundant fibrous tissue associated with granulomatous reaction that was surrounded by tubuliform structures. Due to clinical complications, euthanasia was performed and in necroscopic examination a markedly increased stomach and duodenum was observed. An; histological examination of this areas it was observed that they contained granulation tissue with giant cells and epithelioids macrophages around necrosed areas associated with lymphocytes infiltrate. Also, it was possible to observe tubuliform structures by the Grocott-Gomori’s Methenamine Silver (GMS) stain, this finding is compatible with the agent Pythium insidiosum. Therefore, this presumptive identification was confirmed by PCR analysis which amplicon had 97.83% similarity with current available genomic sequence of P. insidiosum.

Metastatic calcification and granulomatous grastroenteritis associated to Pythium insidiosum in a dog

Pythiosis is a granulomatous process of which the oomycete Pythium insidiosum is its etiological agent. It can affect animals and humans alike and its infection occurs when free zoospores in the water get in contact with the target tissues and encyst. The disease often occurs in tropical places with abundance of water and aquatic plants that host the fungus. Dogs infection is predominantly gastric with granuloma formations in the stomach and intestine with progressive signs of vomiting, weight loss and diarrhea. In this case report, we described clinical, surgical, necroscopic and histopathological findings of a one year and two months old, male boxer that presented clinical signs of anorexia and persistent vomiting. It was noticed on ultrasound examination an increase in stomach and intestine thickness. Laparotomy confirmed a mass affecting the gastric wall which, an incision biopsy, showed an abundant fibrous tissue associated with granulomatous reaction that was surrounded by tubuliform structures. Due to clinical complications, euthanasia was performed and in necroscopic examination a markedly increased stomach and duodenum was observed. An; histological examination of this areas it was observed that they contained granulation tissue with giant cells and epithelioids macrophages around necrosed areas associated with lymphocytes infiltrate. Also, it was possible to observe tubuliform structures by the Grocott-Gomoris Methenamine Silver (GMS) stain, this finding is compatible with the agent Pythium insidiosum. Therefore, this presumptive identification was confirmed by PCR analysis which amplicon had 97.83% similarity with current available genomic sequence of P. insidiosum.(AU)

Growth of Microcystisstrains isolated from environments with the presence and absence of submerged macrophytes in coexistence with Ceratophyllum demersum

Cyanobacterial blooms can cause severe ecological and health problems in drinking water reservoirs. To alleviate this problem, allelopathically active submerged macrophytes can be used to reduce cyanobacterial growth. Accordingly, this study aimed to evaluate the sensitivity of strains of the Microcystis aeruginosacomplex isolated from reservoirs with the presence and absence of submerged macrophytes to the allelochemicals of Ceratophyllum demersum.A coexistence experiment was carried out between the submerged macrophyte C. demersum and four Microcystisstrains, with two treatments for each strain, one in coexistence with the submerged macrophyte (7 g L-1) and control (in the absence of the macrophyte). Two strains of M. aeruginosa(BMIUFRPE-06 and BMIUFRPE-07) and two of M. panniformis(BMIUFRPE-08 and BMIUFRPE-09) were used, which were isolated from Cajueiro (with submerged macrophytes) and Tapacurá (without submerged macrophytes) reservoirs, respectively. The biomass of Microcystisstrains from the reservoir without macrophytes (BMIUFRPE-08 and BMIUFRPE-09) was significantly inhibited in 96% (T-test: p < 0.01) and 74% (T-test: p< 0.05), when compared to the control, respectively, with lower values of growth rates (ANOVA: p < 0.05). The strains isolated from the reservoir with macrophytes (BMIUFRPE-06 and BMIUFRPE-07) showed a growth delay (biomass reductions of 44 and 58%, respectively) in the coexistence treatment but without significant difference from the control on the sixth day of the experiment (biomass -T-test: p > 0.05; growth rate -ANOVA: p > 0.05). These results suggest that strains isolated from environments with submerged macrophytes are less sensitive to allelochemicals of these plants,as these strains may be adapted to the coexistence with submerged macrophytes.(AU)

Evidence of cytogenetic and histological damage in specimens of Astyanax lacustris (Pisces, Characidae) exposed to the hydrogen cyanide-based herbicide Dormex®

The herbicide Dormex®, a solution of hydrogen cyanamide, is a growth regulator capable of breaking the dormancy of fruit plants, and is commonly applied in agriculture. However, the biological effects of this product on non-target organisms are unknown. The present study investigated the biological response of Astyanax lacustris (Lütken, 1875) specimens exposed to Dormex® using a chromosome aberration test, the mitotic index, and the histological analysis of the gills. Forty specimens of Astyanax lacustris were obtained from a local breeding facility and divided into 10 groups (nine experimental and one control) with four fish in each aquarium (group). The control group was maintained for 24 hours in dechlorinated water while the experimental groups were allocated to one of nine different treatments, with three concentrations of Dormex®, 0.05, 0.1 and 0.5 mL L-1, and exposure for 24, 48 and 72 hours. The fish exposed to Dormex® presented chromosomal aberrations of a number of types, including chromosomal breaks, acentric fragments, decondensation, and gaps at the three Dormex® concentrations, at all exposure times. The mitotic index decreased significantly in comparison with the control group. The histological preparations of the gills revealed alterations such as hyperplasia, and lamellar fusion and edema, whereas in the control group the structure of the gills was preserved. The cytogenetic analysis revealed the genotoxic potential of the herbicide Dormex® and the morphological alterations of the gills demonstrated the sensitivity of the fish, which responded rapidly to the stressor. These findings reinforce the need for special care and restrictions on the use of these herbicides in agricultural areas located near aquatic environments.

Evidence of cytogenetic and histological damage in specimens of Astyanax lacustris (Pisces, Characidae) exposed to the hydrogen cyanide-based herbicide Dormex®

The herbicide Dormex®, a solution of hydrogen cyanamide, is a growth regulator capable of breaking the dormancy of fruit plants, and is commonly applied in agriculture. However, the biological effects of this product on non-target organisms are unknown. The present study investigated the biological response of Astyanax lacustris (Lütken, 1875) specimens exposed to Dormex® using a chromosome aberration test, the mitotic index, and the histological analysis of the gills. Forty specimens of Astyanax lacustris were obtained from a local breeding facility and divided into 10 groups (nine experimental and one control) with four fish in each aquarium (group). The control group was maintained for 24 hours in dechlorinated water while the experimental groups were allocated to one of nine different treatments, with three concentrations of Dormex®, 0.05, 0.1 and 0.5 mL L-1, and exposure for 24, 48 and 72 hours. The fish exposed to Dormex® presented chromosomal aberrations of a number of types, including chromosomal breaks, acentric fragments, decondensation, and gaps at the three Dormex® concentrations, at all exposure times. The mitotic index decreased significantly in comparison with the control group. The histological preparations of the gills revealed alterations such as hyperplasia, and lamellar fusion and edema, whereas in the control group the structure of the gills was preserved. The cytogenetic analysis revealed the genotoxic potential of the herbicide Dormex® and the morphological alterations of the gills demonstrated the sensitivity of the fish, which responded rapidly to the stressor. These findings reinforce the need for special care and restrictions on the use of these herbicides in agricultural areas located near aquatic environments.(AU)

Seasonal performance of aquatic macrophytes in improving physicochemical parameters of swine wastewater / Desempenho sazonal de macrófitas aquáticas na melhoria de parâmetros físico-químicos de efluente de suinocultura

Swine wastewaters (SW) present organic load and nutrient content, what have caused degradation of water quality in many watercourses. Thus, the aquatic macrophytes represent an alternative for the depollution of these wastewaters, due to the high recovery power. The aim of this study was to evaluate the performance of the Eichhornia crassipes (Mart.) Solms, Pistia stratiotes L. and Salvinia auriculata Aubl. in improving the physicochemical targets of SW, as well as to quantify the total ammoniacal nitrogen (NH4+) and total phosphorus (total P) in the plant tissue of the macrophytes and the dry matter biomass (DMB) in two seasons of the year (spring and winter). The experiment was designed in a randomized block design, with 4 treatments (T) with 4 replicates: T1 = Control (without plants); T2 = E. crassipes; T3 = P. stratiotes; and T4 = S. auriculata, submitted to a SW diluted in 50% water. The monitoring is done in tanks during a period of 30 days of each season. Electrical conductivity (EC), dissolved oxygen (DO), turbidity, NH4+ and dissolved phosphorus (P) were analyzed in the SW. In the plants, the contents of NH4+, total P and DMB were determined. It was verified that, in the spring, the plants showed higher production of DMB and a more significant reduction of EC, NH4+ and P, when compared to the plants managed in the SW in the winter. E. crassipes was more efficient at removing P (39%) and total NH4+ (80.2%), and EC reducing (92%) of SW and DMB production in the spring. The results demonstrated that the NH4+ uptake by E. crassipes contributed to a considerable removal of NH4+ and P from SW.(AU)

Os efluentes da suinocultura apresentam elevado teor de carga orgânica e de nutrientes, o que dificulta o seu tratamento. Dessa forma, as macrófitas aquáticas representam uma alternativa para a despoluição desses efluentes, devido ao alto poder de absorção que essas plantas possuem. Neste contexto, o objetivo deste estudo foi avaliar o desempenho das plantas Eichhornia crassipes (Mart.) Solms, Pistia stratiotes L. e Salvinia auriculata Aubl. na melhoria das características físico-químicas de um efluente de suinocultura, bem como quantificar o teor dos elementos nitrogênio amoniacal total (NH4+) e fósforo total (P total) no tecido vegetal das macrófitas e a biomassa de matéria seca (BMS) produzida em duas estações do ano (primavera e inverno). O experimento compreendeu delineamento em blocos casualizados, com 4 tratamentos (T) com 4 repetições, sendo eles: T1 = Testemunha (sem plantas); T2 = E. crassipes; T3 = P. stratiotes; e T4 = S. auriculata, submetidos a efluente de suinocultura diluídos em 50% de água. O cultivo ocorreu em tanques instalados ao ar livre durante 30 dias de cada estação. Foram analisados, nos efluentes, os parâmetros de condutividade elétrica (CE), oxigênio dissolvido (OD), pH, turbidez, NH4+ e fósforo disponível (P). Nas plantas, foram determinados os teores de NH4+, P total e BMS. Foi verificado que, na primavera, as plantas apresentaram maior produção de BMS e redução mais expressiva de CE, NH4+ e P, quando comparadas às plantas manejadas no efluente suíno no inverno. A E. crassipes foi mais eficiente na remoção de P (39%) e NH4+ total (80,2%), e na redução da CE (92%) do efluente suíno e na produção de biomassa seca, na primavera.(AU)

New records of the invasive macrophyte, Urochloa arrecta extend its range to eastern Brazilian Amazon altered freshwater ecosystems / Novos registros da macrófita invasora Urochloa arrecta ampliam sua distribuição a ecossistemas aquáticos alterados na Amazônia Oriental brasileira

Invasive species influence the structure and functioning of ecosystems, as they affect native species, significantly decreasing their diversity. Aquatic ecosystems harbor a great biodiversity, and invasive macrophytes significantly affect the native plant communities, causing a cascade effect on other trophic levels. Among invasive macrophytes, Urochloa arrecta is cause for concern in the Neotropics and is found in several regions of Brazil, specially in the southeastern and southern regions. So far the species had been recorded only in the northern state of Amazonas. We report the first record of the species in the state of Pará, in the eastern Brazilian Amazon. We emphasize that identifying sites where this species is invasive is the best strategy to prevent its spread, aiming at the protection and conservation of Amazonian freshwater ecosystems.(AU)

Espécies invasoras influenciam a estrutura e funcionamento dos ecossistemas, pois afetam as espécies nativas, diminuindo significativamente sua diversidade. Ecossistemas aquáticos abrigam uma grande biodiversidade, e as macrófitas invasoras afetam significativamente a comunidade de plantas nativas, causando um efeito cascata nos diferentes níveis tróficos. Dentre as macrófitas invasoras, Urochloa arrecta é fonte de preocupação nos Neotrópicos, sendo encontrada em diversas regiões do Brasil, principalmente no sul e sudeste. Na região norte, a espécie só havia sido registrada no Amazonas. Trazemos aqui o primeiro registro desta espécie no estado do Pará, na Amazônia oriental brasileira. Destacamos que a identificação dos locais onde a invasão desta espécie ocorre é a melhor estratégia para que medidas de prevenção que evitem sua dispersão sejam tomadas, visando a proteção e conservação dos ecossistemas aquáticos amazônicos.(AU)

Seleção de espécies tolerantes para a fitorremediação de solo contaminado com imazapic / Selection of tolerant species for contaminated soil phytemedication using imazapic

O imazapic por apresentar longo efeito residual no solo pode ocasionar intoxicação visual em culturas sensíveis semeadas em rotação, além de representar riscos ecotoxicológicos em ambientes aquáticos. Diante disso, a fitorremediação é uma proposta inovadora como método alternativo para a remoção de poluentes orgânicos, sendo o sucesso da técnica dependente da seleção criteriosa de plantas com características favoráveis. O objetivo do estudo foi de identificar espécies de plantas tolerantes ao imazapic para potencial uso em programas de fitorremediação. Foram conduzidos oito experimentos em casa de vegetação climatizada com as espécies, Panicum maximum, Crotalaria juncea, Stylosanthes spp., Cajanus cajan, Dolichos lablab, Pennisetum glaucum, Mucuna aterrima, Raphanus sativus e cinco doses de imazapic (0; 58,33; 87,5; 175 e 350 g ha-1). Os tratamentos foram delineados em blocos ao acaso com quatro repetições. Aos 30 e 60 dias após a emergência das plantas foram avaliados os sintomas de intoxicação visual, altura e a massa seca das plantas, determinada ao término do experimento. As espécies M. aterrima, C. cajan e D. lablab não apresentaram sintomas visuais de fitointoxicação. M. aterrima foi a que promoveu maior produção de massa seca quando cultivada como testemunha e a exposição ao imazapic pouco afetou essa característica. Nas espécies tolerantes, a redução da altura e massa...

Imazapic can cause visual intoxication in sensitive crops sown in rotation given its long residual effect in the soil and represents ecotoxicological risks in aquatic environments. In this scenario, phytoremediation is an innovative proposal as an alternative method for removing organic pollutants, with its success depending on the careful selection of plants with favorable characteristics. The objective of this study was to identify imazapic-tolerant plant species for potential use in phytoremediation programs. Eight experiments were conducted in a greenhouse using the species Panicum maximum, Crotalaria juncea, Stylosanthes spp., Cajanus cajan, Dolichos lablab, Pennisetum glaucum, Mucuna aterrima, and Raphanus sativus, considering five doses of imazapic (0; 58.33; 87.5; 175 and 350 g ha-1). The treatments were delineated in randomized blocks with four replicates. The symptoms of visual toxicity, height, and dry mass of the plants were determined at 30 and 60 days after plant emergence and at the end of the experiment. The species M. aterrima, C. cajan, and D. lablab presented no visual symptoms of phyto-intoxication. M. aterrima promoted greater dry mass production when cultivated as a control, and exposure to imazapic did not affect this characteristic. Height and dry mass reduction required higher doses in tolerant species, although the results were not significant for...

Seleção de espécies tolerantes para a fitorremediação de solo contaminado com imazapic / Selection of tolerant species for contaminated soil phytemedication using imazapic

O imazapic por apresentar longo efeito residual no solo pode ocasionar intoxicação visual em culturas sensíveis semeadas em rotação, além de representar riscos ecotoxicológicos em ambientes aquáticos. Diante disso, a fitorremediação é uma proposta inovadora como método alternativo para a remoção de poluentes orgânicos, sendo o sucesso da técnica dependente da seleção criteriosa de plantas com características favoráveis. O objetivo do estudo foi de identificar espécies de plantas tolerantes ao imazapic para potencial uso em programas de fitorremediação. Foram conduzidos oito experimentos em casa de vegetação climatizada com as espécies, Panicum maximum, Crotalaria juncea, Stylosanthes spp., Cajanus cajan, Dolichos lablab, Pennisetum glaucum, Mucuna aterrima, Raphanus sativus e cinco doses de imazapic (0; 58,33; 87,5; 175 e 350 g ha-1). Os tratamentos foram delineados em blocos ao acaso com quatro repetições. Aos 30 e 60 dias após a emergência das plantas foram avaliados os sintomas de intoxicação visual, altura e a massa seca das plantas, determinada ao término do experimento. As espécies M. aterrima, C. cajan e D. lablab não apresentaram sintomas visuais de fitointoxicação. M. aterrima foi a que promoveu maior produção de massa seca quando cultivada como testemunha e a exposição ao imazapic pouco afetou essa característica. Nas espécies tolerantes, a redução da altura e massa...(AU)

Imazapic can cause visual intoxication in sensitive crops sown in rotation given its long residual effect in the soil and represents ecotoxicological risks in aquatic environments. In this scenario, phytoremediation is an innovative proposal as an alternative method for removing organic pollutants, with its success depending on the careful selection of plants with favorable characteristics. The objective of this study was to identify imazapic-tolerant plant species for potential use in phytoremediation programs. Eight experiments were conducted in a greenhouse using the species Panicum maximum, Crotalaria juncea, Stylosanthes spp., Cajanus cajan, Dolichos lablab, Pennisetum glaucum, Mucuna aterrima, and Raphanus sativus, considering five doses of imazapic (0; 58.33; 87.5; 175 and 350 g ha-1). The treatments were delineated in randomized blocks with four replicates. The symptoms of visual toxicity, height, and dry mass of the plants were determined at 30 and 60 days after plant emergence and at the end of the experiment. The species M. aterrima, C. cajan, and D. lablab presented no visual symptoms of phyto-intoxication. M. aterrima promoted greater dry mass production when cultivated as a control, and exposure to imazapic did not affect this characteristic. Height and dry mass reduction required higher doses in tolerant species, although the results were not significant for...(AU)

Heterotrophic flagellates (Amorpha and Diaphoretiches) in phytotelmata bromeliad (Bromeliaceae) / Flagelados heterotróficos (Amorpha e Diaphoretiches) em fitotelmata de bromélia (Bromeliaceae)

Many plants may accumulate rainwater, forming phytotelmata, aquatic microhabitats inhabited by various organisms. The aim of this study was to conduct an inventory of heterotrophic flagellates associated with phytotelmata of the bromeliad Aechmea distichantha Lem., found in rocky cliffs on the Upper Paraná River. The bromeliads were removed manually from the rocky wall, the water was removed and cultures of organisms of each plant were mounted in Petri dishes. Sixteen species of heterotrophic flagellate were recorded, drawn and described, among them one species belonging to the Amorpha Domain and 15 species to the Diaphoretiches Domain. The groups with most species were Euglenida and Kinetoplastea. The low diversity of heterotrophic flagellates recorded in this study, compared to the plankton of lakes and reservoirs, is probably related to the fact that phytotelmata are habitats with extreme environmental conditions, thus selecting organisms tolerant to these environments.(AU)

Em sua superfície externa, muitas plantas podem acumular água da chuva formando fitotelmata, ou seja, micro-habitat aquáticos colonizados por diversos organismos, entre eles, os flagelados protistas. Fez-se um inventário de flagelados heterotróficos associados ao fitotelmata da bromélia Aechmea distichantha Lem., encontrada em paredões rochosos em um trecho da bacia do alto rio Paraná. As bromélias foram retiradas manualmente de paredão rochoso e, em laboratório, a água foi retirada dos tanques de cada planta, e foram montadas culturas dos organismos em placas de Petri. Os flagelados heterotróficos foram, então, observados in vivo sob microscópio óptico Olympus BX51, com sistema de contraste de interferência diferencial (DIC) acoplado. Dezesseis espécies flagelados heterotróficos foram registradas, desenhadas e descritas, sendo uma espécie pertencente ao Domínio Amorpha e 15 espécies ao Domínio Diaphoretiches. Os grupos mais especiosos foram Euglenida e Kinetoplastea. A diversidade relativamente reduzida de flagelados heterotróficos, quando comparada ao plâncton de lagos e reservatórios, pode estar relacionada ao fato de os fitotelmata serem habitats limitados, com condições ambientais extremas, selecionando, assim, organismos tolerantes a esses ambientes.(AU)

Segmental enteritis associated with Pythium insidiosum infection in a horse

Background: Pythiosis is an infectious disease caused by the oomycete Pythium insidiosum, with higher occurrence in wetlands and hot climate regions. This microorganism develops its cycle in aquatic plants, and most cases happen because of the contact of animals or people with water containing the motile zoospores (infectious form). Horses are the principal species affected and develop principally cutaneous and subcutaneous lesions, but the gastrointestinal tract is seldom affected. Humans develop various forms of pythiosis, such as a vascular form. The objectives of the current study are to describe an unusual case of intestinal pythiosis, its clinical signs, aspects of pathogenesis, and diagnosis. Case: A 13-year-old Crioula mare, from Santa Maria, RS, Brazil, presented with reduced food and water intake, apathy, restlessness, rolling, nasal reflux, firm abdomen upon palpation, and tachypnea during 2 days. The horses of this farm were fed native pasture and horse feed, and they had access to a nearby pond. Two days following the start of the clinical signs, the horse died and was necropsied on the farm. During necropsy, there was around 400 mL of reddish effusion in the abdominal cavity (modified transudate). A 15 cm segment of jejunum was firm upon palpation and had a severe transmural thickening. The wall of the affected area was up to 3 cm in thickness and firm, with small yellowish and irregular masses that stood out and looked friable, interpreted as kunkers. Microscopically, the yellowish masses (kunkers) were characterized by dense accumulations of intact and degenerate eosinophils (eosinophilic necrosis). Within these kunkers, and also on their periphery, there were multiple negatively stained hyphal profiles. Hyphae were also seen on the wall of small arteries inside the kunkers. These hyphae had nearly parallel walls and were occasionally...