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1.
Biota Neotrop. (Online, Ed. ingl.) ; 21(2): e20201016, 2021. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1278408

ABSTRACT

Abstract: Benthic macroinvertebrates Functional Feeding Group (FFG) have been used to determine aquatic assemblage dynamics and as a biomonitoring tool. The main goals of this study were to assess the effects of stream variables on the abundance and richness of FFGs and evaluate ecosystem attributes (FFG ratios) as a tool to assess ecological conditions of Atlantic Rainforest streams. We sampled 146 sites with different impairment conditions in Rio de Janeiro, Brazil. Richness was significantly different among impairment conditions for all FFGs. Mixed-effect models show that aquatic macroinvertebrate FFGs differed in their responses to abiotic variables for abundance and richness. Also, they were reduced in the impaired sites when compared to intermediate and reference sites. The FFG ratio indicated significant differences along the impairment gradient. The FFG ratio analysis was shown to be a fast and cheap tool that can be used for monitoring aquatic ecosystems in the Atlantic Forest biome. However, further studies are required to calibrate the method specifically for the Atlantic Forest region.


Resumo: Os Grupos Funcionais de Alimentação (GFA) são utilizados para determinar a dinâmica da comunidade de macroinvertebrados bentônicos e como uma ferramenta de biomonitoramento. Os principais objetivos deste estudo foram: avaliar os efeitos de variáveis de riacho na abundância e riqueza de GFAs e os atributos do ecossistema (razão GFA) como uma ferramenta para avaliar as condições ecológicas dos córregos da Mata Atlântica. Foram amostrados 146 locais com diferentes condições de impacto no Rio de Janeiro, Brasil. A riqueza foi significativamente diferente com as condições de impacto entre todos os GFA. Os modelos de efeito misto mostraram que os GFA diferiam em suas respostas às variáveis abióticas quanto à abundância e riqueza. Além disso, eles diferem nas áreas impactadas quando comparados as áreas intermediária e de referência. A razão de GFA encontrou diferenças significativas ao longo do gradiente de impacto. A análise da razão de GFA evidenciou-se uma ferramenta rápida e barata, com potencial para ser utilizada no monitoramento de ecossistemas aquáticos no bioma Mata Atlântica. No entanto, mais estudos serão necessários para calibrar o método especificamente para a região da Mata Atlântica.

2.
Rev. biol. trop ; 68mar. 2020.
Article in English | LILACS-Express | LILACS | ID: biblio-1507628

ABSTRACT

Introduction: Eichhornia crassipes is a dominant aquatic plant of neotropical-river floodplains and is invasive in warm waters of different continents. Plants provide food and habitat for fish, especially Prochilodus lineatus and Gymnotus omarorum, which are relevant to subsistence fishing by local indigenous communities. Objective: In this study we describe the main traits of E. crassipes floating meadows, and analyze the abundance and composition of macroinvertebrate assemblages associated with their roots in two floodplain wetlands of the Paraná River (within the Ramsar site Wetlands Chaco) and of the Pilcomayo River (within the Pilcomayo River National Park). Methods: During spring and summer, the macroinvertebrates were collected in monospecific stands of E. crassipes with a net of 962 cm2 area and 500 µm mesh size. Leaf density, the biomass of leaves and roots, the length of leaves and roots, and the water quality were measured simultaneously. Results: Temperature, oxygen concentration, and nutrient content were significantly higher and electrical conductivity was lower in the Pilcomayo than in the Paraná floodplain. E. crassipes growing in the Pilcomayo floodplain had longer leaves and less root biomass than those found in the Paraná floodplain. The number of macroinvertebrates per 1 000 g root dry weight and per m2 was significantly different between both floodplains, but the taxon richness was similar. Non Metric Multidimensional Scaling analysis differentiated the abundance of 14 selected taxa between both floodplains, and showed a high correlation between the environmental variables and macroinvertebrate abundance. The most abundant taxonomic groups in the Paraná River floodplain were oligochaetes (Naididae), ostracods mainly Cytheridella ilosvayi and larvae of non-biting midges (Chironomidae). Two families, Hydrobiidae (Heleobia parchappii) and Chironomidae accounted for 49.3 % of the total abundance in the Pilcomayo floodplain. The prawns Macrobrachium jelskii and M. amazonicum, frequent in the Pilcomayo floodplain, were not found in the Paraná floodplain. Conclusions: The different environmental conditions in both floodplains affect the abundance, composition, and the dominance of macroinvertebrate assemblages; however, the total taxa richness was similar. The area occupied by E. crassipes in the floodplains of these rivers provides the habitat that contributes most to overall biotic diversity, which must be considered in management strategies.


Introduccion: Eichhornia crassipes es la planta acuática dominante en la planicie de inundación de los ríos tropicales y ha invadido las aguas cálidas de diferentes continentes. Las plantas proveen alimento y hábitat para los peces, especialmente Prochilodus linneatus y Gymnotus omarorum, que son relevantes para la pesca de subsistencia de las comunidades indígenas locales. Objetivo: En el presente trabajo nosotros describimos las principales características de las formaciones flotantes de E. crassipes, y analizamos la abundancia y composición de los ensambles de macroinvertebrados asociados a sus raíces en dos humedales de las planicies de inundación de los ríos Paraná (dentro del sitio Ramsar Humedales Chaco) y Pilcomayo (dentro del Parque Nacional Río Pilcomayo). Métodos: Durante la primavera y el verano, los macroinvertebrados se recolectaron en formaciones monoespecíficas de E. crassipes con una red de 962 cm2 y 500 µm de tamaño de malla. La densidad de hojas, la biomasa de hojas y raíces, la longitud de las hojas y raíces y la calidad del agua se midieron simultáneamente. Resultados: La temperatura, la concentración de oxígeno disuelto y el contenido de nutrientes fueron significativamente mayores y la conductividad eléctrica fue significativamente menor en la planicie de inundación del Pilcomayo que en la del Paraná. Las plantas de E. crassipes que crecen en la planicie de inundación del Pilcomayo tuvieron hojas más largas y menos biomasa de raíces que las encontradas en la planicie del Paraná. El número de macroinvertebrados por 1 000 g. de peso seco de la raíz y por m2 fueron significativamente diferentes entre ambas planicies de inundación, pero la riqueza de taxa fue similar. El análisis de Escalamiento Multidimensional No Métrico diferenció la abundancia de los 14 taxa seleccionados entre ambas planicies de inundación, y mostró alta correlación entre las variables ambientales y la abundancia de los macroinvetebrados. Los grupos taxonómicos más abundantes en la planicie de inundación del río Paraná fueron los oligoquetos (Naididae), los ostrácodos, principalmente Cytheridella ilosvayi y las larvas de mosquitos no picadores (Chironomidae). Dos familias, Hydrobiidae (Heleobia parchappii) y Chironomidae representaron el 49,3 % de la abundancia total en la planicie de inundación del Pilcomayo. Los camarones Macrobrachium jelskii y M. amazonicum, frecuentes en la planicie de inundación del Pilcomayo, no se encontraron en la planicie de inundación del Paraná. Conclusiones: Las diferentes condiciones ambientales en ambas planicies de inundación afectan la abundancia, composición y la dominancia de los ensambles de macroinvertebrados; sin embargo, la riqueza total de taxa fue similar. El área ocupada por E. crassipes en la planicie de inundación de estos ríos proporciona el hábitat que más contribuye a la diversidad biótica, lo que debe ser considerado en las estrategias de manejo.

3.
Rev. biol. trop ; 68mar. 2020.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1507634

ABSTRACT

Introducción: La distribución de los macroinvertebrados acuáticos en los ríos puede estar determinada por el tipo del sustrato, la forma del canal del río, el régimen hidrológico y las interacciones con factores bióticos y abióticos. En Costa Rica se desconoce en gran parte de los ríos, las variaciones en la distribución de los macroinvertebrados acuáticos producto de las transiciones y consecuentes variaciones en características fisicoquímicas e hidrológicas. Objetivos : 1) Estudiar el cambio del ensamblaje de macroinvertebrados acuáticos en dos sitios dentro del cauce del Río Naranjo, durante los cuatro periodos hidrológicos del año; 2) determinar la relación entre las variables fisicoquímicas, sustrato y el caudal con el ensamblaje. Metodología: El estudio se realizó en el Río Naranjo, Costa Rica, en dos sitios de muestreo durante un año, evaluando los cuatro periodos hidrológicos del año. En cada sitio de muestreo se obtuvieron valores de velocidad y profundidad del agua, caudal, oxígeno disuelto, pH, conductividad, sulfatos, amonio, nitrato, silicatos, fosfatos y sustrato, y se obtuvo una muestra de macroinvertebrados acuáticos por cada tipo de microhábitat determinado por la velocidad del agua. Se realizó una prueba PERMANOVA de dos vías, para determinar si existe una diferencia entre la abundancia de macroinvertebrados acuáticos, por periodo y entre sitios. Se hizo un análisis de correspondencia canónica para observar la relación entre los macroinvertebrados acuáticos y los factores ambientales. Por último, se realizó una prueba de Spearman para determinar la relación positiva o negativa de las variables con los macroinvertebrados Resultados: Hubo una mayor abundancia durante la estación seca, mientras que durante la transición de la estación seca a la lluviosa se registró la menor abundancia de organismos. El ACC indicó que el primer eje presentó una relación positiva con el sustrato limo y arena, y una relación negativa para las variables velocidad de corriente y sustrato rocoso. El segundo eje presentó una relación positiva con el caudal y los nitratos, y negativa para el sustrato canto rodado. La mayoría de los organismos mostraron una respuesta negativa al aumento del flujo y los nitratos. Discusión: Conforme aumenta el caudal, aumenta la velocidad del agua y no todos los organismos registrados en el Río Naranjo cuentan con características para sobrevivir a estas condiciones. Además, la profundidad también aumenta junto con la fuerza de arrastre, provocando el movimiento de los sustratos de menor tamaño y una remoción de organismos. El aumento de nitratos puede generar una disminución de los organismos más sensibles como Plecoptera y Ephemeroptera. A pesar de las variaciones fisicoquímicas y de caudal registradas en el Río Naranjo, éstas no fueron lo suficientemente fuertes como para variar el ensamblaje de macroinvertebrados acuáticos, por lo que la cuenca por el momento no cuenta con factores estresantes que elimine organismos durante uno o varios meses del año.


Introduction: The distribution of aquatic macroinvertebrates in rivers may be determined by the type of substrate, the shape of the river channel, the hydrological regime, and interactions with biotic and abiotic factors. Variations in the distribution of aquatic macroinvertebrates due to transitions and variations in physicochemical and hydrological characteristics are unknown in most rivers. Objectives: 1) to study the change in the aquatic macroinvertebrates assemblages in two sites in Naranjo River, during the four hydrological seasons; 2) to determine the relationship between the physicochemical variables, substrate and flow with the assemblages. Methodology: The study was conducted in the Naranjo River, Costa Rica, at two sampling sites during one year, evaluating the four seasons of the year. In each station we measure, values of water velocity and depth, flow rate, dissolved oxygen, pH, conductivity, sulfates, ammonium, nitrate, silicates, phosphates, and substrate were obtained, and a sample of aquatic macroinvertebrates was obtained for each type of microhabitat determined by water velocity. Two-way PERMANOVA was made to determine if there is a difference among aquatic macroinvertebrate abundance, per period and between sites. Canonical correspondence analysis was used to observe the relationship between aquatic macroinvertebrates and environmental factors. Finally, a Spearman's rank correlation coefficient was performed to determine the positive or negative relationship of variables with macroinvertebrates. Results: There was a greater abundance during the dry season, while during the transition from dry to the rainy season, the lowest abundance of organisms was recorded. The CCA indicates that the first axis presented a positive relationship with the silt and sand substrate and a negative relationship for the current velocity and rock substrate variables. The second axis showed a positive relationship with flow and nitrates and negative for the pebble substrate. Most organisms showed a negative response to increased flow and nitrates. Discussion: As flow increases, current velocity increases, and not all organisms recorded in the Naranjo River have the characteristics to survive these conditions. In addition, the depth also increases along with the drag force, causing movement of smaller substrates and removal of organisms. Increased nitrates can lead to a decrease in more sensitive organisms, such as Plecoptera and Ephemeroptera. In spite of the physicochemical and flow variations registered in the Naranjo River, these were not strong enough to vary the assemblages of aquatic macroinvertebrates, so the basin does not have stressful factors that eliminate organisms during one or several months of the year.

4.
Rev. biol. trop ; 68mar. 2020.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1507638

ABSTRACT

Introducción: En los sistemas fluviales colombianos ha sido poco estudiada la fragmentación del material alóctono por parte de los insectos acuáticos. Uno de los organismos trituradores más abundantes en las corrientes tropicales de América es el tricóptero del género Phylloicus (Calamoceratidae). Objetivo: El presente estudio tuvo como objetivo evaluar el efecto de los atributos químicos (nitrógeno, fósforo y lignina) y físicos (dureza) de las hojas de tres especies ribereñas (Ficus tonduzii, Zygia longifolia y Clusia multiflora) dominantes en la parte media del río Gaira, sobre la preferencia de hojas y el crecimiento de larvas de Phylloicus sp. Métodos: Se realizaron experimentos de multiselección de alimento en campo, en los que se ubicaron cámaras experimentales dentro del río por 21 días. Para la valoración de la calidad foliar se recolectaron hojas del río, las cuales se secaron y se pulverizaron para realizar los análisis químicos. Resultados: No se presentaron diferencias significativas en los porcentajes de lignina y fósforo entre las hojas de las tres especies de árboles, pero si en su dureza y en el contenido de nitrógeno. Las hojas de C. multiflora fueron más suaves (180.1± 53.9 g) que las de F. tonduzii (285.3 ± 88.4 g) y Z. longifolia (232.3 ± 60.8 g), pero sin diferencias entre las dos últimas especies. Las hojas de Z. longifolia también tuvieron más nitrógeno (1.9 ± 0.0%) que las de hojas de las otras especies (1 ± 0.0 %). En cuanto a la preferencia de hojas, las larvas de Phylloicus sp. utilizaron en mayor proporción las hojas de C. multiflora. Aunque las hojas de C. multiflora no tuvieron diferencias significativas en el contenido de lignina y fósforo, presentaron valores menores de dureza, lo que podría hacerlas más palatables para Phylloicus sp. Por otra parte, el crecimiento específico diario de las larvas fue mayor cuando usaron hojas de F. tonduzii. Conclusiones: Nuestros resultados parecen indicar que las hojas más preferidas no son necesariamente las de mejor calidad nutricional y sugieren que la dureza de las hojas es la variable más importante en la selección de la hojarasca por parte de las larvas de Phylloicus sp.


Introduction: Fragmentation of allochthonous material by aquatic insects is a functional process that has been little studied in Colombian rivers. One of the most abundant shredder genus in American tropical stream ecosystems is the caddisfly genus Phylloicus (Calamoceratidae). Objective: In this study we evaluate the effect of chemical (nitrogen, phosphorus and lignin) and physical (toughness) attributes of leaves of three dominant tree species (Ficus tonduzii, Zygia longifolia and Clusia multiflora) in the riverine area of the middle section of the Gaira river, on leaf preferences and larval growth of a species of Phylloicus. Methods: Multiple food selection field experiments were performed, in which experimental chambers were located in the river for twenty-one days. For the assessment of leaf quality, leaves were collected in the river, dried and pulverized to perform chemical analyzes. Results: There were no significant differences in lignin and phosphorous percentages between the leaves of the three species, but nitrogen content and leaf toughness differed among them. The leaves of C. multiflora were softer (180.1± 53.9 g) than those of F. tonduzii (285.3 ± 88.4 g) and Z. longifolia (232.3 ± 60.8 g), but without differences between the last two species. The Z. longifolia leaves also had more nitrogen (1.9 ± 0.0 %) than those of the other species (1 ± 0.0 %). Regarding leaf selection, Phylloicus sp. larvae used in greater proportion the leaves of C. multiflora. Although lignin and phosphorous differences were not significant, the leaves of C. multiflora had lower toughness, which could make them more palatable for Phylloicus sp. On the other hand, the daily specific growth of the larvae was higher when they used leaves of F. tonduzii. Conclusions: Our findings seem to indicate that the most preferred leaves were not necessarily those of better nutritional quality and suggest that leaf toughness was the most important variable in the selection of leaf litter by the larvae of Phylloicus sp.

5.
Biota Neotrop. (Online, Ed. ingl.) ; 19(2): e20180601, 2019. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1001404

ABSTRACT

Abstract: Biological assessments that use the reference condition approach are based on the concept of comparing a site's observed biology to sites where disturbance is minimal or absent. However, in many regions of the world, such areas are scarce or nonexistent. In this study, an alternative approach proposed by Chessman and Royal for bioassessment without reference areas based on environmental filters was tested in Brazil. This approach assumes that key environmental features act in the selection of potential colonists, from a regional pool of taxa, based on the ecological traits (tolerances) possessed by each taxon. We developed the approach by: 1) determining the regional pool, based on a large Atlantic Forest biome database; 2) selecting environmental filters (elevation, original vegetation and soil type); and 3) including information on the tolerance and preferences of aquatic insects to these filters. With this information we were able to determine the expected taxon under natural conditions and compare with observed taxon, developing a predictive index (Observed/Expected). Although the model was intended to predict the fauna in regions without reference sites, we included reference areas to test the model responsiveness, precision and sensitivity. Our results indicated that the index was able to discriminate impairment classes (F=56.9; p<0,001), it has high precision due to low standard deviation across reference sites values (SD=0.098) and high sensitivity due the correlation with environmental variables that are sensitive to human alteration (r=0.74, p<0.01). Also, it was strongly correlated with multimetric indices developed for multiple watersheds in the state, showing agreement between the methods in relation to ecological quality classification. Even though the predictive index had performed well in our study, we make some considerations that may help to improve its sensitivity of similar methods that are being tested using the environmental filters approach.


Resumo: Avaliações biológicas que usam a abordagem de condição de referência se baseiam na comparação entre a biota observada em locais teste e a presente em locais íntegros ou minimamente impactados. Entretanto, em muitas regiões do mundo, estes locais são escassos ou inexistentes. Neste estudo, a abordagem alternativa proposta por Chessman e Royal, que consiste no biomonitoramento baseado em filtros ambientais sem o uso de áreas de referência, foi testado para o Brasil. Esta abordagem assume que características ambientais chave agem na seleção de colonizadores potenciais, a partir do pool regional de táxons, baseado nos traços ecológicos (tolerância) de cada táxon. A abordagem foi desenvolvida através da: (1) determinação do pool regional, baseado em uma ampla base de dados do bioma Mata Atlântica; 2) seleção de filtros ambientais (elevação, vegetação original e tipo de solo); e 3) inclusão de informações sobre a tolerância e preferência ambiental dos insetos aquáticos à esses filtros. Essas informações possibilitam determinar os táxons esperados sob condições naturais (ausência de impacto) e comparar com os táxons observados em cada local, desenvolvendo um índice preditivo (Observado/Esperado). Embora esta abordagem proponha a predição da fauna na ausência de áreas de referência, estas áreas foram incluídas com o propósito de testar a resposta, precisão e sensibilidade desta abordagem. Os resultados indicam que o índice desenvolvido foi capaz de distinguir diferentes classes de impacto (F=56.9; p<0,001), obteve alta precisão, o que foi observado com o baixo desvio padrão obtido para os valores de locais de referência (SD=0.098) e alta sensibilidade, observado através da correlação significativa com variáveis ambientais sensíveis a alterações antrópicas (r=0.74, p<0.01). Além disso, o índice foi fortemente correlacionado com índices multimétricos desenvolvidos especificamente para diferentes regiões hidrográficas, mostrando concordância entre diferentes métodos no que se refere a avaliação da integridade ecológica. Apesar do bom desempenho do índice preditivo neste estudo, nós fizemos algumas considerações para melhorar a sensibilidade e o potencial da abordagem de filtros ambientais em aplicações futuras.

6.
Biota Neotrop. (Online, Ed. ingl.) ; 19(2): e20180541, 2019. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1001406

ABSTRACT

Abstract: Multimetric Indices (MMIs) have been widely applied for ecological assessment in freshwater ecosystems. Most MMIs face difficulties when scaling up from small spatial scales because larger scales usually encompass great environmental variability. Covariance of anthropogenic pressures with natural environmental gradients can be a confounding factor in assessing biologic responses to anthropogenic pressures. This study presents the development and validation of a predictive multimetric index to assess the ecological condition of Atlantic Forest wadeable streams using benthic macroinvertebrates. To do so, we sampled 158 sites for the index development. We adjusted each biological metric to natural variation through multiple regression analyses (stepwise-forward) and considered that the residual distribution describes the metric variation in the absence of natural environmental influence. For metric selection we considered normal distribution, variation explained by the models, redundancy between metrics and sensitivity to differentiate reference from impaired sites. We selected five metrics to the final index: total richness, %MOLD, %Coleoptera, EPT richness and Chironomidae abundance. The residuals were transformed into probabilities and the final index was obtained through the mean of these probabilities. This index performed well in discriminating the impairment gradient and it showed a high correlation (r = 0.85, p <0.001) with a specific index developed for a particular basin indicating a similar sensitivity. This index can be used to assess wadeable streams ecological condition in Atlantic Forest biome, so we believe that this type of approach represents an important step towards the application of biomonitoring tools in Brazil.


Resumo: Índices Multimétricos (MMIs) são ferramentas amplamente aplicadas ao monitoramento ecológico de ecossistemas aquáticos continentais. A maior dificuldade na utilização dos MMIs em amplas escalas espaciais consiste no aumento da variabilidade ambiental associado ao aumento da escala. A covariância entre os impactos antropogênicos e o gradiente ambiental natural pode atuar como fator de confusão, dificultando a avaliação das respostas biológicas às pressões antropogênicas. Este estudo consiste no desenvolvimento e validação de um índice multimétrico preditivo para avaliar a condição ecológica de riachos vadeáveis da Mata Atlântica, utilizando macroinvertebrados bentônicos. Todas as métricas biológicas foram ajustadas a variação natural através da análise de regressão múltipla ("stepwise-forward") e a distribuição dos resíduos foi utilizada para descrever variação de cada métrica na ausência de gradiente ambiental natural. Para a seleção das métricas foram considerados critérios de normalidade da distribuição, variação explicada pelos modelos, redundância entre métricas e sensibilidade para diferenciar gradiente de impacto. Foram selecionadas cinco métricas para compor o índice final: riqueza total, %MOLD (Mollusca+Diptera), %Coleoptera, riqueza de EPT (Ephemeroptera+Plecoptera+Trichoptera) e abundância de Chironomidae. Os resíduos das métricas selecionadas foram transformados em probabilidades e o valor final do índice foi obtido através da média dessas probabilidades. O índice teve ótimo desempenho em discriminar o gradiente de impacto e mostrou alta correlação (r = 0.85, p <0.001) com um índice desenvolvido especificamente para uma das bacias, indicando sensibilidade similar. O índice desenvolvido nesse trabalho pode ser utilizado em todo o estado do Rio de Janeiro e acreditamos que este tipo de abordagem constitui uma contribuição importante para o desenvolvimento e implementação de um programa de monitoramento biológico no Brasil.

7.
Acta sci., Biol. sci ; 39(2): 211-217, abr.- jun. 2017. ilus, tab
Article in English | LILACS | ID: biblio-846751

ABSTRACT

This study present an inventory of the genera of Odonata-Anisoptera in lotic environments of the Iguatemi River basin, upper Paraná River, Mato Grosso do Sul State, Brazil. Samplings were performed from December 2006 to February 2009 in the Iguatemi River and eight streams of the basin. We collected 739 immature Odonata, distributed in 25 genera and three families; of which one genus represent a new record for the Mato Grosso do Sul State. Progomphus, Tramea, Elasmotemis, Macrothemis, Aphyla and Phylocycla were the most representative genera in the Iguatemi River basin. The genus accumulation curve predicts an increase of new genera for the Iguatemi River basin.


Este trabalho apresenta um inventário de gêneros de Odonata-Anisoptera em ambientes lóticos da bacia do rio Iguatemi, alto rio Paraná, Mato Grosso do Sul, Brasil. As amostragens ocorreram no período de dezembro de 2006 a fevereiro de 2009 no rio Iguatemi e em oito riachos distribuídos na bacia. Foram coletados 739 imaturos de Odonatas, distribuídos em 25 gêneros e três famílias, do qual um gênero representa um novo registro para o Estado de Mato Grosso dos Sul. Progomphus, Tramea, Elasmotemis, Macrothemis, Aphyla e Phylocycla foram os gêneros mais representativos na bacia do rio Iguatemi. A curva de acumulação de gênero sugere a expectativa de incremento de novos gêneros para a bacia do rio Iguatemi.


Subject(s)
Biodiversity , Fauna , Odonata
8.
Rev. biol. trop ; 62(supl.2): 221-231, abr. 2014. graf, tab
Article in Spanish | LILACS | ID: lil-753767

ABSTRACT

Biotic integrity of the Chiquito River subwatershed, Morelia, Michoacán México, based on the aquatic macroinvertebrate assemblages. The Chiquito River subwatershed supplies 30% of the potable water consumed by the city of Morelia, Michoacan, Mexico. It is necessary to constantly monitor its waters using metrics that evaluate environmental degradation and aquatic assemblages. In the present study, we used the Index of Biotic Integrity for Aquatic Macroinvertebrate Associations (IBIAMA), the Visual-Based Habitat Assessment, and the Most Probable State to calculate the conservation status of the river at six sites along the main channel, including an upper site as a reference. A total of 51 474 specimens were identified, the taxonomic composition was comprised of 69 families distributed into four Phyla, eight classes, eight sub-classes, and 18 orders. The best preserved sites were found in the subwatershed headwater zone. The intermediate zone had impacted hydraulic conditions, environmental quality and biotic integrity. The downstream part of the subwatershed showed the resilient capacity of the river to reestablish macroinvertebrate assemblages and environmental parameters. There is a strong correlation among environmental qualities and the IIBAMA. The use of macroinvertebrates in combination with environmental parameters showed that the Chiquito River subwatershed is stable, rich and integral in aquatic macroinvertebrate assemblages before entering the city of Morelia, and it conserves the processes that regulate the functional dynamics of the subwatershed. Rev. Biol. Trop. 62 (Suppl. 2): 221-231. Epub 2014 April 01.


La microcuenca del Río Chiquito abastece el 30% de agua potable para la ciudad de Morelia, Michoacán, México. Por ello es necesario el monitoreo constante de sus aguas, utilizando mediciones que evalúen el deterioro ambiental y la comunidad de macroinvertebrados acuáticos. Para el presente estudio se utilizó el Índice de Integridad Biótica para las Asociaciones de Macroinvertebrados Acuáticos (IIBAMA). Además de la Valoración de la Calidad Ambiental Visual y el estado más probable del cauce, en seis sitios dentro de la microcuenca y un séptimo fuera de la misma, como referencia. Se identificaron un total de 51 474 organismos: 69 familias distribuidas en cuatro filos, ocho clases, ocho subclases, y 18 órdenes. Los sitios mejor conservados se encuentran en la cabecera de la microcuenca. La zona intermedia se encuentra afectada en la condición hidráulica, calidad ambiental y en su integridad biótica. En la zona baja de la microcuenca, se observó la capacidad “resiliente” del río al restablecerse las comunidades de macroinvertebrados y los parámetros ambientales. Los resultados muestran que la calidad ambiental y el IIBAMA se encuentran correlacionados (r=0.82, p<0.01). El uso de los macroinvertebrados en combinación con los parámetros ambientales demuestran que antes de entrar a la ciudad de Morelia la microcuenca del río Chiquito es un sistema estable, diverso e íntegro en su comunidad de macroinvertebrados acuáticos, y que conserva los procesos que regulan la dinámica funcional de la cuenca.


Subject(s)
Animals , Environmental Monitoring/methods , Invertebrates/classification , Rivers/chemistry , Mexico
9.
Biota neotrop. (Online, Ed. port.) ; 12(2): 135-146, Apr.-June 2012. ilus
Article in English | LILACS | ID: lil-645392

ABSTRACT

Collections and inventories provide important and essential information for understanding the composition and distribution of biodiversity. This contribution presents an inventory of the species held in the Echinodermata collection in the Setor de Comunidades Bentônicas (LABMAR/ICBS), Universidade Federal de Alagoas. The collections were made over a period of more than 20 years, at several localities of coastal Alagoas. This collection now includes 16,201 catalogued individual specimens, with 50 species in the five extant classes Crinoidea, Asteroidea, Ophiuroidea, Echinoidea and Holothuroidea, based on 640 records; the class Ophiuroidea is best represented. The results of this inventory contribute significantly to knowledge of marine benthic diversity from the state of Alagoas, and the information presented here expands the data for Echinodermata from the northeastern coast of Brazil.


As coleções e inventários fornecem importantes e essenciais informações para entender a composição e distribuição da biodiversidade. Esta contribuição apresenta um inventário da coleção de Echinodermata pertencente ao Setor de Comunidades Bentônicas (LABMAR/ICBS), da Universidade Federal de Alagoas. As coletas foram realizadas ao longo de mais de vinte anos em diversas localidades da costa de Alagoas. A coleção conta com 16.201 exemplares tombados e 50 espécies distribuídas entre as cinco classes viventes Crinoidea, Asteroidea, Ophiuroidea, Echinoidea e Holothuroidea, com base em 640 registros, sendo a classe Ophiuroidea a melhor representada. O resultado deste inventário vem contribuir significativamente para o conhecimento da diversidade bentônica marinha do Estado de Alagoas ampliando as informações sobre a fauna do filo Echinodermata para a costa nordeste do Brasil.

10.
Rev. biol. trop ; 59(4): 1895-1914, Dec. 2011. ilus, graf, mapas, tab
Article in Spanish | LILACS | ID: lil-646560

ABSTRACT

Conservation of species in agroecosystems has attracted attention. Irrigation channels can improve habitats and offer conditions for freshwater species conservation. Two questions from biodiversity conservation point of view are: 1) Can the irrigated channels maintain a rich diversity of macrophytes, macroinvertebrates and amphibians over the cultivation cycle? 2) Do richness, abundance and composition of aquatic species change over the rice cultivation cycle? For this, a set of four rice field channels was randomly selected in Southern Brazilian wetlands. In each channel, six sample collection events were carried out over the rice cultivation cycle (June 2005 to June 2006). A total of 160 taxa were identified in irrigated channels, including 59 macrophyte species, 91 taxa of macroinvertebrate and 10 amphibian species. The richness and abundance of macrophytes, macroinvertebrates and amphibians did not change significantly over the rice cultivation cycle. However, the species composition of these groups in the irrigation channels varied between uncultivated and cultivated periods. Our results showed that the species diversity found in the irrigation channels, together with the permanence of water enables these man-made aquatic networks to function as important systems that can contribute to the conservation of biodiversity in regions where the wetlands were converted into rice fields. The conservation of the species in agriculture, such as rice field channels, may be an important alternative for biodiversity conservation in Southern Brazil, where more than 90% of wetland systems have already been lost and the remaining ones are still at high risk due to the expansion of rice production. Rev. Biol. Trop. 59 (4): 1895-1914. Epub 2011 December 01.


La conservación de especies en los agroecosistemas ha llamado la atención. Los canales de riego pueden mejorar los hábitats y ofrecer condiciones para la conservación de especies de agua dulce. Desde el punto de vista de conservación de la biodiversidad surgen dos preguntas: 1) ¿Pueden los canales de riego mantener una rica diversidad de vegetación acuática, invertebrados y anfibios en el ciclo de cultivo del arroz? 2) ¿Puede la riqueza, abundancia y composición de especies acuáticas cambiar durante el ciclo de cultivo del arroz? Para ello, en el Condado Mostardas, Brazil un grupo de cuatro canales de los campos de arroz fue seleccionado al azar. En cada canal, se llevaron a cabo seis muestreos durante el ciclo de cultivo del arroz (junio 2005 hasta junio 2006). Un total de 160 táxones fueron identificados en los canales de riego, que incluyen 59 especies de macrófitos, 91 táxones de macroinvertebrados y 10 especies de anfibios. La riqueza y la abundancia de vegetación acuática, invertebrados y anfibios no cambió significativamente durante el ciclo de cultivo del arroz. Sin embargo, la composición de las especies de estos grupos en los canales de riego varía entre períodos no cultivados y cultivados. Nuestros resultados muestran que la diversidad de especies en los canales de riego, junto con la permanencia del agua permite que estas redes acuáticas provocadas por el ser humano puedan funcionar como sistemas importantes que contribuyan con la conservación de la biodiversidad en las regiones donde los humedales se han convertido en campos de arroz. La conservación de las especies en la agricultura, tales como los campos de los canales de arroz, que pueden ser una alternativa importante para la conservación de la biodiversidad en el sur de Brasil, donde más del 90% de los sistemas de humedales ya se han perdido y los restantes aún se encuentran en alto riesgo debido a la expansión de la producción de arroz.


Subject(s)
Animals , Amphibians , Agriculture/methods , Biodiversity , Invertebrates , Oryza , Plants , Wetlands , Brazil , Conservation of Natural Resources/methods , Fresh Water , Population Dynamics
11.
Neotrop. entomol ; 37(6): 735-738, Nov.-Dec. 2008. mapas, tab
Article in Portuguese | LILACS | ID: lil-507034

ABSTRACT

Este trabalho apresenta a distribuição de Trichoptera ao longo da Bacia do Rio Paranã, GO, com novos registros para gênero. Foram estabelecidas 18 estações de coleta ao longo da bacia durante as estações chuvosa (março e dezembro/2003) e seca (julho/2003 e agosto/ 2004). Foram utilizadas redes de bentos do tipo Surber e " D" , para a coleta dos organismos nos diversos ambientes.


Distribution of Trichoptera along Paranã River Basin, Goiás State, with new records for genera, is presented. Eighteen sample sites were made along the basin during the rain (March and December/2003) and dry (July/2003 and August/2004) seasons. Surber and D net were used for sampling all habitats.


Subject(s)
Animals , Insecta/classification , Brazil , Rivers
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