Abstract The dry forest is an ecosystem with a relatively high diversity of species. It is also one of the most threatened habitats. This research was carried out between January and November 2010 aiming to describe species richness, composition, and conservation status of the herpetofauna in the Yerbasanta micro-basin in the Central Coast of Oaxaca. Standard visual encounter surveys were used to observe herpetofaunal community in four locations of the micro-basin. Five amphibian species and 37 reptiles species were found. The Shannon-Wienner index showed that Pueblo Viejo had the highest value of diversity, followed by Unión, and the remainder localities had lower values. The similarity index was moderate between locations. Among the registered species, 12 can be classified under some conservation status. These results also suggest that this region can maintain a significant number of herpetofauna species. Additionally, this research represents baseline information that contributes to other studies.

Resumen El bosque seco tropical es un ecosistema con una diversidad de especies relativamente alta, por lo que es también uno de los hábitats más amenazados. Este trabajo se realizó entre enero y noviembre de 2010 con el objetivo de describir la riqueza de especies, composición y estatus de conservación de la herpetofauna de la microcuenca del Río Yerbasanta en la Costa Central de Oaxaca. A través de encuentros visuales estandarizados se realizó la observación de la comunidad herpetofaunística en cuatro localidades de la microcuenca. Se encontraron cinco especies de anfibios y 37 especies de reptiles. El índice Shannon-Wienner mostró que Pueblo Viejo tuvo el valor más alto de diversidad, seguido de Unión, mientras que las restantes localidades tuvieron valores bajos. El índice de similitud fue moderado entre localidades. Entre las especies registradas, 12 pudieron clasificarse bajo algún estatus de conservación. Los resultados también sugieren que esta región puede mantener un número significativamente alto de especies herpetofaunísticas. Adicionalmente, este trabajo representa una línea de información base para futuros estudios.

ABSTRACT The conservation of cocoa agroforestry systems (SAFC) in Tabasco, Mexico, requires the revaluation of their environmental functions, since they represent relicts of arboreal vegetation in a landscape dominated by cultivated areas. For this reason, a research was developed to evaluate the diversity, arboreal structure and carbon stored in the SAFC, according to age, soils and municipalities. For that, the SAFC were inventoried to determinate the diversity through the indexes Shannon-Wienner and Sorenson respectively, arboreal structure through the importance value index, diametric classes and height, as well as the aerial biomass estimated through allometric equations, with which the carbon contents were calculated. We identified 24 families, 37 genera and 39 species. The SAFC > 40 years have slightly more diversity and arboreal density. Based in the age of the SAFC, the arboreal diversity and structure is highest in the SAFC ≥ 40 years with respect to SAFC > 10 years - 15 years and SAFC > 20 years - 35 years; while as with respect to soil group, the aforementioned indicators are higher in the Gleysols, followed by the Fluvisols, Cambisols and Vertisols. The age and soil type determine the carbon stored in the aerial biomass. 75% and 25% of the C of aerial biomass is stored in shade trees and cocoa, respectively. It is concluded that the SAFCs in Tabasco are similar in diversity and tree structure. The older ones established in Fluvisols are slightly more diverse and register a larger basal area, so they store more C in the aerial biomass.

RESUMEN La conservación de los sistemas agroforestales de cacao (SAFC) en Tabasco, México, requiere la revaloración de sus funciones ambientales, debido a que representan relictos de vegetación arbórea en un paisaje dominado por áreas cultivadas. Por tal motivo, se desarrolló una investigación para evaluar la diversidad, estructura arbórea y carbono almacenado en sistemas agroforestales de cacao en la región de la Chontalpa en el estado de Tabasco, México, según edad, suelos y municipios. Para ello, los SAFC se inventariaron para determinar la diversidad a través de los índices de Shannon-Wienner y Sorenson, la estructura arbórea mediante el índice de valor de importancia, clases diamétricas y altura, así como la biomasa aérea estimada a través de ecuaciones alométricas, con lo que se calcularon los contenidos de carbono. Se identificaron 24 familias, 37 géneros y 39 especies. Los SAFC ≥ 40 años poseen ligeramente más diversidad y densidad arbórea. Con base en la edad de los SAFC, la diversidad y estructura arbórea es mayor en los SAFC ≥ 40 años con respecto a los SAFC > (10-15) años y SAFC > (20-35) años; mientras que, con respecto al grupo de suelo, los indicadores antes mencionados son más altos en los Gleysols, seguido de los Fluvisols, Cambisols y Vertisols. La edad y el tipo de suelo determinan el carbono almacenado en la biomasa aérea. Setenta y cinco por ciento del carbono de la biomasa aérea se almacena en los árboles de sombra y 25% en el cacao. Se concluye que los SAFC en Tabasco son similares en diversidad y estructura arbórea. Los más viejos, establecidos en suelos Fluvisoles, son ligeramente más diversos y registran mayor área basal, por lo que almacenan más carbono en la biomasa aérea.

Resumen Las quebradas están fuertemente influenciadas por su vegetación ribereña y la deforestación afecta a la comunidad acuática. Se estudiaron los efectos de la deforestación sobre la diversidad taxonómica y funcional del ensamblaje de macroinvertebrados acuáticos en cuatro quebradas Andinas colombianas. El estudio incluyó 12 sitios, siete de ellos con cobertura arbórea en sus márgenes en áreas boscosas no perturbadas por la deforestación (estaciones de referencia) y los otros cinco sin cobertura arbórea en áreas deforestadas (estaciones alteradas). Se realizaron cuatro muestreos de campo entre junio 2011 y febrero 2012 y se recolectaron muestras de macroinvertebrados bentónicos utilizando el método D-net con malla de 500 μm y recolección manual, y se midieron diferentes variables fisicoquímicas in situ. Se calcularon los índices de Shannon-Wienner (H ‘) y Simpson (D). Se aplicaron análisis unidireccionales de varianza ANOVAs a cada variable ambiental y análisis canónicos discriminantes (CDA). Se recolectaron un total 8 370 individuos correspondientes a 80 taxones durante el estudio. La abundancia y diversidad fue mayor en las estaciones localizadas en áreas boscosas no perturbadas. Thraulodes, Anacroneuria y Rhagovelia, se asociaron con valores más altos de Calidad de Bosque de Ribera Andina (QBR-And), Índice de Hábitat Fluvial (IHF), Biological Monitoring Working Party Colombia (BMWP/Col) y temperatura en estaciones de referencia, mientras que Leptonema, Baetodes y Mayobaetis se asociaron con mayores valores de pH y altura sobre nivel del mar en estaciones alteradas. Los principales grupos funcionales tróficos (GFT) en las estaciones de referencia fueron colectores-recolectores/raspadores (27.2 %), raspadores (25.4 %) y depredadores (24.4 %), mientras que en estaciones alteradas fueron: Colectores filtradores (27.5 %), colectores-recolectores/raspadores (17.4 %) y raspadores (15.7 %). Los hábitos de vida más abundantes en las estaciones de referencia fueron agarradores (50.5 %), taxones con tres o más hábitos (28.7 %) y patinadores (16.1 %), mientras que en las estaciones alteradas fueron agarradores (68.1 %), taxones con tres o más hábitos (13.7 %) y excavadores (5.2 %). El conocimiento de las variables que determinan la estructura taxonómica y funcional de los ensamblajes de macroinvertebrados, y cómo responden a impactos como la deforestación, puede ayudar a determinar acciones de protección o restauración de las condiciones ambientales y ecológicas de las quebradas Andinas y los hábitats riparios.

Abstract The creeks are strongly influenced by their riparian vegetation, and the deforestation affect the aquatic community. The effects of deforestation on taxonomic and functional diversity of aquatic macroinvertebrate assemblage in four Colombian Andean creeks were evaluated. The study included 12 sites, seven of them with arboreal coverage at their margins in forested areas undisturbed by deforestation (reference stations) and the other five without tree cover in deforested areas (altered stations). Four field samplings were carried out between June 2011 and February 2012, and samples of benthic macroinvertebrates were collected using the D-net method with 500 μm mesh and manual collection, and different physicochemical variables were measured in situ. The Shannon-Wienner (H′) and Simpson´s index (D) were calculated. One-way analyses of variance (ANOVAs) to each environmental variable, and canonical discriminant analysis (CDA) to establish differences in environmental variables, taxonomic and functional diversity between references and altered stations were applied. 8 370 macroinvertebrate individuals corresponding to 80 taxa were collected in the study, with 6 758 individuals and 75 taxa in references stations and 1 612 individuals and 50 taxa in altered stations. The reference stations had higher values of diversity and the taxa that made major contributions to the variance between reference and altered stations were Thraulodes, Anacroneuria and Rhagovelia, which were associated with the highest values of Index of Andean riparian vegetation Quality (QBR-And), fluvial habitat index (IHF), Biological Monitoring Working Party Colombia BMWP/Col, EPT index (Ephemeroptera, Plecoptera, and Trichoptera) and temperature in reference stations, whereas Leptonema, Baetodes and Mayobaetis were associated with higher pH and elevation above sea level in altered stations. The main functional feeding groups (FFG) at the reference stations were collectors-gatherers/scrapers CG / SC (27.2 %), scrapers SC (25.4 %) and predators PR (24.4 %), and for altered stations were collectors-filterers CF (27.5 %), collectors-gatherers/scrapers CG / SC (17.4 %) and scrapers SC (15.7 %). The most abundant life habits were clingers Cg (50.5 %), taxa with three or more habits (28.7 %) and skaters Sk (16.1 %), in the reference stations, and clingers Cg (68.1 %), taxa with three or more habits (13.7 %) and burrowers Bu (5.2 %) in the altered stations. The knowledge of the variables that determine the taxonomic and functional structure of the macroinvertebrate assemblages, and how they respond to impacts such as deforestation, can help to determine actions of protection or restoration of the environmental and ecological conditions of the Andean streams and the riparian habitats.

Abstract Introduction: Relief has a significant influence on the spatial distribution and heterogeneity of arboreal vegetation in tropical forests. Objective: Tree structure and diversity were analyzed in three reliefs on the Oaxaca coast: plain, premountain and low mountain. Materials and methods: Three 1,000 m2 randomly selected sampling units were established in each relief to record total height, canopy cover and diameter at breast height (DBH) in three size classes: poles (Po), saplings (Sa) and seedlings (Se). The structure was characterized by vertical stratification, diameter distribution, Importance Value Index (IVI) and Forestry Value Index (FVI). The diversity was estimated with the Shannon-Wiener Index (H') and floristic similarity with the Sorensen Index (SI). Results and discussion: The species with the highest IVI and FVI were: Bravaisia integerrima (poles) and Pithecellobium dulce (saplings and seedlings) in premountain; Cecropia obtusifolia and Swartzia cubensis (poles), Cupania dentata (saplings) and Nectandra globosa (seedlings) in low mountain. The diversity (H') was significantly (p < 0.05) higher in low mountain (3.24) than in premountain (1.76) and plain (2.07). Floristic similarity (SI) of poles and saplings was lower between plain and premountain, and for seedlings it was lower between plain and low mountain. Conclusion: Species richness and diversity were different in each size class in at least one relief.

Resumen Introducción: La influencia del relieve es importante en la distribución espacial y heterogeneidad de la vegetación arbórea en las selvas. Objetivo: La estructura y diversidad arbórea se analizaron en tres relieves de la costa de Oaxaca: planicie, premontaña y montaña baja. Materiales y métodos: En cada relieve, con tres unidades de muestreo de 1,000 m2, se registraron altura total, cobertura de copa y diámetro normal de tres clases de tamaños: fustales, latizales y brinzales. La estructura se caracterizó mediante estratificación vertical, distribución diamétrica, índice de valor de importancia (IVI) y forestal (IVF); la diversidad con el índice de Shannon-Wienner (H´); y la semejanza florística con el coeficiente de Sorensen. Resultados y discusión: Las especies con mayores IVI e IVF fueron Bravaisia integerrima (fustales) y Pithecellobium dulce (latizales y brinzales) en planicie; Faramea occidentalis (fustales, latizales y brinzales) en premontaña; Cecropia obtusifolia (fustales), Cupania dentata (latizales) y Nectandra globosa (brinzales) en montaña baja. La diversidad H’ fue significativamente mayor (P < 0.05) en montaña baja (3.24) que en premontaña (1.76) y planicie (2.07). La semejanza florística de fustales y latizales fue menor entre planicie y premontaña, y para brinzales fue menor entre planicie y montaña baja. Conclusión: La riqueza y diversidad de especies fueron diferentes en cada clase de tamaño en al menos un relieve.

Resumo Objetivo: Identificar os efeitos da composição de sedimento e das condições abióticas da água sobre a diversidade, riqueza, equitabilidade, densidade e composição de espécies de Oligochaeta em lagoas rasas de planície de inundação. Métodos Foram amostradas trimestralmente ao longo do ano de 2010, 13 lagoas isoladas na planície de inundação do rio Paraná. Em cada lagoa, foram coletadas quatro amostras de sedimento nas regiões marginais e centrais, sendo três delas destinadas às análises biológicas, e uma para granulométrica. Concomitantemente, também foram mensurados a temperatura, oxigênio dissolvido, pH, condutividade, alcalinidade, turbidez e clorofila. As amostras biológicas foram primeiramente analisadas em microscópio estereoscópico. Os indivíduos de Oligochaeta, foram identificados em microscópio óptico ao menor nível taxonômico possível. Para análise de dados, mensuramos os atributos da assembléia de Oligochaeta, sendo eles a densidade, riqueza, equitabilidade e o índice de diversidade. Para mostrar diferenças entre os meses e os lagoas analisados, em relação às porcentagens de material orgânico grosso e fino, utilizamos o teste não paramétrico Kruskal Wallis. Também calculamos a diversidade granulométrica do sedimento usando o índice de Shannon-Wienner, por meio uma análise de regressão simples. Relacionamos os atributos de Oligochaeta com a diversidade de sedimento e as espécies dessa assembleia com as variáveis limnológicas por meio de correlação de Spearman. Resultados Foram encontrados 2.090 indivíduos distribuídos em 27 espécies, dentre as quais, 57% foram Pristina americana, seguida por Dero (Dero) righii com 13%. Os atributos de assembléia não foram significativamente correlacionados com a diversidade de sedimento, e 7 das 27 espécies registradas apresentaram correlações significativas com pelo menos alguma das variáveis abióticas da água. Conclusões Verificamos que as variáveis abióticas da água apresentam maior influência sobre os atributos da assembleia de Oligochaeta, quando comparada com as influências do sedimento. Embora a diversidade local das lagoas rasas seja baixa, a ampla variedade de condições limnológicas oferecida, pode ter levado à maior riqueza de espécies quando se considera toda a paisagem.

Abstract Aim: Identify the effects of sediment composition and water conditions on diversity, richness, evenness, density and composition of freshwater Oligochaeta in shallow floodplain lakes. Methods We sampled 13 shallow floodplain lakes quarterly during the year 2010 in the Upper Paraná River floodplain. In each lake, four sediment samples were taken from the shore and central regions, three of them were used for biological analysis, and one for granulometric analysis. Concomitantly, temperature, dissolved oxygen, pH, conductivity, alkalinity, turbidity and chlorophyll-a were also measured. Initially, the biological samples were analyzed by a stereoscopic microscope. Oligochaeta individuals were identified under optical microscope at the lowest possible taxonomic level. For data analysis, we quantified density, richness, evenness and diversity index of freshwater Oligochaeta. In order to show differences between the months and the analyzed lakes, in relation to the percentages of coarse and fine organic material, the nonparametric Kruskal Wallis test was used. We also calculated the sediment granulometric diversity using the Shannon-Wienner index, using a simple regression analysis. We correlated assemblage attributes of Oligochaeta with sediment diversity and the assemblage species with the limnological variables using the Spearman correlation. Results A total of 2,090 individuals were found distributed among 27 species. From the total individuals number, 57% were Pristina americana, followed by Dero (Dero) righii with 13%. Assemblage attributes were not significantly correlated with sediment diversity, and 7 of the 27 species recorded showed significant correlations with at least some of the abiotic variables. Conclusions We verified that the abiotic variables of the water present greater influence on the attributes of the assemblage of freshwater Oligochaeta, when compared with sediment influences. Although we found low local diversity of this group, the wide range of water conditions offered by lakes culminates with a great species richness considering the whole landscape.

In order to contribute to the knowledge of the bird diversity from the Oriental highland, was analyzed the diversity of birds in agricultural areas of Santa María Yahuiche, Oaxaca. The data was obtained with a field work of 1 440 m/network/hour and 86 hours of observation in intensive search, over 14 days of collection distributed in 2012. It was obtained a total of 187 visual records and 52 captured with mist nets. Bird species richness of agricultural lands from Santa Maria Yahuiche is represented by 52 species belonging to 19 families and 6 orders; however there are still species to be recorded. Permanent resident birds were the most abundant. The Shannon-Wiener index was H'= 3.54 nats with an equity value of species J'= 0.89. The bird diversity from Santa María Yahuiche is a priority for conservation, due to the presence of endemic species (9) and under some category of endangerment (1) according to NOM-059-SEMARNAT-2010, associated with agricultural activities.

Con el objeto de contribuir al conocimiento de la avifauna de la Sierra Madre Oriental se analizó la diversidad de aves en áreas agrícolas de Santa María Yahuiche, Oaxaca. Los datos fueron obtenidos con un trabajo de campo de 1 440 m/red/hora y 86 h de observación en búsqueda intensiva, a lo largo de 14 días de colecta distribuidos en 2012. Se obtuvieron un total de 187 registros visuales y 52 capturados con redes niebla. La riqueza específica de los Terrenos Agrícolas de Santa María Yahuiche está representada por 52 especies, pertenecientes a 19 familias y 6 órdenes, sin embargo aún quedan especies por registrar. Las aves con residencia permanente fueron las más abundantes. El índice de Shannon-Wienner fue de H'= 3.54 nats con un valor de equidad de especies de J'=0.89). La avifauna de Santa María Yahuiche es prioritaria para su conservación, debido a la presencia de especies endémicas (9) y bajo alguna categoría de riesgo (1) de acuerdo a la NOM-059-SEMARNAT-2010, asociadas a actividades agrícolas.

El crecimiento urbano no planificado transforma la estructura y funcionamiento de los ecosistemas al disminuir la biodiversidad y la composición de especies. Este impacto es particularmente fuerte en los ecosistemas de humedales, que son importantes en la regulación hídrica y en el ciclado de nutrientes. Este estudio determinó y comparó la composición y estructura funcional de las comunidades de artrópodos en los humedales de El Burro, Techo y La Vaca (Kennedy) Bogotá, Colombia, considerando su abundancia, riqueza y diversidad. En cuadrantes de 5 m de lado en cada hábitat, usando trampas de caída, jameo y captura manual, se colectaron artrópodos en Pastizales, Juncales/Tifales, Vegetación flotante-Macrófitas y en Pradera emergente herbácea. La mayor riqueza de órdenes y familias se presentó en el humedal de La Vaca (17 órdenes y 75 familias; diversidad de Shannon-Wienner = 3,45), seguida por El Burro (16 órdenes y 73 familias; Diversidad de Shannon-Wienner = 2,99) y finalmente, Techo (12 órdenes y 40 familias; Diversidad de Shannon-Wienner = 2,86). Predominaron los órdenes Diptera, Coleoptera e Hymenoptera. En cuanto a hábitats, la mayor riqueza de familias se presentó en Pastizales a excepción de El Burro donde fue en Vegetación Flotante y Macrófitas. Se registran12 familias que no habían sido registradas en estudios previos de la artropofauna de humedales en la Sabana de Bogotá. Los depredadores, descomponedores, nectarívoros/polinívoros fueron los grupos más diversos. Sin embargo la diversidad de microhabitats posibilita una estructura trófica particular para cada humedal y para cada hábitat.

Unplanned urban growth transforms the structure and functioning of ecosystems by reducing biodiversity and species composition. These impacts are particularly b in wetland ecosystems, which are important in hydric regulation and nutrient cycling. This study assessed and compared the composition and functional structure of arthropod communities in the wetlands of El Burro, Techo and La Vaca (Kennedy) Bogotá, Colombia, considering their abundance, richness and diversity. We collected arthropods in grasslands, reedbeds, macrophyte floating vegetation, and emergent prairie meadows by establishing three quadrants of 5x5 m in each habitat, using pitfall traps, insect nets and manual capture. The highest richness of orders and families was at La Vaca wetland (17 orders and 75 families; Shannon-Wiener diversity index (SWD) = 3.45), followed by El Burro (16 orders and 73 families; SWD = 2.99) and Techo (12 orders and 40 families; SWD = 2.86). The predominant orders were Diptera, Coleoptera and Hymenoptera. Richness was higher at grasslands, except at El Burro where it was higher in macrophyte floating vegetation. 12 families had not been previously recorded in arthropod fauna wetland studies in the Bogotá area. Predators, decomposers, and nectar/pollen feeders were the most diverse groups. Nonetheless the diversity of microhabitats enables particular trophic guilds for each wetland and for each habitat.

Espécies vegetais da família Apiaceae podem proporcionar recursos vitais para insetos predadores de pragas agrícolas, promovendo sua eficiência como agentes de controle biológico devido à oferta de recursos como sítios de refúgio, proteção e alimentação. Assim, o objetivo deste trabalho foi avaliar a atração de insetos predadores pelas apiáceas coentro (Coriandrum sativum L.), endro (Anethum graveolens L.) e funcho (Foeniculum vulgare Mill.). O experimento foi conduzido no campus da Universidade Federal de Lavras (UFLA), Lavras, MG, em blocos completos ao acaso, com três tratamentos e quatro repetições. Coletas semanais foram realizadas por meio de batida das plantas em bandejas, sendo os predadores aspirados e acondicionados em frascos com álcool 70%. Determinaram-se a curva do coletor, a riqueza de espécies, o índice de diversidade de Shannon-Wienner e o índice de similaridade (análise de Cluster). O funcho apresentou maior índice de Shannon-Wienner (H' = 1,104) e riqueza, enquanto o coentro mostrou maior abundância, sobretudo para a espécie Orius insidiosus (Hemiptera: Anthocoridae), um importante predador de tripes em hortaliças. Outras espécies predadoras de pragas de hortaliças foram encontradas, de maneira geral, em todas as apiáceas, destacando-se os adultos e larvas de coccinelídeos, importantes predadores de pulgões. A análise de Cluster indicou maior similaridade entre funcho e endro (55,03%). O período de floração promoveu considerável aumento na abundância de predadores, sobretudo no coentro.

Species of plants of the Apiaceae family can provide vital resources for predators of agricultural pests, boosting their efficiency as biological control agents, because they allow their maintenance in the environment by offering features such as sites of refuge, protection and food. The present study was aimed to evaluate the attraction of predator insects by 3 Apiaceae species, namely coriander (Coriandrum sativum L.), dill (Anethum graveolens L.) and fennel (Foeniculum vulgare Mill.). The bioassay was conducted on the campus of UFLA (MG) in a randomized block design with 3 treatments and 4 replications. Weekly collections were carried out by beating the plants on white plastic trays, aspirating the predators and packing them into bottles with 70% alcohol. Determinations were made of the collector curve, the species richness, the Shannon-Wienner diversity index and the index of similarity (cluster analysis). The fennel had a higher richness and Shannon-Wienner index (H' = 1.104), while the coriander was more abundant, especially for the species Orius insidiosus (Hemiptera: Anthocoridae), a major predator of thrips in vegetables. Other predatory species of vegetable pests were found, generally, on all Apiaceae, especially adults and larvae of coccinellids, which are important predators of aphids. Cluster analysis indicated a greater similarity between fennel and dill (55.03%), and a lower value for the other pairs. The flowering period increased the abundance of predators, especially the coriander.

Foram amostrados 17 trechos de riachos com 100 m de extensão, todos de ordem igual ou menor a três, ao longo de ambas as margens do canal principal do Rio Paranapanema, SP e PR. O ponto médio de cada trecho foi georreferenciado via satélite com receptor GPS e o uso de metodologia padronizada de coleta de dados ambientais e peixes (baseada principalmente na pesca elétrica), possibilitou a obtenção das seguintes informações em cada local: 1) composição taxonômica da ictiofauna e contribuição, em termos de número de indivíduos e biomassa, de cada espécie para a ictiofauna local como um todo; 2) documentação fotográfica de espécimes representativos de cada espécie coletada com sua coloração natural; 3) descrição de cada ambiente coletado, com ilustrações fotográficas coloridas, e seus principais parâmetros bióticos e abióticos. No total foram coletados 3.683 exemplares, pertencentes a seis ordens, 16 famílias, 37 gêneros e 52 espécies, com biomassa total de 16,8 kg. Das espécies coletadas, aproximadamente 36% pertencem a ordem Siluriformes, 36% a Characiformes, 11% a Gymnotiformes, 10% a Perciformes, 4% a Cyprinodontiformes e 2% a Synbranchiformes. As espécies mais abundantes em termos de número de indivíduos foram Astyanax altiparanae (15,2%) e Astyanax sp. 1 (12,3%); aquelas com maior biomassa foram A. altiparanae (28%) e Geophagus brasiliensis (13%). A composição da ictiocenose em termos de abundância e biomassa por família indica a predominância expressiva de Characidae, seguida por Loricariidae, Pimelodidae e Cichlidae. Dentre os trechos amostrados, o trecho 14 (24 espécies) e o 13 (cinco espécies), apresentaram a maior e a menor riqueza em espécies, respectivamente, coincidindo com os valores obtidos para o índice de diversidade específica de Shannon-Wienner (H´= 0,99 e 0,32, respectivamente). A riqueza média encontrada foi de 11 espécies por trecho de riacho. Na estimativa de riqueza por extrapolação para o conjunto total de riachos amostrados na bacia do rio Paranapanema, obtivemos um valor de 69 espécies (erro padrão igual a quatro) indicando ser necessário um esforço amostral adicional moderado para atingir a assíntota da curva. Das 52 espécies coletadas, oito (aproximadamente 15% do total) são seguramente novas, cinco (aproximadamente 10% do total) possuem “status” taxonômico ainda indefinido, enquanto outras três (aproximadamente 6% do total) são espécies introduzidas. Analisando a estrutura trófica e espacial da ictiocenose estudada, as 10 espécies numericamente dominantes nos riachos estudados dividem-se, em ordem decrescente de importância numérica, em quatro guildas: onívoros nectônicos; invertívoros bentônicos; perifitívoros; e onívoros bentônicos. Uma chave de identificação para todas as espécies de peixes coletadas durante este estudo é fornecida ao final deste trabalho.

Seventeen 100 m long streams stretches, none of an order higher than three, were sampled to both sides of the main channel of Rio Paranapanema in the States of São Paulo and Paraná, southeastern and southern Brazil. Each stream stretch had its midpoint located with a GPS satellite receiver and had its fish fauna sampled via a standardized environmental data and fish collection methodology (primarily utilizing electrofishing) with the aim of providing the following information about each stream: 1) the taxonomic composition of the fish fauna and the contribution of each species in that stream in terms of both number of individuals and biomass; 2) a photographic documentation of the live coloration of representative speci-mens of each collected species; and 3) the description of each sampled environment, with colored photographic illustra-tions and details of the main biotic and abiotic parameters. Overall 3,683 fishes were collected, belonging to six orders, 16 families, 37 genera, and 52 species, with a total biomass of 16.8 kg. Of the collected species, approximately 36% were Siluriformes, 36% Characiformes, 11% Gymnotiformes, 10% Perciformes, 4% Cyprinodontiformes, and 2% Synbranchiformes. The most abundant species in terms of total number of individuals were Astyanax altiparanae (15.2%) and Astyanax sp. 1 (12.3%); The species with the largest biomasses were Astyanax altiparanae (28%) and Geophagus brasiliensis (13%). In terms of abundance and biomass collected for each family, the Characidae was clearly the predominant family followed by the Loricariidae, Pimelodidae, and Cichlidae. Among the sampled stream stretches, locality 14 with 24 species and locality 13 with five species yielded the highest and lowest richness in terms of species numbers, respectively. This coincides with the values obtained for the Shannon-Wienner index of specific diversity (H´ = 0.99 and 0.32, respectively). The median species richness for all streams stretches was 11. In the species richness estimate by extrapolation for all 17 sampled stream stretches, a value of 69 species was obtained (with a standard error of four) indicating the need for an additional moderate sampling effort to reach the asymptote of the curve. Of the 52 collected species, eight (approximately 15% of the total) are clearly new to science and five other species (approximately 10% of the total) are of indefinite taxonomic status and require further analysis. Three of the captured species are introduced (approximately 6% of the total). Analysis of the trophic and spatial structure of the studied fish fauna indicates that the 10 numerically dominant species in the sampled streams can be grouped into four guilds that are in decreasing order of numeric importance: nektonic omnivores; benthonic invertivores; periphytovores; and benthonic omnivores. An identification key for all the species of fish collected during this study it is provided.