Resumo A flexibilidade alimentar e onivoria são características das espécies de peixes de água doce neotropicais, especialmente em espécies de Astyanax. Tradicionalmente a maioria dos recursos na dieta de peixes é reconhecidamente originária do ambiente aquático, porém estudos recentes têm apontado para a importância das fontes alóctones. Além disso, a colonização de macrófi tas, comuns em vários reservatórios tropicais, pode melhorar os aspectos de insetivoria na dieta dos peixes expandindo ou concentrando a área disponível para a alimentação. Aqui analisamos o conteúdo estomacal de duas espécies de Astyanax simpátricas para avaliar a importância das diferenças de habitats, como a complexidade espacial, em dois reservatórios tropicais com diferentes características ambientais. A análise NMDS indicou separação na dieta destas espécies entre reservatórios (stress = 8.28%). Além disso, a análise de variância revelou uma diferença signifi cativa no volume de itens alimentares consumidos entre os reservatórios (Anova one-way F (1. 132) = 4,4446; p = 0.037), salientando a importância das condições ambientais na composição da dieta de peixes. O estudo destacou o hábito alimentar insetívoro das espécies de Astyanax e revelou diferentes estratégias de alimentação entre esses peixes simpátricos apesar da alta sobreposição de nicho nos dois ambientes. A heterogeneidade de hábitat aumentando a disponibilidade de recursos alimentares teve importância sobre a estratégia alimentar das espécies de Astyanax e consequentemente na manutenção constante de ambas nos dois diferentes reservatórios.

Abstract Food flexibility and omnivory are important features pronounced in Neotropical freshwater fish species, particularly for Astyanax species. Traditionally most fish diet resources are known to be originated in the aquatic environment, however recent studies have pointed to the importance of allochthonous sources. Besides, the colonization of macrophytes, common at several tropical reservoirs, may enhance insectivory in fish diet expanding or concentrating the area of available resources for feeding. Here we employed stomach contents analysis of two sympatric Astyanax species to access the importance of habitat differentiations as spatial complexity in two tropical reservoirs with different environmental features. The NMDS analysis indicated separation in the diet of these species between reservoirs (Stress= 8.28%). Additionally, analysis of variance revealed a significative difference in the volume of food itens ingested between the reservoirs (Anova one-way F(1, 132)=4.4446; p= 0.037). This points out the importance of environmental conditions on the composition of the diet of fishes. This study highlighted the insectivorous feeding habit of Astyanax species and revealed different feeding strategies between sympatric fishes despite high niche overlap in both environments. Habitat heterogeneity increasing food resources availability plays an important role in the diet strategy of these Astyanax species and on their constant maintenance in the two different reservoirs.

Resumen:Aunque las moscas negras tienen importancia médica debido a que algunas de sus especies son vectores de la Oncocercosis y Mansonelosis, su ecología y su potencial como bioindicadores es aún poco estudiado en la Región Neotropical. En Brasil el uso de bioindicadores se centra principalmente en un índice ecológico multimétrico, en este estudio investigamos la distribución espacial de las moscas negras y su relación con los factores abióticos, para su utilización como indicadores de la integridad de los sis&temas lóticos. En este sentido, hemos probado la hipótesis de que los cambios ambientales relacionados con la urba&nización conducen a la disminución de la abundancia y la pérdida de especies de la mosca negra. El muestreo se llevó a cabo en la región montañosa del Estado de Río de Janei&ro, Brasil, en 10 zonas urbanas y 10 arroyos conservados durante la estación seca (agosto-septiembre) de 2012. Los arroyos se caracterizaron por sus condiciones de integridad del ambiente y las propiedades físico-químicas de agua. Las moscas negras se muestrearon en sustratos rocosos con un kick-net sampler.El material se separó y las larvas se ordenaron por morfotipos y más tarde los especímenes en último estadio se disectaron e identificaron con la ayuda de la literatura taxonómica a nivel de especie. Una abundancia total de 488 larvas de nueve especies fueron recolectadas, 5 (1.02 %) en arroyos muy afectados, 470 (96.31 %) en intermedios y 13 (2.66 %) en conservados. La evaluación visual (HII) difiere de la físico-química del agua, en la que se observó una mayor variación. En el Análisis Correspon&dencia Canónica, Simulium subpallidum, S. inscrustatumy S. pertinaxestaban asociadas significativamente con sitios de impacto intermedio, para la mayoría de las variables. Por otro lado, Lutzsimulium hirticosta, S. subnigrumy Simuliumsp. A se asocian con valores bajos de las varia&bles químicas, relacionado a sitios más conservados. La mayoría de los estudios sobre el potencial bioindicador de Simuliidae tienden a enfocarse en los impactos agrícolas, mientras que nuestros resultados, por otro lado, sugieren que las especies de Simuliidae están presentes en arroyos con impactos intermedios de contaminación urbana, pero ausentes en los sitios fuertemente afectados. Por lo tanto, nuestros datos sugieren que algunas especies tales como L. hirticostay Simuliumsp. A están asociadas a lugares de reproducción más prístinos, mientras que otras pueden ser bioindicadores de arroyos moderadamente afectados, como S. pertinax, S. subnigrumy S. subpallidum.

Abstract:Black flies have medical importance because some species are vectors of the Onchocerciasis and Mansonelosis, nevertheless, their ecology and potential use as bioindicators is still poorly studied in the Neotropical Region. In Brazil, bioindicators use is strongly focused in a multimetrical ecological index approach; this way, we investigated the black fly spatial distribution, in relation to abiotic factors correlated to water quality, to provide baseline information for their utilization as standalone indicators of lotic systems integrity. We have tested the hypothesis that environmental changes related to urbanization, lead to decreased abundance and loss in the number of species of the black fly fauna. The sampling was conducted in 10 urban and 10 preserved streams during the dry season (August-September) of 2012, in the mountainous region of Teresópolis, State of Rio de Janeiro, Brazil. The streams were characterized for their environmental integrity conditions and physico-chemical properties of water. In each stream, five different rapid points were sampled in a section of 50 meters, 10 meters apart from each other. The black flies were sampled with a kick-net sampler on rocky substrates. The material was separated and the larvae were sorted in morphotypes, and later, the final instar specimens were dissected and identified with the help of taxonomical literature at species level. A total abundance of 488 larvae from nine species were collected, 5 (1.02 %) in extremely impacted streams, 470 (96.31 %) in intermediate streams and 13 (2.66 %) in preserved streams. The visual evaluation (HII) differed in rela&tion to the water physico-chemical evaluation, in which more variation in the characterization of the sampling sites was observed. In Canonical Correspondence Analysis Simulium subpallidum, S. inscrustatumand S. pertinaxwere significantly associated with intermediate values of most of the variables, and then to intermediate impacted sites. On the other hand, Lutzsimulium hirticosta, S. subnigrumand Simuliumsp. A were associated to low values of chemical variables, and then to more preserved sites. Most studies on the bioindicator potential of Simuliidae have suggested an approach to agricultural impacts, while our results, on the other hand, showed that Simuliidae species were present in streams with intermediate urban pollution impacts, but absent in heavily impacted sites. Thus, our data suggested that some species are associated to more pristine breeding sites, such as L. hirticostaand Simuliumsp. A, while others may be good bioindicators of moderately impacted streams, such as S. pertinax, S. subnigrumand S. subpallidum.

Notonecta itatiaia sp. nov. is described from the state of Rio de Janeiro. Like other Notonecta species that occurs in Brazil, N. itatiaia has no remarkable diagnostic features than the shape of genital capsule. Along with the first description of a Notonecta from Brazil in eighty years, N. disturbata is newly recorded from the states of Pará, Piauí and São Paulo, and N. pulchra from Pará. A key to species of Notonecta (males) occurring in Brazil is given.

En la Floresta Atlántica de Macaé, Rio de Janeiro, se describe una nueva especie del género Oligoneuria. La descripción fue basada en imagos machos y hembras de Oligoneuria macabaiba sp. nov. recolectados con trampas de luz. Estas especies presentan alas con venación y espinas abdominales posterolaterales similares al género, así como la expansión membranosa en la región anterior de la cabeza propia de Oligoneuria. Basado en las características de la nueva especie, el género es redefinido. La especie representa el primer registro del género para el Sudeste del Brasil.

The former monotypic genus Oligoneuria Pictet was known solely by a female subimago of the type-species Oligoneuria anomala Pictet. A new species of the genus Oligoneuria from the Atlantic rainforest of Macaé, Rio de Janeiro is described. The description was based in males and females imagos of Oligoneuria macabaiba sp. nov. caught with light traps. This species presents similar wing venation, abdominal posterolateral spines, as well as a membranous extension on anterior portion of the head as seen in the genus. Based on features of the new species, the genus is herein redefined. The species represents the first record of the genus from Southeastern Brazil. Rev. Biol. Trop. 59 (4): 1553-1557. Epub 2011 December 01.

Based on material collected on streams and lakes from the Amazon River floodplain, Brazil, Microvelia urucara sp. nov. is described, illustrated and compared with similar species. The new species, like many other Neotropical Microvelia Westwood, 1834, does not present striking modifications on the body or appendages, but can be separated from its congeners by features of the male genitalia. Distributional data is presented for other veliids collected along the Amazon River, and Paravelia capixaba Moreira, Nessimian & Rúdio, 2010 and Microvelia summersi Drake & Harris, 1928 are recorded for the first time from the Brazilian Amazon. Rhagovelia jubata Bacon, 1948 is newly recorded from the state of Amazonas, and Microvelia mimula White, 1879, M. pulchella Westwood, 1834 and M. venustatis Drake & Harris, 1933 are recorded for the first time from the state of Pará.

Uma nova espécie de Contulma Flint (Trichoptera, Anomalopsychidae) do Sudeste do Brasil. Contulma sana sp. nov. é descrita e ilustrada com base nos espécimes coletados na Bacia do Rio Macaé, Estado do Rio de Janeiro, Brasil. A nova espécie pode ser distinguida das congêneres pelas seguintes características da genitália masculina: lobos posteriores longos, processos dorsomedianos do segmento IX divergindo a partir do terço apical e esclerito falotremal bem desenvolvido. A fêmea e estágios imaturos são desconhecidos.

A new species of Contulma Flint (Trichoptera, Anomalopsychidae) from southeastern Brazil. Contulma sana sp. nov. is described and illustrated based on specimens collected in the Rio Macaé Basin, Macaé, Rio de Janeiro State, Brazil. The new species can be distinguished from congeners by the following male genitalia characters: long posterior lobes, dorsomedian processes of segment IX diverging on apical third, and well developed phallotremal sclerite. The female and immature stages are unknown.

Eighteen species from seven genera are recorded from the Amazon River floodplain, Brazil. An identification key, diagnoses, drawings, and taxonomic and biological notes are given for these species. The main features used in the identification key and diagnoses are: body and leg segments proportions, coloration patterns, presence and distribution of setae, and modifications of the apical abdominal segments and external genitalia of the male. Based on material collected in the floodplain streams and lakes, Cylindrostethus bassleri Drake, 1952 is recorded for the first time from Brazil, and new municipality records are presented for Brachymetra lata Shaw, 1933, B. shawi Hungerford & Matsuda, 1957, C. erythropus (Herrich-Schäffer, 1850), C. linearis (Erichson, 1848), C. Palmaris Drake & Harris, 1934, C. regulus (White, 1879), Neogerris lotus (White, 1879), N. lubricus (White, 1879), N. visendus (Drake & Harris, 1934), Ovatametra obese Kenaga, 1942, Rheumatobates crassifemur esakii Schroeder, 1931, R. klagei Schroeder, 1931, and Trepobates taylori (Kirkaldy, 1899). Additional new records from the Brazilian Amazon are presented for B. lata and O. obesa.

Triplectides itatiaia sp. nov. is described from specimens collected on the Itatiaia massif, Mantiqueira mountain range, Rio de Janeiro state, Brazil. The new species can be distinguished by the presence of hind wing fork I petiolate, the long dorsal excision of segment X and the flat, apically rounded mesal lobes. Female and immature stages are unknown. A key to the Brazilian species in the genus is provided.

Phylloicus monneorum sp. nov. is described and illustrated based on specimens collected in the Mantiqueira mountain range, Itatiaia, state of Rio de Janeiro, Brazil. The new species is the smallest within the genus. The male can be distinguished by the preanal appendages short, wide, flattened and with irregular margins, and by the deeply V-shaped tergum X. The female is also described and figured. The immature stages are unknown.

Os representantes de Buenoa restringem-se ao hemisfério ocidental, sendo a América do Sul a região que abriga o maior número de espécies descritas. Das 50 espécies descritas, cerca de 20 ocorrem no Brasil. Buenoa pseudomutabilis Barbosa, Ribeiro & Nessimian, sp. nov. é descrita com base em representantes de Maricá, Estado do Rio de Janeiro, sendo similar à B. mutabilis Truxal, 1953 quanto à presença de uma área estridulatória na superfície interna do fêmur anterior dos machos, pelo aspecto estreito do ápice desse fêmur (com o comprimento maior que três vezes a largura do seu ápice) e pelo dente lateral do rostro maior que o seu terceiro segmento. Espécimes machos de B. pseudomutabilis sp. nov. podem ser distinguidos facilmente pela presença de um pente com 21 a 25 dentes na tíbia anterior, enquanto o dos machos de B. mutabilis consiste de aproximadamente 33 a 38 dentes. Os machos de B. pseudomutabilis sp. nov. apresentam um nódulo em ambos os lados do primeiro tergito látero-ventral do abdome. Uma chave de identificação para os representantes machos das espécies de Buenoa ocorrentes no Rio de Janeiro com a espécie nova incluída é fornecida.

Members of Buenoa are restricted to the Western Hemisphere, with the greatest diversity of species in South America. There are about 50 described species and approximately 20 of them have been reported from Brazil. Buenoa pseudomutabilis Barbosa, Ribeiro and Nessimian, sp. nov. is described here from Maricá, Rio de Janeiro State. This species resembles B. mutabilis Truxal, 1953 because males have a stridulatory area on inner surface of forefemur, forefemur narrowed at apex, with length more than three times its width at apex, and rostral prong longer than third rostral segment. Males of B. pseudomutabilis sp. nov. can be readily recognized by the presence of 21 to 25 teeth in the stridulatory comb of foretibia, whereas in B. mutabilis the stridulatory comb of foretibia consists of approximately 33 to 38 teeth. Males of B. pseudomutabilis sp. nov. bear one nodule on each ventral laterotergite 1 of abdomen. A key to male species of Buenoa occurring in Rio de Janeiro State, including the new species, is provided.

Twelve new species of Neotrichia Morton, 1905 from state of Amazonas, Brazil are described and illustrated: N. gilmari sp. nov., N. djalmasantosi sp. nov., N. bellinii sp. nov., N. orlandoi sp. nov., N. niltonsantosi sp. nov., N. zitoi sp. nov., N. didii sp. nov., N. vavai sp. nov., N. garrinchai sp. nov., N. zagalloi sp. nov., N. pelei sp. nov., and N. feolai sp. nov. Neotrichia gilmari sp. nov. can be recognized by elongate and bifid processes on posterodorsal margin of segment IX; Neotrichia djalmasantosi sp. nov. is distinguished from N. colmillosa Harris, 1990 by the posteromesal margin of the segment IX produced into two long lobes in lateral view; N. bellinii sp. nov. differs from N. yanomonoa Harris & Davenport, 1992 by subgenital plate divided apically and with long lateral processes; N. orlandoi sp. nov. is distinguished from N. cuernuda Harris, 1990 by short inner portion of the inferior appendages and by phallus with stout apical hook; N. niltonsantosi sp. nov. is characterized by phallus with two short acute apical processes and a stout subapical spine; N. zitoi sp. nov. differs from other species particularly by phallic apex membranous and with flattened process; N. didii sp. nov. is somewhat similar to N. orlandoi sp. nov., but can be distinguished by stout posterolateral process of segment IX posteriorly directed and the paramere extending anteriorly; N. vavai sp. nov. is easily distinguished from other species of Neotrichia by the chelate processes on posterolateral margins of the segment IX; N. garrinchai sp. nov. can be recognized by asymmetrical posterolateral processes on segment IX and by long subgenital plate; N. zagalloi sp. nov. resembles N. dientera Harris, 1990, but can be easily recognized by broad, quadrangular inferior appendages with two excisions on apical margin and by phallic apex flattened and narrowing apically; N. pelei sp. nov. is characterized by narrow subgenital plate and by phallus apically with three lobes and a sclerotized hook; Neotrichia feolai sp. nov. is distinguished from N. biuncifera Flint, 1974 by phallus with only one apical process. In addition, N. browni Harris, 1990 and N. colmillosa Harris, 1990 are recorded from Brazil for the first time. With these new species and the new records, 26 species are now known from Brazil.

O peixe borboleta Thoracocharax stellatus é uma entre quase 200 espécies que ocorrem no alto rio Tocantins, no trecho represado pela UHE Serra da Mesa. A análise do conteúdo estomacal de 88 espécimes revelou uma dieta composta quase totalmente de insetos (99,6%), sendo, a maioria desses, insetos terrestres (87,6%). Formigas, besouros e efemerópteros foram os principais itens alimentares. A aurora e o crepúsculo parecem ser os períodos de maior atividade de forrageamento de T. stellatus. Sendo especializada em insetos terrestres, esta espécie apresenta uma estreita relação com a área próxima às margens, onde presas são fornecidas pela vegetação ripária associada. Apesar do represamento e da depleção do ecótono terra-água observado em fases posteriores da formação do reservatório, não foram registradas mudanças significativas na dieta dos poucos espécimes remanescentes, o que parece indicar uma baixa flexibilidade alimentar. Desta forma, a alimentação parece ter sido um fator determinante para o deslocamento desta espécie após o represamento.

The silver hatchetfish Thoracocharax stellatus is one of the approximately 200 fish species recorded for the upper rio Tocantins, in the region where it was impounded by the Serra da Mesa hydroelectric dam. Analysis of the stomach contents of 88 specimens revealed a diet consisting almost entirely of insects (99.6%), most of which were terrestrial (87.6%). Ants, beetles, and mayflies were the main food items. Dawn and dusk seemed to be the periods of highest foraging activity for T. stellatus. As a specialist on terrestrial insects, this species has a close connection with the region near the river bank, where prey is provided from the associated riparian vegetation. Despite the impoundment and depletion of the land-water ecotone observed in later stages of reservoir formation, no significant changes in the diet of the few remnant specimens were recorded, which seems to indicate little feeding flexibility. Thus, feeding seemed to be an overriding factor for the displacement of this species after river impoundment.

A larva de terceiro ínstar de M. latus (Fabricius, 1801) é descrita e ilustrada, baseado em espécimes criados da Serra dos Órgãos, Teresópolis, Rio de Janeiro, Brasil. Algumas notas acerca do biótopo onde as larvas foram coletadas são incluídas.

The last instar larva of M. latus (Fabricius, 1801) is described and figured, based on reared specimens from Serra dos Órgãos, Teresópolis, state of Rio de Janeiro, Brazil. Some notes on the biotope are provided.