Spatio-temporal distribution patterns of Chironomidae communities in the wadis of Northern Tunisia / Padrões de distribuição espaço-temporal de comunidades Chironomidae nos wadis do norte da Tunísia

In Northern Tunisia, seasonal streams, called wadi, are characterized by extreme hydrological and thermal conditions. These freshwater systems have very particular features as a result of their strong irregularity of flow due to limited precipitation runoff regime, leading to strong seasonal hydrologic fluctuations. The current study focused on the spatio-temporal distribution of chironomids in 28 sampling sites spread across the Northern Tunisia. By emplying PERMANOVA, the results indicated a significant spatio-temporal variation along various environmental gradients. The main abiotic factors responsible for noted differences in the spatial distribution of chironomids in wadi were the conductivity and temperature, closely followed by altitude, pH, salinity, talweg slope and dissolved oxygen, identified as such by employing distance-based linear models' procedure. The Distance-based redundancy analysis ordination showed two main groups: the first clustered the Bizerte sites, which were characterized by high water conductivity, sodium concentration and salinity. The second main group comprised sites from the Tell zone and was characterized by low temperatures, neutral pH, low conductivity and nutrients content. The subfamily TANYPODIINAE (e.g., Prochladius sp., Prochladius choerus (Meigen, 1804) and Macropelopia sp.) was the dominant group at Tell zone, whereas species such as Diamesa starmachi (Kownacki et Kownacha, 1970) and Potthastia gaedii (Meigen, 1838) were found only in Tell Wadis. In contrast, chironomid species such as Diamesa starmachi (Kownacki et Kownacha, 1970), Potthastia gaedii (Meigen, 1838), Procladius choreus (Meigen, 1804) were specific for Tell Mountain. Cap Bon wadis region was dominated by genus Cladotanytarsus sp. The results of this survey liked the taxonomic composition of chironomid assemblages to the variation of hydromorphological and physic-chemical gradients across the northern Tunisia wadis.

No norte da Tunísia, riachos sazonais chamados wadi são caracterizados por condições hidrológicas e térmicas extremas. Esses sistemas de água doce têm características muito particulares como resultado de sua forte irregularidade de fluxo devido ao regime de escoamento de precipitação limitado, levando a fortes flutuações hidrológicas sazonais. O estudo atual enfocou a distribuição espaço-temporal dos quironomídeos em 28 locais de amostragem espalhados pelo norte da Tunísia. Ao aplicar PERMANOVA, os resultados indicaram uma variação espaço-temporal significativa ao longo de vários gradientes ambientais. Os principais fatores abióticos responsáveis pelas diferenças observadas na distribuição espacial dos quironomídeos no wadi foram a condutividade e a temperatura, seguidos de perto por altitude, pH, salinidade, declive do talvegue e oxigênio dissolvido, identificados como tais empregando o procedimento de modelos lineares baseados na distância. A ordenação da análise de redundância baseada em distância mostrou dois grupos principais: o primeiro agrupou os sítios Bizerte, que foram caracterizados por alta condutividade da água, concentração de sódio e salinidade. O segundo grupo principal compreendia locais da zona de Tell e era caracterizado por baixas temperaturas, pH neutro, baixa condutividade e conteúdo de nutrientes. A subfamília Tanypodiinae (por exemplo, Prochladius sp., Prochladius choerus [Meigen, 1804] e Macropelopia sp.) era o grupo dominante na zona de Tell, enquanto espécies como Diamesa starmachi (Kownacki et Kownacha, 1970) e Potthastia gaedii (Meigen, 1838) foram encontradas apenas em Tell Wadis. Em contraste, espécies de quironomídeos, como Diamesa starmachi (Kownacki et Kownacha, 1970), Potthastia gaedii (Meigen, 1838), Procladius choreus (Meigen, 1804), eram específicas para Tell Mountain. A região de Cap Bon wadis [...].

Potential mammalian species for investigating the past connections between Amazonia and the Atlantic Forest.

Much evidence suggests that Amazonia and the Atlantic Forest were connected through at least three dispersion routes in the past: the Eastern route, the central route, and the Western route. However, few studies have assessed the use of these routes based on multiple species. Here we present a compilation of mammal species that potentially have dispersed between the two forest regions and which may serve to investigate these connections. We evaluate the present-day geographic distributions of mammals occurring in both Amazonia and the Atlantic Forest and the likely connective routes between these forests. We classified the species per habitat occupancy (strict forest specialists, species that prefer forest habitat, or generalists) and compiled the genetic data available for each species. We found 127 mammalian species presently occurring in both Amazonia and the Atlantic Forest for which, substantial genetic data was available. Hence, highlighting their potential for phylogeographic studies investigating the past connections between the two forests. Differently from what was previously proposed, the present-day geographic distribution of mammal species found in both Amazonia and the Atlantic Forest points to more species in the eastern portion of the dry diagonal (and adjoining forested habitats). The Central route was associated with the second most species. Although it remains to be seen how this present-day geography reflects the paleo dispersal routes, our results show the potential of using mammal species to investigate and bring new insights about the past connections between Amazonia and the Atlantic Forest.

New records of three Neotropical arboreal ant species of Camponotus, subgenus Dendromyrmex (Hymenoptera: Formicidae) for the southern Amazon, including biological information / Novos registros de três espécies neotropicais de formigas arborícolas de Camponotus, subgênero Dendromyrmex (Hymenoptera: Formicidae) para a Amazônia meridional, incluindo dados de história natural

Camponotus (Formicinae) is the most specious and abundant genus of the family Formicidae. The genus is represented by ants that both forage and nest in the most diverse terrestrial and arboreal environments. Among the arboreal species of Camponotus are those of the subgenus Dendromyrmex. We recorded, for the first time, evidence of Camponotus chartifex (Smith, 1860) in the state of Mato Grosso, Brazil, and expanded the distributions of Camponotus nidulans (Smith, 1860) and Camponotus apicalis (Mann, 1916). We include information on the biology of the species and a discussion on the sampling of arboreal and winged ants. (AU)

Camponotus é um dos gêneros mais especiosos e abundantes da subfamília Formicidae. O gênero é representado por formigas que se alimentam e nidificam nos mais diversos habitats de ambientes terrestres e arbóreos. Entre as espécies arborícolas de Camponotus, estão as do subgênero Dendromyrmex. Registramos, pela primeira vez, Camponotus chartifex (Smith, 1860) para o estado de Mato Grosso, Brasil, e expandimos a distribuição de Camponotus nidulans (Smith, 1860) e Camponotus apicalis (Mann, 1916), incluindo informações biológicas sobre as espécies e uma discussão sobre a amostragem de formigas arborícolas e aladas.(AU)

Estimating species distribution and abundance in river networks using environmental DNA.

All organisms leave traces of DNA in their environment. This environmental DNA (eDNA) is often used to track occurrence patterns of target species. Applications are especially promising in rivers, where eDNA can integrate information about populations upstream. The dispersion of eDNA in rivers is modulated by complex processes of transport and decay through the dendritic river network, and we currently lack a method to extract quantitative information about the location and density of populations contributing to the eDNA signal. Here, we present a general framework to reconstruct the upstream distribution and abundance of a target species across a river network, based on observed eDNA concentrations and hydro-geomorphological features of the network. The model captures well the catchment-wide spatial biomass distribution of two target species: a sessile invertebrate (the bryozoan Fredericella sultana) and its parasite (the myxozoan Tetracapsuloides bryosalmonae). Our method is designed to easily integrate general biological and hydrological data and to enable spatially explicit estimates of the distribution of sessile and mobile species in fluvial ecosystems based on eDNA sampling.

Spatial segregation between Chalceus guaporensis and Chalceus epakros (Osteichthyes: Characiformes) in the Madeira River, Amazon Basin / Segregação espacial entre Chalceus guaporensis e Chalceus epakros (Osteichthyes: Characiformes) no rio Madeira, Bacia Amazônica

Chalceus guaporensis is an endemic fish to the upper Madeira River whereas C. epakros is widespread in many rivers of the central and lower portions of the Amazon Basin, middle and upper Orinoco River Basin, the Essequibo River in Guyana and in the Nanay River in northern Peru. According to literature, both species do not occur in syntopy. We carried out ichthyological surveys along the Madeira River Basin and its rapids, and data on abundance, diet and habitat use were obtained for both species. Chalceus guaporensis and C. epakros are morphologically similar, occupying floodplain habitats and exploiting similar food resources. The former predominated upstream from the Jirau Fall, whereas the latter had most of its abundance bellow the last fall of the Madeira River; both species co-occurred along part of the rapids stretch and in the Machado River, but with strongly uneven abundances. This pattern may have developed in the past by speciation regarding the presence of the falls, while co-occurrence of the two species seems to be regulated by competitive interactions or maintained by slight differences in environmental requirements nowadays. The recent disruption of the Madeira River by two run-of-river dams built in cascade submerged a large portion of the rapids stretch and substituted it by semi-lenthic habitats created by the dam reservoirs, together with the construction of a fish passage. These environmental changes may allow the invasion of the upper reaches of the Madeira River by C. epakros, and disturb the population of endemic C. guaporensis.

Chalceus guaporensis é descrita como uma espécie endêmica do alto rio Madeira, enquanto C. epakros está amplamente distribuída em rios das porções central e inferior da bacia Amazônica, no médio e alto rio Orinoco, e nos rios Essequibo, na Guiana, e Nanay, no norte do Peru. A literatura não registra essas espécies como sintópicas. Expedições ictiológicas realizadas ao longo do rio Madeira e suas corredeiras nos deram a oportunidade de registrar a presença, abundância, habitat e dieta utilizadas por essas espécies. Chalceus guaporensis e C. epakros são muito similares morfologicamente, ocupam habitats inundáveis e apresentam espectro alimentar semelhante. A primeira espécie predominou a montante da cachoeira Jirau, enquanto que a segunda teve a maior parte de sua abundância registrada à jusante das cachoeiras do rio Madeira. Ambas espécies coocorreram ao longo de parte do trecho de corredeiras e no rio Machado, mas com abundâncias muito desiguais. Esse padrão pode ter se desenvolvido no passado, por especiação, em função da presença das corredeiras, enquanto a coocorrência das duas espécies parece ser regulada por interações competitivas ou mantida por diferenças sutis em requisitos ecológicos no tempo atual. O recente barramento do rio Madeira por duas hidrelétricas construídas em cascata submergiu uma grande porção do trecho de corredeiras e o substituiu por habitats semilênticos, criados pelos reservatórios das hidrelétricas a fio dágua, juntamente com a construção de uma passagem para peixes. Essas alterações ambientais podem permitir que C. epakros invada o trecho superior da bacia do rio Madeira, com possíveis impactos negativos sobre a população da espécie endêmica C. guaporensis.

Predicting the distribution of poorly-documented species, Northern black widow (Latrodectus variolus) and Black purse-web spider (Sphodros niger), using museum specimens and citizen science data.

Predicting species distributions requires substantial numbers of georeferenced occurrences and access to remotely sensed climate and land cover data. Reliable estimates of the distribution of most species are unavailable, either because digitized georeferenced distributional data are rare or not digitized. The emergence of online biodiversity information databases and citizen science platforms dramatically improves the amount of information available to establish current and historical distribution of lesser-documented species. We demonstrate how the combination of museum and online citizen science databases can be used to build reliable distribution maps for poorly documented species. To do so, we investigated the distribution and the potential range expansions of two north-eastern North American spider species (Arachnida: Araneae), the Northern black widow (Latrodectus variolus) and the Black purse-web spider (Sphodros niger). Our results provide the first predictions of distribution for these two species. We also found that the Northern black widow has expanded north of its previously known range providing valuable information for public health education. For the Black purse-web spider, we identify potential habitats outside of its currently known range, thus providing a better understanding of the ecology of this poorly-documented species. We demonstrate that increasingly available online biodiversity databases are rapidly expanding biogeography research for conservation, ecology, and in specific cases, epidemiology, of lesser known taxa.

A random acceleration model of individual animal movement allowing for diffusive, superdiffusive and superballistic regimes.

Patterns of individual animal movement attracted considerable attention over the last two decades. In particular, question as to whether animal movement is predominantly diffusive or superdiffusive has been a focus of discussion and controversy. We consider this problem using a theory of stochastic motion based on the Langevin equation with non-Wiener stochastic forcing that originates in animal's response to environmental noise. We show that diffusive and superdiffusive types of motion are inherent parts of the same general movement process that arises as interplay between the force exerted by animals (essentially, by animal's muscles) and the environmental drag. The movement is superballistic with the mean square displacement growing with time as [Formula: see text] at the beginning and eventually slowing down to the diffusive spread [Formula: see text]. We show that the duration of the superballistic and superdiffusive stages can be long depending on the properties of the environmental noise and the intensity of drag. Our findings demonstrate theoretically how the movement pattern that includes diffusive and superdiffusive/superballistic motion arises naturally as a result of the interplay between the dissipative properties of the environment and the animal's biological traits such as the body mass, typical movement velocity and the typical duration of uninterrupted movement.

Avian Communities in the Amazonian Cangas Vegetation: Biogeographic Affinities, Components of Beta-Diversity and Conservation.

The Amazonian cangas is a vegetation type distributed as patches of open vegetation embedded in a matrix of tropical forest and that grows over iron-rich soils in the Serra dos Carajás region. To characterize cangas avifauna, we surveyed birds in eight patches varying from 43 to 1,366 hectares. Cangas avifauna has compositional affinities with savannas widespread throughout the Amazon and other biomes, and we estimate that more than 200 bird species occurs in this habitat. Species composition was relatively homogeneous, and the similarity among cangas patches was the dominant component of the beta-diversity. Bird communities in cangas patches exhibited statistically significant nested structure in respect to species richness and patch size. In contrast, the nested site arrangement was not affected by the isolation of patches. Number of species and composition are moderately affected by the area of cangas patches but not by its degree of isolation. To conserve this unique habitat are necessary a strict protection of carefully chosen patches of cangas and an investigation of the conservation value of secondary vegetation recovered by the mining companies.

Avian Communities in the Amazonian Cangas Vegetation: Biogeographic Affinities, Components of Beta-Diversity and Conservation

ABSTRACT The Amazonian cangas is a vegetation type distributed as patches of open vegetation embedded in a matrix of tropical forest and that grows over iron-rich soils in the Serra dos Carajás region. To characterize cangas avifauna, we surveyed birds in eight patches varying from 43 to 1,366 hectares. Cangas avifauna has compositional affinities with savannas widespread throughout the Amazon and other biomes, and we estimate that more than 200 bird species occurs in this habitat. Species composition was relatively homogeneous, and the similarity among cangas patches was the dominant component of the beta-diversity. Bird communities in cangas patches exhibited statistically significant nested structure in respect to species richness and patch size. In contrast, the nested site arrangement was not affected by the isolation of patches. Number of species and composition are moderately affected by the area of cangas patches but not by its degree of isolation. To conserve this unique habitat are necessary a strict protection of carefully chosen patches of cangas and an investigation of the conservation value of secondary vegetation recovered by the mining companies.

Feeding ecology of three juvenile mojarras (Gerreidae) in a tropical estuary of northeastern Brazil

Distributions and feeding ecology of mojarra species from shallow water of a tropical estuary in Northeastern Brazil were observed aiming to investigate differences in distribution and resource partitioning among juveniles of three species of mojarras. Fishes were collected with a beach seine across four sites along a salinity gradient from January to December of 2011. Highest abundances were recorded during the rainy season in the upper and middle estuary. Microcrustaceans, mainly copepods, were the preferential prey items of all mojarras, irrespective of size or hydrological season, suggesting these areas may be important nursery habitats. Juveniles of mojarra used two important mechanisms for exploitation of resources: (1) spatial segregation along the salinity and temperature gradient, such as abundance of Eucinostomus melanopterus increased from downstream to upstream estuary, while Eugerres brasilianus displayed an opposite pattern; (2) differences related to the volumetric proportion of the main prey items, with indications that E. melanopterus and Diapterus rhombeus fed predominantly on Calanoida and Cyclopoida, while the diet of E. brasilianus was dominated by items of infauna. Such strategies were important for resource partitioning, favouring the coexistence of these three species in the estuary.

A distribuição e a ecologia alimentar de gerreídeos capturados em águas rasas de um estuário tropical no nordeste do Brasil foram abordados com o objetivo de investigar diferenças na distribuição e partição de recursos entre três espécies de gerreídeos juvenis. Arrastos de praia foram realizados ao longo de quatro locais ao longo do gradiente de salinidade entre janeiro e dezembro de 2011. Maiores abundâncias foram registradas durante a estação chuvosa na zona superior e média do estuário. Microcrustáceos, principalmente copépodos, foram as principais presas para as três espécies, independente do tamanho ou do período hidrológico, sugerindo que essas áreas são importantes para o recrutamento. Gerreídeos juvenis usaram dois importantes mecanismos para exploração dos recursos: (1) segregação espacial no uso dos habitats ao longo do gradiente de salinidade e temperatura, com a abundância de Eucinostomus melanopterus aumentando em direção a parte inferior para porção superior do estuário, enquanto Eugerres brasilianus apresentou um padrão oposto; e (2) diferenças relacionadas com a proporção volumétrica das principais presas ingeridas, com indicações que E. melanopterus e Diapterus rhombeus alimentaram-se principalmente de Calanoida e Cyclpoida, enquanto a dieta de E. brasilianus foi dominada por itens da infauna. Tais estratégias foram importantes para partição dos recursos, favorecendo a coexistência dessas três espécies no estuário.

Development and characterization of seven polymorphic microsatellite loci in Bembidion atrocaeruleum (Coleoptera: Carabidae).

We isolated seven polymorphic microsatellite loci from a ground beetle (Bembidion atrocaeruleum, Coleoptera, Carabidae (Stephens, 1826)) associated with naturally and regularly disturbed floodplain habitat in northwest Europe. Loci were tested on 157 individuals collected from five distinct habitat patches across two adjacent drainage basins in Wales, United Kingdom, to assess their potential for revealing population structure across a relatively short spatial extent. Alleles per locus ranged from 4 to 12. For a central representative population, expected heterozygosity ranged from 0.23 to 0.78 (mean: 0.63), and observed heterozygosity ranged from 0.16 to 0.94 (mean: 0.56). Analysis of molecular variance indicated significant structure among populations, even when one locus potentially containing null alleles was removed. These loci have the potential to aid the study of dispersal mechanisms of this important riparian species along and between river corridors, a recurring question in floodplain conservation studies. In addition, given the diversity of the Bembidion genus, they may have utility in the study of sister species.

A new species of phlebotomine, Trichophoromyia adelsonsouzai (Diptera: Psychodidae) of Brazilian Amazonia

The phlebotomine sandfly Trichophoromyia adelsonsouzai sp. nov. is described and illustrated based on the male and female morphological characteristics of specimens collected at Km 27 of the Trans-Amazonian Highway, municipality of Vitória do Xingu, state of Pará, Brazilian Amazonia. This is an area subject to the direct influence of Belo Monte hydroelectric system. With the description of this new species the number of Trichophoromyia sandflies recorded in Brazil is increased to 20.

A new species of phlebotomine, Trichophoromyia adelsonsouzai (Diptera: Psychodidae) of Brazilian Amazonia.

The phlebotomine sandfly Trichophoromyia adelsonsouzai sp. nov. is described and illustrated based on the male and female morphological characteristics of specimens collected at Km 27 of the Trans-Amazonian Highway, municipality of Vitória do Xingu, state of Pará, Brazilian Amazonia. This is an area subject to the direct influence of Belo Monte hydroelectric system. With the description of this new species the number of Trichophoromyia sandflies recorded in Brazil is increased to 20.

Taxonomic review of the genus Trichomycterus Valenciennes (Siluriformes: Trichomycteridae) from the laguna dos Patos system, Southern Brazil

The species of the genus Trichomycterus inhabiting the laguna dos Patos system are reviewed and five species are recognized. Trichomycterus tropeiro Ferrer & Malabarba has a restricted range and is endemic to the uppermost portion of the rio das Antas. Trichomycterus balios, n. sp., is distributed in the upper portion of the rio das Antas and rio Caí basins. Trichomycterus diatropoporos, n. sp., is endemic to the rio da Prata basin, a tributary of the rio das Antas. Trichomycterus poikilos, n. sp., is widely distributed in the upper portion of the rio Jacuí basin and tributaries of the rio Taquari-Antas. Trichomycterus brachykechenos, n. sp., is endemic to the upper portion of the rio dos Sinos. The new species are distinguishable from most congeners, except for T. davisi, T. mboycy, T. naipi, T. payaya, T. papilliferus, T. perkos, T. plumbeus, and T. tropeiro by the lower number of pectoral-fin rays (I+5-6) and by the first pectoral-fin ray not prolonged as a filament. Other characters distinguish the new taxa from these eight species. The distribution of the genus in the laguna dos Patos system is discussed and a taxonomic key is provided.

O gênero Trichomycterus é revisado no sistema da laguna dos Patos e cinco espécies são reconhecidas. Trichomycterus tropeiro Ferrer & Malabarba tem distribuição restrita, ocorrendo somente na porção mais superior do rio das Antas. Trichomycterus balios, sp. n., distribui-se na porção superior das bacias dos rios das Antas e Caí. Trichomycterus diatropoporos, sp. n., é endêmica da bacia do rio da Prata, tributário do rio das Antas. Trichomycterus poikilos, sp. n., é amplamente distribuída nos cursos superiores da bacia do rio Jacuí e tributários dos rios Taquari-Antas. Trichomycterus brachykechenos, sp. n., é endêmica do curso superior do rio dos Sinos. As espécies novas distinguem-se de grande parte de seus congêneres pelo baixo número de raios na nadadeira peitoral (I+5-6) e o primeiro raio da nadadeira peitoral não prolongado como filamento, exceto de T. davisi, T. mboycy, T. naipi, T. papilliferus, T. payaya, T. perkos, T. plumbeus e T. tropeiro, distinguindo-se destas por outros caracteres. A distribuição do gênero no sistema da laguna dos Patos é discutida e uma chave taxonômica é fornecida.

Distributions and phylogeographic data of rheophilic freshwater fishes provide evidences on the geographic extension of a central-brazilian amazonian palaeoplateau in the area of the present day Pantanal Wetland

The analysis of the distribution patterns presented by examples of freshwater fishes restricted to headwater habitat: the anostomid Leporinus octomaculatus, the characins Jubiaba acanthogaster, Oligosarcus perdido, Moenkhausia cosmops, Knodus chapadae, Planaltina sp., the loricariid Hypostomus cochliodon, and the auchenipterid Centromochlus sp. provided evidences of a relatively recent shared history between the highlands of the upper rio Paraguay and adjoining upland drainage basins. Restricted to headwater of the uplands in the upper rio Paraguay and adjoining basins, these species provide biological evidence of the former extension of the central Brazilian plateau before the origin of the Pantanal Wetland. Disjunction took place due to an ecological barrier to these rheophilic taxa represented tectonic subsidence related to the origin of the Pantanal Wetland. Molecular analysis of Jubiaba acanthogaster revealed that the sample from the upper rio Xingu basin are the sister-group of a clade that includes samples from the upper rio Arinos (upper rio Tapajós) plus the upper rio Paraguay basin, supporting the assumption that the origin of the upper rio Paraguay basin causing vicariance between this basin and the upper rio Tapajós is the least vicariant event in the evolutionary history of the group.

A análise do padrão de distribuição apresentado por exemplos de peixes de água doce neotropicais restritos à habitats reofílicos de cabeceira: o anostomídeo Leporinus octomaculatus, os caracídeos Jubiaba acanthogaster, Oligosarcus perdido, Moenkhausia cosmops, Knodus chapadae, Planaltina sp., o loricariídeo Hypostomus cochliodon e o auquenipterídeo Centromochlus sp. fornecem evidências de uma história compartilhada relativamente recente entre as terras altas do alto rio Paraguai e bacias de terras altas vizinhas. Restritas às cabeceiras das áreas altas nas bacias do alto rio Paraguai e bacias vizinhas, estas espécies fornecem evidências biológicas da pretérita extensão do Planalto Central Brasileiro anteriormente a origem tectônica da planície alagável do Pantanal. Disjunções ocorreram devido a barreira ecológica para estes taxons reofílicos representada pela subsidência tectônica associada à origem do Pantanal. A análise molecular de Jupiaba acanthogaster revelou que amostras da bacia do alto rio Xingu consistem no grupo-irmão de um clado mais inclusivo que inclui amostras do alto rio Arinos (alto rio Tapajós) mais o alto rio Paraguai, suportando a suposição de que a origem do alto rio Paraguai causou vicariância entre esta bacia e o alto rio Tapajós no último evento vicariante na história evolutiva do grupo.

Glanidium botocudo, a new species from the rio Doce and rio Mucuri, Minas Gerais, Brazil (Siluriformes: Auchenipteridae) with comments on taxonomic position of Glanidium bockmanni Sarmento-Soares & Buckup

Glanidium botocudo, new species, is described from the tributaries to the upper rio Doce and Mucuri, eastern Minas Gerais State, Brazil. It represents the northernmost record of a centromochlin catfish from the coastal rivers of the Northeastern Atlantic Forest. Glanidium botocudo is readily distinguished from its congeners, except Glanidium albescens, by the whitish grey body coloration with evenly spaced small dark brown dots. The new species has a long sharpened ventral process on the urohyal, an uncommon condition among congeners, and the lowest vertebral count among the large-sized Glanidium, 36-37. It differs from Glanidium albescens by proportional measurements and higher number of ribs. Glanidium botocudo and Glanidium albescens are probably sister species, exhibiting similar morphological features and a complimentary distribution pattern, associated to an allopatric distribution pattern. Glanidium bockmanni is transferred to the genus Centromochlus .

Glanidium botocudo, espécie nova, é descrita para tributários do alto rio Doce e rio Mucuri, leste de Minas Gerais, Brasil. Representa o registro mais ao norte de um bagre centromoclíneo nos rios do Nordeste da Mata Atlântica. Glanidium botocudo é prontamente distinguido de todos seus congêneres, exceto Glanidium albescens, pelo colorido cinza-esbranquiçado do corpo com máculas castanho-escuras regularmente espaçadas. A espécie nova apresenta processo ventral do uro-hial longo e afilado, uma condição incomum entre os congêneres, e ainda a menor contagem vertebral entre os Glanidium de grande porte, 36-37. Diferencia-se de Glanidium albescens por proporções corporais e maior número de costelas. Glanidium botocudo e Glanidium albescens são possivelmente espécies irmãs, apresentando características morfológicas similares e padrões de distribuição complementar, associados a um padrão de distribuição alopátrica. Glanidium bockmanni é transferido para o gênero Centromochlus .

A new species of Roeboides (Teleostei: Characidae) from Costa Rica and Panama, with a key to the middle American species of the genus

A new species of Roeboides is described from the Pacific slope of Costa Rica and Panama. Roeboides bussingi differs from all other Central American Roeboides and all members of the R. guatemalensis species group by the following combination of characters: presence of 18-22 scales above the lateral line (vs. 12-16 in R. dientito); 15-22 scales below the lateral line (vs. 10-14 in R. dientito, and 20-24 in R. loftini); an inconspicuous, sometimes absent, crescent-shaped humeral spot (vs. a large round, conspicuous humeral spot in R. carti, R. dayi, R. dientonito, R. ilseae, R. loftini, and R. occidentalis); a small wedge-shaped spot that does not reach the lateral line (vs. a large spot crossing the lateral line in R. guatemalensis); a teardrop shaped caudal spot (vs. caudal spot triangle shaped in R. bouchellei); and a dark band at the distal tip of the anal fin (vs. dark band absent in R. bouchellei). A key to all Middle American species of Roeboides is also presented.

Uma espécie nova de Roeboides é descrita da vertente pacífica da Costa Rica e Panamá. Roeboides bussingi difere de todas as outras espécies de Roeboides da América Central e de todos os membros do grupo R. guatemalensis pela seguinte combinação de caracteres: presença de 18-22 escamas acima da linha lateral (vs. 12-16 em R. dientito); 15-22 escamas abaixo da linha lateral (vs. 10-14 em R. dientito e 20-24 em R. loftini); mancha umeral inconspícua, as vezes ausente, no formato de meia lua (vs. mancha humeral conspicua e arredondada em R. carti, R. dayi, R. dientonito, R. ilseae, R. loftini e R. occidentalis); pequena mancha em forma de cunha, não alcançando a linha lateral (vs. mancha grande, atravessando a linha lateral em R. guatemalensis); mancha do pedúnculo caudal em formato de gota d'água (vs. mancha caudal com formato triangular em R. bouchellei); banda escura na margem distal da nadadeira anal (vs. banda escura ausente em R. Bouchellei). Uma chave para todas as espécies de Roeboides da América Média é fornecida.

A new species of Tyttocharax (Characiformes: Characidae: Stevardiinae) from the Güejar river, Orinoco river Basin, Colombia

A new Tyttocharax species from the Güejar River system, near the Macarena Mountains in Colombia is described. This is the first record for the genus from the Orinoco basin. The combination of the following characters distinguish Tyttocharax metae from its congeners: presence of bony hooks on the pectoral and caudal-fin rays; bony hooks on the anal-fin rays larger than those on the pelvic-fin rays; pectoral-fin rays i,5-6,i; presence of three unbranched dorsal-fin rays; absence of an adipose fin; four scales rows between the anal-fin origin and the lateral line; and four scale rows between the pelvic-fin and the lateral line. Ecological characteristics of the habitat of the new species are also presented.

Una nueva especie de Tyttocharax se describe para la cuenca del río Güejar, Serranía de La Macarena en Colombia. Tyttocharax metae es un nuevo registro del género para la cuenca del río Orinoco. La combinación de los siguientes caracteres distingue a Tyttocharax metae de sus congéneres: presencia de ganchos óseos en los radios de las aletas pectorales y caudal; ganchos óseos en los radios de la aleta anal de mayor tamaño que los de las aletas pélvicas; radios de las aletas pectorales i,5-6,i; tres radios simples en la aleta dorsal; ausencia de una aleta adiposa; cuatro escamas entre la línea lateral y el origen de la aleta anal, y cuatro escamas entre la línea lateral y las aletas pélvicas. Se incluyen datos ecológicos del hábitat propio del nuevo taxón.