Food categories reconstruction and feeding consumption estimates for the Sciaenid Macrodon ancylodon (Bloch & Schneider), and the congeneric fishes Stellifer rastrifer (Jordan) and Stellifer naso (Jordan) (Pisces, Perciformes) in the Caeté Estuary, Northern Coast of Brazil

Um método quantitativo para se estimar o consumo alimentar e o aporte energético das diferentes categorias alimentares é apresentado através da reconstrução das presas ingeridas com base em estruturas corporais não digeríveis. Para tal, o presente estudo estabelece, através do exame dos conteúdos estomacais de 1.086 exemplares dissecados de Macrodon ancylodon (Bloch & Schneider, 1801), Stellifer rastrifer (Jordan, 1889) e Stellifer naso (Jordan, 1889), as equações das relações funcionais entre o peso das presas e estruturas corporais. Com as categorias reconstruídas foi possível quantificar o alimento ingerido pelos espécimes. Os resultados indicaram que existe uma marcada diferença, tanto na composição das categorias alimentares, bem como no aporte energético acompanhando o desenvolvimento ontogênico do predador.

Hepatic steatosis associated with microsporidiosis in teleost fishes from Marajó Island, Brazil

Um total de 40 exemplares do peixe teleósteo Gobioides grahamae Palmer & Wheeler, 1955 foram obtidos a partir do município de Salvaterra na Ilha de Marajó, no estado brasileiro do Pará. Os fígados foram removidos e processados para a microscopia de luz. De modo geral, 90% das amostras apresentavam algum grau de esteatose hepática, a qual foi invariavelmente associada com a presença de Microsporidium sp. O presente estudo confirma a ocorrência de esteatose em G. grahamae associada a infecções parasitárias por Microsporidium. Os resultados indicam que as condições de peixes saudáveis em ambiente natural podem ser afetadas negativamente por parasitas.

Profile of micronucleus frequencies and nuclear abnormalities in different species of electric fishes (Gymnotiformes) from the Eastern Amazon

The frequency of spontaneous micronucleus (MN) formation in fish species needs to be determined to evaluate their usefulness for genotoxic biomonitoring. The definition of a good bioindicator takes into account the current knowledge of its metabolic traits as well as other factors including its feeding behavior and relationship to the environment. In this study, we compared the basal frequencies of micronucleated erythrocytes and nuclear abnormalities (NA) among different species of the fish Order Gymnotiformes (Rhamphichthys marmoratus, Steatogenys elegans, Sternopygus macrurus, Parapteronotus hasemani, Gymnotus mamiraua, Gymnotus arapaima, Brachyhypopomus beebei, Brachyhypopomus n. sp. BENN) sampled in several localities of the Eastern Amazon. A baseline of MN and NA frequency in these fish was determined, enabling the identification of potentially useful species as models for genotoxicity studies. Only one impacted sample collected at a site in the River Caripetuba showed a significant number of NAs, which may be due to the release of wastewater by neighbouring mining industries and by the burnt fuel released by the small boats used by a local community. Our results may provide support for further studies in areas of the Eastern Amazon affected by mining, deforestation and other anthropogenic activities.

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

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Development of habitat suitability criteria for Neotropical stream fishes and an assessment of their transferability to streams with different conservation status

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

New host records and a checklist of fishes infected with Austrodiplostomum compactum (Digenea: Diplostomidae) in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sex chromosome composition revealed in Characidium fishes (Characiformes: Crenuchidae) by molecular cytogenetic methods

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bony fishes (Teleostei) caught by small-scale fisheries off central to south coast of São Paulo State, Southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chromosome evolution in fishes: a new challenging proposal from Neotropical species

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of lithium on the proliferation and migration of neuroblasts in the rostral migratory stream in adult mice

The discovery of neurogenesis in adult brains opened the possibility of cellular therapy strategies for the treatment of neurodegenerative diseases, such as Alzheimer’s disease. Neurogenesis in the adult brain occurs in two areas: subgranular zone of the hippocampus and subventricular zone (SVZ) of the lateral ventricles. Neurons that originate from the SVZ migrate to the olfactory bulb (OB) through the rostral migratory stream (RMS). In Alzheimer’s disease, there is a progressive neuronal dysfunction and degeneration, resulting in brain atrophy and cognitive impairments including olfactory dysfunction. Several studies have demonstrated that pharmacological treatment with lithium exerts positive effects on adult neurogenesis, and one pathway seems to be the modulation of factors that regulate the migration of neuroblasts. The objective of this study was to investigate whether treatment with lithium promotes the increase of migratory neuroblasts using as parameter the RMS. Adult male C57BL/6 mice were divided into control and lithium-treated groups. The animals were treated for 6 weeks and, at four different time points, i.e., 10 days, 7 days, 3 days and 1 day before the end of treatments, they received an injection of BrdU (cell proliferation marker). The animals were sacrificed by perfusion fixation and the brains were immunohistochemically labeled for BrdU for analysis of migrating neuroblasts in the RMS. The results showed that the number of BrdU+ cells in the RMS was not significantly different between the two groups, suggesting that lithium, alone, is not capable of increasing the number of neuroblasts migrating from the SVZ to the OB

First record of Palombitrema triangulum (Suriano, 1981) Suriano, 1997 (Monogenea: Dactylogyridae) from freshwater fishes in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fishes from Baía da Medalha, southern Pantanal, Brazil: A 20 years review

Located in the Pantanal of Miranda-Abobral, the Baía da Medalha is the largest pond close to the Base de Estudos do Pantanal of the Universidade Federal de Mato Grosso do Sul. The Baía da Medalha has been a study site for several didactic and scientific projects for years. Nevertheless, its fish fauna has never been inventoried. Based on data collected from the beginning of the 1990s up to 2011, we provide a list of fish species from the Baía da Medalha. A total of 97 species were recorded, corresponding to about 40% of the species stated for the Pantanal. Characiformes and Siluriformes were the most species-rich orders, being Characidae and Cichlidae the families with the highest number of species. Regional seasonal flood dynamics and the abundance of aquatic macrophytes may be associated with this high diversity. The representative richness found in this lagoon highlights the importance of such taxonomic surveys to preserve the diversity of aquatic habitats within the Pantanal ecosystem.

Surface-spreading technique of meiotic cells and immunodetection of synaptonemal complex proteins in teleostean fishes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The endangered species Brycon orbignyanus: genetic analysis and definition of priority areas for conservation

Currently, biodiversity is threatened by several factors often associated with human population growth and the extension of areas occupied by human activity. In particular, freshwater fish fauna is affected by overfishing, deforestation, water pollution, introduction of exotic species and habitat fragmentation promoted by hydroelectric dams, among other environmental impact factors. Several action plans to preserve ichthyofauna biodiversity have been adopted; however, these plans frequently cover only a small number of species, and decisions are often made without strong scientific support. This study aimed to evaluate the genetic aspects of wild groups of Brycon orbignyanus, an endangered fish species, using microsatellites and D-loop regions to identify the genetic structure of the samples and to establish priority areas for conservation based on the genetic patterns of this species. The results indicated that the samples showed levels of genetic variability compatible with others studies with Neotropical fishes. However, the results obtained in the analysis of molecular variance (AMOVA) for microsatellites (F (ST) = 0.258) and D-loop (F (ST) = 0.234) and the interpopulation fixation index revealed that B. orbignyanus was structured in different subpopulations in the La Plata River basin; the areas with better environmental conditions also showed subgroups with higher rates of genetic variability. Future conservation actions addressing these sites should consider two different management units: the complex formed by the Ivinhema River, Upper Parana, Camargo Port and Ilha Grande groups; and the complex formed by the Verde River and Sucuriu River groups.

Coexistence between Nearctic-Neotropical migratory shorebirds and humans on urban beaches of the Southern Hemisphere: a current conservation challenge in developing countries

The arrival of migratory shorebirds on beaches in urban communities in developing countries is a current challenge for the protection of these migrant birds. Nearctic-Neotropical migrants rely on roosting and feeding sites during their stopover on wintering sites in the Southern Hemisphere to acquire sufficient energy to complete their migratory cycles. On the other hand, cities in the Southern Hemisphere are growing rapidly, which results in increasing competition for space between humans and birds, such as for use in beach habitats. In the present study, I analyze the probability for occurrence for Nearctic-Neotropical migratory birds relative to the number of people in southeastern Brazil, the most populated region of South America. The frequency of occurrence of migrants, their distance of tolerance to people and the number of people were recorded in sample areas (circle plots with 20 m radius) on a 9 km stretch of urban beaches from November to February from 2009 to 2013. The probability of occurrence of Nearctic birds decreased as the number of people increased. When the number of people exceeded 20, the probability of occurrence of birds was almost zero. Furthermore, more than 95 % of birds moved off when people were within 16 m of reach. These results are discussed in the context of conservation actions since no management plan has been developed for migrant shorebirds that use urban beaches as stopover or wintering sites in developing countries.