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Sample records for astyanax scabripinnis jenyns

  1. Comparative cytogenetic and morphological analysis of Astyanax scabripinnis paranae (Pisces, Characidae, Tetragonopterinae

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    Maistro Edson Luis

    1998-01-01

    Full Text Available Cytogenetic and morphological studies were carried out on nine local populations of Astyanax scabripinnis paranae. All populations exhibited 2n = 50 chromosomes as well as conspicuous differences involving karyotype morphology, number and position of nucleolar organizer regions (NORs and amount and/or locations of constitutive heterochromatin blocks. A quantitative study of the cytogenetic data showed that eight populations possessed different karyotypes. Morphological analyses based on nine measurements and two meristic parameters were effective in establishing clear identification of five populations. Comparative analysis of cytogenetic and morphological traits suggests that chromosomal changes have occurred at a more rapid rate than morphological differentiation. Despite the close morphological similarity found among some populations, chromosomal differentiation was identified in all of them, even in those presenting only small morphological differences.

  2. Identification and chromosome mapping of repetitive elements in the Astyanax scabripinnis (Teleostei: Characidae) species complex.

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    Barbosa, Patrícia; de Oliveira, Luiz Antonio; Pucci, Marcela Baer; Santos, Mateus Henrique; Moreira-Filho, Orlando; Vicari, Marcelo Ricardo; Nogaroto, Viviane; de Almeida, Mara Cristina; Artoni, Roberto Ferreira

    2015-02-01

    Most part of the eukaryotic genome is composed of repeated sequences or multiple copies of DNA, which were considered as "junk DNA", and may be associated to the heterochromatin. In this study, three populations of Astyanax aff. scabripinnis from Brazilian rivers of Guaratinguetá and Pindamonhangaba (São Paulo) and a population from Maringá (Paraná) were analyzed concerning the localization of the nucleolar organizer regions (Ag-NORs), the As51 satellite DNA, the 18S ribosomal DNA (rDNA), and the 5S rDNA. Repeated sequences were also isolated and identified by the Cot - 1 method, which indicated similarity (90%) with the LINE UnaL2 retrotransposon. The fluorescence in situ hybridization (FISH) showed the retrotransposon dispersed and more concentrated markers in centromeric and telomeric chromosomal regions. These sequences were co-localized and interspaced with 18S and 5S rDNA and As51, confirmed by fiber-FISH essay. The B chromosome found in these populations pointed to a conspicuous hybridization with LINE probe, which is also co-located in As51 sequences. The NORs were active at unique sites of a homologous pair in the three populations. There were no evidences that transposable elements and repetitive DNA had influence in the transcriptional regulation of ribosomal genes in our analyses.

  3. Karyotypic diversity among three species of the genus Astyanax (Characiformes: Characidae).

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    Nishiyama, P B; Vieira, M M R; Porto, F E; Borin, L A; Portela-Castro, A L B; Santos, I C M

    2016-06-01

    The group Incertae sedis within the Characidae family currently includes 88 genera, previously included in the subfamily Tetragonopterinae. Among them is the genus Astyanax comprising a group of species with similar morphology and widely distributed in the Neotropics. Thus, the present study aimed to analyze the karyotype diversity in Astyanax species from different watersheds by conventional Giemsa staining, C-banding and fluorescence in situ hybridization (FISH rDNA 18S) probe.specimens of Astyanax aff. paranae belonging to the "scabripinnis complex", Astyanax asunsionensis and Astyanax aff. bimaculatus were analyzed". Two sympatric karyomorphs were observed in Astyanax.aff paranae, one of them having2n=48andthe other one with 2n=50 chromosomes. Other population of this same species also presented 2n=50 chromosomes, but differing in the karyotype formula and with macro supernumerary chromosome found in 100% of the cells in about 80%of females analyzed. Two population of A. asuncionensis and one population of Astyanax. aff. bimaculatus, also showed a diploid number of 50 chromosomes, but also differing in their karyotype formulas. Therefore, A. asuncionensis was also characterized by intraspecific chromosome diversity. The C-banding analysis was able to demonstrate a distinctable to demonstrate a distinct pattern of heterochromatin differing A. asuncionensis from Astyanax aff. paranae and Astyanax aff. bimaculatus. The supernumerary chromosome of Astyanax aff. paranae proved completely heterochromatic. Only Astyanax.aff. bimaculatus multiple showed multiple sites of nucleolar organizing regions. The other species were characterized by having a simple system of NOR. These data contributes to the know ledge of the existing biodiversity in our fish fauna, here highlighted by the inter- and intraspecific chromosomal diversity in the genus Astyanax. PMID:26934153

  4. Ecomorphology of Astyanax species in streams with different substrates

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    Marcela A. Souza; Daniela C. Fagundes; Cecília G. Leal; Paulo S. Pompeu

    2014-01-01

    In the present study, we assessed the ecomorphology of two species of Astyanax in streams with different substrates found in the Rio São Francisco Basin. The dominant substrate of each stream was defined as either "fine" (0 to 2 mm), "gravel" (2 to 250 mm), "rock" (> 250 mm), or "leaf bank". We analyzed a total of 22 ecomorphological attributes of Astyanax intermedius Eigenmann, 1908 (127 individuals) and Astyanax rivularis (Lütken, 1875) (238 individuals) adults. We detected significant ecom...

  5. The complex origin of Astyanax cavefish

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    Gross Joshua B

    2012-06-01

    Full Text Available Abstract Background The loss of phenotypic characters is a common feature of evolution. Cave organisms provide excellent models for investigating the underlying patterns and processes governing the evolutionary loss of phenotypic traits. The blind Mexican cavefish, Astyanax mexicanus, represents a particularly strong model for both developmental and genetic analyses as these fish can be raised in the laboratory and hybridized with conspecific surface form counterparts to produce large F2 pedigrees. As studies have begun to illuminate the genetic bases for trait evolution in these cavefish, it has become increasingly important to understand these phenotypic changes within the context of cavefish origins. Understanding these origins is a challenge. For instance, widespread convergence on similar features renders morphological characters less informative. In addition, current and past gene flow between surface and cave forms have complicated the delineation of particular cave populations. Results Past population-level analyses have sought to: 1 estimate at what time in the geological past cave forms became isolated from surface-dwelling ancestors, 2 define the extent to which cave form populations originated from a common invasion (single origin hypothesis or several invasions (multiple origin hypothesis, and 3 clarify the role of geological and climatic events in Astyanax cavefish evolution. In recent years, thanks to the combined use of morphological and genetic data, a much clearer picture has emerged regarding the origins of Astyanax cavefish. Conclusions The consensus view, based on several recent studies, is that cave forms originated from at least two distinct ancestral surface-dwelling stocks over the past several million years. In addition, each stock gave rise to multiple invasions of the subterranean biotope. The older stock is believed to have invaded the El Abra caves at least three times while the new stock separately invaded the

  6. Evolution of Space Dependent Growth in the Teleost Astyanax mexicanus

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    Gallo, Natalya D.; Jeffery, William R.

    2012-01-01

    The relationship between growth rate and environmental space is an unresolved issue in teleosts. While it is known from aquaculture studies that stocking density has a negative relationship to growth, the underlying mechanisms have not been elucidated, primarily because the growth rate of populations rather than individual fish were the subject of all previous studies. Here we investigate this problem in the teleost Astyanax mexicanus, which consists of a sighted surface-dwelling form (surfac...

  7. Ecomorphology of Astyanax species in streams with different substrates

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    Marcela A. Souza

    2014-02-01

    Full Text Available In the present study, we assessed the ecomorphology of two species of Astyanax in streams with different substrates found in the Rio São Francisco Basin. The dominant substrate of each stream was defined as either "fine" (0 to 2 mm, "gravel" (2 to 250 mm, "rock" (> 250 mm, or "leaf bank". We analyzed a total of 22 ecomorphological attributes of Astyanax intermedius Eigenmann, 1908 (127 individuals and Astyanax rivularis (Lütken, 1875 (238 individuals adults. We detected significant ecomorphological differences between the populations of A. rivularis and A. intermedius from habitats with different types of substrates. However, the two species did not show the same morphological differences depending on the type of substrate. These results confirmed the hypothesis that individuals from environments with different characteristics may have different ecomorphological patterns. Knowing that morphology is associated with habitat use and available resources, the loss of a resource or a modification in the environment may directly affect the permanence of a species, leading to a loss of morphologic diversity.

  8. Comparative cytogenetics in Astyanax (Characiformes: Characidae with focus on the cytotaxonomy of the group

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    Renata Cristina Claudino de Oliveira Tenório

    2013-09-01

    Full Text Available Astyanax is a diverse group of Neotropical fishes, whose different forms occupy different environments. This great diversity is also reflected on cytogenetic aspects and molecular markers, which have repeatedly been demonstrated by cytogenetic studies. In order to characterize the karyotype of species of this genus, six species were studied: Astyanax altiparanae, A.argyrimarginatus, A. elachylepis, A. xavante, and two new species provisionally called Astyanax sp. and A. aff. bimaculatus. A detailed cytogenetic study based on conventional staining with Giemsa, AgNORs, C-banding, base-specific fluorochromes, and FISH using ribosomal genes 18S and 5S was conducted, aiming to understand some of the chromosomal mechanisms associated with the high diversification that characterizes this group and culminated with the establishment of these species. The results showed 2n = 50 chromosomes for five species and a karyotype with 52 chromosomes in Astyanax sp. Small variations in the macrostructure of the karyotypes were identified, which were quite relevant when analyzed by classical banding, fluorochromes, and FISH methods. These differences among Astyanax spp. (2n = 50 are largely due to changes in the amount and types of heterochromatic blocks. Astyanax sp (2n = 52, in addition to variations due to heterochromatic blocks, has its origin possibly by events of centric fission in a pair of chromosomes followed by minor rearrangements.These results show an interesting karyotypic diversity in Astyanax and indicate the need of a review of the group referred as A. aff. bimaculatus and the description of Astyanax sp., including the possibility of inclusion of this unit in another genus.

  9. Evolution of space dependent growth in the teleost Astyanax mexicanus.

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    Natalya D Gallo

    Full Text Available The relationship between growth rate and environmental space is an unresolved issue in teleosts. While it is known from aquaculture studies that stocking density has a negative relationship to growth, the underlying mechanisms have not been elucidated, primarily because the growth rate of populations rather than individual fish were the subject of all previous studies. Here we investigate this problem in the teleost Astyanax mexicanus, which consists of a sighted surface-dwelling form (surface fish and several blind cave-dwelling (cavefish forms. Surface fish and cavefish are distinguished by living in spatially contrasting environments and therefore are excellent models to study the effects of environmental size on growth. Multiple controlled growth experiments with individual fish raised in confined or unconfined spaces showed that environmental size has a major impact on growth rate in surface fish, a trait we have termed space dependent growth (SDG. In contrast, SDG has regressed to different degrees in the Pachón and Tinaja populations of cavefish. Mating experiments between surface and Pachón cavefish show that SDG is inherited as a dominant trait and is controlled by multiple genetic factors. Despite its regression in blind cavefish, SDG is not affected when sighted surface fish are raised in darkness, indicating that vision is not required to perceive and react to environmental space. Analysis of plasma cortisol levels showed that an elevation above basal levels occurred soon after surface fish were exposed to confined space. This initial cortisol peak was absent in Pachón cavefish, suggesting that the effects of confined space on growth may be mediated partly through a stress response. We conclude that Astyanax reacts to confined spaces by exhibiting SDG, which has a genetic component and shows evolutionary regression during adaptation of cavefish to confined environments.

  10. Variação geográfica em Corydoras paleatus (Jenyns (Siluriformes, Callichthyidae do sul do Brasil Geographic variation in Corydoras paleatus (Jenyns (Siluriformes, Callichthyidae from southern Brazil

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    Oscar A. Shibatta

    2005-06-01

    Full Text Available A espécie Corydoras paleatus (Jenyns, 1842 está amplamente distribuída na região Sul do Brasil, ocorrendo desde o Rio Grande do Sul até o norte do Paraná. Estudos populacionais nessa espécie são considerados importantes devido à sua distribuição em uma região com forte interferência ambiental humana e pelo interesse comercial, uma vez que é vendida como peixe ornamental. Dezesseis caracteres morfométricos e seis caracteres merísticos foram utilizados para avaliação morfológica das populações das bacias dos rios Tibagi e Iguaçu (Paraná e Lagoa dos Quadros (Rio Grande do Sul. Apesar do número de placas laterais ser mais variável nos exemplares do rio Iguaçu, a sobreposição das contagens tanto das placas quanto dos raios das nadadeiras não permitiu a discriminação segura das populações. Entretanto, foi observado com a análise dos componentes principais, que essas podem ser diferenciadas pelo crescimento alométrico dos caracteres morfométricos. Além disso, a amostra do rio Iguaçu ficou discriminada morfometricamente do rio Tibagi e Lagoa dos Quadros no primeiro eixo canônico, enquanto estas ficaram separadas no segundo eixo. A variação intraespecífica, observada nessa espécie, evidencia que análises morfométricas populacionais podem ser úteis na análise da diversidade biológica de determinada região. As diferenças morfométricas, aliadas ao isolamento geográfico, são indícios de que essas populações estão sujeitas a diferentes processos seletivos.The species Corydoras paleatus (Jenyns, 1842 is widely distributed in Southern Brazil, occurring from Rio Grande do Sul to the north of Paraná State. Studies related to this species populations are considered important once this fish is distributed in a region with great anthropogenic interference and also because its economic importance, given that this species is commercialised as ornamental fish. In the present study sixteen morphometric characters

  11. Quantitative genetic analysis of retinal degeneration in the blind cavefish Astyanax mexicanus.

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    Kelly E O'Quin

    Full Text Available The retina is the light-sensitive tissue of the eye that facilitates vision. Mutations within genes affecting eye development and retinal function cause a host of degenerative visual diseases, including retinitis pigmentosa and anophthalmia/microphthalmia. The characin fish Astyanax mexicanus includes both eyed (surface fish and eyeless (cavefish morphs that initially develop eyes with normal retina; however, early in development, the eyes of cavefish degenerate. Since both surface and cave morphs are members of the same species, they serve as excellent evolutionary mutant models with which to identify genes causing retinal degeneration. In this study, we crossed the eyed and eyeless forms of A. mexicanus and quantified the thickness of individual retinal layers among 115 F(2 hybrid progeny. We used next generation sequencing (RAD-seq and microsatellite mapping to construct a dense genetic map of the Astyanax genome, scan for quantitative trait loci (QTL affecting retinal thickness, and identify candidate genes within these QTL regions. The map we constructed for Astyanax includes nearly 700 markers assembled into 25 linkage groups. Based on our scans with this map, we identified four QTL, one each associated with the thickness of the ganglion, inner nuclear, outer plexiform, and outer nuclear layers of the retina. For all but one QTL, cavefish alleles resulted in a clear reduction in the thickness of the affected layer. Comparative mapping of genetic markers within each QTL revealed that each QTL corresponds to an approximately 35 Mb region of the zebrafish genome. Within each region, we identified several candidate genes associated with the function of each affected retinal layer. Our study is the first to examine Astyanax retinal degeneration in the context of QTL mapping. The regions we identify serve as a starting point for future studies on the genetics of retinal degeneration and eye disease using the evolutionary mutant model Astyanax.

  12. Bases biológicas para el cultivo del puye Galaxias maculatus (Jenyns, 1842: una revisión

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    Rolando Vega

    2013-07-01

    Full Text Available Galaxias maculatus (Jenyns, 1842 es un pez gourmet de importancia comercial cuyas pesquerías están sobre-explotadas, siendo esencial el estudio de su biología para desarrollar su tecnología de cultivo (galaxicultura, que se encuentra en etapa piloto. Los objetivos de éste trabajo son: 1 entregar una síntesis de la información de la literatura sobre la biología de la especie, y 2 identificar la carencia de conocimiento científico y puntos críticos para el desarrollo de su tecnología de cultivo comercial. G. maculatus es un pequeño pez carnívoro, con poblaciones eurihalinas diferenciadas en diadrómicas y dulceacuícolas. Las poblaciones diadrómicas desovan en los estuarios y la larva migra al mar, retornando a la edad de seis meses para metamorfosearse en adulto. Son escasos los estudios de su sistemática, poblaciones y estado larvario en aguas chilenas, pero los correspondientes a alimentación, reproducción y enfermedades son más numerosos. Las hembras de un año desovan, aproximadamente, 1.200 huevos adhesivos pero un número importante muere después del primer desove (40%. La especie tiene un crecimiento rápido (1,1% dia-1 y alto metabolismo, con un promedio de vida de dos años. Se puede cultivar en cautividad, desovar, incubar sus huevos y obtener larvas; los adultos comen starter pelletizado de salmón y crecen en estanques. El protozoo ciliado Ichtyophthirius multifilis (ich produce altas mortalidades, en ejemplares en cautiverio, que pueden ser controladas con baños de sal. Los problemas de investigación a resolver para una futura piscicultura comercial son: identificar y seleccionar las poblaciones adecuadas para cultivo, aumentar el número de huevos desovados por hembra, desarrollar alimentos para larvas y reproductores, y controlar las enfermedades ectoparasitarias. El punto crítico es la masificación de la producción mediante el mejoramiento de las técnicas de reproducción y larvicultura.

  13. Micronucleus frequencies in Astyanax bimaculatus (Characidae) treated with cyclophosphamide or vinblastine sulfate

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    Matsumoto F.E.; Cólus I.M.S.

    2000-01-01

    Two known mutagenic drugs, cyclophosphamide and vinblastine sulfate, were tested using the micronucleus test in the native fish species, Astyanax bimaculatus, in order to determine which of these drugs and the doses which would be the most adequate for use as positive controls in this species. This Brazilian fish species was chosen because few toxicity studies have used native fish species and this particular species is widely consumed in various regions of Brazil. Three thousand erythrocytes...

  14. Osteología de Astyanax aurocaudatus Eigenmann, 1913 (Pisces, Characidae, con notas sobre la validez de Carlastyanax Géry, 1972

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    Ruiz-C., R. I.

    2006-06-01

    Full Text Available Osteology of Astyanax aurocaudatus, Eigenmann, 1913 (Pisces, Characidae, with notes on the validity of Carlastyanax, Géry, 1972. The taxonomic status of Astyanax aurocaudatus is difficult to interpret as no relevant osteological data are available to date. In the present paper we studied the osteological, morphometric and meristic characters of this species. The osteological characters of A. aurocaudatus found include the number and shape of premaxilla, maxilla and dentary teeth, second infraorbital separate from the preopercle, anal fins with pterygiophores that differ as towards the anterior, and presence of supra–orbital. These and other characters, body shape and coloring pattern, coincide with descriptions for the genus Astyanax. The characters describing the genus Carlastyanax therefore correspond to incorrect observations and the studied species is situated in the genus Astyanax. Carlastyanax is here considered a synonym of Astyanax.

  15. Evolutionary history of the fish genus Astyanax Baird & Girard (1854 (Actinopterygii, Characidae in Mesoamerica reveals multiple morphological homoplasies

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    Doadrio Ignacio

    2008-12-01

    Full Text Available Abstract Background Mesoamerica is one of the world's most complex biogeographical regions, mostly due to its complex geological history. This complexity has led to interesting biogeographical processes that have resulted in the current diversity and distribution of fauna in the region. The fish genus Astyanax represents a useful model to assess biogeographical hypotheses due to it being one of the most diverse and widely distributed freshwater fish species in the New World. We used mitochondrial and nuclear DNA to evaluate phylogenetic relationships within the genus in Mesoamerica, and to develop historical biogeographical hypotheses to explain its current distribution. Results Analysis of the entire mitochondrial cytochrome b (Cytb gene in 208 individuals from 147 localities and of a subset of individuals for three mitochondrial genes (Cytb, 16 S, and COI and a single nuclear gene (RAG1 yielded similar topologies, recovering six major groups with significant phylogeographic structure. Populations from North America and Upper Central America formed a monophyletic group, while Middle Central America showed evidence of rapid radiation with incompletely resolved relationships. Lower Central America lineages showed a fragmented structure, with geographically restricted taxa showing high levels of molecular divergence. All Bramocharax samples grouped with their sympatric Astyanax lineages (in some cases even with allopatric Astyanax populations, with less than 1% divergence between them. These results suggest a homoplasic nature to the trophic specializations associated with Bramocharax ecomorphs, which seem to have arisen independently in different Astyanax lineages. We observed higher taxonomic diversity compared to previous phylogenetic studies of the Astyanax genus. Colonization of Mesoamerica by Astyanax before the final closure of the Isthmus of Panama (3.3 Mya explains the deep level of divergence detected in Lower Central America. The

  16. Micronucleus frequencies in Astyanax bimaculatus (Characidae treated with cyclophosphamide or vinblastine sulfate

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    F.E. Matsumoto

    2000-06-01

    Full Text Available Two known mutagenic drugs, cyclophosphamide and vinblastine sulfate, were tested using the micronucleus test in the native fish species, Astyanax bimaculatus, in order to determine which of these drugs and the doses which would be the most adequate for use as positive controls in this species. This Brazilian fish species was chosen because few toxicity studies have used native fish species and this particular species is widely consumed in various regions of Brazil. Three thousand erythrocytes per specimen were scored. Doses of 16 and 8 mg/kg body weight of cyclophosphamide and vinblastine sulfate, respectively, were the most effective in causing micronuclei. Cyclophosphamide was the most mutagenic of the two drugs and is recommended for use as a positive control in A. bimaculatus.Duas drogas reconhecidas como mutagênicas, ciclofosfamida e vimblastina sulfato, foram avaliadas usando o teste do micronúcleo em uma espécie de peixe nativa, Astyanax bimaculatus, para detectar que droga e quais doses são as mais adequadas para serem usadas como controles positivos para esta espécie. Esta espécie de peixe brasileira foi escolhida devido à escassez de estudos toxicológicos com espécies de peixes nativos e também porque ela é amplamente consumida em algumas regiões do Brasil. Um total de 3000 eritrócitos por espécimen foram contados. As doses de 16 e 8 mg/kg de peso corporal de ciclofosfamida e de vimblastina sulfato, respectivamente, foram as mais efetivas na indução de micronúcleos. A ciclofosfamida mostrou ser o melhor agente mutagênico para ser usado como um controle positivo para Astyanax bimaculatus.

  17. New Astyanax from the upper rio Tapajós drainage, Central Brazil (Characiformes: Characidae

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    Vinicius A. Bertaco

    2007-03-01

    Full Text Available Astyanax utiariti, new species, is described from the upper rio Tapajós drainage, Mato Grosso, Brazil. Astyanax utiariti has a horizontally oval black humeral spot, a lozenge-shaped caudal-peduncle spot, continuing to the tip of the middle caudal-fin rays, and two brown bars in the humeral region that allows its inclusion in the A. bimaculatus species group. It also possesses a black stripe extending along midlateral body. The new species is distinguished from its congeners by a reticulate scale pattern, a black longitudinal stripe, toothless maxilla, larger dentary teeth and teeth of the inner row of the premaxilla with five to seven cusps, body depth 33.3-39.9% of standard length (SL, head length (HL 23.9-26.4% of SL, caudal-peduncle depth 12.0-13.4% of SL, orbital diameter 28.5-34.3% of HL, interorbital width 32.7-38.4% of HL, 36-38 perforated scales along the lateral line, and 22-26 branched anal-fin rays.Astyanax utiariti, nova espécie, é descrita da drenagem do alto rio Tapajós, Mato Grosso, Brasil. Astyanax utiariti tem uma mancha umeral preta horizontalmente ovalada, uma mancha losangular preta no pedúnculo caudal continuada até a extremidades dos raios caudais medianos e duas barras marrons na região humeral, que permite sua inclusão no grupo de espécies A. bimaculatus. Também possui uma faixa preta estendida ao longo do meio do corpo. A nova espécie distingue-se de suas congêneres pelo padrão reticulado nas escamas, uma faixa preta longitudinal, maxilar sem dentes, dentes maiores do dentário e dentes da série interna do pré-maxilar com cinco a sete cúspides, altura do corpo de 33,3-39,9% do comprimento padrão (CP, comprimento da cabeça (CC de 23,9-26,4% do CP, altura do pedúnculo caudal 12,0-13,4% do CP, diâmetro orbital de 28,5-34,3% do CC, largura interorbital de 32,7-38,4% do CC, 36-38 escamas perfuradas ao longo da linha lateral e 22-26 raios ramificados na nadadeira anal.

  18. Diet of Astyanax species (Teleostei, Characidae in an Atlantic Forest River in Southern Brazil

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    Fábio Silveira Vilella

    2002-06-01

    Full Text Available Feeding habits of six species of Astyanax from river Maquiné are described. Fishes were sampled bi-monthly from November/95 to September/96 in two zones of the river. Items were identified, counted and had their abundance estimated according to a semi-quantitative scale. Frequency of occurrence, alimentary importance index (IFI values and a similarity analysis of diets for each species-river zone sample were examined. All the species were considered typically omnivorous, with insects and vegetal matter being the most important items in their diet. These species could act as seed dispersers, particularly for macrophytes. Intra-specific spatial differences were not observed in comparisons of samples from two diferent regions of the river, except for A. fasciatus. The presence of Podostemaceae macrophytes in the mid-course of the river seemed to be important both as an autochthonous food resource and as habitat for several organisms preyed by the Astyanax species.Seis espécies do gênero Astyanax, presentes no rio Maquiné, RS, foram estudadas quanto aos seus hábitos alimentares. Os exemplares foram amostrados bimensalmente de novembro de 1995 a setembro de 1996 nas zonas ritral e potamal do rio. Os itens alimentares foram identificados e quantificados de acordo com uma escala semi-quantitativa de abundância, utilizando-se para análise a frequência de ocorrência e um índice de importância alimentar para cada espécie e zona do rio. Análises multivariadas de agrupamento e ordenação foram utilizadas para comparar as dietas intra e interespecíficas. Todas as espécies foram consideradas onivoras, sendo que os itens mais importantes foram os insetos e restos de vegetais superiores. Sugere-se que as espécies estudadas possam atuar como dispersoras de sementes, particularmente para macrófitas. Diferenças espaciais intraespecíficas não foram encontradas, exceto para A. fasciatus. A presença de Podostemaceae no curso médio do rio parece

  19. The sensitivity of lateral line receptors and their role in the behavior of Mexican blind cavefish (Astyanax mexicanus)

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    Yoshizawa, Masato; Jeffery, William R; van Netten, Sietse M; McHenry, Matthew J

    2014-01-01

    The characid fish species Astyanax mexicanus offers a classic comparative model for the evolution of sensory systems. Populations of this species evolved in caves and became blind while others remained in streams (i.e. surface fish) and retained a functional visual system. The flow-sensitive lateral

  20. Astyanax ajuricaba: a new species from the Amazon basin in Brazil (Characiformes: Characidae

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    Manoela M. F. Marinho

    2009-06-01

    Full Text Available A new Astyanax species is described from several localities in the rio Negro, rio Solimões and lower rio Tapajós basins, Amazon basin, Brazil. The new species is distinguished from all remaining characids by its unique color pattern consisting of the combination of presence of a conspicuous, narrow dark midlateral stripe, a well-developed vertically-elongated dark humeral spot, and upper caudal-fin lobe and middle caudal-fin rays dark, with a rounded clear ocellated spot present at anterior third of caudal-fin lobe.Uma nova espécie de Astyanax é descrita de diversas localidades nas bacias dos rios Negro, Solimões e baixo Tapajós, bacia Amazônica, Brasil. A nova espécie pode ser distinguida de todos os demais Characidae por um padrão de colorido único, que consiste na combinação da presença de uma linha médio-lateral estreita e escura, uma mácula umeral escura bem desenvolvida e verticalmente alongada e o lobo superior da nadadeira caudal e raios medianos escuros, com uma mancha ocelada clara presente no terço anterior do lobo.

  1. Chromosomal Diversification Higher Than Molecular Variation in Astyanax aff. fasciatus (Teleostei, Characidae).

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    Kavalco, Karine Frehner; Pazza, Rubens; Brandão, Karina de Oliveira; Garcia, Caroline; Bertollo, Luiz Antonio Carlos; de Almeida-Toledo, Lurdes Foresti

    2016-08-01

    Comprising a large number of species, the genus Astyanax has been intensively studied by several approaches to elucidate its evolutionary relationships. Such studies have demonstrated that many nominal species are artificial clusters where distinct taxa are grouped under the same denomination. Astyanax aff. fasciatus stands out due to its high karyotypic diversity, since cytogenetic studies have reported three standard cytotypes (2n = 46, 48, and 50), as well as cases of sympatry between cytotypes, variant cytotypes, and B chromosomes. In this study, we attempted to evaluate the reliability of the chromosomal differences in relation to the analysis of the ATPase6/8 mitochondrial DNA (mtDNA) sequence, thereby providing subsidies to the evolutionary reconstruction of this group. Nine populations from four distinct hydrographic basins along Southeastern Brazil were analyzed. These are the first cytogenetic data collected for four of them. Fluorescent in situ hybridization with 5S rDNA probe evidenced the presence of a standard phenotype for the group and the existence of a new arrangement in the individuals from Ribeira de Iguape River. Besides the karyotypic variation, the genetic distance was low among the studied populations and some aspects of the evolutionary relationships among distinct cytotypes/populations could be ascertained by phylogeographic studies. The incipient molecular structuring of certain cytotypes in different hydrographic basins indicates the role of different evolutionary processes on the diversification of the group. PMID:27148810

  2. Cytogenetic data on Astyanax jacuhiensis (Characidae in the lago Guaíba and tributaries, Brazil

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    Rosiley B. Pacheco

    2010-01-01

    Full Text Available Cytogenetic analyses were performed in Astyanax jacuhiensis from lago Guaíba, Brazil. The diploid number was 50, with a karyotype composed of 8m+30sm+4st+8a chromosomes, FN = 92. The AgNORs were observed in 2 to 5 chromosomes, with intra- and interindividual variation. The sm pair 8 observed always carried NORs on the short arms, presenting size heteromorphism between homologous. Fluorescence in situ hybridization (FISH with an 18S rDNA probe only confirmed the location of ribosomal cistrons in the sm pair 8, and heteromorphism of these regions between the homologous chromosomes. C-banding revealed the occurrence of weak C-positive heterochromatin in the pericentromeric regions of several chromosomes, in addition to more evident bands interstitially located on some chromosome pairs and in the terminal region of the short arms in pair 8. C-banding plus CMA3 revealed light fluorescent signals in different chromosomes of the karyotype, with a strong terminal site in pair 8, indicating the occurrence of several GC-rich heterochromatic regions in this species. Our results provide the first description of the Astyanax jacuhiensis karyotype, showing karyotype similarities when compared to various populations of A. altiparanae and A. bimaculatus, indicating that chromosomal features are very similar for these three species.Análises citogenéticas foram realizadas em Astyanax jacuhiensis do lago Guaíba, Brasil. O número diplóide foi 50, sendo o cariótipo composto por 8m+30sm+4st+8a cromossomos, NF = 92. As regiões organizadoras de nucléolos (AgNORs foram observadas em 2 a 5 cromossomos, evidenciando uma variação intra e interindividual nesta espécie. O par sm 8 foi constantemente detectado com NORs nos braços curtos, mostrando um heteromorfismo de tamanho entre os homólogos. Entretanto, a hibridação in situ fluorescente (FISH com sonda de DNAr 18S, localizou cístrons ribossômicos apenas no par 8, confirmando o heteromorfismo de tamanho

  3. Variación morfológica de las especies de Astyanax, subgénero Zygogaster (Teleostei, Characidae

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    Ruiz-C., R. I.

    2011-06-01

    Full Text Available Morphological variation of Astyanax species, subgenus Zygogaster (Teleostei, Characidae The diverse Neotropical fish genus Astyanax inhabits a variety of aquatic environments. As with other species in this genus, the taxonomic status and phylogenetic relationships of species of this subgenus remain largely undetermined. Based on 354 individuals, we analyzed the morphological variation of four species of the subgenus Zygogaster (A. atratoensis, A. caucanus, A. filiferus, and A. magdalenae using procrustes analysis and compared findings with two species of the sister group: subgenus Poecilurichthys (A. orthodus and A. superbus. The PCA (Principal Component Analysis and CVA (Canonical Variates Analysis showed morphological affinity between the subgenera and indicated variance in body depth, anterior trend of dorsal fin origin and humeral spot, depression on the dorsal surface of the skull, and ventral displacement of the orbit and snout. The variation in these structures may provide evidence supporting adaptive speciation as an alternative to speciation driven by geographical isolation.

  4. Analysis by RAPD of the genetic structure of Astyanax altiparanae (Pisces, Characiformes) in reservoirs on the Paranapanema River, Brazil

    OpenAIRE

    Maria Sueli Papa Leuzzi; Fernanda Simões de Almeida; Mário Luís Orsi; Leda Maria Koelblinger Sodré

    2004-01-01

    In this study, the RAPD technique was used to analyze the genetic structure of populations of the fish Astyanax altiparanae (Characidae, Tetragonopterinae) living in the lower, middle and upper Paranapanema River, Brazil. The aim was to assess this structure regarding fish handling and conservation programs. The genetic variability (P) was found to be 42.64%, 75% and 75% in the low, middle and upper reaches, respectively. The dendrogram of genetic similarity, obtained by comparative analysis ...

  5. Assessment of Water Pollution Signs in the Brazilian Pampa Biome Using Stress Biomarkers in Fish (Astyanax sp.

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    Mauro Nunes

    2015-01-01

    Full Text Available Located in southern Brazil, the Pampa biome has been under constant threat due to improper management of human effluents and use of pesticides. These contaminants accumulate mainly in water resources resulting in chronic poisoning of aquatic biota. Up to date, no studies on the assessment of environmental quality in the Brazilian portion of Pampa biome have been undertaken. Thereby, our main goal in this study was to investigate the ecotoxicological risks caused by human activity in the Santa Maria River, a major water course in the Brazilian Pampa biome. Brain and muscle tissues were used for determining oxidative stress and cholinesterase biomarkers in fish (Astyanax sp. exposed to urban and agricultural effluents. A substantial decrease in fish muscle acetylcholinesterase activity was observed in exposed animals, compared to controls (kept under laboratory conditions. In parallel, increased lipid peroxidation and significant changes in stress-responsive antioxidant enzymes (GST, CAT, GPx, and TrxR were detected. In the fish brain, a significant increase in GST activity is reported. In conclusion, our results showed significant changes in biomarkers of water contamination in Astyanax captured in Santa Maria River, pointing to important levels of water pollution in the region and validating the use of Astyanax in biomonitoring programs within the Pampa biome borders.

  6. Redescription of Astyanax guianensis Eigenmann 1909 (Characiformes: Characidae), a poorly known and widespread fish from the Amazon, Orinoco and Guiana Shield drainages.

    Science.gov (United States)

    Marinho, Manoela M F; Camelier, Priscila; Birindelli, José L O

    2015-01-01

    Astyanax guianensis is redescribed based on the holotype, paratypes, and additional specimens from the rio Essequibo in Guyana, rio Orinoco in Venezuela and from several localities in the Amazon river basin in Brazil, Colombia and Bolivia. Astyanax guianensis is diagnosed by having five to 10 maxillary teeth, 31 to 35 pored lateral-line scales, 21 to 25 branched anal-fin rays, and a dark vertical humeral blotch followed by a clear area and then by a dark longitudinal stripe, ending before the caudal-fin rays. In addition, comments on the importance of revisionary studies on the species of the Characidae are provided. PMID:25781846

  7. Feeding and reproductive patterns of Astyanax intermedius in a headwater stream of Atlantic Rainforest.

    Science.gov (United States)

    Souza, Ursulla P; Ferreira, Fabio C; Carmo, Michele A F; Braga, Francisco M S

    2015-01-01

    In this paper, we determined diet composition, reproductive periodicity and fecundity of Astyanax intermedius in a headwater stream of a State Park of an Atlantic rainforest. We also evaluated the influence of rainfall, water temperature and fish size on niche width and niche overlap. Sampling was conducted monthly throughout one year in the Ribeirão Grande stream, southeastern Brazil. Diet consisted of 31 food items with equal contribution of allochthonous and autochthonous items. Females were larger than males, and the mean sizes at first maturation were 4.44 cm and 3.92 cm, respectively. Based on 212 pairs of mature ovaries, the number of oocytes per female ranged from 538 to 6,727 (mean = 2,688.7). Niche width and niche overlap were not related to rainfall nor water temperature and only niche width increased with fish size, suggesting that as fish grow, more items are included in diet. Our results suggested that A. intermedius fit as a typical opportunistic strategist which may explain the prevalence of this species in several isolated headwater basins of vegetated Atlantic forested streams where food resources are abundant and distributed throughout the year.

  8. Feeding and reproductive patterns of Astyanax intermedius in a headwater stream of Atlantic Rainforest

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    URSULLA P. SOUZA

    2015-12-01

    Full Text Available ABSTRACT In this paper, we determined diet composition, reproductive periodicity and fecundity of Astyanax intermedius in a headwater stream of a State Park of an Atlantic rainforest. We also evaluated the influence of rainfall, water temperature and fish size on niche width and niche overlap. Sampling was conducted monthly throughout one year in the Ribeirão Grande stream, southeastern Brazil. Diet consisted of 31 food items with equal contribution of allochthonous and autochthonous items. Females were larger than males, and the mean sizes at first maturation were 4.44 cm and 3.92 cm, respectively. Based on 212 pairs of mature ovaries, the number of oocytes per female ranged from 538 to 6,727 (mean = 2,688.7. Niche width and niche overlap were not related to rainfall nor water temperature and only niche width increased with fish size, suggesting that as fish grow, more items are included in diet. Our results suggested that A. intermedius fit as a typical opportunistic strategist which may explain the prevalence of this species in several isolated headwater basins of vegetated Atlantic forested streams where food resources are abundant and distributed throughout the year.

  9. Replacement of animal protein with vegetable protein in the diets of Astyanax altiparanae

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    Fábio Rosa Sussel

    2014-09-01

    Full Text Available The aim of this study was to evaluate the effect of replacing animal protein with vegetable protein sources on the productive performance of Astyanax altiparanae (lambari-do-rabo-amarelo. Five experimental diets were formulated with increasing replacement levels of animal protein by vegetable protein. A total of 9000 individuals (initial mean weight 1.18 ± 0.12 g, initial mean length 2.1 ± 0.3 cm were distributed in 20 net cages (1 m3 with a density of 450 ind. m-3. Cages were randomly placed in a pond (180 m2, 1.5 m deep, 10% water renewal per day. After 63 days of cultivation, total count and individual biometrics from 20% of each experimental unit were taken. Mean weight, total length, survival, feed conversion, biomass weight gain and proximate body composition were evaluated. The experimental design was completely randomized with five treatments and four replications. The reduction in the formulation cost achieved by increasing levels of vegetable protein compensated the slight decrease in biomass gain. Besides that, inclusion of vegetable protein resulted in greater fat deposition, suggesting future exploration of A. altiparanae as a functional food.

  10. Intestinal and liver morphometry of the Yellow Tail Tetra (Astyanax altiparanae) fed with oregano oil.

    Science.gov (United States)

    Ferreira, Pollyanna M F; Caldas, Débora W; Salaro, Ana Lúcia; Sartori, Sirlene S R; Oliveira, Jerusa M; Cardoso, Alex J S; Zuanon, Jener A S

    2016-01-01

    This study aimed to evaluate the effect of oregano oil on the intestinal and liver morphometry of yellow tail tetra, Astyanax altiparanae. Fish (1.46 ± 0.09 g) were kept in a 60-L aquaria, at a stocking density of 0.5 fi sh L-1. Six diets containing varying amounts of oregano oil were evaluated (0.0; 0.5; 1.0; 1.5; 2.0 and 2.5 g of oregano oil kg-1). At the end of 90 days, the fi sh were euthanised. Four intestines and four livers were collected per treatment, which were fi xed in Bouin and embedded in resin. For height and width folds, the absorption surface area and thickness of the muscular layer a positive linear effect of oregano oil was observed. A decrescent linear effect on the total number of goblet cells was also observed. For the cytoplasmic percentage of hepatocytes and liver glycogen, a positive linear effect of oregano oil was observed. There was a decreasing linear effect on the percentage of nuclei in the hepatocytes and capillaries. Thus, the oregano essential oil promotes increased absorption areas, modulates the amount of goblet cells involved in protecting the intestinal mucosa and promotes cytoplasmic increase with greater deposition of liver glycogen in yellow tail tetra. PMID:27331801

  11. Intestinal and liver morphometry of the Yellow Tail Tetra (Astyanax altiparanae fed with oregano oil

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    POLLYANNA M.F. FERREIRA

    2016-06-01

    Full Text Available ABSTRACT This study aimed to evaluate the effect of oregano oil on the intestinal and liver morphometry of yellow tail tetra, Astyanax altiparanae. Fish (1.46 ± 0.09 g were kept in a 60-L aquaria, at a stocking density of 0.5 fi sh L-1. Six diets containing varying amounts of oregano oil were evaluated (0.0; 0.5; 1.0; 1.5; 2.0 and 2.5 g of oregano oil kg-1. At the end of 90 days, the fi sh were euthanised. Four intestines and four livers were collected per treatment, which were fi xed in Bouin and embedded in resin. For height and width folds, the absorption surface area and thickness of the muscular layer a positive linear effect of oregano oil was observed. A decrescent linear effect on the total number of goblet cells was also observed. For the cytoplasmic percentage of hepatocytes and liver glycogen, a positive linear effect of oregano oil was observed. There was a decreasing linear effect on the percentage of nuclei in the hepatocytes and capillaries. Thus, the oregano essential oil promotes increased absorption areas, modulates the amount of goblet cells involved in protecting the intestinal mucosa and promotes cytoplasmic increase with greater deposition of liver glycogen in yellow tail tetra.

  12. A developmental staging table for Astyanax mexicanus surface fish and Pachón cavefish.

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    Hinaux, Hélène; Pottin, Karen; Chalhoub, Houssein; Père, Stéphane; Elipot, Yannick; Legendre, Laurent; Rétaux, Sylvie

    2011-12-01

    Every model species requires its own developmental table. Astyanax mexicanus, a teleost fish comprising both sighted river and blind cave populations, is becoming more and more important in the field of developmental and evolutionary biology. As such, a developmental staging table is increasingly necessary, particularly since comparative analysis of early developmental events is widely employed by researchers. We collected freshly spawned embryos from surface fish and Pachón cavefish populations. Embryos were imaged every 10-12 min during the first day of development, and less frequently in the following days. The results provide an illustrated comparison of selected developmental stages from one cell to hatching of these two populations. The two morphs show an essentially synchronous development regarding major events such as epiboly, neurulation, somitogenesis, heart beating, or hatching. We also present data on particular morphological characters appearing during larval development, such as eye size, yolk regression, swim bladder, and fin development. Some details about the development of F1 Pachón cave×surface hybrids are also given. Comparisons are made with Danio rerio (zebrafish) development.

  13. Transport of Astyanax altiparanae Garutti and Britski, 2000 in saline water

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    Ana Lúcia Salaro

    2015-08-01

    Full Text Available Two experiments were performed. The first aimed to assess the tolerance of fingerlings Astyanax altiparanae to water salinity. Fish were exposed to salinity of 0, 3, 6, 9, 12 or 15 g NaCl L-1 for 96 hours. The fish mortality was 0%, in the levels of 0, 3 and 6 g L-1; 75% in the level of 9 g L-1and 100% at 12 and 15 g L-1 of common salt. The second experiment aimed to assess the parameters of water quality, mortality and blood glucose during transport. For this, A. altiparanae were stored in plastic bags at 22, 30 and 37 g of fish L-1 stocking densities and salinity of 0, 3, 6 and 9 g L-1, for. Fish showed similar mortality levels in the different salinities and stocking densities. The increase in fish density reduced the dissolved oxygen levels and salinity decreased the pH. The blood glucose levels were higher in those fish with 0 g L-1 salinity and higher stocking densities. The addition of salt to the water reduces the stress responses of A. altiparanae during transport.

  14. The lens controls cell survival in the retina: Evidence from the blind cavefish Astyanax.

    Science.gov (United States)

    Strickler, Allen G; Yamamoto, Yoshiyuki; Jeffery, William R

    2007-11-15

    The lens influences retinal growth and differentiation during vertebrate eye development but the mechanisms are not understood. The role of the lens in retinal growth and development was studied in the teleost Astyanax mexicanus, which has eyed surface-dwelling (surface fish) and blind cave-dwelling (cavefish) forms. A lens and laminated retina initially develop in cavefish embryos, but the lens dies by apoptosis. The cavefish retina is subsequently disorganized, apoptotic cells appear, the photoreceptor layer degenerates, and retinal growth is arrested. We show here by PCNA, BrdU, and TUNEL labeling that cell proliferation continues in the adult cavefish retina but the newly born cells are removed by apoptosis. Surface fish to cavefish lens transplantation, which restores retinal growth and rod cell differentiation, abolished apoptosis in the retina but not in the RPE. Surface fish lens deletion did not cause apoptosis in the surface fish retina or affect RPE differentiation. Neither lens transplantation in cavefish nor lens deletion in surface fish affected retinal cell proliferation. We conclude that the lens acts in concert with another optic component, possibly the RPE, to promote retinal cell survival. Accordingly, deficiency in both optic structures may lead to eye degeneration in cavefish.

  15. Differentially expressed genes identified by cross-species microarray in the blind cavefish Astyanax.

    Science.gov (United States)

    Strickler, Allen G; Jeffery, William R

    2009-03-01

    Changes in gene expression were examined by microarray analysis during development of the eyed surface dwelling (surface fish) and blind cave-dwelling (cavefish) forms of the teleost Astyanax mexicanus De Filippi, 1853. The cross-species microarray used surface and cavefish RNA hybridized to a DNA chip prepared from a closely related species, the zebrafish Danio rerio Hamilton, 1822. We identified a total of 67 differentially expressed probe sets at three days post-fertilization: six upregulated and 61 downregulated in cavefish relative to surface fish. Many of these genes function either in eye development and/or maintenance, or in programmed cell death. The upregulated probe set showing the highest mean fold change was similar to the human ubiquitin specific protease 53 gene. The downregulated probe sets showing some of the highest fold changes corresponded to genes with roles in eye development, including those encoding gamma crystallins, the guanine nucleotide binding proteins Gnat1 and Gant2, a BarH-like homeodomain transcription factor, and rhodopsin. Downregulation of gamma-crystallin and rhodopsin was confirmed by in situ hybridization and immunostaining with specific antibodies. Additional downregulated genes encode molecules that inhibit or activate programmed cell death. The results suggest that cross-species microarray can be used for identifying differentially expressed genes in cavefish, that many of these genes might be involved in eye degeneration via apoptotic processes, and that more genes are downregulated than upregulated in cavefish, consistent with the predominance of morphological losses over gains during regressive evolution.

  16. Comparative genetics of the central nervous system in epigean and hypogean Astyanax mexicanus.

    Science.gov (United States)

    Strickler, Allen G; Soares, Daphne

    2011-03-01

    The extreme environment of subterranean caves presents an adaptive challenge to troglobitic organisms. The mechanisms by which natural selection modify an ancestral surface neural circuit to produce a novel subterranean behavior remain a mystery. To address this question, we performed cross species microarray experiments to compare differences in gene expression levels in the adult brain of the teleost Astyanax mexicanus. This species provides a unique opportunity for comparative genetic studies as it consists of extant epigean (surface) and hypogean (cave) conspecifics. Microarray experiments herein revealed significant changes in transcription levels of seventeen genes, several of which are important for behaviors involved in metabolic management. We focused on genes central to three neurotransmission and neuromodulation networks: the endocannabinoid system (Cannabinoid receptor CB1), the dopaminergic system (Tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein) and the glutamatergic system (glutamate receptor AMPA 2a). All three genes were upregulated in the hypogean form of A. mexicanus compared to the epigean form, indicating that behavioral differences in the hypogean form of the species could be due to alterations in expression levels of several key genes. This information provides insights into the complex relationships among environmental factors, genetics, nervous systems and adaptive behavior, and can subsequently help us understand how these interactions affect behavior in other biological systems.

  17. Histological alterations in liver and testis of Astyanax aff. bimaculatus caused by acute exposition to zinc

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    Daiane Cristina Marques dos Santos*

    2015-04-01

    Full Text Available This study investigated the effect of acute exposition to zinc (Zn on histology of the liver and testes of yellow tail lambari (Astyanax aff. bimaculatus. The exposure consisted of six concentrations of Zn (0, 3, 5, 10, 15, and 20 mg/L for 96 hours of exposure. Fragments of liver and testis were routinely processed and embedded in plastic resin based on glycol methacrylate. Fragments of bones, muscles, liver and testis were dehydrated and digested to quantify the absorption levels of Zn in the tissue. Acute exposure to concentrations above 10mg/L has produced structural changes in the liver and gonads. The changes found in the liver were vascular congestion; decrease of cellular volume; displacement of the hepatocyte nucleus; necrosis; disarrangement of cordon structure; leukocyte infiltrate and vacuolization. The changes found in the gonads were ruptured cyst, delayed development of germ cells, pyknotic nucleus, cell cluster, displacement of cyst wall and vacuolization. The histological changes observed were compatible with the increasing concentration of zinc in environment, compromising liver and reproductive functions, because there was an increase in relative frequency of hepatocytes and reduced sperm production

  18. Convergent evolution of the red- and green-like visual pigment genes in fish, Astyanax fasciatus, and human.

    OpenAIRE

    Yokoyama, R; Yokoyama, S

    1990-01-01

    We have isolated and sequenced genes from the blind cave fish, Astyanax fasciatus, that are homologous to the human red and green visual pigment genes. The data strongly suggest that, like human, these fish have one red-like visual pigment gene and multiple green-like visual pigment genes. By comparing the DNA sequences of the human and fish visual pigment genes and knowing their phylogenetic relationship, one can infer the direction of amino acid substitutions in the red and green visual pig...

  19. Convergent evolution of the red- and green-like visual pigment genes in fish, Astyanax fasciatus, and human

    International Nuclear Information System (INIS)

    The authors have isolated and sequenced genes from the blind cave fish, Astyanax fasciatus, that are homologous to the human red and green visual pigment genes. The data strongly suggest that, like human, these fish have one red-like visual pigment gene and multiple green-like visual pigment genes. By comparing the DNA sequences of the human and fish visual pigment genes and knowing their phylogenetic relationship, one can infer the direction of amino acid substitutions in the red and green visual pigments. The results indicate that the red pigments in human and fish evolved from the green pigment independently by identical amino acid substitutions in only a few key positions

  20. Molecular cloning and expression analysis of dmrt1 and sox9 during gonad development and male reproductive cycle in the lambari fish, astyanax altiparanae

    NARCIS (Netherlands)

    Adolfi, Mateus C.; Carreira, Ana C O; Jesus, Lázaro W O; Bogerd, Jan; Funes, Rejane M.; Schartl, Manfred; Sogayar, Mari C.; Borella, Maria I.

    2015-01-01

    Background: The dmrt1 and sox9 genes have a well conserved function related to testis formation in vertebrates, and the group of fish presents a great diversity of species and reproductive mechanisms. The lambari fish (Astyanax altiparanae) is an important Neotropical species, where studies on molec

  1. Dactylogyrids (Monogenoidea) parasitizing the gills of Astyanax spp. (Characidae) from Panama and southeast Mexico, a new species of Diaphorocleidus and a proposal for Characithecium N. Gen.

    Science.gov (United States)

    Mendoza-Franco, Edgar F; Reina, Ruth G; Torchin, Mark E

    2009-02-01

    Diaphorocleidus orthodusus n. sp. and Diaphorocleidus kabatai (Molnar, Hanek and Fernando, 1974) Jogunoori, Kritsky, and Venkatanarasaiah, 2004 are detailed from Astyanax orthodus and Astyanax aeneus, respectively. Palombitrema heteroancistrium (Price and Bussing, 1968) is described from specimens collected from A. aeneus, and Urocleidoides strombicirrus (Price and Bussing, 1967) is reported for the first time from A. aeneus and Astyanax fasciatus in Panama. Characithecium costaricensis (Price and Bussing, 1967) n. comb. is detailed based on specimens from A. aeneus. Characithecium costaricensis is characterized by having overlapping gonads, a medioventral vaginal aperture, a copulatory complex consisting of single counterclockwise coil of the copulatory organ that is articulated to the accessory piece, and a haptor having 2 pairs of anchors, dorsal and ventral bars, and 14 hooks. Measurements of body size varied substantially among individual worms, both within and across different host species and locations. However, the morphological differences were insufficient to separate species of Characithecium. This result suggests limited parasite speciation across sympatric species of Astyanax in Mexico and Panama. PMID:19245277

  2. Gene flow and population structure in the Mexican blind cavefish complex (Astyanax mexicanus

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    Bradic Martina

    2012-01-01

    Full Text Available Abstract Background Cave animals converge evolutionarily on a suite of troglomorphic traits, the best known of which are eyelessness and depigmentation. We studied 11 cave and 10 surface populations of Astyanax mexicanus in order to better understand the evolutionary origins of the cave forms, the basic genetic structuring of both cave and surface populations, and the degree to which present day migration among them affects their genetic divergence. Results To assess the genetic structure within populations and the relationships among them we genotyped individuals at 26 microsatellite loci. We found that surface populations are similar to one another, despite their relatively large geographic separation, whereas the cave populations are better differentiated. The cave populations we studied span the full range of the cave forms in three separate geographic regions and have at least five separate evolutionary origins. Cave populations had lower genetic diversity than surface populations, correlated with their smaller effective population sizes, probably the result of food and space limitations. Some of the cave populations receive migrants from the surface and exchange migrants with one another, especially when geographically close. This admixture results in significant heterozygote deficiencies at numerous loci due to Wahlund effects. Cave populations receiving migrants from the surface contain small numbers of individuals that are intermediate in both phenotype and genotype, affirming at least limited gene flow from the surface. Conclusions Cave populations of this species are derived from two different surface stocks denoted "old" and "new." The old stock colonized caves at least three times independently while the new stock colonized caves at least twice independently. Thus, the similar cave phenotypes found in these caves are the result of repeated convergences. These phenotypic convergences have occurred in spite of gene flow from surface

  3. Origin of B chromosomes in the genus Astyanax (Characiformes, Characidae) and the limits of chromosome painting.

    Science.gov (United States)

    de A Silva, Duílio M Z; Daniel, Sandro Natal; Camacho, Juan Pedro M; Utsunomia, Ricardo; Ruiz-Ruano, Francisco J; Penitente, Manolo; Pansonato-Alves, José Carlos; Hashimoto, Diogo Teruo; Oliveira, Claudio; Porto-Foresti, Fábio; Foresti, Fausto

    2016-06-01

    Eukaryote genomes are frequently burdened with the presence of supernumerary (B) chromosomes. Their origin is frequently investigated by chromosome painting, under the hypothesis that sharing the repetitive DNA sequences contained in the painting probes is a sign of common descent. However, the intragenomic mobility of many anonymous DNA sequences contained in these probes (e.g., transposable elements) adds high uncertainty to this conclusion. Here we test the validity of chromosome painting to investigate B chromosome origin by comparing its results for seven B chromosome types in two fish species genus Astyanax, with those obtained (1) by means of the physical mapping of 18S ribosomal DNA (rDNA), H1 histone genes, the As51 satellite DNA and the (AC)15 microsatellite, and (2) by comparing the nucleotide sequence of one of these families (ITS regions from ribosomal DNA) between genomic DNA from B-lacking individuals in both species and the microdissected DNA from two metacentric B chromosomes found in these same species. Intra- and inter-specific painting suggested that all B chromosomes that were assayed shared homologous DNA sequences among them, as well as with a variable number of A chromosomes in each species. This finding would be consistent with a common origin for all seven B chromosomes analyzed. By contrast, the physical mapping of repetitive DNA sequences failed to give support to this hypothesis, as no more than two B-types shared a given repetitive DNA. Finally, sequence analysis of the ITS regions suggested that at least some of the B chromosomes could have had a common origin.

  4. Histological alterations in gills of Astyanax aff. bimaculatus caused by acute exposition to zinc.

    Science.gov (United States)

    dos Santos, Daiane Cristina Marques; da Matta, Sérgio Luis Pinto; de Oliveira, Juraci Alves; dos Santos, Jorge Abdala Dergam

    2012-11-01

    Increasing contamination of aquatic ecosystems by metals has caused various morphological, physiological and biochemical changes in aquatic organisms, and the gills of fish are recognized as indicators of environmental quality. In this context, the present work proposed to study the effects of different concentrations of zinc (Zn) in the histology of gills of yellow tail lambari (Astyanax aff. bimaculatus) after acute exposure. Seventy-two adult males of A. aff. bimaculatus were used, the treatments were six concentrations of Zn: 0; 3; 5; 10; 15; and 20 mg/L of water, by 96 h, and gills, muscle and bone fragments were removed. Fragments of gills were fixed and included, sectioned in a rotary microtome and stained with toluidin blue. Fragments of bone, muscle and gills were dehydrated and digested to quantify the absorption of Zn. The median lethal concentration (LC(50)) 96 h after Zn acute exposure was 10 mg/L of water. Noteworthy, Zn was highly toxic in acute exposure trials starting at the concentration 5 mg/L. The exposure of fish to the metal caused branchial histopathological changes correlated with increasing concentration, caused the death of fish at concentrations of 10, 15 and 20 mg/L. The histological alterations observed in the gills were hyperplasia, lamellar fusion, aneurysm, destruction of the lamellar epithelium, rupture of membrane, deletion of secondary lamellar high, which presented more severity in treatments exposed to the highest concentrations. In conclusion, gills of A. aff. bimaculatus presented profound histological alterations as a result of Zn exposure, and hence, proved to be excellent indicators of environmental contamination.

  5. O lambari Astyanax altiparanae (Characidae pode ser um dispersor de sementes? - DOI: 10.4025/actascibiolsci.v25i2.2045 Can lambari, Astyanax altiparanae (Characidae, be a seed disperser? - DOI: 10.4025/actascibiolsci.v25i2.2045

    Directory of Open Access Journals (Sweden)

    Leandro Muller Gomiero

    2003-04-01

    Full Text Available Este trabalho caracterizou a alimentação natural de Astyanax altiparanae na sub-bacia do rio Corumbataí e bacia do rio Jacaré-pepira, com enfoque principal na ingestão de sementes de Croton urucurana. Os itens alimentares de Astyanax altiparanae, em ordem decrescente de Grau de Preferência Alimentar (GPA, foram: insetos alóctones, restos de insetos, material vegetal alóctone, sementes de Croton urucurana, insetos autóctones, sedimentos, material vegetal autóctone, escamas, ovócitos e aracnídeos. Sementes de Croton urucurana ocorreram no verão, época de cheia dos rios. Sugere-se que Astyanax altiparanae seja um dispersor secundário das sementes de Croton urucurana, sendo que a intensidade e a efetividade dessa dispersão devem, ainda, ser investigadasThis work characterized the feeding of Astyanax altiparanae in the sub-basin of Corumbataí river and in the basin of Jacaré-pepira river with a focus on the ingestion of Croton urucurana seeds. The food items of Astyanax altiparanae were, in decreasing APD (Alimentary Preference Degree order: allochthonous insects, allochthonous plant material, Croton urucurana seeds, autochthonous insects, sediments, autochthonous plant material, scales, oocytes and arachnidans. Croton urucurana seeds occurred during the summer, in the flood period. Lambari, Astyanax altiparanae, could be a secondary disperser of Croton urucurana seeds, however, the intensity and effectiveness of this dispersion may be still investigated

  6. The forebrain of the blind cave fish Astyanax hubbsi (Characidae). I. General anatomy of the telencephalon.

    Science.gov (United States)

    Riedel, G

    1997-01-01

    This paper presents a survey of the cell groups in the telencephalon of the teleost Astyanax hubbsi, based on series of transverse sections stained with the Nissl-Klüver-Barrera and Bodian procedures. The work was conducted for two reasons. Firstly, it was intended to determine the contribution of the forebrain of blind cave fish to certain forms of behavior. An understanding of the anatomy of the telencephalic organization is essential for such a neuroethological approach. The second purpose was to provide the cytoarchitectural basis for the experimental analysis of the fiber connectivity of the telencephalon of A. hubbsi. Furthermore, information about the forebrain of characids is widely lacking, and this study may thus provide important knowledge about the cellular organization of characid forebrains for comparative anatomists. The brain of A. hubbsi is slender and elongated. Both optic nerves and optic tectum are reduced. Three longitudinal sulci-s. ypsiliformis, s. externus and s. limitans telencephali-can be distinguished in the telencephalon. A fiber lamina reaching from the s. externus to the s. limitans telencephali separates the area dorsalis (D) from the area ventralis telencephali (V). The two hemispheres are connected by fibers decussating in the anterior commissure. Although cross sections revealed no distinct fiber laminae between cytoarchitectonic components, 17 cell masses could be delineated: ten of these belong to D, seven to V. The topological analysis yielded the following results. The dorsal telencephalon D consists of three longitudinal columns, termed pars medialis (Dm), pars dorsalis and centralis (Dd and Dc) considered together, and par lateralis (Dl), which converge into a uniform posterior part (Dp). The columns can be divided into several subregions: Dm1 and Dm2, as well as Dlv and Dld, precommissurally, Dm3 and Dm4 postcommisurally. At polus posterior levels nucleus tenia can be identified. The ventral telencephalon (V) is arranged

  7. Discrimination of Astyanax altiparanae (Characiformes, Characidae) populations by applying Fourier transform-infrared photoacoustic spectroscopy in the fish scales

    Science.gov (United States)

    de Almeida, F. S.; Santana, C. A.; Lima, D. M. V.; Andrade, L. H. C.; Súarez, Y. R.; Lima, S. M.

    2016-05-01

    Astyanax altiparanae fish species is considered very generalist and opportunist, occupying different types and sizes of environments. This characteristic turns it very appropriate as bioindicator or biomarked. Therefore, in this work, A. altiparanae fish species was used to identify populations by using the Fourier transform infrared spectroscopy directly in its scales. The discriminant analysis applied in the infrared spectra demonstrated a significant differentiation among the analyzed populations, with the first and second canonical roots explain together 100% of the data variation. The obtained results were correlated with environmental descriptors and diet of fishes, and a better agreement was obtained when spectroscopic data were compared with the composition of food present in the fish stomachs. However, this study indicates that the combination of infrared absorption spectroscopy with discriminant analysis is a very appropriate methodology to be used in fish scales as bioindicator for intraspecific study.

  8. A multi-approach analysis of the genetic diversity in populations of Astyanax aff. bimaculatus Linnaeus, 1758 (Teleostei: Characidae) from Northeastern Brazil

    OpenAIRE

    Vanessa de Carvalho Cayres Pamponet; Paulo Luiz Souza Carneiro; Paulo Roberto Antunes de Mello Affonso; Viviam Souto Miranda; Juvenal Cordeiro Silva Júnior; Claudine Gonçalves de Oliveira; Fernanda Amato Gaiotto

    2008-01-01

    Few reports are available about the ichthyofauna of typical semi-arid rivers, although the regional diversity has been constantly threatened by human activities, mainly related to impoundment and construction of dams. The goal of the present work was to evaluate using different methods, the population genetic structure of a characin fish, Astyanax aff. bimaculatus, widespread throughout hydrographic basins of Bahia, Northeastern Brazil. Morphological (meristic and morphometric data), cytogene...

  9. A Potential Benefit of Albinism in Astyanax Cavefish: Downregulation of the oca2 Gene Increases Tyrosine and Catecholamine Levels as an Alternative to Melanin Synthesis

    OpenAIRE

    Helena Bilandžija; Li Ma; Amy Parkhurst; Jeffery, William R

    2013-01-01

    Albinism, the loss of melanin pigmentation, has evolved in a diverse variety of cave animals but the responsible evolutionary mechanisms are unknown. In Astyanax mexicanus, which has a pigmented surface dwelling form (surface fish) and several albino cave-dwelling forms (cavefish), albinism is caused by loss of function mutations in the oca2 gene, which operates during the first step of the melanin synthesis pathway. In addition to albinism, cavefish have evolved differences in behavior, incl...

  10. Molecular cloning and expression analysis of dmrt1 and sox9 during gonad development and male reproductive cycle in the lambari fish, Astyanax altiparanae

    OpenAIRE

    Adolfi, Mateus C.; Carreira, Ana C O; Lázaro W.O. Jesus; Bogerd, Jan; Funes, Rejane M.; Schartl, Manfred; Sogayar, Mari C.; Borella, Maria I.

    2015-01-01

    Background: The dmrt1 and sox9 genes have a well conserved function related to testis formation in vertebrates, and the group of fish presents a great diversity of species and reproductive mechanisms. The lambari fish (Astyanax altiparanae) is an important Neotropical species, where studies on molecular level of sex determination and gonad maturation are scarce. Methods: Here, we employed molecular cloning techniques to analyze the cDNA sequences of the dmrt1 and sox9 genes, and describe the ...

  11. Light microscopy and ultrastructure ight of the liver of Astyanax altiparanae Garutti and Britski, 2000 (Teleostei, Characidae = Histologia e ultraestrutura do fígado de Astyanax altiparanae Garutti e Britski, 2000 (Teleostei, Characidae

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    Bruno Bertolucci

    2008-01-01

    Full Text Available Livers of thirty specimens of Astyanax altiparanae obtained from a commercial fish farm were subjected to light and transmission electron microscopy, in order to describe the hepatic parenchyma and the intrahepatic exocrine pancreatic tissue. Anatomically, theliver showed only three hepatic lobes. Histological analysis demonstrated that the hepatocytes were spread out as anastomotic cords, arranged in two cellular layers and surrounded by sinusoids. The intrahepatic exocrine pancreatic tissue exhibited an acinararrangement and was diffused in the hepatic parenchyma. Ultrastructural analysis showed that the hepatocytes had a rounded nucleus and a rough endoplasmatic reticulum, with a parallel disposition to the nuclear membrane. The exocrine pancreatic cells showed secretion granules at the apical portion, and the rough endosplasmatic reticulum was concentrically distributed.Fígados de 30 exemplares de Astyanax altiparanae, obtidos de pesqueiros, foram submetidos à microscopia de luz e à microscopia eletrônica de transmissão para descrição do parênquima hepático e do tecido pancreático exócrino intrahepático. Anatomicamente, o fígado apresenta somente três lobos hepáticos. A análise histológica demonstra que os hepatócitos se encontram arranjados na forma de cordões anastomosados, dispostos em duas camadas celulares, sendo que estes estão cercados por sinusóides. O tecido pancreático exócrino intra-hepático apresenta arranjo acinar difuso pelo parênquima hepático. A análise ultraestrutural demonstra que os hepatócitos possuem um núcleo arredondado e retículo endoplasmático rugoso, com disposição paralela à membrana nuclear. As células pancreáticas exócrinas apresentam grânulos de secreção na porção apical e retículo endoplasmático rugoso com distribuição concêntrica.

  12. Comentários sobre a distribuição geográfica de Astyanax altiparanae Garutti & Britski, 2000 (Osteichthyes, Characidae na bacia do rio Iguaçu Astyanax altiparanae Garutti & Britski, 2000 (Osteichthyes, Characidae in the Iguaçu River basin

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    Weferson Júnio da Graça

    2002-05-01

    Full Text Available Garutti (1995 fez a revisão de algumas espécies de Astyanax (Osteichthyes, Characidae e aquela, conhecida como “tambiú” na bacia do alto rio Paraná, anteriormente identificada como Astyanax bimaculatus, foi considerada nova e posteriormente descrita por Garutti & Britski (2000 como Astyanax altiparanae (Pisces, Characiformes. Naquela oportunidade, entretanto, não foram analisados exemplares da bacia do rio Iguaçu. Esse afluente do rio Paraná apresenta um alto grau de endemismo em sua ictiofauna devido ao isolamento geográfico causado pelas cataratas situadas próximo à sua foz. No entanto, muitas dúvidas relacionadas ao status específico da população da bacia do Iguaçu, também chamada de A. bimaculatus antes dos trabalhos de Garutti, permaneceram. Com o escopo de verificar se a população do Iguaçu era da espécie A. altiparanae, comparamos espécimes das duas bacias e concluímos que elas pertencem à mesma espécie, sendo, portanto, sua distribuição geográfica ampliada.Garutti (1995 made a revision of some Astyanax (Osteichthyes, Characidae species and the species called tambiú from the upper Paraná River basin, formerly identified as Astyanax bimaculatus, was considered new. Garutti & Britski (2000 later described it as Astyanax altiparanae (Pisces, Characiformes. However, they did not analyze specimens from the Iguaçu River basin at that time. The Iguaçu River, affluent to the Paraná River, has a high degree of endemism in its ichthyofauna because of the geographic isolation caused by the falls near its mouth. Thus, there were still many doubts regarding the specific status of the population from the Iguaçu River basin, also called A. bimaculatus before Garutti’s studies. To verify if the population from the Iguaçu River belongs to the A. altiparanae species, we compared specimens from both basins and concluded that they belong to the same species, widening their geographic distribution.

  13. The sensitivity of lateral line receptors and their role in the behavior of Mexican blind cavefish (Astyanax mexicanus).

    Science.gov (United States)

    Yoshizawa, Masato; Jeffery, William R; van Netten, Sietse M; McHenry, Matthew J

    2014-03-15

    The characid fish species Astyanax mexicanus offers a classic comparative model for the evolution of sensory systems. Populations of this species evolved in caves and became blind while others remained in streams (i.e. surface fish) and retained a functional visual system. The flow-sensitive lateral line receptors, called superficial neuromasts, are more numerous in cavefish than in surface fish, but it is unclear whether individual neuromasts differ in sensitivity between these populations. The aims of this study were to determine whether the neuromasts in cavefish impart enhanced sensitivity relative to surface fish and to test whether this aids their ability to sense flow in the absence of visual input. Sensitivity was assessed by modeling the mechanics and hydrodynamics of a flow stimulus. This model required that we measure the dimensions of the transparent cupula of a neuromast, which was visualized with fluorescent microspheres. We found that neuromasts within the eye orbit and in the suborbital region were larger and consequently about twice as sensitive in small adult cavefish as in surface fish. Behavioral experiments found that these cavefish, but not surface fish, were attracted to a 35 Hz flow stimulus. These results support the hypothesis that the large superficial neuromasts of small cavefish aid in flow sensing. We conclude that the morphology of the lateral line could have evolved in cavefish to permit foraging in a cave environment.

  14. Analysis by RAPD of the genetic structure of Astyanax altiparanae (Pisces, Characiformes in reservoirs on the Paranapanema River, Brazil

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    Maria Sueli Papa Leuzzi

    2004-01-01

    Full Text Available In this study, the RAPD technique was used to analyze the genetic structure of populations of the fish Astyanax altiparanae (Characidae, Tetragonopterinae living in the lower, middle and upper Paranapanema River, Brazil. The aim was to assess this structure regarding fish handling and conservation programs. The genetic variability (P was found to be 42.64%, 75% and 75% in the low, middle and upper reaches, respectively. The dendrogram of genetic similarity, obtained by comparative analysis of the sets of samples from the three sites, showed the formation of three clusters. All of the genetic parameters used indicate that the population in the lower Paranapanema is genetically different from those in the middle and upper sections. The theta P test shows that the low Paranapanema is highly differentiated from the middle (0.2813 and upper (0.2912 Paranapanema, while the differentiation between the last two is moderate (0.0895. The data obtained in the present work suggest that recolonization and conservation studies should not be focused on the species A. altiparanae as such, but on the conservation units, because they are the genetically differentiated populations.

  15. Tissue levels of the antioxidant enzymes superoxide dismutase and catalase in fish Astyanax bimaculatus from the Una River Basin

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    Maria Tereza Oliveira Batista

    2014-10-01

    Full Text Available STRACT This paper seeks to identify the biomarker response to oxidative stress in Astyanax bimaculatus, a freshwater fish, collected from the Una River and its associated water bodies. The fish were collected using fishing nets at three different points on the river basin, namely Fazenda Piloto (FP, Ipiranga (IP and Remédios (RM, during the period from December 2013 to March 2014. Physical and chemical analyses of the water at the sample locations indicate that IP and RM possibly have larger concentration of either natural or anthropic pollutants as compared to FP. FP can therefore be considered as the point less impacted by pollutants than other points. Hepatic activity of antioxidant stress enzymes, superoxide dismutase (SOD and catalase (CAT, were measured in the specimens. The levels of SOD were reduced at RM while they were elevated in fish collected at IP. The CAT levels for the fish at RM and IP were about 148.9% and 202.4% above the values at FP, respectively. These results suggest that antioxidant enzymes could be used as biomarkers to measure oxidative stress caused by pollutants in the Una River Basin.

  16. Spatial and temporal biomarkers responses of Astyanax jacuhiensis (Cope, 1894(Characiformes: Characidae from the middle rio Uruguai, Brazil

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    Vania Lucia Loro

    2015-09-01

    Full Text Available Due to intense agricultural activity in the rio Uruguai (South Brazil, there is the potential for aquatic contamination by agrochemicals. In this region, there are many reservoirs to meet the water demand for rice fields, forming lentic environments. In line with this information, the aim of this study was to show a comparative analysis of some biomarkers, such as lipid peroxidation (TBARS, gluthatione S-transferase (GST, non-protein thiols (NPSH, amino acids (AA and piscine micronucleus tests (MNE in Astyanax jacuhiensis from lentic and lotic environments in the middle rio Uruguai region, comparing warm and cold seasons. Eight pesticides were found in water samples, with propoxur having the highest concentration found in both environments and seasons. Fish from the warm season showed higher levels of biochemical biomarkers, and fish from the cold season showed higher levels of MNE and AA. TBARS and AA presented higher levels in fish from the river, while GST, NPSH, MNE and AA presented higher levels in fish from dams. These environments have different characteristics in terms of redox potential, aeration, sedimentation, trophic structure, agrochemicals input and others, which may affect the physiological and biochemical responses of fish in against adverse situations.

  17. Estimation of the dietary essential amino acid requirements of colliroja Astyanax fasciatus by using the ideal protein concept

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    Wilson Massamitu Furuya

    2015-11-01

    Full Text Available Colliroja, Astyanax fasciatus, is a new aquaculture species, and information on its dietary essential amino acid requirements is lacking. The whole body composition of 120 farmed fish (16.2 ± 8.8 g was determined to estimate the dietary essential amino acid requirement based on the ideal protein concept ((each essential amino acid/lysine x100, and the findings were correlated to the whole body essential amino acid content of Nile tilapia Oreochromis niloticus. The dietary essential amino acids, including cysteine and tyrosine, accounted for 5.46, 4.62, 1.16, 3.28, 5.63, 2.01, 2.59, 2.84, 4.66, 3.39, 0.65, and 3.51% of the total protein for lysine, arginine, histidine, isoleucine, leucine, methionine, methionine+tyrosine, phenylalanine, phenylalanine+tyrosine, threonine, tryptophan, and valine, respectively. There were positive linear and high correlations (r = 0.971 between the whole body amino acid profiles of colliroja and Nile tilapia. Thus, the whole body amino acid profile of colliroja might be used to estimate accurately the essential amino acid requirement.

  18. Three sympatric karyomorphs in the fish Astyanax fasciatus (Teleostei, Characidae do not seem to hybridize in natural populations

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    Maressa Ferreira-Neto

    2012-01-01

    Full Text Available Ninety individuals of the characid fish Astyanax fasciatus (Cuvier, 1819 were collected at Água da Madalena stream (Botucatu, São Paulo, Brazil and analyzed for diploid chromosome number 2n and karyotype composition as well as for the chromosomal location of the 5S and 18S ribosomal DNA (rDNA. Whereas no chromosome differences were associated with sex, three different karyomorphs with diploid chromosome numbers 2n=46, 2n=48 and 2n=50 were found. No intermediate 2n numbers were discovered. The 2n=50 karyomorph showed some differences in 18S rDNA location compared to the two other karyomorphs. Finally, all specimens with the 2n=46 karyomorph showed the presence of a partly heterochromatic macro supernumerary chromosome, which was absent in all individuals with the two other karyomorphs. All these results suggest that indviduals of the three different karyomorphs are not likely to hybridize in the examined populations. Our findings strongly suggest the presence of three separate species (sensu biological species concept easily diagnosed on the basis of differences in the diploid chromosome numbers and other chromosomal markers.

  19. A potential benefit of albinism in Astyanax cavefish: downregulation of the oca2 gene increases tyrosine and catecholamine levels as an alternative to melanin synthesis.

    Science.gov (United States)

    Bilandžija, Helena; Ma, Li; Parkhurst, Amy; Jeffery, William R

    2013-01-01

    Albinism, the loss of melanin pigmentation, has evolved in a diverse variety of cave animals but the responsible evolutionary mechanisms are unknown. In Astyanax mexicanus, which has a pigmented surface dwelling form (surface fish) and several albino cave-dwelling forms (cavefish), albinism is caused by loss of function mutations in the oca2 gene, which operates during the first step of the melanin synthesis pathway. In addition to albinism, cavefish have evolved differences in behavior, including feeding and sleep, which are under the control of the catecholamine system. The catecholamine and melanin synthesis pathways diverge after beginning with the same substrate, L-tyrosine. Here we describe a novel relationship between the catecholamine and melanin synthesis pathways in Astyanax. Our results show significant increases in L-tyrosine, dopamine, and norepinephrine in pre-feeding larvae and adult brains of Pachón cavefish relative to surface fish. In addition, norepinephrine is elevated in cavefish adult kidneys, which contain the teleost homologs of catecholamine synthesizing adrenal cells. We further show that the oca2 gene is expressed during surface fish development but is downregulated in cavefish embryos. A key finding is that knockdown of oca2 expression in surface fish embryos delays the development of pigmented melanophores and simultaneously increases L-tyrosine and dopamine. We conclude that a potential evolutionary benefit of albinism in Astyanax cavefish may be to provide surplus L-tyrosine as a precursor for the elevated catecholamine synthesis pathway, which could be important for adaptation to the challenging cave environment.

  20. A potential benefit of albinism in Astyanax cavefish: downregulation of the oca2 gene increases tyrosine and catecholamine levels as an alternative to melanin synthesis.

    Directory of Open Access Journals (Sweden)

    Helena Bilandžija

    Full Text Available Albinism, the loss of melanin pigmentation, has evolved in a diverse variety of cave animals but the responsible evolutionary mechanisms are unknown. In Astyanax mexicanus, which has a pigmented surface dwelling form (surface fish and several albino cave-dwelling forms (cavefish, albinism is caused by loss of function mutations in the oca2 gene, which operates during the first step of the melanin synthesis pathway. In addition to albinism, cavefish have evolved differences in behavior, including feeding and sleep, which are under the control of the catecholamine system. The catecholamine and melanin synthesis pathways diverge after beginning with the same substrate, L-tyrosine. Here we describe a novel relationship between the catecholamine and melanin synthesis pathways in Astyanax. Our results show significant increases in L-tyrosine, dopamine, and norepinephrine in pre-feeding larvae and adult brains of Pachón cavefish relative to surface fish. In addition, norepinephrine is elevated in cavefish adult kidneys, which contain the teleost homologs of catecholamine synthesizing adrenal cells. We further show that the oca2 gene is expressed during surface fish development but is downregulated in cavefish embryos. A key finding is that knockdown of oca2 expression in surface fish embryos delays the development of pigmented melanophores and simultaneously increases L-tyrosine and dopamine. We conclude that a potential evolutionary benefit of albinism in Astyanax cavefish may be to provide surplus L-tyrosine as a precursor for the elevated catecholamine synthesis pathway, which could be important for adaptation to the challenging cave environment.

  1. Genetic variability in Astyanax altiparanae Garutti & Britski, 2000 (Teleostei, Characidae from the Upper Paraná River basin, Brazil

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    Maria Dolores Peres

    2005-12-01

    Full Text Available Allozyme data was used to assess the genetic diversity Astyanax altiparanae populations from the floodplain of the Upper Paraná River (PR. Specimens were collected in the southern Brazilian state of Paraná from PR in Porto Rico municipality and Ribeirão Ficha (RF in Ubiratã municipality. The authors used 15% (w/v corn starch gel electrophoresis to identify 21 putative loci for 13 enzymatic systems: Aspartate aminotransferase, 2.6.1.1 (AAT, Acid phosphatase, 3.1.3.2 (ACP, Esterase, 3.1.1.1 (EST, Glycerol-3-phosphate dehydrogenase, 1.1.1.8 (G3PDH, Glucose-6-phosphate dehydrogenase, 1.1.1.49 (G6PDH, Glucose-6-phosphate isomerase, 5.3.1.9 (GPI, Iditol dehydrogenase, 1.1.1.14 (IDDH, Isocitrate dehydrogenase - NADP+, 1.1.1.42 (IDH, L-Lactate dehydrogenase, 1.1.1.27 (LDH, Malate dehydrogenase, 1.1.1.37 (MDH, Malate dehydrogenase - NADP+, 1.1.1.40 (MDHP, Phosphoglucomutase, 5.4.2.2 (PGM, and Superoxide dismutase, 1.15.1.1 (SOD. The proportion of polymorphic loci were estimated as 52.38% in the PR population and 38.10% in the RF population. Expected estimated heterozygosities were 0.1518 ± 0.0493 for the PR population and 0.0905 ± 0.0464 for the RF population. The A. altiparanae heterozygosity data were similar to previous estimates for other PR basin characid species. Allele frequencies were significantly different between the PR and RF populations in respect to some loci (Acp-1, G3pdh-1, Gpi-A, Iddh-1, Mdhp-1 and Mdhp-2. Wright’s statistics for all loci were estimated as Fis = 0.3919, Fit = 0.4804 and Fst = 0.1455. Our results show that the A. altiparanae populations studied are genetically different and have a high degree of genetic variability.

  2. DNA sequences of troglobitic nicoletiid insects support Sierra de El Abra and the Sierra de Guatemala as a single biogeographical area: Implications for Astyanax

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    Luis Espinasa

    2014-03-01

    Full Text Available The blind Mexican tetra fish, Astyanax mexicanus, has become the most influential model for research of cave adapted organisms. Many authors assume that the Sierra de Guatemala populations and the Sierra de El Abra populations are derived from two independent colonizations. This assumption arises in part from biogeography. The 100 m high, 100 m wide Servilleta Canyon of the Boquillas River separates both mountain ranges and is an apparent barrier for troglobite dispersion. Anelpistina quinterensis (Nicoletiidae, Zygentoma, Insecta is one of the most troglomorphic nicoletiid silverfish insects ever described. 16S rRNA sequences support that this species migrated underground to reach both mountain ranges within less than 12,000 years. Furthermore, literature shows a plethora of aquatic and terrestrial cave restricted species that inhabit both mountain ranges. Thus, the Servilleta canyon has not been an effective biological barrier that prevented underground migration of troglobites between the Sierra de Guatemala and the Sierra de El Abra. The Boquillas River has changed its course throughout time. Caves that in the past connected the two Sierras were only recently geologically truncated by the erosion of the new river course. It is likely that, with the geological changes of the area and throughout the 2-8 million years of evolutionary history of cave Astyanax, there have been opportunities to migrate across the Servilleta canyon.

  3. Chromosomal characterization in two species of an Astyanax bimaculatus complex (Characidae, Characiformes) using different techniques of chromosome banding.

    Science.gov (United States)

    Da Silva, Laura L L; Dos Santos, Angélica R; Giuliano-Caetano, Lucia; Dias, Ana L

    2016-08-01

    Astyanax has been the subject of extensive cytogenetic studies due to its wide karyotypic diversity. This genus comprises species complexes, namely groups of fish of difficult morphological differentiation, such as the bimaculatus complex, which includes the characids with a rounded humeral spot. Thence, the present study proposed to accomplish a cytogenetic characterization of two species of this complex: A. asuncionensis and A. altiparanae, aiming to find chromosomal markers that differentiate these species, as well as achieve a better understanding of the karyotype evolution in the genus. For this we used different techniques of chromosome banding as C-banding, impregnation by silver nitrate, fluorochrome staining and FISH with 18S rDNA probe. This is the first cytogenetic study in A. asuncionensis, from Miranda river, which presented 2n = 50 and 18 m + 22sm + 6st + 4a (FN = 96) and single NORs. The populations of A. altiparanae also presented 2n = 50, but with different karyotypic formulae: the population of the Quexada river presented 16 m + 24sm + 4st + 6a (FN = 94) and the Esperança stream and Jacutinga river showed 16 m + 20sm + 4st + 10a (FN = 90). All analyzed populations showed an interindividual variation in the number and location of the nucleolar organizer regions (NORs). Single and multiple NORs were detected either by impregnation with silver nitrate or by FISH with 18S rDNA probe. After C-banding, the two species differed in relation to the composition and heterochromatin distribution. The meiotic cells of A. altiparanae male individuals were also analyzed, showing that, despite the high karyotype variability, chromosome pairing occurs normally. The data show that A. altiparanae and A. asuncionensis share some characteristics with other species of the bimaculatus complex, suggesting a close phylogenetic relationship among those species. However, some features can be used as differentiation chromosomal markers in

  4. Spot the difference: Two cryptic species of Gyrodactylus von Nordmann, 1832 (Platyhelminthes: Monogenea) infecting Astyanax aeneus (Actinopterygii, Characidae) in Mexico.

    Science.gov (United States)

    Razo-Mendivil, Ulises; García-Vásquez, Adriana; Rubio-Godoy, Miguel

    2016-10-01

    Over the course of one year, undescribed specimens of Gyrodactylus were recovered from banded tetra, Astyanax aeneus collected in the La Antigua and Nautla river basins in central Veracruz, Mexico. Parasites were processed for morphometric and molecular analyses. Morphometrically, Gyrodactylus samples collected in the La Antigua river had slightly smaller haptoral structures than those collected from the Nautla river. During the 12month-collection of samples, however, water temperature varied considerably (ca. 20°C to 30°C), and this abiotic factor is known to affect the size of gyrodactylid attachment structures. Moreover, no clear discrimination was possible between individual parasites collected from the two rivers based on the morphology of the marginal hook, which is recognised as a very informative character to discriminate between species. The morphology of the ventral bar, however, differed between specimens from both rivers: worms from Nautla all had long, rounded processes on the ventral bar, which formed a relatively closed angle with the dorsal edge of the bar proper, while most - but not all - specimens from La Antigua had comparatively slender processes forming a more open angle with respect to the ventral bar. Phylogenetic analyses based on the sequences of the ITS1, 5.8S rRNA gene, and ITS2 of gyrodactylids indicated the existence of two distinct, well-supported lineages whose sequences differ by >4%, one of which was only found in the Nautla basin, while the other was collected in both river systems. A posteriori, principal component analysis (PCA) of the morphometric data of sequenced specimens indicated that features of the dorsal bar, the hamuli and the ventral bar enable discrimination between the two phylogenetic lineages. Based on these independent sources of information (morphometric and molecular data), two new species of Gyrodactylus are described: Gyrodactyluspakan n. sp. and Gyrodactylusteken n. sp. The phylogenetic relationships of

  5. Morphological and neurotoxicological findings in tropical freshwater fish (Astyanax sp.) after waterborne and acute exposure to water soluble fraction (WSF) of crude oil.

    Science.gov (United States)

    Akaishi, F M; de Assis, H C Silva; Jakobi, S C G; Eiras-Stofella, D R; St-Jean, S D; Courtenay, S C; Lima, E F; Wagener, A L R; Scofield, A L; Ribeiro, C A Oliveira

    2004-02-01

    The water-soluble fraction (WSF) of crude oil is a complex highly volatile and toxic mixture of hydrocarbon chains (polyaromatics, heterocyclics), phenols, and heterocyclic compounds containing nitrogen and sulfur. To evaluate the toxic effects of WSF in tropical freshwater teleosts and to develop methodologies that could investigate the toxic mechanisms of WSF in tropical organisms, an acute toxicity experiment was conducted with Astyanax sp. Three dilutions (15%, 33%, and 50%) of WSF obtained from Campos Bay's crude oil (Brazil) were used to study morphological and biochemical responses of the fish. Prior to exposure, the distribution and rate of volatilization of the WSF into each aquarium for the same exposure period was quantified by spectrofluorimetry. Five individuals of Astyvanax sp. were exposed to duplicate WSF of 0, 15, 33, and 50% for each of 12-, 24-, and 96-h exposures for a total of 120 individuals. Liver and gills were sampled from five fish from each treatment and were analyzed by histology, scanning and transmission electron microscopy. A fragment of muscle was also collected from each fish to measure acetylcholinesterase activity. Water analysis showed that only 4 h after dilution, an important loss of hydrocarbons in 33% and 50% of WSF was observed. In addition, 50% of hydrocarbon mass was lost in all tested dilutions after 24 h with significant difference for the 50% WSF at all measured times, demonstrating the high volatility of WSF in freshwater. Damage in the liver and the gills included the presence of necrosis, loss of hepatocytes limit, inflammation areas, cellular proliferation, aneurysms, and disorganization of the second lamellae. The 33% WSF significantly reduced acetylcholinesterase activity in fish. Our study demonstrated that the WSF of crude oil caused damage in organs and tissues of tropical freshwater Astyanax sp. and provided also the basis for a better understanding of the toxic mechanisms of WSF in freshwater fishes. PMID

  6. Population structure, reproductive biology and feeding of Astyanax fasciatus (Cuvier, 1819 in an Upper Paraná River tributary, Misiones, Argentina Estrutura populacional, biologia reprodutiva e alimentação de Astyanax fasciatus (Cuvier, 1819 em um tributário do alto Rio Paraná, Misiones, Argentina

    Directory of Open Access Journals (Sweden)

    Lourdes María Hirt

    2011-03-01

    Full Text Available AIM: The genus Astyanax is one of the richest in number of species and has one of the widest geographical distributions in Argentina, being possible to find in nine ichthyogeographic ecoregions. The aim of the present work was to analyze the population structure of Astyanax fasciatus in the Garupá Stream, Province of Misiones, Argentina, considering its distribution by size, standard length-total weight relationship and aspects of its reproductive and feeding biology; METHODS: A total of eight experimental fishing campaigns were carried out between September 2002 and May 2004, in agreement with the seasons of the year, using a set of gillnets; RESULTS: We captured a total of 386 individuals, 70% of which in the Middle Basin in autumn and winter. The following gonad stages were identified in both males and females: resting, maturing, mature and spawning. The highest gonadal activity corresponded to the autumn-winter period. The Middle Basin showed the highest capture of individuals in reproductive activity, thus reflecting the seasonality of spawning. The average fecundity was of 4000 oocytes, being 1100 µm the largest oocyte diameter. The mean standard length of the total catch was 99.3 mm and females reached larger sizes than males (P OBJETIVO: O gênero Astyanax é um dos mais ricos em número de espécies e tem uma das maiores distribuições geográficas na Argentina, sendo possível encontrar em nove ecorregiões ictiogeográfica. O objetivo do presente trabalho foi analisar a estrutura populacional de Astyanax fasciatus no arroio Garupá, Província de Misiones, na Argentina, considerando a sua distribuição por tamanho, relação peso-padrão de comprimento total e aspectos de sua biologia reprodutiva e alimentação; MÉTODOS: Foram realizadas oito operações de pescaria sazonais, entre setembro de 2002 e maio de 2004, com uma bateria de redes de emalhar; RESULTADOS: Foram capturados 386 indivíduos, 70% na Bacia Média no outono e

  7. A new species of Henneguya, a gill parasite of Astyanax altiparanae (Pisces: Characidae from Brazil, with comments on histopathology and seasonality

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    Barassa Bianca

    2003-01-01

    Full Text Available A new species of Myxosporea, Henneguya chydadea, is described parasitizing the gills of Astyanax altiparanae collected from a lake on Rio das Pedras farm near Campinas, state of São Paulo, Brazil. Of the fish examined, 88.3% had gills parasitized by myxosporeans. The prevalence of the parasite ranged from 80% in the spring and fall, 93% in the summer and 100% in the winter. The parasite induced the formation of white, oval-shaped cysts measuring 40-64 µm x 64-80 µm which deformed the gill lamellae, compressed the capillaries, and caused retraction of the neighboring lamellae. The mature spores were elongated and had two identical, parallel elongate polar capsules. Each capsule contained a polar filament with 9-10 turns. There was no mucous envelope or iodinophilous vacuole. Morphometric differences between this parasite and other species of the genus Henneguya indicated, that he parasite observed in A. altiparanae is a new species. This is the first report of a myxosporeanparasitizing A. altiparanae.

  8. Delimiting the origin of a B chromosome by FISH mapping, chromosome painting and DNA sequence analysis in Astyanax paranae (Teleostei, Characiformes.

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    Duílio M Z de A Silva

    Full Text Available Supernumerary (B chromosomes have been shown to contain a wide variety of repetitive sequences. For this reason, fluorescent in situ hybridisation (FISH is a useful tool for ascertaining the origin of these genomic elements, especially when combined with painting from microdissected B chromosomes. In order to investigate the origin of B chromosomes in the fish species Astyanax paranae, these two approaches were used along with PCR amplification of specific DNA sequences obtained from the B chromosomes and its comparison with those residing in the A chromosomes. Remarkably, chromosome painting with the one-arm metacentric B chromosome probe showed hybridization signals on entire B chromosome, while FISH mapping revealed the presence of H1 histone and 18S rDNA genes symmetrically placed in both arms of the B chromosome. These results support the hypothesis that the B chromosome of A. paranae is an isochromosome. Additionally, the chromosome pairs Nos. 2 or 23 are considered the possible B chromosome ancestors since both contain syntenic H1 and 18S rRNA sequences. The analysis of DNA sequence fragments of the histone and rRNA genes obtained from the microdissected B chromosomes showed high similarity with those obtained from 0B individuals, which supports the intraspecific origin of B chromosomes in A. paranae. Finally, the population hereby analysed showed a female-biased B chromosome presence suggesting that B chromosomes in this species could influence sex determinism.

  9. Spatial, seasonal and ontogenetic variation in the diet of Astyanax aff. fasciatus (Ostariophysi: Characidae in an Atlantic Forest river, Southern Brazil

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    Luciano Lazzarini Wolff

    2009-06-01

    Full Text Available This study described the feeding habits of the characin Astyanax aff. fasciatus. The diet compositions of specimens from two sites (A and B on a river in Southern Brazil were compared according to the size of individuals and seasonal period. The collections were performed monthly from March 2005 to February 2006, where the stomach contents of 290 specimens were assessed. Food items for A. aff. fasciatus were basically composed of plants and insects, especially leaf fragments, seeds, fruits, filamentous algae, aquatic and terrestrial insects and insect fragments. At site A, the most common items were insect and plant fragments. Conversely at site B, plant fragments were more representative. In general, all items of animal origin showed the highest feeding index values at site A, whereas at site B detritus and grass items were more abundant. The composition of items varied seasonally, with higher diversity of items being recorded during the spring at both sites. Smaller individuals preferred items of animal origin, while the larger ones consumed mainly items of plant origin. According to its size, A. aff. fasciatus in this study may be considered a species with insectivorous tendencies when immature or herbivorous tendencies when adult. Nevertheless, its feeding habits may be flexible according to resource availability, showing wide ontogenetic, besides spatial and temporal variation.Este estudo descreveu os hábitos alimentares do lambari Astyanax aff. fasciatus. Foram comparadas as composições alimentares de espécimes de dois sítios (A e B de um rio no sul do Brasil de acordo com o tamanho dos indivíduos e do período sazonal. As coletas foram realizadas mensalmente de março de 2005 a fevereiro de 2006, sendo o conteúdo estomacal de 290 exemplares analisado. A dieta de A. aff. fasciatus foi composta basicamente por plantas e insetos, especialmente fragmentos de folhas, sementes, frutos, algas filamentosas, insetos aquáticos e terrestres

  10. Histochemical and immunohistochemical study on endocrine cells (5HT, GAS, and SST) of the gastrointestinal tract of a teleost, the characin Astyanax bimaculatus.

    Science.gov (United States)

    Cardoso, Nathália das Neves; Firmiano, Enely Maris da Silveira; Gomes, Iracema D; do Nascimento, Aparecida A; Sales, Armando; Araújo, Francisco G

    2015-09-01

    Endocrine cells secrete hormones through the mucosa of the gastrointestinal tract (GIT) and act on the overall regulation of digestive processes such as nutrient absorption, gut motility and intestinal blood flow. This study aimed to determine regional distribution and frequency of endocrine cells secretory of serotonin (5-HT), somatostatin (SST) and gastrin (GAS) in the GIT of a small-bodied widespread characin Astyanax bimaculatus using histological, histochemical and immunohistochemical techniques. Fragments of the stomach and gut fixed for 8h in Bouin liquid were subjected to histological processing and immunohistochemical routine. For the histological analyses, the technique of staining with hematoxylin and eosin (HE) was used, whereas for the histochemical analyses Gomori's trichrome, periodic acid+Schiff (PAS) and Alcian blue pH 2.5 (AB) were used to further immunohistochemical processing. The stomach has a mucosa lined with a simple columnar epithelium with mucus-secreting cells; the glandular region (proximal and distal portions) has folds and pits, whereas the non-glandular region has pits only. The intestinal epithelium is simple with plain cylindrical grooved and goblet cells. The anterior region has thin folds with few goblet cells, and the posterior region with thick folds and many goblet cells. The regional distribution and frequency of endocrine cells varied across regions of the GIT with the stomach showing the highest amount of immunoreactive (IR) cells. Only the 5-HT was found in the stomach (epithelia and glands) and gut regions, with comparatively higher frequency in the stomach. SST-IR cells were found in the stomach (epithelia and gastric glands) with higher frequency in the glandular region, whereas GAS-IR were found in the gastric glands only. The stomach was the only organ to have all the three types of endocrine cells, indicating that this organ is the main site of digestion of food in this species. PMID:26073464

  11. A novel role for Mc1r in the parallel evolution of depigmentation in independent populations of the cavefish Astyanax mexicanus.

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    Joshua B Gross

    2009-01-01

    Full Text Available The evolution of degenerate characteristics remains a poorly understood phenomenon. Only recently has the identification of mutations underlying regressive phenotypes become accessible through the use of genetic analyses. Focusing on the Mexican cave tetra Astyanax mexicanus, we describe, here, an analysis of the brown mutation, which was first described in the literature nearly 40 years ago. This phenotype causes reduced melanin content, decreased melanophore number, and brownish eyes in convergent cave forms of A. mexicanus. Crosses demonstrate non-complementation of the brown phenotype in F(2 individuals derived from two independent cave populations: Pachón and the linked Yerbaniz and Japonés caves, indicating the same locus is responsible for reduced pigmentation in these fish. While the brown mutant phenotype arose prior to the fixation of albinism in Pachón cave individuals, it is unclear whether the brown mutation arose before or after the fixation of albinism in the linked Yerbaniz/Japonés caves. Using a QTL approach combined with sequence and functional analyses, we have discovered that two distinct genetic alterations in the coding sequence of the gene Mc1r cause reduced pigmentation associated with the brown mutant phenotype in these caves. Our analysis identifies a novel role for Mc1r in the evolution of degenerative phenotypes in blind Mexican cavefish. Further, the brown phenotype has arisen independently in geographically separate caves, mediated through different mutations of the same gene. This example of parallelism indicates that certain genes are frequent targets of mutation in the repeated evolution of regressive phenotypes in cave-adapted species.

  12. Reproductive biomarkers responses induced by xenoestrogens in the characid fish Astyanax fasciatus inhabiting a South American reservoir: An integrated field and laboratory approach

    Energy Technology Data Exchange (ETDEWEB)

    Prado, Paula S.; Pinheiro, Ana Paula B. [Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, C.P. 486, 30161-970, Minas Gerais (Brazil); Bazzoli, Nilo [Programa de Pós-Graduação em Zoologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, PUC Minas, Belo Horizonte 30535-610, Minas Gerais (Brazil); Rizzo, Elizete, E-mail: ictio@icb.ufmg.br [Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, C.P. 486, 30161-970, Minas Gerais (Brazil)

    2014-05-01

    Field studies evaluating the effects of endocrine disruption chemicals (EDCs) on the fish reproduction are scarce worldwide. The goal of this study was to assess hepatic levels of vitellogenin (Vtg), zona radiata proteins (Zrp) and insulin-like growth factors (IGF-I and IGF-II), and relating them to reproductive endpoints in a wild fish population habiting a reservoir that receive domestic sewage, agricultural and industrial residues. Adult fish Astyanax fasciatus were sampled during the reproductive season in five sites from the Furnas Reservoir, Grande River, and Paraguay–Paraná basin. As a control to field data, fish were experimentally exposed via dietary intake, to oestradiol benzoate (OB) for 7 days. Fish from site with little anthropogenic interference showed hepatic levels of Vtg, Zrp and IGF-I and IGF-II similar to those from the non-treated experimental group. In sites located immediately downstream from the municipal wastewater discharges, the water total oestrogen was >120 ng/l, and male fish displayed increased Vtg and Zrp and decreased IGF-I levels similar to OB treated fish. In females, levels of Vtg, Zrp, IGF-I and IGF-II suggest an impairment of final oocyte maturation and spawning, as also detected by frequency of over-ripening, follicular atresia and fecundity. At the sites that receive agricultural and industrial residues, the water total oestrogen was <50 ng/l and females showed decreased Zrp and increased IGF-II levels associated to reduced diameter of vitellogenic follicles, indicating an inhibition of oocyte growth. Overall, the current study reports oestrogenic contamination impairing the reproduction of a wild fish from a hydroeletric reservoir and, the data contribute to improving the current knowledge on relationship between hepatic Vtg, Zrp and IGF-I and IGF-II, and reproductive endpoints in a teleost fish. In addition, our data point out novel reproductive biomarkers (IGF-I, IGF-II and over-ripening) to assessing xenoestrogenic

  13. Atividades de lactato desidrogenase e malato desidrogenase de Astyanax bimaculatus (lambari da bacia hidrográfica do rio Una como biomarcadoras de impacto ambiental

    Directory of Open Access Journals (Sweden)

    Anne Caroline Ribeiro

    2015-11-01

    Full Text Available Os peixes vivem todo o ciclo de vida na água e recebem a influência dos seus componentes físico-químicos e biológicos ao longo do tempo. As atividades de lactato desidrogenase (LDH e malato desidrogenase (MDH de organismos aquáticos podem ser alteradas devido à presença de poluentes na água. O objetivo deste estudo foi determinar se as atividades de LDH e MDH nas brânquias e no fígado de Astyanax bimaculatus (lambari do rabo amarelo podem ser utilizadas como biomarcadoras do impacto ambiental na bacia hidrográfica do rio Una (SP. Para isso, esses lambaris foram coletados em três corpos d’água dessa bacia, denominados p1 (rio Itaim, p2 (córrego à beira da Estrada Municipal de Remédios e p3 (lago na Estrada Municipal Dr. José Luiz Cembranelli. As brânquias e o fígado foram homogeneizados e, a seguir, esse material foi centrifugado e o sobrenadante foi utilizado para determinação das atividades de LDH e MDH, através do método espectrofotométrico que determina a taxa de oxidação de NADH. As atividades de LDH e MDH no fígado e de MDH branquial não foram estatisticamente diferentes nos lambaris coletados nos três locais. No tecido branquial a atividade de LDH foi inferior nos peixes de p3 em relação aos de p1. Essa inibição da atividade de LDH, bem como a qualidade inferior da água nesse ponto, sugerem a ocorrência de poluentes nessa água. Conclui-se que LDH branquial de lambari possui potencial para utilização como marcador bioquímico de impacto ambiental no rio Una.

  14. Reproductive biomarkers responses induced by xenoestrogens in the characid fish Astyanax fasciatus inhabiting a South American reservoir: An integrated field and laboratory approach

    International Nuclear Information System (INIS)

    Field studies evaluating the effects of endocrine disruption chemicals (EDCs) on the fish reproduction are scarce worldwide. The goal of this study was to assess hepatic levels of vitellogenin (Vtg), zona radiata proteins (Zrp) and insulin-like growth factors (IGF-I and IGF-II), and relating them to reproductive endpoints in a wild fish population habiting a reservoir that receive domestic sewage, agricultural and industrial residues. Adult fish Astyanax fasciatus were sampled during the reproductive season in five sites from the Furnas Reservoir, Grande River, and Paraguay–Paraná basin. As a control to field data, fish were experimentally exposed via dietary intake, to oestradiol benzoate (OB) for 7 days. Fish from site with little anthropogenic interference showed hepatic levels of Vtg, Zrp and IGF-I and IGF-II similar to those from the non-treated experimental group. In sites located immediately downstream from the municipal wastewater discharges, the water total oestrogen was >120 ng/l, and male fish displayed increased Vtg and Zrp and decreased IGF-I levels similar to OB treated fish. In females, levels of Vtg, Zrp, IGF-I and IGF-II suggest an impairment of final oocyte maturation and spawning, as also detected by frequency of over-ripening, follicular atresia and fecundity. At the sites that receive agricultural and industrial residues, the water total oestrogen was <50 ng/l and females showed decreased Zrp and increased IGF-II levels associated to reduced diameter of vitellogenic follicles, indicating an inhibition of oocyte growth. Overall, the current study reports oestrogenic contamination impairing the reproduction of a wild fish from a hydroeletric reservoir and, the data contribute to improving the current knowledge on relationship between hepatic Vtg, Zrp and IGF-I and IGF-II, and reproductive endpoints in a teleost fish. In addition, our data point out novel reproductive biomarkers (IGF-I, IGF-II and over-ripening) to assessing xenoestrogenic

  15. A multi-approach analysis of the genetic diversity in populations of Astyanax aff. bimaculatus Linnaeus, 1758 (Teleostei: Characidae from Northeastern Brazil

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    Vanessa de Carvalho Cayres Pamponet

    2008-12-01

    Full Text Available Few reports are available about the ichthyofauna of typical semi-arid rivers, although the regional diversity has been constantly threatened by human activities, mainly related to impoundment and construction of dams. The goal of the present work was to evaluate using different methods, the population genetic structure of a characin fish, Astyanax aff. bimaculatus, widespread throughout hydrographic basins of Bahia, Northeastern Brazil. Morphological (meristic and morphometric data, cytogenetic (karyotype and Ag-NOR, and molecular (RAPD and SPAR analyses were carried out in specimens collected upstream and downstream of Pedra Dam, in the main channel of Contas River (Contas River Basin, and in the Mineiro stream, which belongs to the adjacent Recôncavo Sul basin. Few external differences were detected among populations, where the individuals collected upstream of Pedra Dam were slightly larger than the others. Cytogenetic data also showed a similar karyotypic pattern (2n=50; 6m+28sm+12st+4a; FN= 96 and NORs located on the short arms of up to two chromosome pairs, with numerical inter- and intra-populational variation. Nonetheless, RAPD and SPAR analyses differentiated reliably the three populations, revealing striking differences in the allele frequencies among the localities studied and a significant difference in population structure index (Fst=0.1868, PPoucos estudos ictiofaunísticos estão disponíveis em rios típicos do semi-árido, apesar da constante ameaça à diversidade local devido a influências antrópicas, com destaque para o represamento e construção de barragens. O presente trabalho teve como objetivo avaliar, por meio de diferentes metodologias, a estrutura genética de populações de uma espécie de caracídeo, Astyanax aff. bimaculatus, amplamente distribuída em bacias hidrográficas da Bahia, Nordeste do Brasil. Análises morfológicas (dados merísticos e morfométricos, citogenéticas (cariótipo e Ag-RONs e

  16. [An investigation of the helminth fauna of Triturus vittatus (Jenyns, 1835) and Triturus karelinii (Strauch, 1870)].

    Science.gov (United States)

    Yildirimhan, Hikmet Sami

    2008-01-01

    Twenty banded newts and 16 southern crested newts collected from Bursa on different dates from 1997-2006 were examined for helminths .As a result of the examination, 3 helminths (Oswaldocruzia filiformis (Goeze, 1782), Megalobatrachonema terdentatum (Linstow 1890) and Oxysomatium brevicaudatum (Zeder 1800) were found on banded newts. One nematode (Oxysomatium brevicaudatum) was found on southern crested newts. This is the first helminthological study of Triturus spp. in Turkey and is a new detection of Megalobatrachonema terdentatum in Turkey. PMID:18645950

  17. Isolation Driven Divergence in Osmoregulation in Galaxias maculatus (Jenyns, 1848 (Actinopterygii: Osmeriformes.

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    Ignacio Ruiz-Jarabo

    Full Text Available Marine species have colonized extreme environments during evolution such as freshwater habitats. The amphidromous teleost fish, Galaxias maculatus is found mainly migrating between estuaries and rivers, but some landlocked populations have been described in lakes formed during the last deglaciation process in the Andes. In the present study we use mtDNA sequences to reconstruct the historical scenario of colonization of such a lake and evaluated the osmoregulatory shift associated to changes in habitat and life cycle between amphidromous and landlocked populations.Standard diversity indices including the average number of nucleotide differences (Π and the haplotype diversity index (H indicated that both populations were, as expected, genetically distinctive, being the landlocked population less diverse than the diadromous one. Similarly, pairwise GST and NST comparison detected statistically significant differences between both populations, while genealogy of haplotypes evidenced a recent founder effect from the diadromous stock, followed by an expansion process in the lake. To test for physiological differences, individuals of both populations were challenged with a range of salinities from 0 to 30 ppt for 8 days following a period of progressive acclimation. The results showed that the landlocked population had a surprisingly wider tolerance to salinity, as landlocked fish survival was 100% from 0 to 20 ppt, whereas diadromous fish survival was 100% only from 10 to 15 ppt. The activity of ATPase enzymes, including Na+/K+-ATPase (NKA, and H+-ATPase (HA was measured in gills and intestine. Activity differences were detected between the populations at the lowest salinities, including differences in ATPases other than NKA and HA. Population differences in mortality are not reflected in enzyme activity differences, suggesting divergence in other processes.These results clearly demonstrate the striking adaptive changes of G. maculatus osmoregulatory system, especially at hyposmotic environments, associated to a drastic shift in habitat and life cycle at a scale of a few thousand years.

  18. Phylogeography in Galaxias maculatus (Jenyns, 1848 along Two Biogeographical Provinces in the Chilean Coast.

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    Claudio A González-Wevar

    Full Text Available Major geologic and climatic changes during the Quaternary exerted a major role in shaping past and contemporary distribution of genetic diversity and structure of aquatic organisms in southern South America. In fact, the northern glacial limit along the Pacific coast, an area of major environmental changes in terms of topography, currents, and water salinity, represents a major biogeographic transition for marine and freshwater species. We used mitochondrial DNA sequences (D-loop to investigate the consequences of Quaternary glacial cycles over the pattern of genetic diversity and structure of G. maculatus (Pisces: Galaxiidae along two biogeographical provinces in the Chilean coast. Extreme levels of genetic diversity and strong phylogeographic structure characterize the species suggesting a low amount of influence of the last glacial cycle over its demography. However, we recognized contrasting patterns of genetic diversity and structure between main biogeographical areas here analyzed. Along the Intermediate Area (38°-41° S each estuarine population constitutes a different unit. In contrast, Magellanic populations (43°-53° S exhibited low levels of genetic differentiation. Contrasting patterns of genetic diversity and structure recorded in the species between the analyzed biogeographic areas are consistent with the marked differences in abiotic factors (i.e., different coastal configurations, Quaternary glacial histories, and oceanographic regimes and to inherent characteristics of the species (i.e., salt-tolerance, physiology, and reproductive behavior.

  19. Efecto de la salinidad en la supervivencia embrionaria de puye Galaxias maculatus (Jenyns, 1842

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    Juan Barile

    2015-05-01

    Full Text Available Se evaluó e l efecto de la salinidad en la supervivencia embrionaria, período embrionario y período de eclosión de puye, Galaxias maculatus. Se utilizaron ocho tratamientos, con salinidades de 0, 4, 8, 12, 16 y 20 obteniéndose supervivencias embrionarias promedios respectivas de 84,9; 84,0; 85,5; 86,1; 82,6 y 75,8%, sin diferencias significativas entre ellas, mientras que con salinidad de 24 se obtuvo sobrevivencia de 10,4%, significativamente diferente al resto de los tratamientos y con salinidad de 28 causó 100% de mortalidad. A diferencia del estado juvenil y adulto, el embrión es incapaz de resistir la salinidad marina y su umbral de tolerancia se encuentra entre salinidades de 24 y 28. Las mayores supervivencias promedios larvales a 10 días de vida fueron con salinidades intermedias de 8, 12 y 16 de 79,3; 80,3 y 74,6% respectivamente, sin diferencias significativas entre ellas, demostrando alta viabilidad del embrión post-eclosión. Los períodos embrionarios promedios (50% más breves fueron a bajas salinidades 0, 4, 8, 12 con 28,7; 28,0; 29,7 y 29,7 días y los más extensos en los tratamientos con salinidades de 16 y 20, con 34,0 y 34,3 días, sin diferencias significativas entre ellos. Los períodos de eclosión promedio (50% con salinidades de 0, 4, 8, 12, 16, 20 y 24 fueron de 5,0; 5,5; 7,5; 8,8; 13,0; 14,3 y 15,8 días respectivamente, sin diferencias significativas entre ellos.

  20. Phylogeography in Galaxias maculatus (Jenyns, 1848) along Two Biogeographical Provinces in the Chilean Coast.

    Science.gov (United States)

    González-Wevar, Claudio A; Salinas, Pilar; Hüne, Mathias; Segovia, Nicolás I; Vargas-Chacoff, Luis; Astorga, Marcela; Cañete, Juan I; Poulin, Elie

    2015-01-01

    Major geologic and climatic changes during the Quaternary exerted a major role in shaping past and contemporary distribution of genetic diversity and structure of aquatic organisms in southern South America. In fact, the northern glacial limit along the Pacific coast, an area of major environmental changes in terms of topography, currents, and water salinity, represents a major biogeographic transition for marine and freshwater species. We used mitochondrial DNA sequences (D-loop) to investigate the consequences of Quaternary glacial cycles over the pattern of genetic diversity and structure of G. maculatus (Pisces: Galaxiidae) along two biogeographical provinces in the Chilean coast. Extreme levels of genetic diversity and strong phylogeographic structure characterize the species suggesting a low amount of influence of the last glacial cycle over its demography. However, we recognized contrasting patterns of genetic diversity and structure between main biogeographical areas here analyzed. Along the Intermediate Area (38°-41° S) each estuarine population constitutes a different unit. In contrast, Magellanic populations (43°-53° S) exhibited low levels of genetic differentiation. Contrasting patterns of genetic diversity and structure recorded in the species between the analyzed biogeographic areas are consistent with the marked differences in abiotic factors (i.e., different coastal configurations, Quaternary glacial histories, and oceanographic regimes) and to inherent characteristics of the species (i.e., salt-tolerance, physiology, and reproductive behavior). PMID:26161896

  1. Isolation Driven Divergence in Osmoregulation in Galaxias maculatus (Jenyns, 1848) (Actinopterygii: Osmeriformes)

    Science.gov (United States)

    Ruiz-Jarabo, Ignacio; Oyarzún, Ricardo; Fuentes, Juan; Poulin, Elie; Bertrán, Carlos; Vargas-Chacoff, Luis

    2016-01-01

    Background Marine species have colonized extreme environments during evolution such as freshwater habitats. The amphidromous teleost fish, Galaxias maculatus is found mainly migrating between estuaries and rivers, but some landlocked populations have been described in lakes formed during the last deglaciation process in the Andes. In the present study we use mtDNA sequences to reconstruct the historical scenario of colonization of such a lake and evaluated the osmoregulatory shift associated to changes in habitat and life cycle between amphidromous and landlocked populations. Results Standard diversity indices including the average number of nucleotide differences (Π) and the haplotype diversity index (H) indicated that both populations were, as expected, genetically distinctive, being the landlocked population less diverse than the diadromous one. Similarly, pairwise GST and NST comparison detected statistically significant differences between both populations, while genealogy of haplotypes evidenced a recent founder effect from the diadromous stock, followed by an expansion process in the lake. To test for physiological differences, individuals of both populations were challenged with a range of salinities from 0 to 30 ppt for 8 days following a period of progressive acclimation. The results showed that the landlocked population had a surprisingly wider tolerance to salinity, as landlocked fish survival was 100% from 0 to 20 ppt, whereas diadromous fish survival was 100% only from 10 to 15 ppt. The activity of ATPase enzymes, including Na+/K+-ATPase (NKA), and H+-ATPase (HA) was measured in gills and intestine. Activity differences were detected between the populations at the lowest salinities, including differences in ATPases other than NKA and HA. Population differences in mortality are not reflected in enzyme activity differences, suggesting divergence in other processes. Conclusions These results clearly demonstrate the striking adaptive changes of G. maculatus osmoregulatory system, especially at hyposmotic environments, associated to a drastic shift in habitat and life cycle at a scale of a few thousand years. PMID:27168069

  2. A comunidade de peixes de um riacho de Floresta com Araucária, alto rio Iguaçu, sul do Brasil The fish community in an Araucaria Forest stream, upper Iguaçu River basin, southern Brazil

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    Vinicius Abilhoa

    2008-06-01

    Full Text Available Foram avaliadas a composição, a dieta, as táticas alimentares e ocupação espacial da ictiofauna em um pequeno riacho dentro de um remanescente de Floresta com Araucária. Seis espécies de peixes foram coletadas, pertencentes a três ordens e quatro famílias, totalizando 110 exemplares. No ambiente de corredeira foram coletados e observados apenas Trichomycterus castroi Pinna, 1992 and Trichomycterus davisi Haseman, 1911, enquanto que no ambiente de remanso foram observados e capturados exemplares de Astyanax aff. scabripinnis (sensu Eigenmann, 1921, Astyanax totae Haluch & Abilhoa, 2005, Trichomycterus castroi Pinna, 1992, T. davisi, Phalloceros caudimaculatus (Hensel, 1868 e Jenynsia eigenmanni Haseman, 1911. Dezoito itens alimentares de origem autóctone, seis de alóctone e três de origem incerta foram identificados e tiveram sua freqüência de ocorrência calculada. Uma grande quantidade de itens exclusivos foi registrada, todavia os insetos constituíram a base alimentar mais importante, principalmente na forma de fragmentos e estágios imaturos (larvas e pupas, o que permitiu inferências a respeito de sobreposição alimentar. As espécies registradas no riacho foram classificadas em quatro guildas tróficas e quatro grupos funcionais. As espécies estudadas são capazes de utilizar diversos recursos alimentares e microambientes, o que é favorecido provavelmente pelo seu pequeno porte. O remanescente florestal estudado exerce grande importância no fornecimento de alimento, hábitats e refúgios, fatores importantes para manutenção da biota aquática.The species composition, diet, feeding tactics, and spatial occupation of fishes in a headwater stream which flows within a remaining fragment of Araucaria Forest were studied. One hundred and ten fishes of six species were collected, members of three orders and four families. In riffle areas, only Trichomycterus castroi Pinna, 1992 and Trichomycterus davisi Haseman, 1911 were

  3. Effect of UV radiation on the genetic inactivation of sperm of the bullseye puffer Sphoeroides annulatus (Jenyns, 1842); Efecto de la radiacion UV en la inactivacion genetica del esperma de botete diana Sphoeroides annulatus (Jenyns, 1842)

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    Arias-Rodriguez, Lenin; Rodriguez-Ibarra, Luz Estela; Del Valle-Pignataro, Gabriela [Laboratorio de Genetica, Centro de Investigacion en Alimentacion y Desarrollo, A. C., Sinaloa (Mexico)

    2004-09-15

    Genetic (DNA) inactivation of fish sperm with ultraviolet irradiation is generally accompanied by a paradoxical effect on survival rates (Hertwig effect). In the present study, sperm samples from ten males bullseye puffer fish (Sphoeroides annulatus) were diluted 1:50 using Cortland's extender solution and used to test the effect of nine ultraviolet doses (0.2-1.0 J cm{sup -}2 ) on motility time in seconds, motility index, and embryo survival rate after fertilizing eggs from five bullseye puffer females. Motility time of sperm irradiated with 0.2-0.9 J cm{sup -}2 were not statistically different from the controls, but sperm irradiated with a dosage of 1.0 J cm{sup -}2 dosage had significant lower motility time. Motility indices (MI) allowed for the statistical differentiation of four groups in relation to their response to different radiation doses: the first had high MI, and included the controls and 0.2-0.3 J cm{sup -}2 treatments; the second had lower MI and included the 0.4-0.7 J cm{sup -}2 treatments; the third showed recovery of MI and included the 0.8-0.9 J cm{sup -}2 treatments; and the fourth showed the lowest MI with the 1.0 J cm{sup -}2 treatment. Embryo survival was highest for the controls and 0.2 J cm{sup -}2 treatment, decreasing in the 0.3-0.4 J cm{sup -}2 treatments, increasing again in the 0.5-0.8 J cm{sup -}2 treatments, until reaching lowest survival in the 0.9-1.0 J cm{sup -}2 treatments. These results indicate that the best ultraviolet dosage to achieve genetic inactivation of sperm of this species is close to 0.7 J cm{sup -}2, a dosage in which fish fry showed typical haploid syndrome characteristics. [Spanish] La inactivacion genetica (ADN) del esperma de peces se realiza mediante luz ultravioleta que, en irradiaciones crecientes, genera efectos paradojicos (efecto Hertwig) en los porcentajes de supervivencia. En este trabajo se diluyeron muestras de semen provenientes de diez machos de botete diana (Sphoeroides annulatus) en solucion extendedora Cortland modificada en dilucion 1:50, y se utilizaron para probar el efecto de nueve dosis de radiacion ultravioleta (0.2-1.0 J cm{sup -}2 ) sobre la duracion de la motilidad en segundos, el indice de motilidad del esperma, y los porcentajes de superviviencia de embriones obtenidos de la fertilizacion de huevos provenientes de cinco hembras de la misma especie. Los tiempos de motilidad del esperma en las muestras irradiadas con 0.2-0.9 J cm{sup -}2 resultaron estadisticamente no diferentes de los controles, mientras que las muestras irradiadas con 1.0 J cm{sup -}2 fueron significativamente menores. El indice de motilidad (IM), por otra parte, permitio la diferenciacion estadistica de cuatro grupos en cuanto a su respuesta a diferentes dosis de radiacion. El primer grupo se caracterizo por valores altos del IM, e incluyo a los controles y a las muestras irradiadas con 0.2-0.3 J cm{sup -}2; el segundo agrupo a las irradiaciones de 0.4 a 0.7 J cm{sup -}2, en las cuales se observo un descenso del IM; en el tercer grupo (0.8-0.9 J cm{sup -}2 ) el IM aumento nuevamente; y en el ultimo (1.0 J cm{sup -}2) se observo el menor IM. En cuanto a los porcentajes de supervivencia, se observo una curva descendente con valores altos de supervivencia en los controles y en las muestras irradiadas con 0.2 J cm{sup -}2, con un descenso en los tratamientos de 0.3 a 0.4 J cm{sup -}2, y una recuperacion significativa a partir del tratamiento de 0.5 y hasta 0.8 J cm{sup -}2, observandose nuevamente un decremento en la supervivencia de los tratamientos de 0.9 a 1.0 J cm{sup -}2 . Ambos resultados, IM y supervivencia, indican que la dosis optima para la produccion de organismos haploides se encuentra cercana a 0.7 J cm{sup -}2. En el tratamiento de 0.7 J cm{sup -}2 se observaron larvas con las caracteristicas tipicas del sindrome haploide, indicando nuevamente que esta puede ser la dosis mas adecuada para producir organismos ginogeneticos.

  4. Contrasting Genetic Structure and Diversity of Galaxias maculatus (Jenyns, 1848) Along the Chilean Coast: Stock Identification for Fishery Management.

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    González-Wevar, Claudio; Salinas, Pilar; Hüne, Mathias; Segovia, Nicolás; Vargas-Chacoff, Luis; Oda, Esteban; Poulin, Elie

    2015-01-01

    Galaxias maculatus (Pisces: Galaxiidae) commonly known as "puye" has a disjunct distribution along the Southern Hemisphere including landlocked and migratory populations at latitudes over 30°S in South America, Australia, Tasmania, and New Zealand. Chilean artisanal fishery of G. maculatus has become less important as a resource due to multiple factors including overexploitation, pollution, introduction of predators, and competitors. At the same time, the current conservation status of the species in Chile is still uncertain. Here, we used mtDNA control region sequences (925bp) to investigate main patterns of genetic diversity and structure in populations from 2 biogeographic areas along the Chilean coast. Extremely high levels of genetic diversity characterize the species, suggesting a low amount of influence of the last glacial cycle over its demography compared with other studies in freshwater and marine South American fishes. However, we recognized contrasting genetic patterns between the Intermediate Area (between 30°S and 42°S) and the Magellanic Province (between 42°S and 56°S). On the one hand, over a narrow geographical range (<200 km) each Intermediate Area estuarine population constitutes a different genetic unit. On the other hand, the Magellanic populations of the species exhibited low levels of differentiation in an area extending for more than 500 km. Such differences may be a consequence of different coastal configurations, oceanographic regimes, and Quaternary glacial histories. Finally, our results support the existence of different stock units for G. maculatus and this information should be integrated in future management strategies and aquaculture programs for this species. PMID:26245779

  5. Extended incubation affects larval morphology, hatching success and starvation resistance in a terrestrially spawning fish, Galaxias maculatus (Jenyns 1842).

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    Semmens, D; Swearer, S E

    2011-10-01

    The effect of extended incubation (delayed hatching) on larval morphology in the terrestrially spawning common galaxias Galaxias maculatus was investigated by inducing larvae to hatch 1 and 2 weeks after the normal 2 week incubation period. After 1 week of extended incubation, larvae were larger (longer in standard length, L(S), and greater in body depth) compared to controls (larvae that experienced normal incubation durations). After 2 weeks of extended incubation, larvae were smaller (shorter in L(S) and smaller in body depth) than larvae that experienced 1 week of extended incubation. Furthermore, eye area increased while yolk-sac size decreased monotonically with increasing incubation duration. These results suggest that larvae experiencing long periods of extended incubation are using somatic tissue to meet their metabolic demands. Larvae that experienced 2 weeks of extended incubation succumbed to starvation sooner than control larvae, but hatching success was not significantly different. Temperature mediated the effect of extended incubation on the morphology of larvae at hatching, most likely, through its effects on developmental rate and efficiency of yolk utilization. This study demonstrates some of the consequences of terrestrial spawning with extended incubation, which will assist in determining why this intriguing behaviour has evolved several times in a diverse range of taxa. PMID:21967585

  6. Feeding ω-3 PUFA enriched rotifers to Galaxias maculatus (Jenyns, 1842 larvae reared at different salinity conditions: effects on growth parameters, survival and fatty acids profile

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    Patricio Dantagnan

    2013-07-01

    Full Text Available Despite the well known importance of ω-3 polyunsaturated fatty acids (PUFA in marine and freshwater fish larvae, there are few studies on how essential fatty acid requirements and composition on whole body can be altered by changes in water salinity. The present study aimed to determine the effect of salinity on ω-3 PUFA requirements, larval growth survival and fatty acid composition of Galaxias maculatus larvae cultured at two different salinities (0 and 15 g L-1 for 20 days while fed rotifers containing two different levels of ω-3 PUFA (1.87 and 3.16%. The results denoted a marked difference in ω-3 PUFA requirements and in the pattern of fatty acid deposition in the whole body of larvae reared at different salinities, depending of ω-3 PUFA in diets. Thus, to improve growth and survival larvae of G. maculatus reared at 0 g L-1 require higher levels of ω-3 PUFA, principally 18:3 ω-3. Larvae reared at salinities of 15 g L-1 require low levels of ω-3 PUFA for optimal survival, especially 18:3 ω-3. Eicosapentaenoic acid and docosahexaenoic acid content in the whole body of larvae was also affected by water salinity.

  7. A study of the population structure of the Pacific sardine Sardinops sagax (Jenyns, 1842) in Mexico based on morphometric and genetic analyses

    OpenAIRE

    Cota Gómez, Víctor Manuel; De La Cruz Agüero, José; García Gasca, Silvia Alejandra; García Rodríguez, Francisco Javier

    2011-01-01

    Several studies on the Pacific sardine Sardinops sagax have focused on the identification of stock composition and boundaries, using morphometric and genetic analysis. In this study, geometric morphometric body landmarks and control region mtDNA sequences were used to examine the population structure of sardines along the Pacific coast of the Baja California Peninsula. Samples from commercial landings in Ensenada (ENS), Baja California, and Bahia Magdalena (BM), Baja California Sur, were obta...

  8. Population structure and reproductive aspects of puffer fish Sphoeroides annulatus (Jenyns, 1842 (Osteichthyes: Tetraodontidae, landed in Teacapán, Sinaloa, Mexico

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    María Candelaria Valdez-Pineda

    2014-03-01

    Full Text Available The puffer fish Sphoeroides annulatus is an important target species for the artisanal fishing fleets of NW Mexico. To obtain information on population structure of the local stock, we determined the total length and total weight (TL and TW ranges, sex ratio and reproductive stages of 745 specimens of this species, landed from May 2010 to April 2011 in Teacapán, Sinaloa, NW Mexico. TL ranged from 15 to 40 cm and TW from 100 to 1600 g. There were no differences between mean TL (27.41 ± 4.14 cm and TW (534.5 ± 226.0 g of males and females respectively. Sex ratio was not significantly different (χ2 = 0.03, P > 0.05 from 1F:1M. The length-weight relationship for both sexes was TW = 0.044TL2.815, R² = 0.895. The value of the slope b was significantly lower than 3 (P < 0.05, and indicated negative allometric growth. The distribution of maturity stages indicated one main reproductive period from June to September and one less intense, from November to December for females, and in December for males. Size at first maturity (L50% of females was 26.52 cm and that of males was 27.41 cm.

  9. Blood cytology of the common jollytail (Galaxias maculatus (Jenyns, 1842 (Osmeriformes: Galaxiidae at postlarval and adult stages Estudio de la citología sanguínea del puye (Galaxias maculatus (Jenyns, 1842 (Osmeriformes: Galaxiidae en estado postlarval y adulto

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    I Valdebenito

    2011-01-01

    Full Text Available “Puye” (Galaxias maculatus is a small freshwater fish species of great interest to Chilean aquaculture diversification, because of the high commercial value reached by its transparent larvae or “cristalino”. This study presents the first data with regard to blood cytology in larvae and adults of this specie. Blood smears stained with May Grünwald-Giemsa were analysed through optical microscopy. The results show that in G. maculatus larvae the flowing blood has a transparent look and mature erythrocytes were not observed, as opposed to the adults of this species where the complete erythrocyte developmental line could be observed. In leucocytes, there was no presence of coarse grain cells such as basophils and eosinophyls. In general, the morphology of the blood cells found in larvae and adults of G. maculatus have the same characteristic traits as described elsewhere in reports of other teleosts.El puye (Galaxias maculatus es un pequeño pez nativo de gran interés para la diversificación de la acuicultura chilena, debido al alto valor comercial de su estado postlarval cristalino. La presente investigación entrega los primeros antecedentes respecto de la citología sanguínea de postlarvas y adultos de esta especie, determinada mediante microscopía óptica utilizando frotis sanguíneos preparados con May Grünwald-Giemsa. Los resultados muestran que en la sangre circulante de G. maculatus en estado de postlarva no se observan eritrocitos maduros y la sangre es de aspecto transparente. Sin embargo, en adultos se pudo observar la línea eritrocitaria completa y en leucocitos no se observó la presencia de células de grano grueso como son los basófilos y eosinófilos. La morfología de las células encontradas en ambos estados del desarrollo del puye mantienen las características propias entregadas en la literatura para peces teleósteos.

  10. Efecto de la ración alimenticia sobre la maduración gonadal y acumulación de grasa de anchoveta peruana (Engraulis ringens Jenyns, 1842 en cautiverio Effect of feeding ration on gonad maturation and fat accumulation in Peruvian anchovy (Engraulis ringens Jenyns, 1842 in captivity

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    Carlos Espinoza

    2009-01-01

    Full Text Available Se evaluó el efecto de la ración alimenticia sobre la tasa de maduración gonadal, el desempeño de las gónadas maduras y la redistribución de la energía consumida en gónada, músculo o grasa corporal en ejemplares de anchoveta peruana Engraulis ringens en condiciones de cautiverio Estos resultados ayudan a comprender los procesos reproductivos ocurridos en el medio natural ante alteraciones de factores ambientales tales como los eventos El Niño y La Niña, de gran implicancia en el ecosistema y las pesquerías del Pacífico oriental. El tiempo trascurrido desde el estadio inmaduro hasta vitelogénico fue de 45 días bajo condiciones alimenticias energéticamente óptimas y temperatura alrededor de 16,5°C (46,1 cal g-1 pez día-1 . Las hembras alimentadas con 138,3 cal g-1 pez día-1 alcanzaron la máxima vitelogénesis en 30 días y, aunque el alimento fue excesivo, no incrementaron su masa muscular pero si presentaron mayor acumulación de grasa corporal y presencia de ovocitos más grandes, lo cual indica un incremento en el almacenamiento energético en la hembra y su progenie. Los ovocitos vitelogénicos de los peces alimentados con 46,1 cal g-1 pez día-1 presentaron atresia más rápido que los ovocitos vitelogénicos de peces alimentados con 138,3 cal g-1 pez día-1 . Aunque la cantidad de alimento fue adecuada, las hembras no desovaron durante el experimento. En machos, la disponibilidad de alimento también aceleró la maduración gonadal pero la expulsión de espermatozoides parece haber estado condicionada por la presencia de hembras con ovocitos en máximo estado de vitelogénesis.We analyzed the effect that feeding rations have on gonad maturation, mature gonad performance, and the redistribution of the energy taken up by the gonads, muscle, and body fat in captive specimens of Peruvian anchovy (Engraulis ringens. These results help us understand the reproductive processes occurring in the natural environment given changes in the environmental factors such as El Niño and La Niña events, which heavily affect the ecosystem and fisheries in the East Pacific. The specimens required 45 days under optimal feeding conditions (46.1 cal g-1 fish day-1 and at a temperature of 16,5°C to go from an unyoked to a vitellogenic stage. Those females fed 138.3 cal g-1 fish day-1 reached maximum vitellogenesis in 30 days. Despite the excessive amount of food, the specimens' muscle mass did not increase. However, greater body fat accumulation and larger vitellogenic ovocytes were observed, indicating augmented energy storage for the female and her offspring. The yoked oocytes from fish fed 46.1 cal g-1 fish day-1 became atretic earlier than oocytes from fish fed 138.3 cal g-1 fish day-1. Although the food supply was adequate, the females did not spawn during the experiment. In males, food availability also accelerated gonad maturation, but the release of sperm was apparently conditioned by the presence of females with ovocytes in the advanced vitellogenic stage.

  11. Genetic and Hematologic Endpoints in Astyanax altiparanae (Characidae) After Exposure and Recovery to Water-Soluble Fraction of Gasoline (WSFG).

    Science.gov (United States)

    Galvan, Gabrieli L; Lirola, Juliana R; Felisbino, Karoline; Vicari, Taynah; Yamamoto, Carlos I; Cestari, Marta M

    2016-07-01

    The sublethal effects of water-soluble fraction of gasoline (WSFG, 1.5 % v/v) were evaluated in the freshwater fish, Astynax altiparanae, after acute exposure (96 h) under a semi-static system. In addition, the recovery process was assessed in the fish following contaminant depuration. Recovery treatments were carried out with gradual depuration (GD), consisting of 7 days in the WSFG, followed by 8 days in clean water; and treatments with total depuration in clean water for 15 (DEP 15) and 30 days (DEP 30). The effects were evaluated through the piscine micronucleus test and by differential counting of organic defense cells. Acute exposure increased the frequency of neutrophils. In the GD treatment, the thrombocyte count and erythrocytic nuclear abnormalities (ENA) increased. In the DEP 15 treatment, there was a reduction of ENA; and following 30 days of depuration (i.e., DEP 30), the number of lymphocytes increased and the thrombocyte count remained high. These results indicate a long-term response to a condition of stress from WSFG. PMID:27189358

  12. Morfologia e desenvolvimento do núcleo vitelínico do lambari Astyanax bimaculatus (Linnaeus, 1758 (Osteichthyes, Characidae

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    Silvia Dantas Cangussu-Mariani

    1990-01-01

    Full Text Available A morphological study of the yolk nucleus in previtellogenic oocytes from A. bimacularus has been carried out. Six phases of development were described from its formation closed to the oocyte nucleus to its dispersion in the periferic ooplasm. Histochemical techniques indicate proteins, lipids and RNA in the yolk nucleus of A. bimaculatus, but there are no carbohydrate in this structure. The origin and functional activity of the teleost yolk nucleus are discussed.

  13. Effect of the inclusion of fish residue oils in diets on the fatty acid profile of muscles of males and females lambari (Astyanax altiparanae

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    Ligia Uribe Gonçalves

    2012-09-01

    Full Text Available This study evaluated the effects of two lipids sources of fish residue (tilapia and salmon compared with a vegetable oil source (soybean oil on the fatty acid profiles of male and female lambari. This experiment was developed in a completely randomized experimental design in a 3 × 2 factorial arrangement, totaling 6 treatments resulting from the combination of the three experimental diets for both sexes, with four replications for each treatment. This study involved 120 male (2.58±0.13 g and 72 female lambari (4.00±0.09 g, fed the experimental diets twice a day until apparent satiation for a period of 60 days. Oleic, linoleic, palmitic and stearic fatty acids were found at higher concentrations in all experimental oils and diets, as well in the muscle of male and female lambari. The low amounts of arachidonic, eicosapentaenoic and docosahexaenoic acids in the experimental diets and subsequent greater concentrations in muscle tissue, suggested that lambari are able to desaturate and elongate the chain of fatty acids with 18 carbons. The fish of both sexes that received the diet with soybean oil showed high levels of n-6 fatty acids, especially of C18: 2n-6 and low levels of eicosapentaenoic and docosahexaenoic acids. The diet with salmon residue oil promoted higher levels of fatty acids of the n-3 series and resulted in the best n-3/n-6 ratio in the muscle of male and female lambari. The oils from fish residues can be a substitute for traditional fish oil and its use in the lambari diets does not impair its growth.

  14. Dynamics and cytochemistry of oogenesis in Astyanax fasciatus (Cuvier (Teleostei, Characiformes, Characidae from Rio Sapucaí, Minas Gerais State, Brazil

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    José Antônio Dias Garcia

    2001-12-01

    Full Text Available Oogenesis involves a set of transformations which are undergone by female germ cells These cells change into oogonias and then into mature oocytes. Sexually mature female fish were collected monthly, during one year, from the Sapucaí River, a tributary of the Rio Grande, which is part of the Furnas Reservoir in the state of Minas Gerais. During the several stages of maturation, we observed small round oogonias with a large nucleus, a single nucleolus, and weakly stained cytoplasm with eosinophilic granules. The primary oocytes showed a large basophilic nucleus, with a developed peripheral nucleolus and a reduced cytoplasm. The previtellogenic oocytes presented voluminous cytoplasm and nucleus with several small peripheral nucleoli. The oocytes underwent vitellogenesis with the development of the zona radiata and the follicle cells. Their cytochemical reactions indicated that the two layers of the zona radiata of A. fasciatus contained proteins and polysaccharides. The initially squamous follicle cells, became cuboidal. In mature oocytes, the nucleus moved toward the periphery, next to the micropyle, and the yolk granules formed by proteins, fulfilled the cytoplasm. The clear unstained vesicles are likely to be the cortical alveoli in the perivitelline region.

  15. Diet of Cnesterodon decemmaculatus (Poeciliidae and Jenynsia multidentata (Anablepidae in a hypertrophic shallow lake of Uruguay Dieta de Cnesterodon decemmaculatus (Poeciliidae y Jenynsia multidentata (Anablepidae en un lago hipereutrófico de Uruguay

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    Federico Quintans

    2009-03-01

    Full Text Available Se analizaron las dietas de Cnesterodon decemmaculatus (Jenyns, 1842 y Jenynsia multidentata (Jenyns, 1842 en el Lago Rodó, un lago urbano hipereutrófico de Montevideo, Uruguay. Ambas especies mostraron un comportamiento omnívoro. Los ítems más consumidos por C. decemmaculatus fueron zooplancton, perifiton, fitoplancton y detritos; la dieta de J. multidentata incluyó zooplancton, insectos, crustáceos y peces juveniles. Estos resultados sugieren que ambas especies pueden actuar como planctívoros facultativos. La comunidad de peces de este lago se caracteriza por la dominancia de C. decemmaculatus y J. multidentata. Bajo esta condición, la depredación sobre el zooplancton de gran tamaño podría indirectamente estar contribuyendo a una alta abundancia de fitoplancton y una baja transparencia del agua.Diet of Cnesterodon decemmaculatus (Jenyns, 1842 and Jenynsia multidentata (Jenyns, 1842 were analysed in Lake Rodó, an urban hypertrophic lake from Montevideo, Uruguay. Both species displayed omnivory. The most consumed items for C. decemmaculatus were zooplankton, periphyton, phytoplankton and detritus; the diet of J. multidentata included zooplankton, insects, crustaceans and juvenile fish. Our results suggest that both species could be acting as facultative planktivores. The fish community of this lake is characterised by the dominance of C. decemmaculatus and J. multidentata. Under this condition, predation on large-bodied zooplankton could indirectly be contributing to maintain a high phytoplankton abundance and a low water transparency.

  16. Philureter trigoniopsis, a new genus and species (Dactylogyridae, Ancyrocephalinae) from the ureters and urinary bladder of Galaxias maculatus (Osmeriformes: Galaxiidae) in Patagonia (Argentina).

    Science.gov (United States)

    Viozzi, G P; Gutiérrez, P A

    2001-04-01

    The monotypic Philureter n. gen. (Ancyrocephalinae; Dactylogyridae) is proposed to accommodate Philureter trigoniopsis n. sp. with the following features: presence of a cuplike ventral haptor armed with 14 hooks and 2 anchor/bar complexes; dorsal pair of anchors poorly defined and variable in shape, 1 frequently absent; tandem, intercecal gonads, testis bilaterally lobulated. Philureter trigoniopsis n. sp. is described from the ureters and urinary bladder of Galaxias maculatus (Jenyns, 1842) (Osmeriformes) in Patagonian Andean lakes, Argentina. PMID:11318570

  17. Abundancia y distribución de las especies ícticas (Osteichthyes del río San Francisco-Cosquín, Córdoba, Argentina Abundance and distribution of fish species (Osteichthyes from San Francisco - Cosquín river in Córdoba, Argentina

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    Andrea Cecilia Hued

    Full Text Available It was made the characterization of the San Francisco-Cosquín Mountain River fish community, Córdoba, Argentina. Samples of fish were taken from selected sites from November 1998 to November 1999. Eleven species were recorded, eight of which are first reports for this river. Relative abundance for each species, species richness, diversity and dominance were estimated. Bryconamericus iheringi (Boulenger, 1887 y Jenynsia multidentata (Jenyns, 1842 were the most abundant.

  18. The life history of Pygidiopsis macrostomum Travassos, 1928 (Digenea: Heterophyidae

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    Susana Balmant Emerique Simões

    2009-02-01

    Full Text Available The life history of the trematode Pygidiopsis macrostomum Travassos, 1928 is described for the first time. Rediae and cercariae were obtained from naturally infected snails Heleobia australis (d´Orbigny, a new first intermediate host. Metacercariae were found encysted in the mesenteries of three naturally infected guppies, Phalloptychus januarius (Hensel, Jenynsia multidentata (Jenyns (new host records and Poecilia vivipara Bloch and Schneider. Experimental infections were successfully completed in the intermediate hosts H. australis and Poe. vivipara reared in the laboratory and hamsters Mesocricetus auratus Waterhouse were utilised as a definitive host.

  19. Post-cyclic transmission in Acanthocephalus tumescens (Acanthocephala: Echinorhynchidae).

    Science.gov (United States)

    Rauque, Carlos A; Semenas, Liliana G; Viozzi, Gustavo P

    2002-01-01

    The aim of this study was to investigate the post-cyclic transmission of Acanthocephalus tumescens (von Linstow, 1896) from Galaxias maculatus Jenyns to Oncorhynchus mykiss (Walbaum). Wild G. maculatus naturally infected with A. tumescens were fed to cultured rainbow trout, which were sacrificed at the second, third and fourth weeks post infection. Normally attached male and female acanthocephalans were recovered alive from the intestine of rainbow trout. Parasites survive at least four weeks post infection, growing and attaining full sexual maturity. Prevalence and mean intensity generally decreased after infection. A. tumescens is the eighth acanthocephalan species in which post-cyclic transmission has been proven. PMID:12194485

  20. Parasites of four ornamental fish from the Chumucuí River (Bragança, Pará, Brazil).

    Science.gov (United States)

    Fujimoto, Rodrigo Yudi; Barros, Zaira Monik Nunes de; Marinho-Filho, Adjalbas Nunes; Diniz, Daniel Guerreiro; Eiras, Jorge Costa

    2013-01-01

    The objective of the present study was to evaluate the parasite fauna of four species of ornamental fish collected in the Chumucuí River, municipality of Bragança, Pará, Brazil. From June 2006 to December 2007. Fishes (n=307) belonging to four species were collected, including 23 specimens of Moenkhausia sanctaefilomenae (redeye tetra), 37 Carnegiella strigata (marbled hatchetfish), 7 Chilodus punctatus (spotted headstander), and 240 Astyanax bimaculatus (twospot astyanax). The parasites found belonged to three taxa: monogeneans in the gills, nematodes (larvae of Capillaria sp. and Contracaecum sp.) in the digestive tract and liver and acanthocephalans (Quadrigyrus torquatus, Q. brasiliensis and Q. nickoli) in the stomach and intestine. Astyanax bimaculatus presented higher prevalence of acanthocephalans in the wet season, and lower prevalence of nematodes in the dry season. The possible importance of these parasites in the exportation of ornamental fish is discussed. PMID:23538504

  1. Redescription of Prosthenhystera obesa (Diesing, 1850) (Callodistomidae, Digenea) with New Host Records and Data on Morphological Variability

    OpenAIRE

    1997-01-01

    Prosthenhystera obesa (Diesing,1850) Travassos, 1922 from the gall bladder of Astyanax bimaculatus, Caranx gibbosus, Galeocharax humeralis, Leporinus copelandii, Pimelodus fur, Pseudopimelodus roosevelti, Salminus brevidens, Salminus maxillosus and from the new hosts, Cynopotamus amazonum and Triurobrycon lundii is redescribed, demonstrating a large morphological variation, mainly in body and testes size and shape. New hosts harbouring immature specimens of P. obesa are presented: Brycon sp.,...

  2. Mercury bioaccumulation in fishes of a paddy field in Southern of Brazil

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    Vinicius Tavares Kütter

    2015-06-01

    Full Text Available Aim: The aim of present study was to evaluate the Hg concentration in two species of fish (Astyanax sp and Corydoras paleatus and its potential use as a biomonitor, in order to know if the use of pesticides and fertilizers in paddy can enhance the Hg contamination to adjacent aquatic environment.MethodsSoil, suspended particulate matter and fish samples were sampled in a paddy field in South Brazil. A cold vapor system, coupled with a GBC 932 atomic absorption spectrophotometer was used for total Hg determinations in samples.ResultsThe paddy soil shows Hg concentration 2-fold higher (mean 31 ng g-1 in comparison to background areas (not cultivated. Suspended particle matter Hg concentration in paddy channels (mean 232.5 ± 44.2 ng g–1 are 1.5 times higher than the regional background. The analyzed fish specimens Astyanax sp in paddy showed Hg concentration 4-fold higher and significant different to background area. The mean Hg concentration in fish was: 51.7 ± 19.5 ng g–1 in Astyanax sp and 156.8 ± 44.0 ng g–1 in Corydoras paleatus.ConclusionsConsidering the linear regression and Man whitney test hypothesis to Hg concentration in fish tissue from paddy suggests that Astyanax sp. can be a good biomonitor of Hg contamination, whereas Corydoras paleatus is a potential biomonitor. However, more studies with Corydoras are necessary in order to aggregate consistency to this hypothesis.

  3. Myxidium biliare sp. n. (Myxozoa) from gall bladder of Galaxias maculatus (Osmeriformes: Galaxiidae) in Patagonia (Argentina).

    Science.gov (United States)

    Viozzi, Gustavo P; Flores, Verónica R

    2003-09-01

    Myxidium biliare sp. n., a new myxosporean species parasitizing the gall bladder of Galaxias maculatus (Jenyns), in Patagonia, is described. Its coelozoic plasmodia were floating free in the bile. Spores are fusiform 13.7 +/- 0.9 microm long and 6.9 +/- 0.6 microm wide, with rounded ends in frontal view and slightly pointed ends in sutural view; shell with ridges and sinuous sutural line. Both maximum prevalence and maximum percentage of immature plasmodia occurred in summer. In winter the prevalence and the percentage of immature plasmodia fell to their lowest values. Prevalence was independent of host sex but increased with host length. Prevalence in 15 Patagonian Andean lakes (situated from 39 degrees 25'S to 41 degrees 30'S) ranged between 4.2% and 70%. PMID:14535344

  4. A new genus of dactylogyrid from the gills of Galaxias maculatus (Osmeriformes: Galaxiidae) in Maullín Basin, Patagonia, Chile.

    Science.gov (United States)

    Viozzi, Gustavo P; Marin, Sandra L; Carvajal, Juan; Brugni, Norma; Mancilla, Melinka

    2007-06-01

    During a parasitological survey of Galaxias maculatus (Jenyns, 1842) in the Maullín Basin (Chilean Patagonia), specimens of a new species of Monogenea were collected from the gills. This species is described as the only member of a proposed new genus, Inserotrema n. gen. (Dactylogyridae, Ancyrocephalinae), characterized by similar hooks with 2 subunits, overlapping gonads, coiled cirrus with counterclockwise rings, articulated accessory piece formed by 2 parts, a needlelike sclerite threading the distal part of the MCO, and a sclerotized midventral vagina. This new genus is proposed for dactylogyrids from gills of galaxiids (Galaxiidae). Inserotrema puyei n. sp. infects gills of G. maculatus from Llanquihue Lake, Maullín River, and Maullín Estuary. This is the first species of Ancyrocephalinae described from gills of a galaxiid. PMID:17626345

  5. Composição e diversidade da ictiofauna em riachos do Cerrado, bacia do ribeirão Ouvidor, alto rio Paraná, Goiás, Brasil Fish diversity and composition in Cerrado streams, Ribeirão Ouvidor basin, upper Paraná River basin, Goiás, Brazil

    Directory of Open Access Journals (Sweden)

    Nicelly B. Araújo

    2007-12-01

    Full Text Available Este estudo tem como objetivo descrever ecologicamente a ictiofauna quanto à riqueza, abundância, diversidade de Shannon-Wiener, uniformidade, relação riqueza/abundância e constância. As amostragens da ictiofauna foram realizadas bimestralmente de agosto de 2004 a junho de 2005 num trecho de 50 m de comprimento em nove afluentes e na calha principal do ribeirão Ouvidor, bacia do Alto Paraná. A coleta dos peixes foi realizada utilizando-se a pesca elétrica. Foram coletados 4049 indivíduos distribuídos em 35 espécies, seis ordens e 14 famílias. As espécies mais abundantes na bacia foram Astyanax cf. fasciatus Cuvier, 1819 (762 indivíduos, Poecilia reticulata Peters, 1859 (725 e Astyanax altiparanae Garutti & Britski, 2000 (650. A correlação encontrada entre a largura da calha e a riqueza sugere que riachos largos apresentam maior riqueza que estes estreitos. Apenas a diversidade de Shannon-Wiener variou significativamente entre os riachos amostrados. Astyanax cf. fasciatus e Rhamdia quelen Quoy & Gaimard, 1824 estiveram presentes em todos os trechos considerados, enquanto que a maior quantidade de espécies constantes foi encontrada no riacho Santo Antônio.This study aims to describe the fish assemblage using ecological descriptors (richness, abundance, diversity of Shannon-Wiener, uniformity, relation richness/abundance and constancy. Fish sampling were carried out every two month from August 2004 to June 2005 in a stretch of 50 m long in nine tributaries and in the main channel of the Ribeirão Ouvidor. Four thousand forty-nine fish were collected using electric fishing equipment. These individuals are distributed in 35 species, six Orders and fourteen families. The most abundant species were Astyanax cf. fasciatus Cuvier, 1819 (762 individuals, Poecilia reticulata Peters, 1859 (725 and Astyanax altiparanae Garutti & Britski, 2000 (650. The correlation between the channel width and the richness suggests that width streams has

  6. Evaluation of transferability of microsatellite loci in eight species of Astyanax” Avaliação da transferibilidade de lócus de microssatélites em oito espécies de “Astyanax”. DOI: 10.7902/ecb.v2i1.33

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    Sabrina Alves da Silva

    2011-06-01

    Full Text Available

    The fish of the genus Astyanax are popularly known as lambaris or piabas and are one of the most specious of the Neotropics. Microsatellites are a type of molecular markerformed by arrangements of tandem repetitions up to six nucleotides. They are widely used for individual identification and tracking of the biological history of populations, since they typically generate species-specific patterns. This study aimed to verify the cross-amplification of primers for six microsatellite loci developed from Astyanax mexicanus in other Astyanax species. There were tested for the transferability of the loci eight species of Astyanax. Aiming to determine the best annealing temperature of each primer amplification, tests were performed using temperature gradient termocycler. We get amplification with four primer sets in at least some species. Four species shows positive amplification pattern for one primer, with a quite polymorphic pattern.

    Os peixes do gênero Astyanax são popularmente conhecidos como lambaris ou piabas e são uns dos mais especiosos da região neotropical. Os microssatélites são um tipo de marcador molecular formado por arranjos de repetições em tandem de dois a seis nucleotídeos. São extremamente utilizados para identificação de indivíduos e no rastreamento da história biológica de populações, uma vez que normalmente geram padrões espécie-específicos. Este trabalho teve por objetivo verificar a amplificação cruzada utilizando seis pares de primers para lócus de microssatélites desenvolvidos a partir da espécie Astyanax mexicanus em outras espécies de Astyanax. Foram testadas quanto a transferibilidade de lócus oito espécies do gênero Astyanax. Para definir a melhor temperatura de anelamento

  7. Paralogous origin of the red- and green-sensitive visual pigment genes in vertebrates.

    Science.gov (United States)

    Yokoyama, S; Starmer, W T; Yokoyama, R

    1993-05-01

    The nucleotide sequence of the red-sensitive visual pigment gene, R007Af, in the fish Astyanax fasciatus, from the initiation codon to the stop codon of this gene, including introns, is 1,592 bp, making it the shortest visual pigment gene known in vertebrates. Analysis of this and other homologous sequence data suggests that vertebrates initially had two duplicate genes and that each ancestor of Astyanax, human, and chicken independently duplicated the gene in the process of developing their red-green color vision. Furthermore, many extant red-green colorblind organisms may be explained simply by the failure of achieving very specific nucleotide substitutions at the three codon positions 180, 277, and 285, rather than by the lack of duplicate loci. PMID:8336542

  8. Sesame oil in diets for lambari: Effects on growth parameters, corporal chemical composition and physiological alterations

    OpenAIRE

    Mariene Miyoko Natori; Rachel Cristina Prehl Alves; Ricardo Henrique Franco de Oliveira; Julio Guerra Segura; Elisabete Maria Macedo Viegas

    2016-01-01

    ABSTRACT: The inclusion of sesame oil associated with soybean, linseed and freshwater fish residue oil in the diets fed to Lambaris Astyanax altiparanaewas evaluated by the growth performance parameters, body composition and possible physiological changes (GARUTTI & BRISTSKI, 2000). The experiment was a completely randomized design in two factorial parameters tested: three oil types (soy oil (SO), linseed oil (LO) and freshwater fish residue oil (FRO)), combined or not with sesame oil (SEO), ...

  9. Reproductive strategies and genetic variability in tropical freshwater fish

    OpenAIRE

    Maria Dolores Peres Lassala; Erasmo Renesto

    2007-01-01

    We estimated the genetic variability of nine fish species from the Brazilian upper Paraná River floodplain (Astyanax altiparanae, Hoplias malabaricus, Leporinus lacustris, Loricariichthys platymetopon, Parauchenipterus galeatus, Pimelodus maculatus, Rhaphiodon vulpinus, Roeboides paranensis and Serrasalmus marginatus) based on data for 36 putative allozyme loci obtained using corn starch gel electrophoresis of 13 enzymatic systems: aspartate aminotransferase (EC 2.6.1.1), acid phosphatase (EC...

  10. Avaliação da toxicidade dos compostos fipronil, nitrato de chumbo e naftaleno em peixes

    OpenAIRE

    Ransdorf, Wanessa

    2012-01-01

    Resumo: Diante da grande diversidade de compostos quimicos chegando as aguas naturais, e de grande interesse conhecer os efeitos destes nos organismos aquaticos. No Brasil, ainda sao poucos os estudos visando estudar os efeitos dos agentes xenobioticos nas especies endemicas. Nesse sentido, no presente trabalho, sao apresentados os resultados da toxicidade de tres compostos quimicos (fipronil, nitrato de chumbo e naftaleno) em duas especies de peixes nativas: Rhamdia quelen e Astyanax sp, ale...

  11. Parasites of four ornamental fish from the Chumucuí River (Bragança, Pará, Brazil Parasitas de quatro peixes ornamentais do Rio Chumucuí (Bragança-Pará, Brasil

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    Rodrigo Yudi Fujimoto

    Full Text Available The objective of the present study was to evaluate the parasite fauna of four species of ornamental fish collected in the Chumucuí River, municipality of Bragança, Pará, Brazil. From June 2006 to December 2007. Fishes (n=307 belonging to four species were collected, including 23 specimens of Moenkhausia sanctaefilomenae (redeye tetra, 37 Carnegiella strigata (marbled hatchetfish, 7 Chilodus punctatus (spotted headstander, and 240 Astyanax bimaculatus (twospot astyanax. The parasites found belonged to three taxa: monogeneans in the gills, nematodes (larvae of Capillaria sp. and Contracaecum sp. in the digestive tract and liver and acanthocephalans (Quadrigyrus torquatus, Q. brasiliensis and Q. nickoli in the stomach and intestine. Astyanax bimaculatus presented higher prevalence of acanthocephalans in the wet season, and lower prevalence of nematodes in the dry season. The possible importance of these parasites in the exportation of ornamental fish is discussed.O objetivo do presente trabalho foi avaliar a fauna parasitária de quatro espécies de peixes ornamentais capturados no rio Chumucuí, no município de Bragança-PA. Foram coletados um total de 307 peixes pertencentes a 4 espécies, sendo elas: Moenkhausia sanctaefilomenae (olho de fogo, n = 23, Carnegiella strigata (borboleta, n = 37, Chilodus punctatus (cabeça-para-baixo, n = 7 e Astyanax bimaculatus (lambari, n = 240 coletados de junho de 2006 a dezembro de 2007. Foram observados 3 taxa parasitando os peixes: monogenéticos nas brânquias, nematóides (larvas de Capillaria sp. e Contracaecum sp. no trato digestório e fígado e acantocéfalos (Quadrigyrus torquatus, Q. brasiliensis e Q. nickoli no estômago e intestino. Astyanax bimaculatus apresentou maior prevalência de acantocéfalos na estação chuvosa, menor prevalência de nematóides na estação seca. Discute-se a eventual importância destes parasitas na exportação de peixes ornamentais.

  12. Caracterización del consumo de larvas de culícidos (Diptera en dos especies de peces indígenas de la zona central de Argentina

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    Alejo F. Bonifacio

    2014-09-01

    Full Text Available Los mosquitos representan una amenaza para la salud del hombre y de los animales debido a que actúan como vectores de distintas enfermedades. Especies de peces nativos son potenciales candidatos a tenerse en cuenta para control biológico de poblaciones de culícidos. Experiencias de consumo de media hora y de 24 horas por Cnesterodon decemmaculatus (Jenyns, 1842 y Jenynsia multidentata (Jenyns, 1842 se llevaron a cabo con larvas de Culex pipiens (Linnaeus, 1758, midiéndose longitud estándar, ancho de boca y peso en individuos de las dos especies. En ambas pruebas, J. multidentata consumió más C. pipiens que C. decemmaculatus, consumiendo las hembras de esta última especie más que los machos (e igual a ambos sexos de J. multidentata en la prueba de 24 horas de duración. Estos resultados no variaron cuando se compararon tantos consumos absolutos o relativos para las pruebas de media hora, sin embargo cuando se compararon los consumos relativos al peso no se encontraron diferencias entre las especies para las pruebas de 24 horas. Análisis de regresión entre las tasas de consumo versus las variables morfométricas y el peso mostraron poco valor explicativo en las pruebas de media hora de duración, mientras que en las pruebas de 24 horas de duración los análisis de regresión tuvieron un mayor valor explicativo, especialmente con el ancho de la boca. Por último, pruebas de media hora de duración fueron llevadas a cabo exponiendo a hembras de C. decemmaculatus con larvas de C. pipiens y Aedes aegypti (Linnaeus, 1742 observándose una fuerte preferencia por las últimas. Este trabajo permitió evidenciar que las especies de peces en estudio presentan grandes diferencias en las tasas de consumo de C. pipiens en periodos cortos. Estas diferencias se atenuaron cuando las tasas de consumo se prolongaron y hasta llegar a desaparecer cuando el peso se tuvo en cuenta.

  13. Morphological development of Corydoras aff. paleatus (Siluriformes, Callichthyidae and correlation with the emergence of motor and social behaviors

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    Daniel Rodríguez-Ithurralde

    2014-06-01

    Full Text Available Here we examine major anatomical characteristics of Corydoras aff. paleatus (Jenyns, 1842 post-hatching development, in parallel with its neurobehavioral evolution. Eleutheroembryonic phase, 4.3-8.8 days post-fertilization (dpf; 4.3-6.4 mm standard length (SL encompasses from hatching to transition to exogenous feeding. Protopterygiolarval phase (8.9-10.9 dpf; 6.5-6.7 mm SL goes from feeding transition to the commencement of unpaired fin differentiation, which marks the start of pterygiolarval phase (11-33 dpf; 6.8-10.7 mm SL defined by appearance of lepidotrichia in the dorsal part of the median finfold. This phase ends with the full detachment and differentiation of unpaired fins, events signaling the commencement of the juvenile period (34-60 dpf; 10.8-18.0 mm SL. Eleutheroembryonic phase focuses on hiding and differentiation of mechanosensory, chemosensory and central neural systems, crucial for supplying the larval period with efficient escape and nutrient detection-capture neurocircuits. Protopterygiolarval priorities include visual development and respiratory, digestive and hydrodynamic efficiencies. Pterygiolarval priorities change towards higher swimming efficacy, including carangiform and vertical swimming, necessary for the high social interaction typical of this species. At the end of the protopterygiolarval phase, simple resting and foraging aggregations are seen. Resting and foraging shoals grow in complexity and participant number during pterygiolarval phase, but particularly during juvenile period.

  14. Developmental stages and fecundity of Lepeophtheirus simplex (Copepoda: Caligidae) parasitic on bullseye puffer fish (Sphoeroides annulatus).

    Science.gov (United States)

    Neptali Morales-Serna, Francisco; Rivas-Salas, Ana Ines; Gomez, Samuel; Fajer-Avila, Emma Josefina

    2015-01-01

    Lepeophtheirus simplex Ho, Gómez et Fajer-Avila, 2001 is a parasite of Sphoeroides annulatus (Jenyns), an economically important fish species, with potential for aquaculture, in northwestern Mexico. The goal of this study was to describe the developmental stages under experimental conditions and seasonal fecundity of this parasite on wild fish. There are two naupliar, one copepodid, two chalimus and two pre-adult stages preceding the adult of L. simplex. The results support previous findings, which point out that the life cycle of the caligid copepods includes only six post-naupliar stages. The generation time from egg extrusion to adult for L. simplex was approximately 10 days at 22 °C. The body length of the ovigerous females ranged between 2.2 and 4.1 mm, and its fecundity between 12 and 36 eggs per string. Fecundity was negatively correlated with the egg size and positively correlated with the egg string length. Our data did not reveal significant differences in fecundity among sampling months, but ovigerous females were significantly larger in March (when water temperature was 22 °C) than in June and July (when water temperature was 30 °C). To some extent, our fecundity results contrast with those found in species of sea lice from higher latitudes. Undoubtedly, biological information on different species of sea lice from different environmental conditions will enhance our understanding of their infection strategies and will be valuable, given the increasing interest in marine fish farming in Mexico. PMID:25960548

  15. A new hedrurid species (Nematoda) from galaxiid fishes in Patagonia (Argentina) and infection of amphipods as intermediate host.

    Science.gov (United States)

    Brugni, Norma L; Viozzi, Gustavo P

    2010-02-01

    During a parasite survey of galaxiid fishes (Galaxiidae) from Patagonian Andean lakes, a new species of nematode, Hedruris suttonae n. sp. was collected from the stomach of the native Galaxias maculatus (Jenyns) and G. platei (Steindachner). Specimens were examined by light and scanning electron microscopy, especially head morphology, female caudal prehensile structure, and distribution of spines. The new species is distinguished by body and tail size, morphology and size of spicules, the arrangement of caudal papillae in the male, the female caudal hook, and size of eggs. Hyalella patagonica (Ortmann), a Neotropical species of Amphipoda, is reported as its natural intermediate host. Data regarding prevalence and mean intensity in the intermediate and definitive hosts are included. The diet and habitat of the hosts, the percentage of gravid females, the high values of prevalence, and mean intensity in galaxiid fishes, as well as the wide distribution of H. suttonae , collectively indicate that, in these oligotrophic Andean lakes, G. maculatus and G. platei are true definitive hosts of this nematode. PMID:19737026

  16. Component population study of Acanthocephalus tumescens (Acanthocephala) in fishes from Lake Moreno, Argentina.

    Science.gov (United States)

    Rauque, Carlos A; Viozzi, Gustavo P; Semenas, Liliana G

    2003-03-01

    Seasonal samples of all fish species from Lake Moreno were taken in order to determine the presence of paratenia, to evaluate the status of the hosts and to characterise the transmission of Acanthocephalus tumescens (von Linstow, 1896) at the component population level. Prevalence, mean abundance, mean intensity, numbers of gravid females, relative abundance of the different fish species, relative output of eggs and relative flow rates for each host species were computed. Acanthocephalus tumescens showed low host specificity, successfully parasitizing six out of eight fish species present in the lake. No paratenic infection was registered. If prevalence, mean abundance, and number of gravid females are considered, host species can be placed in a continuum from the most to least suitable as follows: Galaxias platei Steindachner, Diplomystes viedmensis (Mac Donagh), Oncorhynchus mykiss (Walbaum), Salvelinus fontinalis (Mitchill), Percichthys trucha (Cuvier et Valenciennes) and Galaxias maculatus (Jenyns). However, when parasite flow rates and egg output were calculated, including relative abundance of each fish species, the continuum was rearranged as follows: P. trucha, O. mykiss, G. platei / G. maculatus, S. fontinalis and D. viedmensis. The first four species would be the main contributors to the population of A. tumescens in this lake, P. trucha being the major one. Different regulatory and non-regulatory mechanisms are suggested. PMID:12735727

  17. Ailinella mirabilis gen. n., sp. n. (eucestoda: pseudophyllidea) from Galaxias maculatus (Pisces: Galaxiidae) in the Andean-Patagonian region of Argentina.

    Science.gov (United States)

    de Pertierra, Alicia A Gil; Semenas, Liliana G

    2006-12-01

    Ailinella gen. n. (Pseudophyllidea: Triaenophoridae) is proposed to accommodate Ailinella mirabilis sp. n. from Galaxias maculatus (Jenyns, 1842), a freshwater fish inhabiting the Andean lakes in Argentinean Patagonia. Ailinella belongs to the Triaenophoridae because it has a marginal genital pore, a follicular vitelline gland, and a ventral uterine pore. The new genus can be distinguished from other triaenophorids by the following combination of characters: a small body size, a low number of proglottides, which are longer than wide, a truncated pyramidal to globular scolex, a rectangular apical disc, presence of the neck, lack of internal longitudinal musculature separating the cortex from the medulla, testes distributed in one central field surrounding the ovary laterally and posteriorly, the vagina predominantly anterior to the cirrus sac, vitelline follicles circum-medullary, the genital pores post-equatorial, a saccate uterus, and operculate eggs. Blade-like spiniform microtriches were present on all tegument surfaces, and tumuli on all surfaces of the scolex and the anterior surface of the neck. Microtriches were characterized according to their size and density, and tumuli according to their size, inter-tumulus distance and density. Ailinella mirabilis is the first cestode described from G. maculatus and the second triaenophorid species recorded from a South American freshwater fish. PMID:17256203

  18. A new genus of Cystidicolid nematode from the stomach of Galaxias maculatus (Osmeriformes: Galaxiidae) in Patagonia (Argentina).

    Science.gov (United States)

    Brugni, Norma L; Viozzi, Gustavo P; Fernández, María V; Vega, Rocío M

    2009-02-01

    During a parasitological survey of Galaxias maculatus (Jenyns) from Patagonian Andean Lakes, specimens of a new species of nematode were collected from the stomach of fish and studied by light and scanning electron microscopy. This species is described as the only member of a newly proposed genus of Cystidicolidae by having oral opening dorsoventrally elongated, 2 lateral pseudolabia, 4 cephalic papillae, stoma (vestibule) elongated, esophagus divided into anterior muscular and posterior glandular sections, and caudal alae in males. Placonema n. gen. (Habronematoidea, Cystidicolidae) is characterized by the combination of the following features: oral opening dorsoventrally elongated demarcated by 4 sclerotized plates and 2 well-developed pseudolabia projected to the buccal cavity, each pseudolabium with conspicuous, conical, anterior protuberances. Four cephalic papillae and deirids simple. Male with caudal alae, area rugosa absent, 4 pairs of preanal papillae, unpaired papilla present on anterior cloacal lip, and 6 pairs of postanal papillae. Larvigerous eggs without filaments. Placonema pataguense n. gen. n. sp. infects the stomach of G. maculatus from Lake Patagua (Patagonia, Argentina) and is the first species of Cystidicolidae described from G. maculatus. PMID:18652524

  19. New evidence on a cold case: trophic transmission, distribution and host-specificity in Hedruris spinigera (Nematoda: Hedruridae).

    Science.gov (United States)

    Luque, José L; Vieira, Fabiano M; Herrmann, Kristin; King, Tania M; Poulin, Robert; Lagrue, Clément

    2010-09-01

    The life cycle of Hedruris spinigera Baylis, 1931 (Nematoda: Hedruridae) is determined here with the first formal identification of the parasite's intermediate host: the crustacean amphipod Paracorophium excavatum Thomson. Adult H. spinigera are redescribed from specimens collected from the stomach of fishes, Retropinna retropinna (Richardson) and Aldrichettaforsteri (Valenciennes), from Lake Waihola, New Zealand. Immature adults of the parasite collected from intermediate hosts (P. excavatum) are also described for the first time. The prevalence, abundance and intensity of infection of H. spinigera in several fish species are quantified along with the occurrence of P. excavatum, the parasite's intermediate host, in fish stomach contents. Although H. spinigera's transmission mode (trophic transmission) and fish diet potentially expose all fish species to infection, some level of host specificity must exist as parasite prevalence, abundance and intensity of infection vary greatly between potential definitive host species. We suggest here that the anatomy of the fish digestive tract and especially that of the stomach plays an important role in host suitability for H. spinigera. While P. excavatum is the only intermediate host in Lake Waihola, H. spinigera was found in six different fish species: Aldrichetta forsteri, Galaxias maculatus (Jenyns), Retropinna retropinna, Rhombosolea retiaria Hutton, Perca fluviatilis Linnaeus and Salmo trutta Linnaeus; although typical hedrurid attachment and mating positions were observed only in R. retropinna and A. forsteri. The limited distribution of H. spinigera is most likely due to that of its different host species (intermediate and definitive), all inhabitants of coastal fresh and brackish waters. PMID:20941914

  20. Food resource used by small-sized fish in macrophyte patches in ponds of the upper Paraná river floodplain = Uso do alimento por peixes de pequeno porte associados às macrófitas aquáticas em lagoas da planície de inundação do alto rio Paraná

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    Valdirene Esgarbosa Loureiro Crippa

    2009-04-01

    Full Text Available This study analyzed the diet of seven small-sized fish species(Characidae and assessed their use of food resources. The species were collected in 2001 from nine ponds with aquatic macrophytes in the Paraná river floodplain, Brazil. Astyanax altiparanae, Astyanax fasciatus, Hemigrammus marginatus and Moenkhausia intermedia consumed aquatic and terrestrial insects. Bryconomericus stramineus andMoenkhausia sanctaefilomenae co-dominantly ate insects and microcrustaceans, whereas Hyphessobrycon eques had microcrustaceans as their most important food resource. Overlapping feeding coefficients varied from intermediate (0.4-0.6 to low (Uso do alimento por peixes de pequeno porte associados a macrófitas aquáticas em lagoas da planície de inundação do alto rio Paraná. Nesse estudo foi investigada a dieta de sete espécies de peixesde pequeno porte (Characidae, em nove lagoas providas de macrófitas aquáticas, da planície aluvial do alto rio Paraná, Brasil, no ano de 2001. Astyanax altiparanae, Astyanax fasciatus, Hemigrammus marginatus e Moenkhausia intermedia consumiram insetos aquáticos e terrestres; para Bryconomericus stramineus e Moenkhausia sanctaefilomenae houve co-dominância de insetos aquáticos e microcrustáceos na dieta, enquanto que Hyphessobrycon eques exploroupredominantemente microcrustáceos. Os valores de sobreposição alimentar variaram de intermediário (0,4-0,6 a baixos (< 0,4 para a maioria dos pares de espécies. Com relação ao comprimento do intestino constatou-se a maior média ajustada para A. altiparanae eA. fasciatus e a menor para H. eques. Todos esses resultados analisados conjuntamente permitem inferir que a dimensão de nicho trófico segregou parcialmente essas espécies. E ainda que, a co-existência e elevada abundância desses pequenos peixes nas regiõesmarginais das lagoas é proporcionada pela alta adaptabilidade trófica, pela ausência de especializações no trato digestivo (exceto para o

  1. Redescription of Prosthenhystera obesa (Diesing, 1850 (Callodistomidae, Digenea with New Host Records and Data on Morphological Variability

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    Anna Kohn

    1997-03-01

    Full Text Available Prosthenhystera obesa (Diesing,1850 Travassos, 1922 from the gall bladder of Astyanax bimaculatus, Caranx gibbosus, Galeocharax humeralis, Leporinus copelandii, Pimelodus fur, Pseudopimelodus roosevelti, Salminus brevidens, Salminus maxillosus and from the new hosts, Cynopotamus amazonum and Triurobrycon lundii is redescribed, demonstrating a large morphological variation, mainly in body and testes size and shape. New hosts harbouring immature specimens of P. obesa are presented: Brycon sp., Leporellus vittatus, Pachyurus squamipinnis, Pimelodus clarias, Pseudoplatystoma corruscans and Salminus hilarii. Scanning electron microscopy micrographies, original figures and measurements of adult and immature specimens from different Brazilian hosts and localities are presented

  2. Complete mitochondrial genome of the penguin tetra, Thayeria boehlkei.

    Science.gov (United States)

    Xiao, Gui-Bao; Li, Jiong-Tang; Li, Xiao-Min; Wang, Xiu-Li; Sun, Xiao-Wen

    2016-09-01

    The penguin tetra (Thayeria boehlkei) is one of the most popular aquarium fish and belongs to the family of Characidae. The composition, phylogeny, and classification of this family are uncertain. Here, the complete mitogenome of T. boehlkei was reported to be 16,524 bp in length. It contains 13 protein-coding genes, 22 transfer RNA genes and 2 ribosomal RNA genes. Comparing the mitochondrial genome of T. boehlkei with its congener Astyanax mexicanus revealed high-sequence similarity. The mitochondrial genome of T. boehlkei will contribute to conservation studies and evolution analysis of Characidae family. PMID:25707407

  3. Uso de biomarcadores para monitoramento das águas do Córrego Arara no município de Rio Brilhante, MS, Brasil

    OpenAIRE

    Elisangela Bortoluci Maceda; Alexéia Barufatti Grisolia/; Jussara Oliveira Vaini; Liliam Silvia Candido

    2015-01-01

    O objetivo deste trabalho foi avaliar a mutagenicidade, genotoxicidade e citotoxicidade de amostras de água provenientes do Córrego Arara no município de Rio Brilhante, MS, Brasil, por meio de testes toxicológicos utilizando biomarcadores. Para avaliar a mutagenicidade utilizou-se o teste de micronúcleo, para a genotoxicidade o ensaio cometa, ambos com Astyanax altiparanae, e para analisar a citotoxicidade utilizou-se o teste de Allium cepa. As coletas foram realizadas nos meses de abril e ju...

  4. Nuclear DNA content determination in Characiformes fish (Teleostei, Ostariophysi from the Neotropical region

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    Carvalho Margarida Lima

    2002-01-01

    Full Text Available In the present study, nuclear DNA content was analyzed in 53 species of Characiformes fish from the Neotropical region. Diploid number ranged from 2n = 48 in Astyanax fasciatus, Gymnocorymbus ternetzi and Hyphessobrycon griemi to 2n = 102 in Potamorhina squamoralevis, with a modal number of 54 chromosomes. Nuclear DNA content ranged from 1.70 ± 0.04 pg of DNA per diploid nucleus in Acestrorhynchus pantaneiro to 3.94 ± 0.09 pg in Tetragonopterus chalceus. A general analysis showed a mean value of 2.9 pg of DNA per diploid nucleus. Very similar DNA content values were observed in the species of the family Cynodontidae which showed a variation of 3% between the two genera studied. Small variations were observed between populations of Gymnocorymbus ternetzi, Astyanax fasciatus and Moenkhausia sanctaefilomenae (Characidae, Tetragonopterinae. The subfamilies Tetragonopterinae and Acestrorhynchinae (Characidae presented the widest range, about 96%. Even in those families in which diploid number and karyotypic formulae were conserved such as the families Anostomidae, Curimatidae, and Prochilodontidae, episodes leading to losses or gains of genetic material became fixed in their evolutionary history.

  5. Food resource used by small-sized fish in macrophyte patches in ponds of the upper Paraná river floodplain - DOI: 10.4025/actascibiolsci.v31i2.3266

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    Norma Segatti Hahn

    2009-05-01

    Full Text Available This study analyzed the diet of seven small-sized fish species (Characidae and assessed their use of food resources. The species were collected in 2001 from nine ponds with aquatic macrophytes in the Paraná river floodplain, Brazil. Astyanax altiparanae, Astyanax fasciatus, Hemigrammus marginatus and Moenkhausia intermédia consumed aquatic and terrestrial insects. Bryconomericus stramineus and Moenkhausia sanctaefilomenae co-dominantly ate insects and microcrustaceans, whereas Hyphessobrycon eques had microcrustaceans as their most important food resource. Overlapping feeding coefficients varied from intermediate (0.4-0.6 to low (A. altiparanae and A. fasciatus, while a smaller mean was found for H. eques. When comparing all these results, it is possible to conclude that the species were partially segregated by the trophic niche dimension. Thus, the co-existence and higher abundance of these small fish in the shoreline of the ponds is explained by high feeding adaptability, absence of specializations in the feeding tract (except intestinal length and the wide food supply provided by aquatic macrophytes.

  6. The impact of water pollution on fish species in southeast region of Goiás, Brazil.

    Science.gov (United States)

    Vaz S Silva, Sabrina; Dias, Aurélio Henrique C; Dutra, Elaine S; Pavanin, Alfredo L; Morelli, Sandra; Pereira, Boscolli B

    2016-01-01

    The rivers from the region of Catalão, Southeast Goiás State, Brazil, are exposed to intense anthropogenic influences including agricultural activities, industry, and urban waste. The aim of this study was to determine the severity of water pollution by conducting an experiment involving in situ biomonitoring of water constituents on genotoxicity in fish inhabiting these sites. The genotoxicity of three sites of the region were analyzed utilizing the micronucleus (MN) test. It was of interest to determine whether there were differences between sampling sites such as urban perimeter, agriculture, and fertilizer industry in control, and monitored species including Astyanax fasciatus, Astyanax altiparanae, and Characidium fasciatum. Data demonstrated that the species at sites 1, 2, and 3 exhibited a marked increase in frequency of MN compared to fish from site 4. Significant elevation in frequency of MN occurred in erythrocytes of A. fasciatus and A. altiparanae at sites 1 and 2. At site 3 higher frequencies of MN were observed in C. fasciatum. MN induction in C. fasciatum was correlated with chromium levels in water and sediment, while A. fasciatum and A. altiparanae showed an association with zinc in water and sediment. Data suggest that benthic and nektonic fish species display different sensitivities in relation to anthropogenic contaminant influences. PMID:26699803

  7. Profile of micronucleus frequencies and DNA damage in different species of fish in a eutrophic tropical lake.

    Science.gov (United States)

    Grisolia, Cesar K; Rivero, Carla L G; Starling, Fernando L R M; da Silva, Izabel C R; Barbosa, Antonio C; Dorea, Jose G

    2009-01-01

    Lake Paranoá is a tropical reservoir for the City of Brasilia, which became eutrophic due to inadequate sewage treatment associated with intensive population growth. At present, two wastewater treatment plants are capable of processing up to 95% of the domestic sewage, thereby successfully reducing eutrophization. We evaluated both genotoxic and cytotoxic parameters in several fish species (Geophagus brasiliensis, Cichla temensis, Hoplias malabaricus, Astyanax bimaculatus lacustres, Oreochromis niloticus, Cyprinus carpio and Steindachnerina insculpita) by using the micronucleus (MN) test, the comet assay and nuclear abnormality assessment in peripheral erythrocytes. The highest frequencies of MN were found in Cichla temensis and Hoplias malabaricus, which were statistically significant when compared to the other species. However, Steindachnerina insculpita (a detritivorous and lake-floor feeder species) showed the highest index of DNA damage in the comet assay, followed by C. temensis (piscivorous). Nuclear abnormalities, such as binucleated, blebbed, lobed and notched cells, were used as evidence of cytotoxicity. Oreochromis niloticus followed by Hoplias malaricus, ominivorous/detritivotous and piscivorous species, respectively, presented the highest frequency of nuclear abnormalities, especially notched cells, while the herbivorous Astyanax bimaculatus lacustres showed the lowest frequency compared to the other species studied. Thus, for biomonitoring aquatic genotoxins under field conditions, the food web should also be considered.

  8. Profile of micronucleus frequencies and DNA damage in different species of fish in a eutrophic tropical lake

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    Cesar K. Grisolia

    2009-01-01

    Full Text Available Lake Paranoá is a tropical reservoir for the City of Brasilia, which became eutrophic due to inadequate sewage treatment associated with intensive population growth. At present, two wastewater treatment plants are capable of processing up to 95% of the domestic sewage, thereby successfully reducing eutrophization. We evaluated both genotoxic and cytotoxic parameters in several fish species ( Geophagus brasiliensis , Cichla temensis , Hoplias malabaricus , Astyanax bimaculatus lacustres , Oreochromis niloticus , Cyprinus carpio and Steindachnerina insculpita by using the micronucleus (MN test, the comet assay and nuclear abnormality assessment in peripheral erythrocytes. The highest frequencies of MN were found in Cichla temensis and Hoplias malabaricus , which were statistically significant when compared to the other species. However, Steindachnerina insculpita (a detritivorous and lake-floor feeder species showed the highest index of DNA damage in the comet assay, followed by C. temensis (piscivorous. Nuclear abnormalities, such as binucleated, blebbed, lobed and notched cells, were used as evidence of cytotoxicity. Oreochromis niloticus followed by Hoplias malaricus , ominivorous/detritivotous and piscivorous species, respectively, presented the highest frequency of nuclear abnormalities, especially notched cells, while the herbivorous Astyanax bimaculatus lacustres showed the lowest frequency compared to the other species studied. Thus, for biomonitoring aquatic genotoxins under field conditions, the food web should also be considered.

  9. Effects of river damming in Neotropical piscivorous and omnivorous fish: feeding, body condition and abundances

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    Larissa Strictar Pereira

    2016-01-01

    Full Text Available ABSTRACT The increase in abundance of small-sized fishes is common after a reservoir is formed. There is an increase in the consumption of fish, from typically piscivorous fish to opportunistic species that take advantage of abundant resources. This study aims to evaluate the effects of diet changes induced by damming on the feeding activity and condition factor of typically piscivorous (Hoplias aff. malabaricus and Oligosarcus longirostris and opportunistic (Astyanax lacustris (ex Astyanax altiparanae and Pimelodus britskii . Sampling was conducted before and after the impoundment in the Iguaçu River in the region of Salto Caxias, Paraná State, Brazil. Stomach contents were analysed by the volumetric method. Feeding activity and body condition were inferred by the mean stomach repletion index and the mean condition factor. Typically piscivorous species presented a general tendency of decreased feeding activity and increased condition factor, while opportunistic species, presented a decrease in condition and feeding activity in the most affected sites. The increase in the condition factor of piscivorous fish suggests that these species benefit by the increased abundance of small size prey fish. Some opportunist species that do not have adjustments for the piscivorous diet, regardless of the intensity of consumption and resource availability, can suffer negative reflex when adopting a piscivorous diet.

  10. Integrative taxonomy detects cryptic and overlooked fish species in a neotropical river basin.

    Science.gov (United States)

    Gomes, Laís Carvalho; Pessali, Tiago Casarim; Sales, Naiara Guimarães; Pompeu, Paulo Santos; Carvalho, Daniel Cardoso

    2015-10-01

    The great freshwater fish diversity found in the neotropical region makes management and conservation actions challenging. Due to shortage of taxonomists and insufficient infrastructure to deal with such great biodiversity (i.e. taxonomic impediment), proposed remedies to accelerate species identification and descriptions include techniques that combine DNA-based identification and concise morphological description. The building of a DNA barcode reference database correlating meristic and genetic data was developed for 75 % of the Mucuri River basin's freshwater fish. We obtained a total of 141 DNA barcode sequences from 37 species belonging to 30 genera, 19 families, and 5 orders. Genetic distances within species, genera, and families were 0.74, 9.5, and 18.86 %, respectively. All species could be clearly identified by the DNA barcodes. Divergences between meristic morphological characteristics and DNA barcodes revealed two cryptic species among the Cyphocharax gilbert and Astyanax gr. bimaculatus specimens, and helped to identify two overlooked species within the Gymnotus and Astyanax taxa. Therefore, using a simplified model of neotropical biodiversity, we tested the efficiency of an integrative taxonomy approach for species discovery, identification of cryptic diversity, and accelerating biodiversity descriptions.

  11. The impact of water pollution on fish species in southeast region of Goiás, Brazil.

    Science.gov (United States)

    Vaz S Silva, Sabrina; Dias, Aurélio Henrique C; Dutra, Elaine S; Pavanin, Alfredo L; Morelli, Sandra; Pereira, Boscolli B

    2016-01-01

    The rivers from the region of Catalão, Southeast Goiás State, Brazil, are exposed to intense anthropogenic influences including agricultural activities, industry, and urban waste. The aim of this study was to determine the severity of water pollution by conducting an experiment involving in situ biomonitoring of water constituents on genotoxicity in fish inhabiting these sites. The genotoxicity of three sites of the region were analyzed utilizing the micronucleus (MN) test. It was of interest to determine whether there were differences between sampling sites such as urban perimeter, agriculture, and fertilizer industry in control, and monitored species including Astyanax fasciatus, Astyanax altiparanae, and Characidium fasciatum. Data demonstrated that the species at sites 1, 2, and 3 exhibited a marked increase in frequency of MN compared to fish from site 4. Significant elevation in frequency of MN occurred in erythrocytes of A. fasciatus and A. altiparanae at sites 1 and 2. At site 3 higher frequencies of MN were observed in C. fasciatum. MN induction in C. fasciatum was correlated with chromium levels in water and sediment, while A. fasciatum and A. altiparanae showed an association with zinc in water and sediment. Data suggest that benthic and nektonic fish species display different sensitivities in relation to anthropogenic contaminant influences.

  12. Descripción del cráneo de Bramocharax caballeroi Contreras & Rivera 1985 (Pisces, Characidae, pez endémico del Lago de Catemaco, Veracruz, México Description of the skull of Bramocharax caballeroi Contreras & Rivera 1985 (Pisces, Characidae, endemic fish to Catemaco Lake, Veracruz, Mexico

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    Martha Elena Valdez-Moreno

    2009-04-01

    Full Text Available El género Bramocharax se distribuye del centro-norte de Centro América a México. Hasta este momento se conoce a Bramocharax bransfordi de Nicaragua y Costa Rica, a B. dorioni y B. baileyi de Guatemala y a B. caballeroi del lago de Catemaco, Veracruz, México. El trabajo tuvo por objetivo estudiar detalladamente el cráneo de Bramocharax caballeroi a partir del análisis de 37 topotipos de diferentes tallas y compararlo con otras especies relacionadas. B. caballeroi presenta 58 huesos en su cráneo, de los cuales 49 son elementos pareados. En vista lateral su perfil es ovalado, debido a los huesos que conforman el hocico (etmoides, vómer, etmoides lateral, mandíbula, maxila, premaxila, ecto y mesopterigoides, así como el frontal y los circunorbitales, son alargados. El margen dorsal es ligeramente cóncavo y la parte anterior alargada. En los ejemplares menores a 80 mm todos los huesos son más lisos y conforme los organismos tienen una talla mayor, se hacen más robustos y los bordes de cada hueso se hacen más irregulares. Al comparar el cráneo de B. caballeroi con el de Astyanax mexicanus se encontraron diferencias en 25 huesos, mientras que al hacerlo con A. fasciatus, los principales contrastes fueron la longitud del supraoccipital, la forma del opérculo y del infraorbital 3. Adicionalmente, se encontraron diferencias importantes en la dentición y en las branquiespinas así, como en las placas y suspensores faríngeos con respecto a los Astyanax.The Bramocharax genus is distributed from Central America to Mexico. Until now the species known are Bramocharax bransfordi collected in Nicaragua and Costa Rica, B. dorioni and B. baileyi from Guatemala and B. caballeroi from Catemaco Lake, Veracruz, Mexico. The aim of this work is to realize a detailed description of the skull for Bramocharax caballeroi from the analysis of 37 different topotypes. The skull of this species has 58 osteological elements, 49 of them coupled. Shape is oval in

  13. Six new and one previously described species of Pseudorhabdosynochus (Monogenoidea, Diplectanidae) infecting the gills of groupers (Perciformes, Serranidae) from the Pacific coasts of Mexico and Panama.

    Science.gov (United States)

    Mendoza-Franco, Edgar F; Violante-González, Juan; Rojas Herrera, Agustín A

    2011-02-01

    Six new and 1 previously described species of Pseudorhabdosynochus (Diplectanidae) are described and/or reported from the gill lamellae of 5 serranid (Perciformes) fish species from the Pacific waters in Guerrero State of Mexico and Panama City, Panama. These species are Pseudorhabdosynochus guerreroensis n. sp. from the Pacific mutton hamlet Alphestes inmaculatus Breder (type host), rivulated mutton hamlet Alphestes multiguttatus (Günther), and spotted grouper Epinephelus analogus Gill from Mexico; Pseudorhabdosynochus urceolus n. sp. from the Pacific graysby Cephalopholis panamensis (Steindachner) from Taboga Island in Panama; Pseudorhabdosynochus spirani n. sp. from the starry grouper Epinephelus labriformis (Jenyns) from Mexico and the Perlas Archipelago and Taboga Island in Panama; Pseudorhabdosynochus fulgidus n. sp. from E. labriformis from Mexico and the Perlas Archipelago and Taboga Island (type locality) in Panama; Pseudorhabdosynochus tabogaensis n. sp. from E. labriformis from Mexico and the Perlas Archipelago and Taboga Island (type locality) in Panama; Pseudorhabdosynochus anulus n. sp. from E. labriformis from Mexico and Taboga Island (type locality) in Panama; and Pseudorhabdosynochus amplidiscatum (Bravo-Hollis, 1954) Kritsky and Beverley-Burton, 1986 from E. analogus and E. labriformis from Mexico and the Perlas Archipelago and Taboga Island in Panama. All new species are mainly distinguished from other species of the genus by the shape and size of the sclerotized vagina and haptoral structures. The present specimens of Alphestes, Cephalopholis, and Epinephelus spp. represent new host records and Panama represents a new geographic record for species of Pseudorhabdosynochus. The apparent common feature supporting a close similarity of these diplectanids is a single, secondary ejaculatory bulb with thickened wall. PMID:21348602

  14. Diet and dietary overlap of three sympatric fish species in lakes of the upper Paraná River floodplain

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    Karla Danielle Gaspar da Luz

    1999-01-01

    Full Text Available For a dietary study, specimens of Astyanax bimaculatus, Astyanax schubarti, and Moenkhausia intermedia were caught monthly with seines-nets in six lakes (Pau Veio, Porto Rico, Três Amigos, Mutum, Pontal, and Canal do Meio, on the floodplain of the Upper Paraná River, from March 1992 through February 1993. We analyzed stomach contents of 599 A. bimaculatus, 293 A. schubarti, and 394 M. intermedia, by the Occurrence and Points methods, combined in the Alimentary Index (AI. This analysis revealed that these species have broad dietary spectra. A. bimaculatus was an omnivore, with a tendency toward herbivory-insectivory. In most of the lakes it consumed terrestrial insects, followed by higher plants and microcrustaceans. A. schubarti was an omnivore, consuming the same type of items in the different lakes, in different proportions depending on the locality. M. intermedia was a planktophage, feeding mainly on cladocerans (more than 50% in all the lakes except for Pontal, where higher plants were predominant (45.1%. Although A. bimaculatus and A. schubarti consumed similar items in the different localities, detrended correspondence analysis (DCA showed distinct segregation among the three species in all lakes studied.Para estudo da dieta foram capturados mensalmente exemplares de Astyanax bimaculatus, Astyanax schubarti e Moenkhausia intermedia com redes de arraste, em seis lagoas (Pau Velho, Porto Rico, Três Amigos, Mutum, Pontal e Canal do Meio, na planície de inundação do alto rio Paraná, de março/92 a fevereiro/93. Foram analisados 599 conteúdos gástricos de A. bimaculatus, 293 de A. schubarti e 394 de M. intermedia, pelos métodos de Ocorrência e Pontos, combinados no Índice Alimentar (IAi. Tal análise revelou que estas espécies apresentam amplo espectro alimentar. A. bimaculatus foi caracterizada como onívora com tendência a herbivoria-insetivoria, consumindo, na maioria das lagoas, insetos terrestres, seguidos de vegetal superior

  15. Relação peso-comprimento e estrutura da população de nove espécies de Characidae na planície de inundação do Alto Rio Paraná, Brasil Length/weight relationships and population structure of nine species of Characidae fish in the high Paraná River floodplain, Brazil

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    Maria de los Angeles Perez Lizama

    1999-01-01

    Full Text Available The length/weight relationships are described for Astyanax bimaculatus, A. schubarti, Aphyocharax nasutus, Cheirodon notomelas, Hyphessobrycon callistus, Hemigrammus marginatus, Moenkhausia intermedia, M. sanctae-filomenae and Roeboides paranensis of tropical freshwater fishes in the high Paraná River floodplain. The fishes were caught over a period of 12 month (March 1993 to February 1994. The equations of the length/weight relationships for each species were: Wt=0.0235.Ls3.13; Wt=0.0162.Ls2.89; Wt=0.0179.Ls3.11; Wt=0.0199.Ls3.09; Wt=0.0183.Ls3.10; Wt=0.0140.Ls3.14; Wt= 0.0200.Ls3.21 and Wt=0.0101.Ls3.21, respectively.

  16. Aquatic macrophytes as feeding site for small fishes in the Rosana Reservoir, Paranapanema River, southeastern Brazil.

    Science.gov (United States)

    Casatti, L; Mendes, H F; Ferreira, K M

    2003-05-01

    In the present investigation we studied the feeding habits of the fishes associated with aquatic macrophytes in the Rosana Reservoir, southeastern Brazil. Twenty fish species were collected during four field trips, regularly distributed across the dry and wet seasons. Focal snorkeling observations of the fishes were made over a total of six hours. Nine species were present in abundances of more than 1% and, therefore, had their feeding habits analyzed. Hemigrammus marginatus, Roeboides paranensis, Hyphessobrycon eques, Astyanax altiparanae, Serrasalmus spilopleura, and Bryconamericus stramineus were predominantly invertivores, with predominance of aquatic insects (Diptera, Ephemeroptera, and Trichoptera immatures) among their food items. The predominantly algivores were Apareiodon affinis, Serrapinnus notomelas, and Satanoperca pappaterra, with high frequency of filamentous blue-green algae, diatoms, clorophyts, and periderm. The different microhabitat exploitation plus diet composition suggests partitioning of resources and absence of food competition among the most representative fish species in the studied community, indicating the importance of the naturalistic approach to fish ecology studies.

  17. [Ecophysiological adaptability of tropical water organisms to salinity changes].

    Science.gov (United States)

    Chung, K S

    2001-03-01

    Physiological response of tropical organisms to salinity changes was studied for some marine, estuarine and freshwater fishes (Astyanax bimaculatus, Petenia karussii, Cyprinodon dearborni, and Oreochromis mossambicus), marine and freshwater crustaceans (Penaeus brasiliensis, Penaeus schmitti and Macrobrachium carcinus), and marine bivalves (Perna perna, Crassostrea rhizophorae, and Arca zebra) collected from Northeast Venezuela. They were acclimated for four weeks at various salinities, and (1) placed at high salinities to determine mean lethal salinity, (2) tested by increasing salinity 5@1000 per day to define upper lethal salinity tolerance limit, or (3) observed in a saline gradient tank to determine salinity preference. Acclimation level was the most significant factor. This phenomenon is important for tropical aquatic organisms in shallow waters, where they can adapt to high salinity during the dry season and cannot lose their acclimation level at low salinity during abrupt rain. For saline adaptation of tropical organisms, this behavior will contribute to their proliferation and distribution in fluctuating salinity environments.

  18. Alimentação de Oligosarcus longirostris Menezes & Gèry (Osteichthyes, acestrorhynchinae do Reservatório de Salto Segredo, Paraná, Brasil Feeding of Oligosarcus longirostris Menezes & Gèry (Osteichthyes, acestrorhynchinae of the Salto Segredo Reservoir, Paraná, Brazil

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    Ana Maria Gealh

    1998-12-01

    Full Text Available In the feeding study of O. longirostris Menezes & Gèry, 1983, 211 stomachs from fish caught between March 1993 and February 1994 were analysed. Diet composition was analysed by the index of relative importance which deals with the numerical and gravimetric occurrence frequency. Results indicated that the species is piscivorous and its preferential food consisted oíAslyanax sp. 2. It was also found that Astyanax sp. 3 became an important food item, depending on the site of capture and its availability. Availability of prey seems to have a strong influence on the diet of O. longirostris. This same tendency has been observed during the different seasons of the year. Ontogenetic changes have also been found in the basic diet.

  19. Biologia reprodutiva e reprodução induzida de duas espécies de Characidae (Osteichthyes, Characiformes) da bacia do São Francisco, Minas Gerais, Brasil Reproductive biology and induced breeding of two Characidae species (Osteichthyes, Characiformes) from the São Francisco River basin, Minas Gerais, Brazil

    OpenAIRE

    Yoshimi Sato; Edson V. Sampaio; Nelsy Fenerich-Verani; José R. Verani

    2006-01-01

    Astyanax bimaculatus (Linnaeus, 1758) e Tetragonopterus chalceus Spix & Agassiz, 1829 são duas importantes espécies de peixes forrageiros da bacia do São Francisco. Espécimes destas duas espécies foram submetidos à indução da desova através de hipofisação, para observação de aspectos reprodutivos e obtenção de subsídios para definição de protocolo de reprodução artificial. Machos e fêmeas receberam dose única de extrato bruto de hipófise de carpa comum (6 mg/kg de peixe). A extrusão de ovócit...

  20. Feeding association between benthic and nektonic Neotropical stream fishes

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    Fabrício Barreto Teresa

    2008-03-01

    Full Text Available Following behaviour among Neotropical stream fishes have been scarcely reported. This type of feeding association was observed in a small stream in the upper rio Paraná system between the catfish, Aspidoras fuscoguttatus, acting as a nuclear species, and Knodus moenkhausii, Poecilia reticulata, and Astyanax altiparanae as follower species. Aspidoras fuscoguttatus individuals dug in the bottom during feeding, causing sediment suspension. Their followers picked food items in the "cloud" of suspended particles. Food items of sediment are no longer consumed by the catfish when in suspension, but are still available for K. moenkhausii, P. reticulata and A. altiparanae. Following behaviour is an alternative feeding tactic for these species, which reinforces the general idea of behavioural plasticity among follower species.A interação nuclear-seguidor tem sido raramente registrada entre peixes de riachos Neotropicais. Este tipo de associação foi observada em um riacho de cabeceira, no sistema do Alto rio Paraná envolvendo o cascudinho, Aspidoras fuscoguttatus, como espécie nuclear, e Knodus moenkhausii, Poecilia reticulata e Astyanax altiparanae como seus seguidores. Indivíduos de Aspidoras fuscoguttatus revolveram o substrato durante alimentação, promovendo a suspensão de sedimento. Os seguidores, por sua vez, movimentaram-se pela "nuvem" de partículas em suspensão, capturando itens alimentares. As particulas alimentares em suspensão parecem não ser utilizadas pelo cascudinho, mas tornam-se disponíveis para K. moenkhausii, P. reticulata e A. altiparanae. O comportamento de seguidor representa uma tática alimentar alternativa para estas espécies, reforçando a idéia geral de plasticidade comportamental entre as espécies seguidoras.

  1. Minilernaea floricapitella gen. nov., sp. nov. (Copepoda, Lernaeidae from freshwater fishes of Southern Brazil Minilernaea floricapitella gen. nov., sp. nov.(Copepoda, Lernaeidae de peixes de água doce do Sul do Brazil

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    Vernon E. Thatcher

    2005-12-01

    Full Text Available Minilernaea floricapitella gen. nov., sp. nov. (Copepoda, Cyclopoida, Lernaeidae a parasite of the freshwater fishes, Astyanax spp. and Corydoras ehrhardti Regan, 1912 of Santa Catarina and Paraná States, Brazil, is described, based on 10 postmetamorphic females. The new genus and species has the following characteristics that distinguish it from all other known lernaeids: (1 The body is very small (3.4-5.8 mm in length; (2 The head is provided anteriorly with six lobes and posteriorly with four undivided anchor arms. (3 The first pair of thoracopods is on the head, 2-4 are all on the "neck"; (4 Thoracopod 5 is reduced to a simple papillus near the genital pores; (5 The genital pores are equatorial in the hindbody and there is no pre-genital prominence. Since the head and part of the neck are inserted beneath the skin, the host produces a strong encapsulating reaction.Minilernaea floricapitella gen. nov., sp. nov. (Copepoda, Cyclopoida, Lernaeidae um parasito dos peixes, Astyanax spp. and Corydoras ehrhardti Regan, 1912 dos estados de Santa Catarina e Paraná, Brasil, é descrita baseada em 10 fêmeas pós-metamórficas. O novo gênero e espécie tem as seguintes características que servem para distingui-la dos demais lerneídeos: (1. O corpo é muito pequeno (3.4-5.8 mm de comprimento; (2 A cabeça é provida anteriormente com seis lóbulos e posteriormente com quatro âncoras não divididas; (3 O primeiro par de toracópodos encontra-se na cabeça, quando 2-4 estão no pescoço; Toracópodo 5 é reduzido a uma papila simples perto dos poros genitais; (5 Os poros genitais são localizados na área equatorial do corpo posterior e não existe uma proeminência pre-genital. Já que a cabeça e uma parte do pescoço são inseridas sob a pele, o hospedeiro demostra uma reação encapsuladora forte.

  2. Behavioural responses of Odontophrynus americanus tadpoles (Anura: Leptodactylidae to fish chemical cues

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    Scarabotti, Pablo A.

    2007-02-01

    Full Text Available Las larvas de muchas especies de anfibios viven en ambientes con vegetación y de aguas turbias, donde la visibilidad es muy limitada. En estos ambientes, la utilización de señales químicas para la detección de depredadores podría ser más confiable que la utilización de señales visuales. Las larvas de Odontophrynus americanus habitan en las lagunas del valle aluvial del río Paraná Medio, Argentina, donde normalmente se dan condiciones de baja visibilidad. La hipótesis de este trabajo fue que los renacuajos de esta especie pueden detectar a los depredadores y responder subsecuentemente con conducta antipredador ante la percepción de señales químicas de los depredadores. En el presente trabajo se llevaron a cabo tres experimentos de laboratorio para evaluar si los renacuajos de O. americanus responden conductualmente al estímulo químico del pez Astyanax fasciatus. Las respuestas conductuales fueron evaluadas observando cambios en actividad, utilización de refugio y distribución espacial de los renacuajos. En presencia del estímulo químico del pez, los renacuajos redujeron su actividad en un 27%, incrementaron cinco veces la utilización de refugios, pero no exhibieron una respuesta de elusión espacial al estímulo del depredador. Las respuestas conductuales de los renacuajos de esta especie podrían reducir las probabilidades de encuentro y ataque por parte de los depredadores. Many amphibian larvae live in turbid and vegetated habitats with very limited visibility. In these habitats, the use of chemical cues for predator detection may be more reliable than visual ones. Odontophrynus americanus tadpoles inhabit floodplain ponds of the middle Paraná River, Argentina, where they frequently encounter low visibility conditions. We hypothesize that tadpoles of this species can detect predators and subsequently respond with antipredator behaviour by means of chemical cues from predators. In the present work, we ran three separate

  3. Estrutura da comunidade de peixes da represa “Lago del Fuerte”, Tandil, Argentina Fish community structure of “Lago del Fuerte” reservoir, Tandil, Argentina

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    Fabián Grosman

    1999-07-01

    Full Text Available A represa “Lago del Fuerte” constitui um centro de atividades recreativas onde a pesca esportiva do peixe-rei Odontesthes bonariensis, espécie introduzida para tal fim, tem um lugar de importância. Este trabalho tem como objetivo determinar a estrutura da comunidade de peixes, sua distribuição, principais relações tróficas e os parâmetros demográficos da população do peixe-rei. A vegetação marginal submersa da represa forma um ambiente favorável para o desenvolvimento dos peixes de pequeno porte; em compensação, o peixe-rei utiliza as águas livres. A competição interespecífica é reduzida pela segregação dos habitats e/o dos nichos tróficos. Astyanax eigenmanniorum é principalmente herbívoro; O. bonariensis, zooplanctófago e Cichlasoma facetum, onívoro. Existem relações muito estreitas entre os diferentes níveis energéticos presentes no sistema. A disponibilidade de zooplâncton regula os parâmetros da população do peixe-rei, o qual regula a composição do mesmo através da predação; na ausência de ictiófagos, o pescador é o responsável por influir nas variações demográficas do peixe-rei.Lago del Fuerte reservoir is a leisure center where sport fishing of silverside (Odontesthes bonariensis, a species stocked for this purpose, is very important. The objective of this paper is to determine the current fish community structure in this reservoir, their distribution, main trophic relationships and demographic parameters of the silverside population. The demersed vegetation present in the littoral region shapes favourable microenvironments for the development of shorter fish species; the silverside population use the pelagic region. The interspecific competition is reduced by means of habitat and/or trophic niche segregation. Astyanax eigenmanniorum is principally herbivorous; O. bonariensis is principally zooplanktophagous, and Cichlasoma facetum has a generalistic diet. There are very strong

  4. Eyeless Mexican cavefish save energy by eliminating the circadian rhythm in metabolism.

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    Damian Moran

    Full Text Available The eyed surface form and eyeless cave form of the Mexican tetra Astyanax mexicanus experience stark differences in the daily periodicities of light, food and predation, factors which are likely to have a profound influence on metabolism. We measured the metabolic rate of Pachón cave and surface fish at a fixed swimming speed under light/dark and constant dark photoperiods. In constant darkness surface forms exhibited a circadian rhythm in metabolism with an increase in oxygen demand during the subjective daytime, whereas cave forms did not. The lack of circadian rhythm in metabolism leads to a 27% energy savings for Pachón cave fish compared to surface fish when comparing both forms in their natural photoperiods. When surface forms were tested under constant dark conditions they expended 38% more energy than cave forms under equivalent conditions. Elimination of the circadian rhythm in metabolism may be a general feature of animals that live in perpetually dark food-limited environments such as caves or the deep sea.

  5. A multibiomarker evaluation of urban, industrial, and agricultural exposure of small characins in a large freshwater basin in southern Brazil.

    Science.gov (United States)

    Freire, Carolina A; Souza-Bastos, Luciana R; Chiesse, Juliana; Tincani, Flávio H; Piancini, Laercio D S; Randi, Marco A F; Prodocimo, Viviane; Cestari, Marta M; Silva-de-Assis, Helena C; Abilhoa, Vinícius; Vitule, Jean R S; Bastos, Leonardo P; de Oliveira-Ribeiro, Ciro A

    2015-09-01

    Iguaçu River is the second most polluted river of Brazil. It receives agrochemicals and contaminants of urban and industrial sources along its course. A multibiomarker approach was employed here to evaluate the health of a small characin (Astyanax spp.) at two sites along the river, sampled during a dry (autumn) and a rainy (spring) season. Biomarkers were condition factor and somatic indices (gonads and liver); genetic damage (comet assay and micronucleus test); enzyme activities such as hepatic catalase (CAT) and glutathione S-transferase (GST), lipoperoxidation (LPO), branchial and renal carbonic anhydrase (CA), acetylcholinesterase (AChE) in the muscle and the brain, histopathology of the liver and gills, and concentrations of polycyclic aromatic hydrocarbons (PAHs) in bile. There were no consistent differences in biomarker responses between the two study sites. Some biomarkers revealed greater potential impact in the rainy season, when increased amounts of contaminants are washed into the river (combined CAT inhibition and LPO increase, CA upregulation). Other biomarkers, however, revealed potential greater impact in the dry season, when contaminants potentially concentrate (GST induction, AChE inhibition, and liver histopathological alterations). Although of a complex nature, field experiments such as this provide rich data for monitoring protocols and assessment of general risk of exposure to pollutants of river systems. PMID:25940483

  6. Which is the best environment for the development of the early life stages of fish during the dry season?

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    André Luiz Henríques Esguícero

    2010-09-01

    Full Text Available AIM: The main objective of this study was to investigate the quality of habitats for early life stages of fish in the Jacaré-Guaçu River, during the dry phase; METHODS: For assessing the quality of the habitats for the development of early life stages, the relative condition factor was applied to the juveniles of five species of fishes, captured in four different habitats (reservoir, floodplain lake, main river, and tributary. The juveniles were caught in macrophytes of the littoral zone by a rectangular sieve, in the dry season of 2008 and 2009; RESULTS: The species Astyanax altiparanae thrived similarly in the four habitats, and A. fasciatus, Hyphessobrycon eques, Hoplias malabaricus and Serrapinnus notomelas, showed higher values of relative condition factors in the reservoir and in the lake. Among the species, A. fasciatus showed the highest values of the relative condition factor in these two habitats; CONCLUSIONS: It is likely that the complexity of the macrophytes' stands and the current velocity were the main factors influencing the development of juveniles. It was found that a lower current velocity can propitiated the establishment of a greater richness of macrophytes, which in turn can influence positively the development of fish juveniles. Moreover, a higher current velocity ends in a higher energy demand for swimming.

  7. Influence of local and landscape characteristics on the distribution and diversity of fish assemblages of streams in the Ivinhema River basin, Upper Paraná River

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    Ana Paula Lemke

    2013-12-01

    Full Text Available OBJECTIVES: Among the most relevant issues in community ecology is the influence of different ways of addressing the pattern of diversity and distribution of species, and based on this, the present study sought to evaluate the influence of landscape and local characteristics on the richness and composition of fish assemblages in the Ivinhema River basin. METHOD: In the present study, we used data of distribution of fish species in 25 stretches of streams of the Ivinhema River basin, Upper Paraná River, aiming to know the role of local characteristics and land use on fish assemblages. RESULTS: We identified 113 fish species, and those sampled in a greater number of sites were: Astyanax altiparanae and Serrapinnus notomelas. The richness varied between 4 and 65 species. The regression tree allowed explaining 89.3% of richness variation, and permitted to identify that altitude is the main predictor of richness. According to the canonical correspondence analysis, variables that most influenced the species distribution were: altitude, depth, width, velocity, conductivity and percentage of built-up areas. CONCLUSIONS: Our results suggested that factors that most influenced fish assemblages in the Ivinhema River basin were physiographic and limnological characteristics, followed by land use.

  8. Spatial and temporal patterns and their influence on fish community at Itupararanga Reservoir, Brazil.

    Science.gov (United States)

    Smith, Welber Senteio; Petrere, Miguel

    2008-12-01

    The Itupararanga Reservoir is located at the Sorocaba River Basin, São Paulo State, Brazil. Five cities use the waters of this reservoir for human consumption. Despite this intensive use of the water resource, no study has been undertaken on the ichthyofauna of this reservoir. Collections were performed in nine sampling stations, where each three were located in the riverine, transitional and lacustrine zones. Fish specimens were collected using eight monofilament gillnets of 10 m length each, with varied mesh sizes, in the rainy and dry seasons, which corresponded to our spatial scale of analysis. Overall, 14 species of fish were identified, with the highest contribution from Characidae and Curimatidae. The most abundant species were: the "lambari", Astyanax fasciatus, the "saguiru", Cyphocharax modestus, the "lambari bocarra", Oligosarcus paranaensis, and the "mandi", Iheringichthys labrosus. Diversity tended to be higher during the dry season, although the difference was not statistically significant. Cluster analysis identified four season sampling groups differentiated by within-season distribution of species. Mantel's test showed that this distribution was little affected by environmental factors, suggesting that biotic factors were more important in determining the species distribution within the reservoir. PMID:19419097

  9. Monogeneans of freshwater fishes from cenotes (sinkholes) of the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Mendoza-Franco, E F; Scholz, T; Vivas-Rodríguez, C; Vargas-Vázquez, J

    1999-01-01

    During a survey of the parasites of freshwater fishes from cenotes (sinkholes) of the Yucatan Peninsula the following species of monogeneans were found on cichlid, pimelodid, characid and poeciliid fishes: Sciadicleithrum mexicanum Kritsky, Vidal-Martinez et Rodriguez-Canul, 1994 from Cichlasoma urophthalmus (Günther) (type host), Cichlasoma friedrichsthali (Heckel), Cichlasoma octofasciatum (Regan), and Cichlasoma synspilum Hubbs, all new host records; Sciadicleithrum meekii Mendoza-Franco, Scholz et Vidal-Martínez, 1997 from Cichlasoma meeki (Brind); Urocleidoides chavarriai (Price, 1938) and Urocleidoides travassosi (Price, 1938) from Rhamdia guatemalensis (Günther); Urocleidoides costaricensis (Price et Bussing, 1967), Urocleidoides heteroancistrium (Price et Bussing, 1968), Urocleidoides anops Kritsky et Thatcher, 1974, Anacanthocotyle anacanthocotyle Kritsky et Fritts, 1970, and Gyrodactylus neotropicalis Kritsky et Fritts, 1970 from Astyanax fasciatus; and Gyrodactylus sp. from Gambusia yucatana Regan. Urocleidoides chavarriai, U. travassosi, U. costaricensis, U. heteroancistrium, U. anops, Anacanthocotyle anacanthocotyle and Gyrodactylus neotropicalis are reported from North America (Mexico) for the first time. These findings support the idea about the dispersion of freshwater fishes and their monogenean parasites from South America through Central America to southeastern Mexico, following the emergence of the Panamanian isthmus between 2 and 5 million years ago. PMID:10730199

  10. Habitat characteristics and environmental parameters influencing fish assemblages of karstic pools in southern Mexico

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    María Eugenia Vega-Cendejas

    2013-01-01

    Full Text Available Fish assemblage structure was evaluated and compared among 36 karstic pools located within protected areas of the Calakmul Biosphere Reserve (southern Mexico and unprotected adjacent areas beyond the Reserve. Nonmetric multidimensional scaling (MDS, indicator species analysis (ISA, and canonical correspondence analysis (CCA were used to identify which environmental factors reflected local influences and to evaluate the correlation of these variables with fish assemblages structure. Thirty-one species were encountered in these karstic pools, some for the first time within the Reserve. These aquatic environments were separated into three groups based on physico-chemical characteristics. Although CCA identified significant associations between several fish species (based on their relative abundance and environmental variables (K, NH4, NO3, and conductivity, the most abundant species (Astyanax aeneus, Poecilia mexicana, and Gambusia sexradiata occur in most pools and under several environmental conditions. Baseline data on fish diversity along with a continued monitoring program are essential in order to evaluate the conservation status of fish assemblages and their habitats, as well as to measure the influence of anthropogenic impacts on pristine habitats such as the karstic pools of the Calakmul Biosphere Reserve.

  11. Hybrid zone origins, species boundaries, and the evolution of wing-pattern diversity in a polytypic species complex of North American admiral butterflies (Nymphalidae: Limenitis).

    Science.gov (United States)

    Mullen, Sean P; Dopman, Erik B; Harrison, Richard G

    2008-06-01

    Hybrid zones present opportunities to study the effects of gene flow, selection, and recombination in natural populations and, thus, provide insights into the genetic and phenotypic changes that occur early in speciation. Here we investigate a hybrid zone between mimetic (Limenitis arthemis astyanax) and nonmimetic (Limenitis arthemis arthemis) populations of admiral butterflies using DNA sequence variation from mtDNA and seven nuclear gene loci. We find three distinct mitochondrial clades within this complex, and observe a strong overall concordance between wing-pattern phenotypes and mitochondrial variation. Nuclear gene genealogies, in contrast, revealed no evidence of exclusivity for either wing-pattern phenotype, suggesting incomplete barriers to gene exchange and/or insufficient time for lineage sorting. Coalescent simulations indicate that gene flow between these two subspecies is highly asymmetric, with the majority of migration occurring from mimetic into nonmimetic populations. Selective sweeps of alleles responsible for mimetic phenotypes may have occurred more than once when mimetic and nonmimetic Limenitis occurred together in the presence of the model (Battus philenor).

  12. Reproductive strategies and genetic variability in tropical freshwater fish

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    Maria Dolores Peres Lassala

    2007-01-01

    Full Text Available We estimated the genetic variability of nine fish species from the Brazilian upper Paraná River floodplain (Astyanax altiparanae, Hoplias malabaricus, Leporinus lacustris, Loricariichthys platymetopon, Parauchenipterus galeatus, Pimelodus maculatus, Rhaphiodon vulpinus, Roeboides paranensis and Serrasalmus marginatus based on data for 36 putative allozyme loci obtained using corn starch gel electrophoresis of 13 enzymatic systems: aspartate aminotransferase (EC 2.6.1.1, acid phosphatase (EC 3.1.3.2, esterase (EC 3.1.1.1, glycerol-3-phosphate dehydrogenase (EC 1.1.1.8, glucose-6-phosphate dehydrogenase (EC 1.1.1.49, glucose-6-phosphate isomerase (EC 5.3.1.9, Iditol dehydrogenase (EC 1.1.1.14, isocitrate dehydrogenase - NADP+ (EC 1.1.1.42, L-lactate dehydrogenase (EC 1.1.1.27, malate dehydrogenase (EC 1.1.1.37, malate dehydrogenase-NADP+ (EC 1.1.1.40, phosphoglucomutase (EC 5.4.2.2 and superoxide dismutase, (EC 1.15.1.1. The mean expected heterozygosity varied from zero to 0.147. When data from the literature for 75 species of tropical fish were added to the nine species of this study, the heterozygosity values differed significantly among the groups of different reproductive strategies. The highest mean heterozygosity was for the non-migratory without parental care, followed by the long-distance migratory, and the lowest mean was for the non-migratory with parental care or internal fecundation.

  13. Trematode Centrocestus formosanus infection and distribution in ornamental fishes in Mexico.

    Science.gov (United States)

    Ortega, César; Fajardo, Raúl; Enríquez, Ricardo

    2009-03-01

    The aim of this study was to determine the ornamental fish species affected by the metacercariae of the digenean trematode Centrocestus formosanus and its distribution in 48 fish farms in Morelos, central Mexico. The parasite was found to form various numbers of branchial cysts in 11 of the 25 species analyzed. Goldfish Carassius auratus was the most commonly affected species; 20 of 30 farms were positive for this parasite, the fish showing severe clinical signs and having a high mortality rate. For the first time in the region, koi (a variant of common carp Cyprinus carpio), zebrafish Danio rerio, suckermouth catfish Hypostomus plecostomus and blue gourami Trichogaster trichopterus (also known as the threespot gourami) were positive; meanwhile, Mexican tetra Astyanax mexicanus, which had previously been reported positive in other studies in this region, was found to be negative. The parasite was observed in fish from 27 of the 48 farms studied. Ten of 15 municipalities had farms that were positive for the parasite. These results suggest that the distribution of C. formosanus is closely related to the use of water that had been contaminated with the parasite and to the presence of a snail, the red-rimmed melania Melanoides tuberculata.

  14. Molecular Identification and Traceability of Illegal Trading in Lignobrycon myersi (Teleostei: Characiformes), a Threatened Brazilian Fish Species, Using DNA Barcode

    Science.gov (United States)

    Rodrigues, Alexandre dos Santos; Brandão, José Henrique Souza Galdino; Bitencourt, Jamille de Araújo; Jucá-Chagas, Ricardo; Sampaio, Iracilda; Schneider, Horácio

    2016-01-01

    Lignobrycon myersi is a threatened freshwater fish species and endemic of a few coastal rivers in northeastern Brazil. Even though the Brazilian laws prohibit the fisheries of threatened species, L. myersi is occasionally found in street markets, being highly appreciated by local population. In order to provide a reliable DNA barcode dataset for L. myersi, we compared mitochondrial sequences of cytochrome c oxidase subunit I (COI) from fresh, frozen, and salt-preserved specimens. Phylogenetically related species (Triportheus spp.) and other fish species (Astyanax fasciatus) commonly mixed with L. myersi in street markets were also included to test the efficiency of molecular identification. In spite of the differences in conservation processes and advanced deterioration of some commercial samples, high-quality COI sequences were obtained and effective in discriminating L. myersi specimens. In addition, while populations from Contas and Almada River basins seem to comprise a single evolutionary lineage, the specimens from Cachoeira River were genetically differentiated, indicating population structuring. Therefore, DNA barcoding has proved to be useful to trace the illegal trading of L. myersi and to manage threatened populations, which should focus on conservation of distinct genetic stocks and mitigation on human impacts along their range. PMID:27668281

  15. Manipulation of Fgf and Bmp signaling in teleost fishes suggests potential pathways for the evolutionary origin of multicuspid teeth.

    Science.gov (United States)

    Jackman, William R; Davies, Shelby H; Lyons, David B; Stauder, Caitlin K; Denton-Schneider, Benjamin R; Jowdry, Andrea; Aigler, Sharon R; Vogel, Scott A; Stock, David W

    2013-01-01

    Teeth with two or more cusps have arisen independently from an ancestral unicuspid condition in a variety of vertebrate lineages, including sharks, teleost fishes, amphibians, lizards, and mammals. One potential explanation for the repeated origins of multicuspid teeth is the existence of multiple adaptive pathways leading to them, as suggested by their different uses in these lineages. Another is that the addition of cusps required only minor changes in genetic pathways regulating tooth development. Here we provide support for the latter hypothesis by demonstrating that manipulation of the levels of Fibroblast growth factor (Fgf) or Bone morphogenetic protein (Bmp) signaling produces bicuspid teeth in the zebrafish (Danio rerio), a species lacking multicuspid teeth in its ancestry. The generality of these results for teleosts is suggested by the conversion of unicuspid pharyngeal teeth into bicuspid teeth by similar manipulations of the Mexican Tetra (Astyanax mexicanus). That these manipulations also produced supernumerary teeth in both species supports previous suggestions of similarities in the molecular control of tooth and cusp number. We conclude that despite their apparent complexity, the evolutionary origin of multicuspid teeth is positively constrained, likely requiring only slight modifications of a pre-existing mechanism for patterning the number and spacing of individual teeth.

  16. The Effects of Urbanization on the Food Web of a Mid-order Stream in Rio de Janeiro, Brazil

    Science.gov (United States)

    Detweiler, A. M.; Hershey, A. E.; Moulton, T. P.; Brito, E. F.

    2005-05-01

    Stream degradation caused by point source and non-point source pollution, loss of riparian vegetation, erosion and sedimentation can alter aquatic food webs. Due to the lack of proper sewage treatment, the main polluter in urban streams of Brazil is raw sewage. The purpose of this study is to determine if sewage-derived carbon and nitrogen are incorporated into the aquatic system and how this may affect the food web. We collected food web components at four sites along an urban stream, Rio Paineiras, and a reference stream, Rio Andorinha. Samples were analyzed for natural abundance of 13C and 15N. Raw sewage signatures were distinct and enriched compared to primary sources. Riparian vegetation and CPOM samples became significantly more enriched in 15N along the urban stream, compared to the reference stream. Periphyton 15N and 13C signatures were not significantly different between streams. Fish (Astyanax hastatus and Poecilids) showed some incorporation of sewage-derived 13C and 15N, in distinct trophic groups. Macroinvertebrate Hetaerina sp. reflected some incorporation of sewage-derived 15N. We also observed a reduction in functional feeding groups in the sewage-influenced reach of Rio Paineiras. Collectors, gatherers, and shredders were absent as stream degradation increased. Downstream communities were composed mostly of fish.

  17. Karyotype differentiation patterns in species of the subfamily Scarabaeinae (Scarabaeidae, Coleoptera).

    Science.gov (United States)

    Cabral-de-Mello, Diogo Cavalcanti; de Oliveira, Sárah Gomes; Ramos, Ituza Celeste; de Moura, Rita de Cássia

    2008-12-01

    The aim of this study was to describe the karyotype of species belonging to the subfamily Scarabaeinae (Coleoptera, Scarabaeidae) and to compile the conventional cytogenetic data available in the literature for this group. The karyotypes of ten species belonging to the tribes Canthonini, Coprini, Onthophagini and Phanaeini were analyzed by conventional staining. Eight of these species were described for the first time (Canthon aff carbonarius, Canthon chalybaeus, Coprophanaeus dardanus, Deltochilum aff amazonicum, Dichotomius geminatus, Oxysternon silenus, Phanaeus chalcomelas and Malagoniella aff astyanax) and two were redescribed (Diabroctis mimas and Digitonthophagus gazella) since their karyotypes differed from those previously published in the literature. Four species studied showed a diploid number of 2n=20 and a parachute type sex determining system and the karyotype was 2n=20,Xy in two species and 2n=18,Xy(p), 2n=19,X0, 2n=12,XY and 2n=14,neoXY in one each. The chromosome morphology of the different species varied, with the observation of metacentric, submetacentric, subacrocentric and acrocentric chromosomes. The X chromosome was predominantly meta or submetacentric in the species analyzed, whereas the y chromosome presented two arms or was punctiform. In conclusion, the subfamily Scarabaeinae comprises 120 species analyzed cytogenetically, and are observed the occurrence of five chromosome rearrangements (autosome-autosome and X-autosome fusions, pericentric inversions, fissions and loss of the y chromosome) that are related to the chromosome variability and evolution in the group. PMID:18495484

  18. Habitat preferences of common native fishes in a tropical river in Southeastern Brazil

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    Marcus Rodrigues da Costa

    2013-01-01

    Full Text Available We determined in this study the habitat preferences of seven native fish species in a regulated river in Southeastern Brazil. We tested the hypothesis that fishes differ in habitat preference and that they use stretches of the river differing in hydraulic characteristics and substrate type. We surveyed fishes in four 1-km long river stretches encompassing different habitat traits, where we also measured water depth, velocity, and substrate type. We investigated preference patterns of four Siluriformes (Loricariichthys castaneus, Hoplosternum littorale, Pimelodus maculatus, and Trachelyopterus striatulus and three Characiformes (Astyanax aff. bimaculatus, Oligosarcus hepsetus, and Hoplias malabaricus, representing approximately 70% of the total number of fishes and 64% of the total biomass. We classified fishes into four habitat guilds: (1 a slow-flowing water guild that occupied mud-sand substrate, composed of two Siluriformes in either shallow ( 8 m, L. castaneus waters; (2 a run-dwelling guild that occurs in deep backwaters with clay-mud substrate, composed of the Characiformes A. aff. bimaculatus and O. hepsetus; (3 a run-dwelling guild that occurs in sandy and shallow substrate, composed of T. striatulus; and (4 a fast-flowing guild that occurs primarily along shorelines with shallow mud bottoms, composed of H. malabaricus and P. maculatus. Our hypothesis was confirmed, as different habitat preferences by fishes appear to occur in this regulated river.

  19. Lens gene expression analysis reveals downregulation of the anti-apoptotic chaperone alphaA-crystallin during cavefish eye degeneration.

    Science.gov (United States)

    Strickler, Allen G; Byerly, Mardi S; Jeffery, William R

    2007-12-01

    We have conducted a survey of the expression patterns of five genes encoding three different classes of major lens proteins during eye degeneration in the blind cavefish Astyanax mexicanus. This species consists of two forms, an eyed surface-dwelling form (surface fish) and a blind cave-dwelling (cavefish) form. Cavefish form an optic primordium with a lens vesicle and optic cup. In contrast to surface fish, however, the cavefish lens does not differentiate fiber cells and undergoes massive apoptosis. The genes encoding the lens intrinsic membrane proteins MIP and MP19 and the divergent betaB1- and gammaM2-crystallins are expressed during cavefish lens development, although their levels are reduced because of a smaller lens, and the spatial distribution of their transcripts is modified because of the lack of differentiated fiber cells. In contrast, the alphaA-crystallin gene, which encodes a heat shock protein-related chaperone with antiapoptotic activity, is substantially downregulated in the developing cavefish lens. The results suggest that suppression of alphaA-crystallin antiapoptotic activity may be involved in cavefish eye degeneration.

  20. Biology and ecomorphology of stream fishes from the rio Mogi-Guaçu basin, Southeastern Brazil

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    Katiane M. Ferreira

    2007-09-01

    Full Text Available The córrego Paulicéia is a direct tributary of the rio Mogi-Guaçu, located in Santa Rita do Passa Quatro, State of São Paulo, Southeastern Brazil. This stream runs inside a savannah-like (cerrado environment and it associated vegetation. Biological and ecomorphological aspects of its fish community were studied in three stretches of the stream, denominated herein as the upper, middle and lower courses. The fish fauna recorded in this study consisted of 15 species, belonging to five orders and nine families, based in a total of 715 collected individuals representing 1,450 kg of biomass. The most important abiotic factors related to the occurrence and distribution of the fish fauna were the substrate, current speed, and presence or absence of riparian vegetation. The analysis of 336 stomach contents of 13 species demonstrated that 65% of food items are autochthonous, 32% allochthonous, and 3% are of unknown origin. Four alimentary guilds could be identified, based on the predominant food items: omnivores with tendency to insectivory - Astyanax paranae, A. fasciatus and Piabina argentea; larvivores - Corydoras difluviatilis, Cetopsorhamdia iheringi, Phenacorhamdia tenebrosa, Characidium gomesi, Eigenmannia virescens, and Rhamdia quelen; periphyton feeders - Hisonotus sp., Hypostomus ancistroides and Synbranchus marmoratus; and piscivore - Hoplias malabaricus. Reproductions data are presented for Astyanax altiparanae and Hisontus sp. Three ecomorphological groups could be established, based on swimming, feeding, and microhabitat strategies: nektonic (A. fasciatus, A. paranae, Bryconamericus stramineus, P. argentea, H. malabaricus and Phallotorynus jucundus, benthic (C. gomesi, P. tenebrosa, C. iheringi, R. quelen, C. difluviatilis, H. ancistroides and Hisonotus sp., and necktobenthic (E. virescens and S. marmoratus.O córrego Paulicéia é um afluente direto do rio Mogi-Guaçu, situado no município de Santa Rita do Passa Quatro, Estado de S

  1. Using genotoxic and haematological biomarkers as an evidence of environmental contamination in the Ocoa River native fish, Villavicencio-Meta, Colombia.

    Science.gov (United States)

    Corredor-Santamaría, Wilson; Serrano Gómez, Marlon; Velasco-Santamaría, Yohana María

    2016-01-01

    The studies evaluating the impact of environmental pollution on aquatic organisms have had a growing concern in recent decades. The Ocoa River runs through Villavicencio city, receiving the wastewater produced in the city. To date studies reporting the effect and the consequences of Ocoa River pollution on aquatic organisms inhabiting this water body are unknown. Haematological and genotoxicity biomarkers were evaluated in peripheral blood of two native fish species Astyanax gr. bimaculatus and Aequidens metae during rainy and dry season at three different sites of Ocoa River called Nacimiento (site 1, before entering the city), Centauros (site 2, inside the city), Caño Seco (site 3, after the city). Also, fish from a reference site with little likelihood of contamination were sampled. Alterations such as decrease in erythrocyte count, lymphocytes, haemoglobin concentration and haematocrit percentage, and increased thrombocytes and neutrophils counts, together with nuclear abnormalities in erythrocytes such as increased frequency of micronuclei, lobed, blebbed and notched nuclei and binucleate cells were observed in fish from the site 3, followed by the site 2 in rainy season. These results shown that during rainy season, sites 2 and 3 receive domestic and industrial wastewater leading to genotoxic and haematological changes in the monitored organisms.

  2. Using genotoxic and haematological biomarkers as an evidence of environmental contamination in the Ocoa River native fish, Villavicencio-Meta, Colombia.

    Science.gov (United States)

    Corredor-Santamaría, Wilson; Serrano Gómez, Marlon; Velasco-Santamaría, Yohana María

    2016-01-01

    The studies evaluating the impact of environmental pollution on aquatic organisms have had a growing concern in recent decades. The Ocoa River runs through Villavicencio city, receiving the wastewater produced in the city. To date studies reporting the effect and the consequences of Ocoa River pollution on aquatic organisms inhabiting this water body are unknown. Haematological and genotoxicity biomarkers were evaluated in peripheral blood of two native fish species Astyanax gr. bimaculatus and Aequidens metae during rainy and dry season at three different sites of Ocoa River called Nacimiento (site 1, before entering the city), Centauros (site 2, inside the city), Caño Seco (site 3, after the city). Also, fish from a reference site with little likelihood of contamination were sampled. Alterations such as decrease in erythrocyte count, lymphocytes, haemoglobin concentration and haematocrit percentage, and increased thrombocytes and neutrophils counts, together with nuclear abnormalities in erythrocytes such as increased frequency of micronuclei, lobed, blebbed and notched nuclei and binucleate cells were observed in fish from the site 3, followed by the site 2 in rainy season. These results shown that during rainy season, sites 2 and 3 receive domestic and industrial wastewater leading to genotoxic and haematological changes in the monitored organisms. PMID:27066365

  3. [Rapid ecological assessment of tropical fish communities in a gold mine area of Costa Rica].

    Science.gov (United States)

    Espinoza Mendiola, Mario

    2008-12-01

    Gold mining impacts have generated a great concern regarding aquatic systems and habitat fragmentation. Anthropogenic disturbances on the structure and heterogeneity of a system can have an important effect on aquatic community stability. Ecological rapid assessments (1996, 2002, and 2007) were employed to determine the structure, composition and distribution of tropical fish communities in several rivers and smaller creeks from a gold mining area in Cerro Crucitas, Costa Rica. In addition, species composition and relative abundance were related with habitat structure. A total of 35 species were registered, among which sardine Astyanax aeneus (Characidae) and livebearer Alfaro cultratus (Poeciliidae) were the most abundant fish (71%). The highest species richness was observed in Caño Crucitas (s=19) and Minas Creek (s=18). Significant differences in fish communities structure and composition from Infiernillo river and Minas creek were observed (lamda = 0.0, F(132, 66) = 2.24, p fish species and habitat structure was observed. This study reveals a high complexity in tropical fish communities that inhabit a gold mine area. Furthermore, it highlights the importance of habitat heterogeneity in fish community dynamics. The loss and degradation of aquatic systems in Cerro Crucitas can have a strong negative effect on fish community structure and composition of local species. A better understanding of the use of specific habitats that serve as essential fish habitats can improve tropical fish conservation and management strategies, thus increasing local diversity, and thereby, the biological importance of the area.

  4. Feeding ecology of stream-dwelling Characidae (Osteichthyes: Characiformes from the upper Tocantins River, Brazil

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    Maíra Moraes

    2013-12-01

    Full Text Available In this contribution we studied the trophic ecology of four Characidae species from the Cavalo Stream, upper Tocantins River, considering diet overlap and trophic niche breadth. The diet of the four species was composed of adult and immature insects, both autochthonous and allochthonous in origin. Autochthonous items dominated the diet of Moenkhausia dichroura (Kner, 1858, Bryconamericus sp., and Creagrutus atrisignum Myers, 1917. By contrast, allochthonous items were dominant in the diet of Astyanax bimaculatus (Linnaeus, 1758. Trophic niche breadth varied among species, with the highest value recorded for M. dichroura (0.48, followed by Bryconamericus sp. (0.39, A. bimaculatus (0.33 and C. atrisignum (0.29. Similarity analysis revealed two groups with different patterns of food preference. The first group was composed of insectivorous and the second by omnivorous species. The overlap in food items consumed by the four species studied was high. We suggest that resources are not limited in this stream and that competition might not be regulating these populations. This is one more case corroborating the general pattern registered for Tropical environments, where resource partitioning and specialization are responsible by the organization of fish communities.

  5. Metazoários parasitos de seis espécies de peixes do Reservatório de Lajes, Estado do Rio de Janeiro, Brasil Metazoan parasites of six fishes species from Lajes Reservoir in the State of Rio de Janeiro, Brazil

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    Aline R. Paraguassú

    2007-09-01

    Full Text Available Entre abril de 2002 e julho de 2003, foram necropsiados 231 espécimes de peixes: 39 Astyanax bimaculatus (Linnaeus, 1758, 79 A. fasciatus (Cuvier, 1819, 23 Hypostomus affinis (Steindachner, 1877, 26 Hoplias malabaricus (Bloch, 1794, 30 Loricariichthys castaneus (Castelnau, 1855 e 34 Trachelyopterus striatulus (Steindachner, 1876 provenientes do Reservatório de Lajes (22º42' - 22º50'S, 43º53' 44º05'O, Estado do Rio de Janeiro, Brasil, para estudo das suas comunidades parasitárias. A maioria dos espécimes de H. affinis (95,6% e H. malabaricus (84,6% estavam parasitados por pelo menos uma espécie de metazoário. Em A. bimaculatus, A. fasciatus, L. castaneus e T. striatulus 41%, 39,2%, 56,7% e 14,7% dos espécimes estavam parasitados, respectivamente. Foram coletadas oito diferentes espécies de metazoários parasitos: 2 em A. bimaculatus, 3 em A. fasciatus, 3 em H. affinis, 4 em H. malabaricus, 4 em L. castaneus e 1 em T. striatulus. As comunidades de metazoários parasitos das seis espécies de peixes estudadas apresentaram típico padrão de distribuição agregada. Foram observados dois casos de correlação negativa entre a abundância e a prevalência parasitárias e o comprimento total dos hospedeiros. A comunidade parasitária de L. castaneus apresentou os maiores valores de intensidade média, índice de dispersão e diversidade. As comunidades parasitárias dos peixes estudados apresentaram escassez de correlação entre a abundância, riqueza parasitária e diversidade com o comprimento total dos hospedeiros. Os baixos valores de riqueza e diversidade das comuni-dades parasitárias podem ser atribuídos as características oligotróficas do Reservatório de Lajes.From April 2002 to July 2003, 231 freshwater fishes from Lajes Reservoir in the State of Rio de Janeiro, Brazil (22º42' - 22º50'S, 43º53' - 44º05'W were necropsied to study their community metazoan parasites: 39 Astyanax bimaculatus (Linnaeus, 1758, 79 A. fasciatus

  6. Which is the best environment for the development of the early life stages of fish during the dry season? Qual o melhor ambiente para o desenvolvimento das fases jovens de peixes durante a estação seca?

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    André Luiz Henríques Esguícero

    2010-09-01

    Full Text Available AIM: The main objective of this study was to investigate the quality of habitats for early life stages of fish in the Jacaré-Guaçu River, during the dry phase; METHODS: For assessing the quality of the habitats for the development of early life stages, the relative condition factor was applied to the juveniles of five species of fishes, captured in four different habitats (reservoir, floodplain lake, main river, and tributary. The juveniles were caught in macrophytes of the littoral zone by a rectangular sieve, in the dry season of 2008 and 2009; RESULTS: The species Astyanax altiparanae thrived similarly in the four habitats, and A. fasciatus, Hyphessobrycon eques, Hoplias malabaricus and Serrapinnus notomelas, showed higher values of relative condition factors in the reservoir and in the lake. Among the species, A. fasciatus showed the highest values of the relative condition factor in these two habitats; CONCLUSIONS: It is likely that the complexity of the macrophytes' stands and the current velocity were the main factors influencing the development of juveniles. It was found that a lower current velocity can propitiated the establishment of a greater richness of macrophytes, which in turn can influence positively the development of fish juveniles. Moreover, a higher current velocity ends in a higher energy demand for swimming.OBJETIVO: O objetivo principal deste estudo foi investigar a qualidade dos habitats para as primeiras fases de vida dos peixes no Rio Jacaré-Guaçu, durante a estação seca; MÉTODOS: Para avaliar a qualidade dos hábitats para o desenvolvimento das primeiras fases, o fator de condição relativo foi aplicado aos juvenis de cinco espécies de peixes, capturados em quatro habitats diferentes (reservatório, lago de planície de inundação, canal principal e tributário. Os juvenis foram coletados em macrófitas litorâneas com uma peneira retangular, na estação seca de 2008 e 2009; RESULTADOS: Somente Astyanax

  7. Caracterização da piscicultura na região do Vale do Ribeira - SP Characterization of fish farming in the Ribeira Valley region - SP

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    Daniela Castellani

    2005-02-01

    Full Text Available Este trabalho buscou caracterizar a piscicultura na Região do Vale do Ribeira quanto aos sistemas de manejo. Estudaram-se quarenta e duas pisciculturas sendo que, destas, 36 praticam o sistema semi-intensivo e seis o sistema intensivo, com os seguintes objetivos: engorda de peixes, produção de alevinos e pesque-pagues. Foram listadas 41 espécies de peixes cultivadas. Apenas 6 espécies são nativas da Bacia do Rio Ribeira de Iguape: lambari (Astyanax sp Linneaus, 1758, traíra (Hoplias malabaricus Bloch, 1794, robalo (Centropomus ssp Cuvier e Valenciennes, 1928, jundiá (Rhamdia quelen Quoy e Gaimard, 1824, cascudo (Hypostomus sp Marschall, 1873 e cará (Geophagus brasiliensis Quoy e Gaimard, 1824. Em 95% das pisciculturas foram verificadas fugas de peixes exóticos e alóctones dos cultivos. A tilápia nilótica (Oreochromis niloticus Linneaus, 1758 foi a espécie mais freqüente em escapes, e também é a segunda mais cultivada pelos piscicultores, perdendo somente para o pacu (Piaractus mesopotamicus Halmberg, 1887. Foi possível verificar mediante o cálculo da conversão alimentar, que há um desperdício anual de cerca de 32% da ração utilizada nos cultivos pesquisados. A piscicultura encontra-se em plena expansão nesta região, e já representa a atividade agropecuária mais importante após a bananicultura.The aim of this work was to characterize the fish farming in the Ribeira de Iguape Basin, southern São Paulo State (Brazil, in relation to the management systems. Forty two farms were studied. A semi-intensive system is used by 36 farmers, while an intensive system is used only by 6 studied farmers. Their objectives were raising fish, juvenile fish production and sportive fishery. Forty one fish species were found to be cultivated, but only six were native species from Ribeira Valley: lambari (Astyanax sp Linneaus, 1758, traíra (Hoplias malabaricus Bloch, 1794, robalo (Centropomus ssp Cuvier and Valenciennes, 1928, jundi

  8. Can weight/length relationship predict size at first maturity? A case study with two species of Characidae

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    Nelson F. Fontoura

    2010-01-01

    Full Text Available A weight/length relationship was established for Astyanax jacuhiensis (Cope, 1894 (n = 370 and Cheirodon ibicuhiensis Eigenmann, 1915 (n = 701, from samples taken monthly in Fortaleza Lagoon, Cidreira, Rio Grande do Sul, from December 1991 through November 1992. Both species showed a polyphasic allometric growth pattern, each stanza described by an independent power equation controlled by a switch function. For C. ibicuhiensis, this change in the growth pattern occurred at 2.948 cm standard length (SL, close to published sizes for the attainment of female maturity. The change in the growth pattern of A. jacuhiensis (SL = 3.481 cm was below the predicted size at first maturity, and merits further investigation. Although not conclusive, our data suggest that a complex growth pattern is frequent in nature, and perhaps is not usually identified because trends are obscured by natural variability. Despite the increased complexity resulting from the application of a more-complex equation, the identification of a change in the growth pattern could indicate important aspects of fish biology, including the attainment of sexual maturity.A relação peso/comprimento para Astyanax jacuhiensis (Cope, 1894 (n = 370 e Cheirodon ibicuhiensis Eigenmann, 1915 (n = 701 foi estimada a partir de amostras mensais efetuadas na lagoa Fortaleza, Cidreira, Rio Grande do Sul (dezembro de 1991 a novembro de 1992. As espécies analisadas apresentaram padrão de crescimento alométrico polifásico, sendo cada fase descrita por uma equação potência independente controlada por uma função interruptora. Para C. ibicuhiensis foi identificada uma modificação no padrão de crescimento com 2,948 cm de comprimento padrão (CP, valor próximo à dados publicados relativos ao início da maturação sexual. A alteração observada no padrão de crescimento de A. jacuhiensis (CP = 3,481 cm encontra-se abaixo do tamanho previsto para a primeira maturação e sugere a necessidade de

  9. Estudio comparativo de la frecuencia de micronúcleos y anormalidades nucleares en eritrocitos de tres especies ícticas Comparative studies of the frequency of micronuclei and nuclear abnormalities in erythrocytes of three species fishes

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    Favio E Pollo

    2012-12-01

    Full Text Available Los ecosistemas acuáticos cercanos a las zonas urbanas sufren un deterioro constante ocasionado por diversos factores físico-químicos relacionados con la actividad antrópica, representando un riesgo para los organismos que los habitan, en especial los peces. Estos efectos pueden ser biomonitoreados mediante técnicas de amplia utilización, como el Test de Micronúcleos (Mn y el de Anormalidades nucleares (AN, entre otros. El objetivo de este trabajo fue verifcar y comparar la frecuencia de micronúcleos y anormalidades nucleares en tres especies ícticas colectadas en un lago urbano, Cyprinus carpio, Astyanax eigenmanniorum y Cheirodon interruptus. Luego de la captura y anestesia de los peces, se extrajo de cada individuo una muestra de sangre y se registró el peso y la longitud total. Las muestras fueron fjadas y luego teñidas con Giemsa al 10%, posteriormente se las analizó con microscopio (1000X y se les tomaron fotografías con cámara digital. Se calculó, además, el índice de condición corporal (K para cada uno de los ejemplares capturados. Se aplicó un análisis de correlación de rangos de Spearman (rs entre frecuencia de Mn y AN vs K para cada especie. La prueba de Kruskal-Wallis se aplicó para evaluar diferencias de Mn y AN entre las especies. Los resultados no mostraron una correlación estadísticamente signifcativa (P> 0,05 entre las frecuencias de Mn y AN vs K. Las frecuencias de Mn entre las diferentes especies no arrojaron diferencias signifcativas (P> 0,05, mientras que las AN sí (PAquatic ecosystems near urban areas suffer a steady deterioration caused by physical and chemical factors related to human activity, representing a danger to organisms that inhabit them, especially the fsh. These effects may be biomonitored by widely used techniques, such as the Micronucleus Test (Mn and Nuclear Abnormalities (NA, among others. The aim of this study was to verify and compare the frequency of micronuclei and nuclear

  10. An Index of Biotic Integrity for shallow streams of the Hondo River basin, Yucatan Peninsula

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    Schmitter-Soto, Juan J., E-mail: jschmitt@ecosur.mx; Ruiz-Cauich, Lissie E.; Herrera, Roberto L.; Gonzalez-Solis, David

    2011-01-15

    An Index of Biotic Integrity (IBI) is proposed, based on the fish communities and populations in streams of the Hondo River basin, Mexico-Belize. Freshwater environments in this area are threatened by exotic fishes, eutrophication, and pesticide pollution, among other problems. This IBI should allow to identify the most vulnerable sites and eventually guide rehabilitation efforts. Data on composition, structure, and function of fish communities were evaluated. Twenty-three sites in the Mexican part of the basin were explored; a stratified sample of 13 sites was used to design the IBI, and the rest were used to test and refine the index. Thirty-four candidate indicator metrics were scanned for their correlation with an index of water and habitat quality (IWHQ), as well as for the possible influence of stream width and altitude or distance to the Hondo River mainstem. Twelve variables were selected to constitute the IBI: relative abundances of Astyanax aeneus, 'Cichlasoma' urophthalmus, Poecilia mexicana, Poecilia sp. (a new species, probably endemic to the upper Hondo River basin), Xiphophorus hellerii, and X. maculatus; relative abundances of bentholimnetic, herbivore, and sensitive species; percentage of native and tolerant species; and Pielou's evenness index. Most of the sites have a low-medium quality and integrity, showing impact due to partial channelization or to suboptimal water quality, reflected in scarcity or absence of sensitive species, frequent excess of tolerant species, occasional presence of exotics, dominance of herbivores (perhaps due to proliferation of filamentous algae), or dominance of the opportunistic species P. mexicana. The streams with better water and habitat quality are those farthest away from the river mainstem, probably because of lower human population and economical production. - Research Highlights: {yields} An Index of Biotic Integrity based on fishes is proposed for streams of the Hondo River basin. {yields

  11. Competência de peixes como predadores de larvas de Aedes aegypti, em condições de laboratório Efficacy of fish as predators of Aedes aegypti larvae, under laboratory conditions

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    Luciano Pamplona de Góes Cavalcanti

    2007-08-01

    Full Text Available OBJETIVO: Avaliar a competência de peixes na predação de larvas de Aedes aegypti, em condições de laboratório. MÉTODOS: Foram testados machos e fêmeas de cinco espécies de peixe. Os testes de predação duravam cinco semanas para cada espécie. Cada ensaio compreendia quatro caixas testes e quatro caixas controles. Das caixas controle, duas tinham somente um peixe e as outras duas, apenas larvas. Cada caixa teste continha um peixe e larvas. Na primeira semana foram expostas 100 larvas em cada caixa, e a cada semana acrescentavam-se 100 larvas por caixa/dia, até se obter um máximo de 500 larvas/dia. Comprimento e peso dos peixes foram medidos semanalmente. RESULTADOS: Foram utilizadas 369.000 larvas no total. O Trichogaster trichopteros foi a única espécie em que ambos os sexos predaram 100% das larvas oferecidas. O Betta splendens deixou de predar apenas 15 larvas. Machos do Poecilia reticulata apresentaram baixa capacidade larvófaga quando comparados às fêmeas da mesma espécie. Em relação ao peso e tamanho o Betta splendens mostrou-se capaz de predar 523 larvas/grama/dia. CONCLUSÕES: Fêmeas e machos de Trichogaster trichopteros e de Astyanax fasciatus, e fêmeas de Betta splendens e de Poecillia sphenops foram os peixes que apresentaram maior competência para predar as larvas. Embora com competência menor, machos de Poecillia sphenops e fêmeas de Poecilia reticulata foram capazes de eliminar o número de larvas de Aedes aegypti que possam emergir durante 24 horas num criadouro, em condições naturais. Machos de Poecilia reticulata não foram predadores eficazes.OBJECTIVE: To evaluate the efficacy of fish as predators of the Aedes aegypti larvae in laboratory conditions. METHODS: The male and female of five different fish were included in the experiment. The tests to measure their consumption ability lasted five weeks for each species. Each trial involved four test tanks and four control tanks. Two control tanks

  12. Mercúrio total em pescado de água-doce Total mercury in fresh-water fish

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    Sandra Emi KITAHARA

    2000-08-01

    Full Text Available O mercúrio total foi quantificado em 11 espécies de peixes de água-doce, originárias de diferentes procedências comerciais. O mercúrio vem sendo utilizado na agricultura, indústria, mineração, etc., e isso tem provocado drástico aumento desse metal no meio ambiente, atingindo em conseqüência a cadeia trófica. Nesse contexto, o homem, através do consumo de alimentos, principalmente pescado, torna-se vulnerável à ação tóxica do mercúrio. Os resultados obtidos para as espécies mandi - Pimelodus maculatus, tilápia - Tilapia sp, sagüiru - Cyphocharax modestus, lambari - Astyanax sp, sardela - Triportheus sp, traíra - Hoplias sp, curimbatá - Prochilodus sp e dourado - Salminus sp, comercializadas em São Paulo - SP, e para o jaraqui - Semaprochilodus insignis, curimatã - Prochilodus nigricans e matrinchã - Brycon sp, procedentes da Amazônia brasileira, variaram de 0,01 a 0,39mgHg/Kg. Os resultados observados, sob o ponto-de-vista de Saúde Pública, estão abaixo dos limites de tolerância brasileiros, de 0,5 e 1,0mgHg/Kg, para espécies não-predadoras e predadoras, respectivamente. Nas espécies de hábito alimentar carnívoro (traíra e dourado os teores de mercúrio foram de 0,26 a 0,39mgHg/Kg. A expectativa de ocorrência de espécies excessivamente contaminadas não se confirmou.Total mercury was quantified in 11 fresh-water fish species from different commercial origins. Mercury has been used in agriculture, industry, mining, etc. Consequently there was an increase of mercury discharge to environment, that enters into the throphic chain. In this context, the man, through the consumption of foods, mainly fishery products, turns vulnerable to mercury. The obtained results for mandi - Pimelodus maculatus, tilápia - Tilapia sp, sagüiru - Cyphocharax modestus, lambari- Astyanax sp, sardela - Triportheus sp, traíra - Hoplias sp, curimbatá - Prochilodus sp and dourado - Salminus sp, commercialized in São Paulo-SP, and

  13. Effects of trophic exposure to dexamethasone and diclofenac in freshwater fish.

    Science.gov (United States)

    Guiloski, Izonete Cristina; Ribas, João Luiz Coelho; Pereira, Letícia da Silva; Neves, Ana Paula Perbiche; Silva de Assis, Helena Cristina

    2015-04-01

    Steroidal and non-steroidalanti-inflammatories are pharmaceutical prescribed in human medicine and have the potential to contaminate water and sediments via inputs from sewage treatment plants. Their impacts on humans and ecosystems are emerging issues in environmental health. The aim of the present work was to evaluate the effects of diclofenac and dexamethasone in male fish Hoplias malabaricus after trophic exposure. Fish were fed twice every week with Astyanax sp. submitted to intraperitoneal inoculation with diclofenac (0; 0.2; 2.0 or 20.0 μg/kg) or dexamethasone (0; 0.03; 0.3 or 3.0 μg/kg). After 12 doses, blood was collected for testosterone dosage. The gonad and liver were collected to calculate gonadosomatic (GSI) and hepatosomatic index (HSI). Antioxidants enzymes activity and biotransformation were also evaluated in liver and gonads. In liver, diclofenac caused oxidative stress with increased superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and lipoperoxidation (LPO). The GST activity was reduced by diclofenac in liver. Trophic exposure of H. malabaricus to dexamethasone caused an increase in antioxidant system (GPx, CAT, GST, and GSH) and LPO in liver. However, it reduced antioxidant system (GPX and GST activities and GSH) in gonads. Both diclofenac and dexamethasone reduced the levels of testosterone, causing impairment to reproduction. Diclofenac reduced HSI at the 0.2 μg/kg, but not GSI. Our results suggest that the anti-inflammatory drugs diclofenac and dexamethasone caused oxidative stress and reduced testosterone levels that can have a negative impact in aquatic organisms. PMID:25645142

  14. Spatial, seasonal and ontogenetic changes in food resource use by a piscivore fish in two Pantanal lagoons, Brazil

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    Michele de Faveri Gimenes

    2013-03-01

    Full Text Available We evaluated the factors that affect the food resource use by Plagioscion ternetzi using three approaches: spatial, seasonal, and ontogenetic changes. Fish were sampled between March 2000 and February 2001 and March 2003 and February 2004 in the Sinhá Mariana and Chacororé lagoons, wetlands of the Pantanal Matogrossense. Fish was the predominant food in the diet, but shrimps and insects have been also consumed. The diet of P. ternetzi was significantly different between lagoons, but no difference was detected between dry and flood periods. In Sinhá Mariana lagoon, the diet mainly consisted of Psectrogaster curviventris, in both periods. In the flood period in Chacororé lagoon, fish was the dominant food (especially Astyanax spp., Leporinus spp. and Schizodon borellii, and in dry, shrimp and Eigenmannia spp. The Spearman coefficient indicated no correlation between the abundance of caught fish species and their abundances in the diet of P. ternetzi in Sinhá Mariana lagoon, and a strong negative correlation at Chacororé lagoon, although some very consumed preys were numerically abundant in the environment. Despite the intake of insect and shrimp, P. ternetzi was piscivorous since immature stages. A correlation between each item and the size classes of P. ternetziwas tested by means of Pearson correlation that showed that the changes in the use of resources over ontogenetic development have been represented by increased intake of P. curviventris in Mariana lagoon, and S. borellii at Chacororé lagoon, accompanying the increase in the size of the predator. In this way, the results suggest that several factors can be involved in the use of food resources by P. ternezi, among them the abundance, the size and morphological characteristics of the prey.

  15. Isotopic variation in five species of stream fishes under the influence of different land uses.

    Science.gov (United States)

    Carvalho, D R; Castro, D; Callisto, M; Moreira, M Z; Pompeu, P S

    2015-09-01

    The aim of this study was to test if changes in land use alter the isotopic signature of fish species, promoting changes in the trophic position and food resource partitioning between these consumers. Three different systems were investigated: pasture streams (n = 3), streams in sugar cane plantations (n = 3) and reference streams (n = 3). Fish species Aspidoras fuscoguttatus, Astyanax altiparanae, Characidium zebra, Hisonotus piracanjuba and Knodus moenkhausii were selected, and their nitrogen and carbon isotopic compositions were estimated to assess changes in the trophic level and partitioning of food items consumed. The composition of δ(13) C (‰) only differed among the land use categories for A. altiparanae, H. piracanjuba and K. moenkhausii. Resource partitioning was different for all species, with changes in the sources or proportions they consumed in each land use category, but only A. altiparanae introduced new food sources in large quantity in altered land uses. It is important to note, however, that the results from the resource partitioning analysis are limited due to large overlapping of isotopic signatures between the analysed food resources. All fish species exhibited variation in δ(15) N (‰), with the highest values found in streams under sugar cane or pasture influence. Despite the variation in nitrogen isotopic values, only C. zebra and H. piracanjuba displayed changes in trophic level. Therefore, it is believed that the increase in the δ(15) N (‰) value of the individuals collected in streams under the influence of sugar cane or pasture was due to the greater influence of livestock dung and chemical and organic fertilizers. The results also highlight the importance of studying consumer species along with all forms of resources available at each location separately, because the signatures of these resources also vary within different land uses. PMID:26201419

  16. Hematological findings in neotropical fish Hoplias malabaricus exposed to subchronic and dietary doses of methylmercury, inorganic lead, and tributyltin chloride.

    Science.gov (United States)

    Oliveira Ribeiro, C A; Filipak Neto, F; Mela, M; Silva, P H; Randi, M A F; Rabitto, I S; Alves Costa, J R M; Pelletier, E

    2006-05-01

    Hematological indices are gaining general acceptance as valuable tools in monitoring various aspects the health of fish exposed to contaminants. In this work some effects of methyl mercury (MeHg), inorganic lead (Pb2+), and tributyltin (TBT) in a tropical fish species were evaluated by hematological methods after a trophic exposition at a subchronic level. Forty-two mature individuals of the freshwater top predator fish Hoplias malabaricus were exposed to trophic doses (each 5 days) of MeHg (0.075 microg g(-1)), Pb2+ (21 microg g(-1)), and TBT (0.3 microg g(-1)) using young fish Astyanax sp. as prey vehicle. After 14 successive doses over 70 days, blood was sampled from exposed and control groups to evaluate hematological effects of metals on erythrocytes, total leukocytes and differential leukocytes counts, hematocrit, hemoglobin concentration, and red blood cell indices mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). Transmission electron microscopy and image analysis of erythrocytes were also used to investigate some morphometric parameters. Results show no significant effects in MCH and MCHC for all tested metals, but differences were found in erythrocytes, hemoglobin, hematocrit, MCV, and white blood cells counts. The number of leukocytes was increased in the presence of MeHg, suggesting effects on the immune system. Also the MCV increased in individuals exposed to MeHg. No ultrastructural damages were observed in red blood cells but the image analysis using light microscopy revealed differences in area, elongation, and roundness of erythrocytes from individuals exposed to Pb2+ and TBT but not in the group exposed to MeHg. The present work shows that changes in hematological and blood indices could highlight some barely detectable metal effects in fish after laboratory exposure to contaminated food, but their application in field biomonitoring using H. malabaricus will need more detailed

  17. Variation in the diet of a small characin according to the riparian zone coverage in an Atlantic Forest stream, northeastern Brazil

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    Márcia Emília de Jesus Trindade

    2013-03-01

    Full Text Available AIM: in this study we present data from the diet of Astyanax vermilion which were used as a tool to compare two sites of streams with different vegetation cover in Ribeirão Limoeiro, Cachoeira River Basin, BA. METHODS: Four samples were taken (March, June, September and December using electrofishing as the collection method in two contiguous sites of the headwaters: stretch without riparian vegetation and with riparian vegetation. RESULTS: The qualitative composition of the diet was analyzed by the method of frequency of occurrence. The allochthonous resources of vegetal origin made up the bulk of the diet in the stretch without riparian vegetation with a frequency of occurrence of 64%. In the section with riparian vegetation allochthonous resources of animal origin made up the bulk of the diet with a frequency of 62%, which emphasizes the importance of food items from the surrounding environment. The mean Shannon diversity index, calculated from the frequency of occurrence of food items was significantly different (p = 0.04 when comparing reach deforested (H'= 1.44 with reach forested (H'= 1.80. The average weight of stomachs in the deforested reach (WS D = 0.18g was significantly higher than that of the forested reach (WS F = 0.14g. CONCLUSIONS: in the stretch with riparian vegetation, the food diversity was greater and the fish that are in the riparian stretch do not need as much food to satisfy their physiological needs. These results underscore the importance of the type of riparian vegetation as a food source for fish

  18. Fatty Acid Composition of Tropical Fish Depends on Reservoir Trophic Status and Fish Feeding Habit.

    Science.gov (United States)

    Gomes, Aline D; Tolussi, Carlos E; Boëchat, Iola G; Pompêo, Marcelo L M; Cortez, Maíra P T; Honji, Renato M; Moreira, Renata G

    2016-10-01

    Eutrophication results in a deficiency of n-3 LC-PUFA (long-chain polyunsaturated fatty acids) in aquatic food chains, affecting fish nutrition and physiology. The trophic transfer of FA (fatty acids) to fish species of different feeding habits was investigated in two reservoirs in southeast Brazil-the mesotrophic Ponte Nova Reservoir (PN) and the hypereutrophic Billings Reservoir (Bil). Total FA profile of stomach contents and adipose tissue, triacylglycerols (TAG), and phospholipids (PL) from liver and muscle of the omnivorous Astyanax fasciatus and the carnivorous Hoplias malabaricus were analyzed by gas chromatography. A prevalence of n-6PUFA, as 18:2n-6 (linoleic acid) and 20:4n-6 (arachidonic acid, ARA) was observed in the stomach contents and in the tissues of A. fasciatus from the PN reservoir. In contrast, n-3 LC-PUFA, as 20:5n-3 (eicosapentaenoic acid, EPA) was accumulated in fish tissues from Bil, resulting in higher n3/n6 and EPA/ARA ratios, compared to fish from PN. This differential FA accumulation was also observed for H. malabaricus, but differences were slightly minor, and no changes were observed in the EPA/ARA ratios between fish from both reservoirs. Regardless reservoir, FA profiles of TAG resembled that of their diet, whereas FA profiles of PL were more conservative and mainly comprised by LC-PUFA. We conclude that reservoir trophic status affected the FA composition of food resources available to these fish species, resulting in differential allocation of n-3 and n-6 FA. As expected, FA profile of the investigated fish species also reflected their feeding habit and physiological demands. PMID:27631676

  19. Effects of mercury intoxication on the response of horizontal cells of the retina of thraira fish (Hoplias malabaricus

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    C.L. Tanan

    2006-07-01

    Full Text Available Methyl mercury (MeHg is highly neurotoxic, affecting visual function in addition to other central nervous system functions. The effect of mercury intoxication on the amplitude of horizontal cell responses to light was studied in the retina of the fish Hoplias malabaricus. Intracellular responses were recorded from horizontal cells of fish previously intoxicated with MeHg by intraperitoneal injection (IP group or by trophic exposure (T group. Only one retina per fish was used. The doses of MeHg chloride administered to the IP group were 0.01, 0.05, 0.1, 1.0, 2.0, and 6.0 mg/kg. The amplitudes of the horizontal cell responses were lower than control in individuals exposed to 0.01 (N = 4 retinas, 0.05 (N = 2 retinas and 0.1 mg/kg (N = 1 retina, whereas no responses were recorded in the 1.0, 2.0, and 6.0 mg/kg groups. T group individuals were fed young specimens of Astyanax sp previously injected with MeHg corresponding to 0.75 (N = 1 retina, 0.075 (N = 8 retinas or 0.0075 (N = 4 retinas mg/kg fish body weight. After 14 doses, one every 5 days, the amplitude of the horizontal cell response was higher than control in individuals exposed to 0.075 and 0.0075 mg/kg, and lower in individuals exposed to 0.75 mg/kg. We conclude that intoxication with MeHg affects the electrophysiological response of the horizontal cells in the retina, either reducing or increasing its amplitude compared to control, and that these effects are related to the dose and/or to the mode of administration.

  20. Lake size and fish diversity in southern Brazil coastal lagoons

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    Lucia Ribeiro Rodrigues

    2015-10-01

    Full Text Available The coastal plain of Rio Grande do Sul, southern Brazil, presents a series of shallow lagoons with diverse size and morphology. The objective of this study is to determine whether the size of the lagoon is an effective factor for structuring fish diversity. In this regard, nine lagoons with distinct areas were sampled: three with an area up to 40 hectares, three with area between 40 and 80 hectares, and three with an area of over 80 hectares. Each lagoon was sampled once on the littoral and pelagic zones. At each point, fish were captured through a set of gill nets with different mesh sizes. Captured specimens were identified, quantified and evaluated for weight and length. A total of 24 fish species belonging to 10 families was obtained, with Characidae presenting the highest species richness. Cyanocharax alburnus was the only species that occurred in all lagoons. Cyphocharax voga, Astyanax eigenmmaniorum, Oligosarcus jenynsii and O. robustus were also frequent species, present in most of the sampled lagoons. Lycengraulis grossidens was captured in just two lagoons with increased conductivity. The community structure showed the highest species richness in lakes with an area over 40 ha, however the highest mean diversity values were observed in ponds up to 40 ha. Cluster Analysis yielded the formation of two groups: a group formed by just one lagoon and a second one cluster grouping all the other lagoons. This pattern may be associated with the presence of Lycengraulis grossidens as a dominant species in this lagoon clustered apart. The results indicate that lagoons with up to 40 ha present greater homogeneity on the species composition and higher average values of diversity; while intermediate ponds (between 40 and 80 ha have lower average diversity for the fish fauna due to increased heterogeneity in species abundance.

  1. Cobalt Chloride Treatment Used to Ablate the Lateral Line System Also Impairs the Olfactory System in Three Freshwater Fishes.

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    Julie M Butler

    Full Text Available Fishes use multimodal signals during both inter- and intra-sexual displays to convey information about their sex, reproductive state, and social status. These complex behavioral displays can include visual, auditory, olfactory, tactile, and hydrodynamic signals, and the relative role of each sensory channel in these complex multi-sensory interactions is a common focus of neuroethology. The mechanosensory lateral line system of fishes detects near-body water movements and is implicated in a variety of behaviors including schooling, rheotaxis, social communication, and prey detection. Cobalt chloride is commonly used to chemically ablate lateral line neuromasts, thereby eliminating water-movement cues to test for mechanosensory-mediated behavioral functions. However, cobalt acts as a nonspecific calcium channel antagonist and could potentially disrupt function of all superficially located sensory receptor cells, including those for chemosensing. Here, we examined whether CoCl2 treatment used to ablate the lateral line system also impairs olfaction in three freshwater fishes, the African cichlid fish Astatotilapia burtoni, goldfish Carassius auratus, and the Mexican blind cavefish Astyanax mexicanus. To examine the impact of CoCl2 on the activity of peripheral receptors, we quantified DASPEI fluorescence intensity of the olfactory epithelium from fish exposed to control and CoCl2 solutions. In addition, we examined brain activation in olfactory processing regions of A. burtoni immersed in either control or cobalt solutions. All three species exposed to CoCl2 had decreased DASPEI staining of the olfactory epithelium, and in A. burtoni, cobalt treatment caused reduced neural activation in olfactory processing regions of the brain. To our knowledge this is the first empirical evidence demonstrating that the same CoCl2 treatment used to ablate the lateral line system also impairs olfactory function. These data have important implications for the use of

  2. Cobalt Chloride Treatment Used to Ablate the Lateral Line System Also Impairs the Olfactory System in Three Freshwater Fishes.

    Science.gov (United States)

    Butler, Julie M; Field, Karen E; Maruska, Karen P

    2016-01-01

    Fishes use multimodal signals during both inter- and intra-sexual displays to convey information about their sex, reproductive state, and social status. These complex behavioral displays can include visual, auditory, olfactory, tactile, and hydrodynamic signals, and the relative role of each sensory channel in these complex multi-sensory interactions is a common focus of neuroethology. The mechanosensory lateral line system of fishes detects near-body water movements and is implicated in a variety of behaviors including schooling, rheotaxis, social communication, and prey detection. Cobalt chloride is commonly used to chemically ablate lateral line neuromasts, thereby eliminating water-movement cues to test for mechanosensory-mediated behavioral functions. However, cobalt acts as a nonspecific calcium channel antagonist and could potentially disrupt function of all superficially located sensory receptor cells, including those for chemosensing. Here, we examined whether CoCl2 treatment used to ablate the lateral line system also impairs olfaction in three freshwater fishes, the African cichlid fish Astatotilapia burtoni, goldfish Carassius auratus, and the Mexican blind cavefish Astyanax mexicanus. To examine the impact of CoCl2 on the activity of peripheral receptors, we quantified DASPEI fluorescence intensity of the olfactory epithelium from fish exposed to control and CoCl2 solutions. In addition, we examined brain activation in olfactory processing regions of A. burtoni immersed in either control or cobalt solutions. All three species exposed to CoCl2 had decreased DASPEI staining of the olfactory epithelium, and in A. burtoni, cobalt treatment caused reduced neural activation in olfactory processing regions of the brain. To our knowledge this is the first empirical evidence demonstrating that the same CoCl2 treatment used to ablate the lateral line system also impairs olfactory function. These data have important implications for the use of CoCl2 in future

  3. The impact of organochlorines and metals on wild fish living in a tropical hydroelectric reservoir: bioaccumulation and histopathological biomarkers.

    Science.gov (United States)

    Paulino, Marcelo Gustavo; Benze, Tayrine Paschoaletti; Sadauskas-Henrique, Helen; Sakuragui, Marise Margareth; Fernandes, João Batista; Fernandes, Marisa Narciso

    2014-11-01

    This study evaluates the contaminants in water and their bioaccumulation in the gills and liver of two ecologically distinct fish species, Astyanax fasciatus and Pimelodus maculatus, living in the reservoir of the Furnas hydroelectric power station located in Minas Gerais in the southeastern Brazil. The histological alterations in these organs are also examined. Water and fish were collected in June and December from five sites (site 1: FU10, site 2: FU20, site 3: FU30, site 4: FU40 and site 5: FU50) in the reservoir, and agrochemicals and metals selected based on their use in the field crops surrounding the reservoir were analyzed in the water and in the fish gills and livers. The concentrations of the organochlorines aldrin/dieldrin, endosulfan and heptachlor/heptachlor epoxide as well as the metals copper, chromium, iron and zinc in the gills and livers of both fish species were higher in June than in December; the liver accumulated higher concentrations of contaminants than the gills. The organochlorine metolachlor was detected only in the liver. The histological pattern of changes was similar in both species with regard to contaminant accumulation in the gills and liver. Fish from FU10, the least contaminated site, exhibited normal gill structure and moderate to heavy liver damage. Fish collected at FU20 to FU50, which were contaminated with organochlorines and metals, showed slight to moderate gill damage in June and irreparable liver damage in the livers in June and December. The histological changes in the gills and liver were suitable to distinguishing contaminated field sites and are therefore useful biomarkers for environmental contamination representing a biological end-point of exposure.

  4. An Index of Biotic Integrity for shallow streams of the Hondo River basin, Yucatan Peninsula

    International Nuclear Information System (INIS)

    An Index of Biotic Integrity (IBI) is proposed, based on the fish communities and populations in streams of the Hondo River basin, Mexico-Belize. Freshwater environments in this area are threatened by exotic fishes, eutrophication, and pesticide pollution, among other problems. This IBI should allow to identify the most vulnerable sites and eventually guide rehabilitation efforts. Data on composition, structure, and function of fish communities were evaluated. Twenty-three sites in the Mexican part of the basin were explored; a stratified sample of 13 sites was used to design the IBI, and the rest were used to test and refine the index. Thirty-four candidate indicator metrics were scanned for their correlation with an index of water and habitat quality (IWHQ), as well as for the possible influence of stream width and altitude or distance to the Hondo River mainstem. Twelve variables were selected to constitute the IBI: relative abundances of Astyanax aeneus, 'Cichlasoma' urophthalmus, Poecilia mexicana, Poecilia sp. (a new species, probably endemic to the upper Hondo River basin), Xiphophorus hellerii, and X. maculatus; relative abundances of bentholimnetic, herbivore, and sensitive species; percentage of native and tolerant species; and Pielou's evenness index. Most of the sites have a low-medium quality and integrity, showing impact due to partial channelization or to suboptimal water quality, reflected in scarcity or absence of sensitive species, frequent excess of tolerant species, occasional presence of exotics, dominance of herbivores (perhaps due to proliferation of filamentous algae), or dominance of the opportunistic species P. mexicana. The streams with better water and habitat quality are those farthest away from the river mainstem, probably because of lower human population and economical production. - Research Highlights: → An Index of Biotic Integrity based on fishes is proposed for streams of the Hondo River basin. → Twelve variables were

  5. Uso de biomarcadores para monitoramento das águas do Córrego Arara no município de Rio Brilhante, MS, Brasil

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    Elisangela Bortoluci Maceda

    2015-01-01

    Full Text Available O objetivo deste trabalho foi avaliar a mutagenicidade, genotoxicidade e citotoxicidade de amostras de água provenientes do Córrego Arara no município de Rio Brilhante, MS, Brasil, por meio de testes toxicológicos utilizando biomarcadores. Para avaliar a mutagenicidade utilizou-se o teste de micronúcleo, para a genotoxicidade o ensaio cometa, ambos com Astyanax altiparanae, e para analisar a citotoxicidade utilizou-se o teste de Allium cepa. As coletas foram realizadas nos meses de abril e junho de 2013, em três pontos distintos (pontos 1, 2 e 3 do Córrego Arara e no Tanque de Irrigação da UFGD (ponto 4. Os resultados indicaram aumento significativo na frequência de micronúcleos pisceos na coleta do mês de junho quando comparada com a realizada em abril. No teste de Allium cepa, o efeito citotóxico apresentou-se significativamente maior na coleta de abril, porém a genotoxicidade das águas não apresentou diferença estatística entre os meses de coleta. O maior número de danos no ensaio cometa ocorreu no ponto 4, em ambos períodos de coleta. A análise química da água indicou níveis de cádmio, cromo, cobre, chumbo e níquel, com valores superiores ao permitido pela legislação vigente. A presença de metais acima dos níveis permitidos nas amostras de água analisadas do Córrego Arara indica possíveis potenciais mutagênicos, genotóxicos e citotóxicos aos organismos devido a esses poluentes derivados ou não de ações antrópicas. Assim sendo, este trabalho pode contribuir como ferramenta adicional ao controle da qualidade da água do Córrego Arara, considerando sua utilização e importância para a região.

  6. Trophic structure of a fish community in Bananal stream subbasin in Brasília National Park, Cerrado biome (Brazilian Savanna, DF

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    Mariana Schneider

    2011-01-01

    Full Text Available The aim of this study was to determine the trophic structure of the fish community in the Bananal stream subbasin, which belongs to a well-preserved Cerrado area (Brazilian Savanna in Brasília National Park, Brazil. We also evaluated the influence of environmental variations in the diet of fish species. Four samples were taken in each 30 m long established transect, two in the rainy season and two in the dry season. A total of 1,050 stomachs of the 13 most abundant species were analyzed. A total of 36 food items were consumed, where 24 were autochthonous, 8 allochthonous, and 4 of undetermined origin. Non-metric multidimensional scaling (NMDS analysis, in addition to the results of frequency of occurrence and abundance charts, was used to determine four groups of feeding guilds: detritivores, omnivores (tending toward herbivory and invertivory, invertivores and piscivores. Around 69% of the volume of resources consumed was allochthonous, which proves the importance of the resources provided by riparian vegetation. The contribution of autochthonous and allochthonous items in the diet differed due to seasonality for Aspidoras fuscoguttatus, Astyanax sp., Characidium xanthopterum, Hyphessobrycon balbus, Kolpotocheirodon theloura, Moenkhausia sp., Phalloceros harpagos, and Rivulus pictus. Despite the Cerrado climate characteristics, there was no significant influence of season on the fish diet. The absence of seasonal variation and the predominance of allochthonous items in the fish diet are probably associated with the presence of riparian vegetation, which acts as a transition area in the Cerrado biome and provides resources for the aquatic fauna. This work shows the importance of studies in non-disturbed areas considered here as a source of information concerning the biology of fish species and as a guide for direct conservation policies on the management of aquatic resources, recovery of damaged areas and determination of priority areas for

  7. Feeding ecology of stream-dwelling fishes from a coastal stream in the Southeast of Brazil

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    Rosana Mazzoni

    2007-07-01

    Full Text Available The relationship between ontogenetic variation of intestine length and feeding habits of five stream-dwelling fish species from the Ubatiba River were investigated. Analysed data were based on two size categories (juveniles and adults and two food categories (animal and vegetal. Diet composition of each size category revealed that Astyanax janeiroensis and Geophagus brasiliensis changed food preference throughout ontogeny and switched from omnivorous/carnivorous to omnivorous/herbivorous and from omnivorous/carnivorous to omnivorous, respectively. These changes were followed by ontogenetic changes in the Intestinal Coefficient (IC. No ontogenetic differences were registered for IC and food categories consumed by Hoplias malabaricus but significant differences in the size of consumed preys as well as positive correlation between fish size (predator and prey size was observed. Food items (within animal category consumed by the adult Pimelodella lateristriga were mainly based on allochthonous arthropods whereas juvenile individuals fed with the same intensity on allochthonous and autochthonous arthropods; both juveniles and adult individuals of Mimagoniates microlepis were mainly allochthonous feeders. Mean IC values of Pimelodella lateristriga and Mimagoniates microlepis did not change along body growth. Although changes in food category consumption were not common among all the studied species, changes in the resource exploitation strategy was a rule among them, except for Mimagoniates microlepis.Foi investigada a relação entre as variações ontogenéticas do comprimento do intestino e os hábitos alimentares de cinco espécies de peixes do rio Ubatiba, RJ. Os dados analisados foram baseados em duas categorias de tamanho (jovens e adultos de cada espécie e duas categorias de alimento (animal e vegetal. A composição da dieta de cada categoria de tamanho revelou que Astyanax janeiroensis e Geophagus brasiliensis mudaram a prefer

  8. ESTADO DEL CONOCIMIENTO DE LAS CONCENTRACIONES DE MERCURIO Y OTROS METALES PESADOS EN PECES DULCEACUÍCOLAS DE COLOMBIA Current State of Knowledge of the Concentration of Mercury and Other Heavy Metals in Fresh Water Fish in Colombia

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    NÉSTOR JAVIER MANCERA-RODRÍGUEZ

    2006-06-01

    Full Text Available Una de las problemáticas ambientales más importantes en el país se refiere al uso indiscriminado de precursores químicos en actividades ilícitas, el uso de metales pesados como mercurio en actividades mineras, el vertimiento de aguas servidas y otro tipo de compuestos relacionados con actividades industriales y prácticas agrícolas inadecuadas. Lo anterior, ha llevado a que la contaminación química en especial por metales pesados, constituya una de las más peligrosas para los ecosistemas acuáticos y las especies presentes en ellos. Los peces tienen la capacidad de almacenar en su organismo una concentración mayor de estos compuestos en comparación con la presente en el medio, por lo que son un indicador importante de la contaminación, pero también esto implica que su consumo se puede convertir en un problema de salud para las poblaciones que se alimentan de este recurso. La concentración de metales pesados en peces de agua dulce es conocida de mejor manera en la cuenca del río Magdalena, especialmente en la región de la Mojana y en las ciénagas del sur del departamento de Bolívar donde se han estudiado los niveles de contaminación por mercurio y otros metales producida por el desarrollo de múltiples actividades industriales, entre las cuales sobresalen la minería de oro y la petroquímica. Sin embargo, es escaso el conocimiento que se tiene en el país de la problemática generada por la disposición en los cuerpos de agua de metales pesados y su impacto sobre el recurso íctico, el deterioro de ecosistemas y la salud humana. Con base en las normas vigentes se han realizado bioensayos como criterio para comprobar los efectos de la contaminación acuática con organismos dulceacuícolas y la evaluación de por lo menos tres parámetros (metales pesados, temperatura, efluentes, utilizando ocho especies de peces dulceacuícolas: Carassius auratus, Oreochromis spp., Piractus brachypomus, Prochilodus magdalenae, Astyanax

  9. Estado del conocimieno de las concentraciones de mercurio y otros metales pesados en peces dulceacuícolas de Colombia Current State of Knowledge of the Concentration of Mercury and Other Heavy Metals in Fresh Water Fish in Colombia

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    Álvarez-León Ricardo

    2006-06-01

    Full Text Available Una de las problemáticas ambientales más importantes en el país se refiere al uso indiscriminado de precursores químicos en actividades ilícitas, el uso de metales pesados como mercurio en actividades mineras, el vertimiento de aguas servidas y otro tipo de compuestos relacionados con actividades industriales y prácticas agrícolas inadecuadas. Lo anterior, ha llevado a que la contaminación química en especial por metales pesados, constituya una de las más peligrosas para los ecosistemas acuáticos y las especies presentes en ellos. Los peces tienen la capacidad de almacenar en su organismo una concentración mayor de estos compuestos en comparación con la presente en el medio, por lo que son un indicador importante de la contaminación, pero también esto implica que su consumo se puede convertir en un problema de salud para las poblaciones que se alimentan de este recurso. La concentración de metales pesados en peces de agua dulce es conocida de mejor manera en la cuenca del río Magdalena, especialmente en la región de la Mojana y en las ciénagas del sur del departamento de Bolívar donde se han estudiado los niveles de contaminación por mercurio y otros metales producida por el desarrollo de múltiples actividades  industriales, entre las cuales sobresalen la minería de oro y la petroquímica. Sin embargo, es escaso el conocimiento que se tiene en el país de la problemática generada por la disposición en los cuerpos de agua de metales pesados y su impacto sobre el recurso íctico, el deterioro de ecosistemas y la salud humana. Con base en las normas vigentes se han realizado bioensayos como criterio para comprobar los efectos de la contaminación acuática con organismos dulceacuícolas y la evaluación de por lo menos tres parámetros (metales pesados, temperatura, efluentes, utilizando ocho especies de peces
    dulceacuícolas: Carassius auratus, Oreochromis spp., Piractus brachypomus, Prochilodus magdalenae, Astyanax

  10. Directory of Open Access Journals (Sweden)

    Michele de Faveri Gimenes

    2013-03-01

    Full Text Available We evaluated the factors that affect the food resource use by Plagioscion ternetzi using three approaches: spatial, seasonal, and ontogenetic changes. Fish were sampled between March 2000 and February 2001 and March 2003 and February 2004 in the Sinhá Mariana and Chacororé lagoons, wetlands of the Pantanal Matogrossense. Fish was the predominant food in the diet, but shrimps and insects have been also consumed. The diet of P. ternetzi was significantly different between lagoons, but no difference was detected between dry and flood periods. In Sinhá Mariana lagoon, the diet mainly consisted of Psectrogaster curviventris, in both periods. In the flood period in Chacororé lagoon, fish was the dominant food (especially Astyanax spp., Leporinus spp. and Schizodon borellii, and in dry, shrimp and Eigenmannia spp. The Spearman coefficient indicated no correlation between the abundance of caught fish species and their abundances in the diet of P. ternetzi in Sinhá Mariana lagoon, and a strong negative correlation at Chacororé lagoon, although some very consumed preys were numerically abundant in the environment. Despite the intake of insect and shrimp, P. ternetzi was piscivorous since immature stages. A correlation between each item and the size classes of P. ternetzi was tested by means of Pearson correlation that showed that the changes in the use of resources over ontogenetic development have been represented by increased intake of P. curviventris in Mariana lagoon, and S. borellii at Chacororé lagoon, accompanying the increase in the size of the predator. In this way, the results suggest that several factors can be involved in the use of food resources by P. ternezi, among them the abundance, the size and morphological characteristics of the prey.Neste estudo foram avaliados fatores que afetam o uso dos recursos alimentares por Plagioscion ternetzi, Boulenger, 1895, utilizando três abordagens: variações espacias, sazonais e ontogen

  11. Mechanisms of pigmentation loss in subterranean fishes

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    Vanessa Felice

    2008-12-01

    Full Text Available Troglobitic (exclusively subterranean organisms usually present, among their apomorphies related to the subterranean life (troglomorphisms, the regression of eyes and melanic pigmentation. The degree of regression varies among species, from a slight reduction to the complete loss of eyes and dark pigmentation, without a taxonomic correlation. While mechanisms of eye reduction have been intensively investigated in some troglobites such as the Mexican blind tetra characins, genus Astyanax, and the European salamander, Proteus anguinus, few studies have focused on pigmentation. The Brazilian subterranean ichthyofauna distinguishes not only by the species richness (23 troglobitic fishes so far known but also by the variation in the degree of reduction of eyes and pigmentation. This study focused on Brazilian fishes completely devoid of melanic pigmentation: the characiform Stygichthys typhlops (Characidae and the siluriforms Ancistrus formoso (Loricariidae, Rhamdiopsis sp.1 (Heptapteridae; from caves in the Chapada Diamantina, Bahia and Rhamdiopsis sp. 2 (cave in Campo Formoso, Bahia. In order to investigate if such depigmentation is the result of blockage in some step in the melanogenesis, in vitro tests of administration of L-DOPA were done, using caudal-fin fragments extracted from living fish. Except for Rhamdiopsis sp. 2, all the studied species were DOPA(+, i.e., melanin was synthesized after L-DOPA administration. This indicates these fish do have melanophores but they are unable to convert L-tyrosine to L-DOPA. On the other hand, Rhamdiopsis sp. 2, like the albino specimens of Trichomycterus itacarambiensis previously studied (which correspond to one third of the population, are DOPA(-, either because the block of melanin synthesis occurs downstream in melanogenesis, which is probably the case with T. itacarambiensis (monogenic system in view of the phenotypic discontinuity, or because the so-called albinos do no possess melanophores. The

  12. Longitudinal habitat disruption in Neotropical streams: fish assemblages under the influence of culverts

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    José Roberto Mariano

    2012-10-01

    Full Text Available This study assessed differences in fish assemblages existing upstream and downstream two types of culverts, one on each of two different Neotropical streams. We analyzed the composition and structure of the ichthyofauna and tested for spatial patterns. Fish sampling was carried out monthly between November 2009 and October 2010 using different fishing gears. We collected 2,220 fish of 33 species; 901 in stretches of the Lopeí stream - circular culvert and 1,310 in stretches of the Pindorama stream - box culvert. Fish abundance was similar in upstream and downstream stretches of the circular culvert, whereas it was slightly higher in the upstream than downstream stretch for the box culvert. Characiformes predominated in the upstream stretch of both culverts. On the other hand, Siluriformes was abundant in the downstream stretch of the circular culvert, with similar abundance in the stretches of the box culvert. Species richness and diversity (Shannon-Weiner Index were higher in the downstream stretch of the circular culvert, but they were similar in both stretches of the box culvert. The most abundant species were Astyanax altiparanae, A. paranae, A. fasciatus, Ancistrus sp., and Hypostomus sp. The last two species were more abundant in the downstream stretch of the circular culvert, and similar in stretches of the box culvert. Our study indicated variations in the species abundance, richness, and diversity between upstream and downstream stretches in particular of the circular culvert in the Lopeí stream, suggesting that fish movements are restrained more intensively in this culvert, especially for Siluriformes. The drop in the circular culvert outlet probably created passage barriers especially for those fish that has no ability to jump, where downstream erosion could lead to culvert perching. Studies on appropriate road crossing design or installation are fundamental whereas improvements in these structures can restore the connectivity of

  13. Testing the ecomorphological hypothesis in a headwater riffles fish assemblage of the rio São Francisco, southeastern Brazil

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    Lilian Casatti

    2006-06-01

    Full Text Available The ecomorphology of 14 fish species resident in a headwater riffles area of the São Francisco river, southeastern Brasil, was analyzed and combined with diet and feeding behavior data, previously obtained by us. The three larger species groups formed in the ecomorphological analysis were found to reflect primarily microhabitat occupation in the following manner: a nektonic characids with compressed bodies, lateral eyes and lateral pectoral fins, with diurnal and opportunistic feeding habits (Astyanax rivularis, Bryconamericus stramineus, and Bryconamericus sp.; b nektobenthic characiforms and siluriforms with fusiform bodies and expanded pectoral fins, including sit-and-wait characidiins, predators of aquatic insect larvae (Characidium fasciatum and Ch.zebra, as well as the algae grazing parodontids (Apareiodon ibitiensis and Parodon hilarii, and also the heptapterid and trichomycterid catfishes that practice substrate speculation and feed on benthic aquatic insect larvae (Cetopsorhamdia iheringi, Imparfinis minutus, Rhamdia quelen, and Trichomycterus sp.; c benthic species with depressed bodies, suctorial oral discs, dorsal eyes, and horizontal pectoral fins, represented by the periphytivorous loricariid catfishes (Hisonotus sp., Harttia sp., and Hypostomus garmani. Correlation between diet and general morphology was not significant in our analysis, unless when the analyzed set included only nektonic and benthic species, indicating that the lack of correlation between these factors is most pronounced in the group of nektobenthic species. The unequivocal case of morphological convergence found between the nektobenthic Characidiinae and Parodontidae is a clear example of the integration between phylogenetic information and ecomorphology, and provides a way to objectively identify cases of morphological and adaptive convergence and divergence. Furthermore, the general congruence between the ecomorphological results and the independently obtained

  14. Níveis de energia digestível e proteína bruta em rações para alevinos de lambari tambiú Dietary levels of digestible energy and crude protein for lambari tambiú fingerlings

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    Jorge Luiz Vieira Cotan

    2006-06-01

    Full Text Available Com o objetivo de determinar os níveis de energia digestível (ED em função do nível de proteína bruta (PB da ração para alevinos de lambari tambiú (Astyanax bimaculatus, foram utilizados 600 peixes com 1,30 ± 0,01 g, distribuídos em 40 aquários de 100 L, dotados de abastecimento de água, com temperatura controlada e sistema de aeração individual. O experimento foi realizado em um esquema fatorial 5 x 2 (cinco níveis de ED: 2.900, 3.000, 3.100, 3.200 e 3.300 kcal/kg combinados com dois níveis de PB: 32,0 e 38,0%, em delineamento inteiramente ao acaso, com quatro repetições e 15 peixes por unidade experimental. Os peixes foram submetidos à alimentação controlada com base no consumo diário médio dos peixes dos tratamentos com rações contendo nível mais alto de energia (3.300 kcal/kg para cada nível protéico, corrigido diariamente, durante 49 dias. Foi avaliado o ganho de peso, a taxa de crescimento específico, os consumos de ração, de PB e de ED, a conversão alimentar, a taxa de eficiência protéica, o rendimento de carcaça, a eficiência de retenção de nitrogênio e os teores de umidade, proteína e gordura corporais. Com o nível de 32% de PB, foram obtidos maiores consumos de ração e de ED, mais altas taxas de eficiência protéica e de retenção de nitrogênio, menores consumo de PB e rendimento de carcaça, além de reduzida umidade corporal. Com níveis crescentes de ED nas rações com 32% de PB, os peixes apresentaram menor taxa de crescimento específico, mais baixa taxa de eficiência protéica e maior conversão alimentar, enquanto com as rações com 38% de PB apresentaram maior rendimento de carcaça. A exigência de ED para lambari tambiú é de 2.900 kcal/kg para rações com 32 e 38% de PB.Six hundred lambari tambiú (Astyanax bimaculatus averaging initial weight of 1.30 ± 0.01 g, placed in 40 aquariums (100 L with water renewal, controlled temperature and individual aeration, were used to

  15. Utilization of the fish ladder at the Engenheiro Sergio Motta Dam, Brazil, by long distance migrating potamodromous species

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    Sérgio Makrakis

    2007-01-01

    Full Text Available Utilization of the fish ladder installed at the Engenheiro Sergio Motta Dam (also known as Porto Primavera on the Paraná River, Southern Brazil, by long-distance migrating potamodromous species (sampling Protocol I, and ascending and descending movements (Protocol II were evaluated. Three pools along the fish ladder (designated as lower, middle, and upper were sampled monthly between December, 2004 and March, 2005 to determine the abundance of species in the ladder. The ascending and descending movements of the species in the ladder were also analyzed in the same period. In the samples for both protocols, 37 species representing 17 families and 5 orders (Characiformes, Siluriformes, Perciformes, Gymnotiformes, and Myliobatiformes were recorded. Characiformes were represented by 21 species. Long- distance migratory species (11 species predominated in the ladder (60% of the total number of individuals, with high abundance of Rhinelepis aspera (5645 individuals. For protocol I, mean abundance varied greatly among the months and pools, with lowest values in December and March for all pools, and highest in January for the lower pool due to high capture of R. aspera. Fish abundance declined from the lower to the upper pool, especially for R. aspera and Rhaphiodon vulpinus. For Protocol II, 17 species were recorded ascending the ladder, where Astyanax altiparanae and Leporinus friderici were the most abundant species (684 and 111 individuals, respectively. However, 18 species showed descending movements, with high captures of Metynnis maculatus and A. altiparanae (339 and 319 individuals, respectively. Twelve species (52% moved in both directions, and among the seven migratory species sampled, four were recorded ascending and descending, and three species only ascending the ladder. The fish ladder appears to selectively favor species with high swimming capabilities. A discussion is presented on the requirements for future research on attraction to the

  16. Procamallanus brasileiros (Nematoda, Camallanoidea: considerações finais, com chave para determinação das espécies Brazilian Procamallanus (Nematoda, Camallanoidea: final remarks on the subject, with a key to the species

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    R. Magalhães Pinto

    1976-01-01

    Full Text Available Encerrando uma série de observações em nematódeos do gênero Procamallanus Baylis, 1923, que ocorrem no Brasil, reunimos no presente trabalho a descrição de uma nova espécie: Procamallanus (Spirocamallanus paraensis, a redescrição de Procamallanus (S. hilarii vaz & Pereira, 1934 e as descrições originais de Procamallanus (S. barroslimai Pereira, 1935 e Procamallanus (S. macaensis vicente & Santos, 1972, modificadas e adaptadas. Quanto a barroslimai, colocamos em dúvida sua validade e somente não a tomamos sinônima a Procamallanus (S. inopinatus Travassos, Artigas & Pereira, 1928, devido à falta absoluta de material, impossibilidade de acesso ao tipo e dados concretos que justificassem tal procedimento, no que somos apoiados por Kloss (1966. Relacionamos amostras de material parcialmente danificado que não nos permitiu uma diagnose específica. Referências são feitas a Procamallanus (S. iheringi Travassos, Artigas & Pereira, 1928. Para Procamallanus (S. inopinatus é assinalado um novo hospedador. Como a maioria do material observado provinha de necrópsias realizadas em peixes dulcícolas caracídeos, fizemos um estudo comparativo entre os Procamallanus anteriormente referidos nesses hospedadores a fim de estabelecermos possíveis afinidades entre os caracteres morfológicos considerados distintivos quando da proposição das diversas espécies. Desta forma, pudemos ratificar as afirmações de Kloss (1966, com relação aos Procamallanus, quando do estudo dos parasitos de espécies simpátricas de Astyanax. Finalmente, incluímos uma chave para a determinação dos Procamallanus brasileiros.With this work, we went through the Brazilian Procamallanus, all of them but one recovered from freshwater fishes. We describe Procamallanus (Spirocamallanus paraensis n. sp., which is related to Procamallanus (S. pexatus pinto, Fabio, Noronha & Rolas, 1976 and to Procamallanus (S. inopinatus Travassos, Artigas & Pereira, 1928

  17. Identification and Expression Analysis ofemx1from Paralichthys olivaceus%牙鲆emx1基因的克隆及表达

    Institute of Scientific and Technical Information of China (English)

    孙文慧; 张俊玲; 施志仪; 孙近近; 向玉婷; 陈晓武

    2016-01-01

    To explore the function of the empty spiracles homeobox 1(emx1)gene in the development of Paralichthys olivaceus,the emx1 was cloned by PCR,the sequence feature was analyzed by BioEdit and MEGA software,and the expression in early development and adult tissues was detected by real-time quantitative PCR. The obtained emx1 cDNA was 1 127 bp,including a 708 bp open reading frame(ORF), encoding a polypeptide of 235 amino acids. The alignment analysis of amino acid sequence discovered that the emx1 from P. olivaceusshowed the highest 95% homology with that of Stegastes partitus and Poecilia formosa,the sequence similarities between P. olivaceus and Danio rerio, Astyanax mexicanus,Xenopus tropicalis,Gallus gallus,Mus musculusand Homo sapiens,were 87%,84%,83%,80%,72% and 72%, respectively. The Emx1 protein was highly homologous with that in other fish through phylogenic analysis. Real-time quantitative PCR revealed that the emx1mRNA was expressed in all detected tissues of P. olivaceus. The expression of emx1was the highest in the ovary and secondly highest in the testis,while relatively low in other tissues. In early development stage,i.e.,from gastrula to 10 d after hatching,a relatively high expression of the emx1 mRNA was also observed,and the highest expression occurred in the blastopore stage and heart-beating stage. The findings indicated that the emx1 played an important role in early development and gonad development stages of P. olivaceus.%为阐述空通气孔同源框1(empty spiracles homeobox 1,emx1)基因在牙鲆发育中的作用,通过PCR技术克隆牙鲆emx1基因,运用BioEdit、MEGA等软件分析其序列结构特征,并采用荧光定量PCR技术分析其在牙鲆早期发育和组织分布中的表达情况。结果成功获得一长度为1127bp的牙鲆emx1 cDNA序列,其中包括708bp的开放阅读框,编码235个氨基酸。同源性比对发现,牙鲆emx1基因的氨基酸序列与雀鲷和花鳉同源性最高,为95%,