Trophic ecology of Brycon henni (Pisces: Bryconidae) in Nare and Guatapé Rivers, Magdalena River basin, Colombia / Ecología trófica de Brycon henni (Pisces: Bryconidae) en afluentes de los Ríos Nare y Guatapé, cuenca del río Magdalena, Colombia

ABSTRACT Understanding the trophic ecology of fish and how they use resources in space and time is important to support conservation and management actions. The trophic ecology of Brycon henni in the Nare and Guatapé rivers, Magdalena river basin, Colombia was determined. Five field samplings were carried out between October 2007 and January 2010, in rainy, dry, and dry-to-rainy transition periods. Stomachs of 262 specimens were collected. A Kruskall-Wallis analysis and a Mann-Whitney pairwise comparison test was performed to detect differences in the alimentary importance index of each food category between sex, size class, hydrological period and basins (Nare vs Guatapé). The Levin's Measure of Niche Breadth and the Morisita's Diet Overlapping Index were calculated to establish differences between size class in the different hydrological periods. Vegetable material was the most important food item, followed by Insecta, and fish. Individuals from Guatapé basin consumed more plant material and fish and fewer insects. We observed increased consumption of plant material and fish in ontogeny. Levin's niche breadth was lower and diet overlapping between individuals of length classes was higher during rainy period because the diet was mainly based on plant material. The diet of B. henni was composed mainly of plant material and Insects, and to a lesser extent from other groups such as fish, crustaceans and arachnids.

RESUMEN La comprensión de la ecología trófica de los peces y la forma en que utilizan los recursos en el espacio y en el tiempo es importante para la toma de acciones para su conservación y manejo. Se determinó la ecología trófica de Brycon henni en los ríos Nare y Guatapé, cuenca del río Magdalena, Colombia. Se realizaron cinco muestreos entre octubre de 2007 y enero de 2010, en periodos de lluvia, seca y transición de seca a lluvia. Se recolectaron estómagos de 262 ejemplares. Para detectar diferencias en el índice de importancia alimentaria de cada categoría de alimentos entre sexo, clase de talla, período hidrológico y cuencas se realizó un análisis de Kruskall-Wallis y una prueba de Mann-Whitney. Se calculó la amplitud del nicho de Levin y el Índice de superposición de dieta de Morisita para establecer diferencias entre clases de talla en diferentes períodos hidrológicos. El material vegetal fue el alimento más importante, seguido de Insecta y peces. Los individuos de la cuenca del Guatapé consumieron más material vegetal y peces, y menos insectos. Se detectó mayor consumo de material vegetal y de peces en individuos de mayor tamaño. La amplitud de nicho fue menor y la superposición entre clases de talla fue mayor en temporada de lluvias porque la dieta se basó principalmente en material vegetal. La dieta de B. henni estuvo compuesta principalmente por material vegetal e insectos y en menor proporción de otros grupos como peces, crustáceos y arácnidos.

Molecular cytogenetics insights in two pelagic big-game fishes in the Atlantic, the tarpon, Megalops atlanticus (Elopiformes: Megalopidae), and the sailfish, Istiophorus platypterus (Istiophoriformes: Istiophoridae)

Some pelagic and usually large sized fishes are preferential targets for sport and commercial fishing. Despite their economic importance, cytogenetic data on their evolutionary processes and management are very deficient, especially due to logistical difficulties. Here, information for two of such charismatic species, the tarpon, Megalops atlanticus (Elopiformes: Megalopidae), and the sailfish, Istiophorus platypterus (Istiophoriformes: Istiophoridae), both with a wide Atlantic distribution, were provided. Cytogenetic data were obtained using conventional methods (Giemsa staining, Ag-NORs technique, and C-banding), base-specific fluorochrome staining and fluorescence in situ hybridization (FISH) with rDNA probes. Megalops atlanticus has 2n = 50 chromosomes, all acrocentric ones (NF = 50), while Istiophorus platypterus has 2n = 48 chromosomes, 2m + 2st + 44a (NF = 52). Megalops atlanticus populations from the South Atlantic and Caribbean share identical karyotypic patterns, likely associated with gene flow between them. In turn, I. platypterus presents karyotype similarities with phylogenetically close groups, such as Carangidae. The chromosomal characteristics of these species highlight their independent evolutionary paths. Additionally, the current data contribute to knowledge of new aspects of pelagic fish fauna and will support further comparative studies with congeneric species, clarifying evolutionary karyotype trends of these fish groups.(AU)

Alguns peixes pelágicos de grande porte são alvos preferenciais para a pesca esportiva e comercial. Apesar de sua importância econômica, os dados citogenéticos sobre seus processos evolutivos e de manejo são muito deficientes, principalmente devido às dificuldades logísticas. Aqui são apresentadas informações cromossômicas de duas espécies carismáticas, o tarpão, Megalops atlanticus (Elopiformes: Megalopidae), e o agulhão-vela, Istiophorus platypterus (Istiophoriformes: Istiophoridae), ambos com ampla distribuição no oceano Atlântico. Os dados citogenéticos foram obtidos usando métodos convencionais (coloração em Giemsa, técnica de Ag-NORs e bandamento C), coloração com fluorocromos específicos e hibridização fluorescente in situ (FISH) com sondas DNAr. Megalops atlanticus possui 2n = 50 cromossomos, todos acrocêntricos (NF = 50), enquanto Istiophorus platypterus possui 2n = 48 cromossomos, 2m + 2st + 44a (NF = 52). Populações de M. atlanticus do Atlântico Sul e Caribe compartilham padrões cariotípicos idênticos, provavelmente associados ao fluxo gênico entre regiões. Por sua vez, I. platypterus apresenta semelhanças cariotípicas micro e macroestruturais com grupos filogeneticamente próximos, como Carangidae. As características cromossômicas destas espécies destacam seus caminhos evolutivos independentes. Adicionalmente, os dados apresentados contribuem com novos aspectos da fauna pelágica e apoiarão futuros estudos comparativos com espécies congenéricas, esclarecendo as tendências evolutivas do cariótipo destes grupos de peixes.(AU)

Lead tolerance and accumulation in initial sporophytes of Regnellidium diphyllum Lindm. (Marsileaceae) / Tolerância e acumulação de chumbo em esporófitos jovens de Regnellidium diphyllum Lindm. (Marsileaceae)

Regnellidium diphyllum Lindm. is a heterosporous fern which grows in shallow waters and wetlands, and water pollution contributes to its vulnerability. Environmental lead contamination is mostly caused by industrial and agricultural residues as well as domestic sewage. Given its persistence in the environment, lead can cause important toxicity in living organisms. Megaspore germination and the initial growth of R. diphyllum sporophytes were assessed in Meyer's solution with lead nitrate (Pb(NO3)2) concentrations of 0 (control), 1, 5, 10 and 50 mg L–1. The study was conducted in a growth chamber at 25±1°C and a 12 hour photoperiod with a nominal irradiance of 100 μmol m–2 s–1, for 28 days. Lead concentration in sporophytes was assessed using atomic absorption spectrometry. In the absence of lead, 74% of spores germinated, while significantly lower germination percentages were observed in Pb(NO3)2 concentrations of 1, 10 and 50 mg L–1. The presence of lead did not significantly influence root growth. At 28 days, primary leaf development was significantly lower in Pb(NO3)2 concentrations of 5 mg L–1 and higher in relation to the control. The length of secondary leaves did not significantly differ between sporophytes exposed to different concentrations of lead and those of the control at 28 days. Sporophytes exposed to 10 and 50 mg L–1 Pb(NO3)2 accumulated 1129 mg kg–1 and 5145 mg kg–1 of Pb, respectively. The presence of high levels of lead in R. diphyllum sporophytes did not prevent initial development. Future studies should investigate the ability of the species to accumulate and tolerate high levels of lead in advanced stages of its development and in environmental conditions.

Regnellidium diphyllum Lindm. é uma samambaia heterosporada que se desenvolve em águas rasas ou em solos úmidos, sendo que a poluição da água contribui para sua vulnerabilidade. A contaminação ambiental por chumbo ocorre principalmente por resíduos industriais e agrícolas, bem como por efluentes domésticos. Devido à sua persistência no ambiente, esse metal pode apresentar importante toxicidade aos organismos vivos. A germinação de megásporos e o desenvolvimento inicial de esporófitos de R. diphyllum foram avaliados em solução de Meyer com concentrações de 0 (controle), 1, 5, 10 e 50 mg L–1 de nitrato de chumbo (Pb(NO3)2). O estudo foi conduzido em câmara de germinação a 25±1 °C e fotoperíodo de 12 horas sob irradiância nominal de 100 μmol m–2 s–1, por 28 dias. A concentração de chumbo em esporófitos foi analisada por espectrometria de absorção atômica. Na ausência de chumbo, 74% dos esporos germinaram, enquanto que porcentagens de germinação significantemente menores foram observadas nas concentrações de 1, 10 e 50 mg L–1 de Pb(NO3)2. A presença de chumbo não influenciou significativamente o crescimento das raízes. O desenvolvimento das folhas primárias foi significativamente menor em relação ao controle a partir de 5 mg L–1 de Pb(NO3)2 aos 28 dias. O comprimento das folhas secundárias não diferiu significativamente entre esporófitos expostos às diferentes concentrações de chumbo e aqueles do controle, aos 28 dias. Esporófitos expostos a 10 e 50 mg L–1 de Pb(NO3)2 acumularam 1129 mg kg–1 e 5145 mg kg–1 de Pb, respectivamente. A presença de altas concentrações de chumbo nos esporófitos de R. diphyllum não impediu seu desenvolvimento inicial. Estudos futuros deverão investigar a capacidade de a espécie acumular e tolerar altas concentrações de chumbo em estádios avançados de desenvolvimento e também em condições ambientais.

In vitro assay on homeopathic solutions on Metarhizium anisopliae (Metsch) Sorok (Ascomycota: Clavicipitaceae) / Efeito in vitro de soluções homeopáticas sobre Metarhizium anisopliae (Metsch) Sorok (Ascomycota: Clavicipitaceae)

This study aimed to evaluate the in vitro effect of homeopathic solutions Arsenicum Album 24CH; Calcarea carbonica 30CH; Kali iodatum 100CH;Phosphorus 3CH; Silicea 30CH; Staphysagria 6, 30 and 100CH; Spodoptera frugiperda 30CH; Sulphur 100 and 200CH and Thuya occidentalis 200CH on biological parameters of the fungus Metarhizium anisopliae . The solutions were diluted in sterile distilled water (0.1%) and were sprayed on the previously inoculated fungus on PDA culture medium. Germination, colony forming units, vegetative growth, conidial production and insecticidal activity of the fungus against larvae of Diatraea saccharalis (Lepidoptera: Crambidae) were evaluated. Homeopathic solutions did not affect negatively the parameters evaluated. Thus, all treatments were considered compatible to the fungus M. anisopliae.(AU)

O presente trabalho teve por objetivo avaliar o efeito in vitro das soluções homeopáticas Arsenicum album 24CH;Calcarea carbonica 30CH; Kali iodatum100CH; Phosphorus 3CH; Silicea 30CH; Staphysagria 6, 30 e 100CH; Spodoptera frugiperda 30CH; Sulphur 100 e 200CH eThuya occidentalis 200CH sobre parâmetros biológicos do fungo Metarhizium anisopliae. As soluções medicamentosas foram diluídas em água destilada (esterilizada) (0,1%) e pulverizadas sobre o fungo previamente inoculado no meio de cultura BDA. Os parâmetros biológicos avaliados foram: germinação de conídios, unidades formadoras de colônias, crescimento vegetativo, produção de conídios e atividade inseticida contra lagartas de Diatraea saccharalis (Lepidoptera: Crambidae). As soluções não afetaram os parâmetros avaliados. Todos os tratamentos foram considerados compatíveis ao M. anisopliae .(AU)

Is the population of Crotalus durissus (Serpentes, Viperidae) expanding in Brazil?

Crotalus durissus are found from Mexico to northern Argentina in a highly disjunct distribution. According to some studies, this species is prone to occupy areas disturbed by human activities and floods comprise a plausible method of dispersal as inferred for some North American rattlesnakes. Based on the literature, it seems plausible that Crotalus durissus expanded their natural distribution in Brazil due to floods, but only in a few municipalities in Rio de Janeiro State. Data entries of Butantan Institute, in São Paulo, Brazil, from 1998 to 2012 show a declining tendency of snakes brought by donors. In addition, research shows no evidence of Crotalus durissus being an expanding species in the Brazilian territory.(AU)

Is the population of Crotalus durissus (Serpentes, Viperidae) expanding in Brazil?

Crotalus durissus are found from Mexico to northern Argentina in a highly disjunct distribution. According to some studies, this species is prone to occupy areas disturbed by human activities and floods comprise a plausible method of dispersal as inferred for some North American rattlesnakes. Based on the literature, it seems plausible that Crotalus durissus expanded their natural distribution in Brazil due to floods, but only in a few municipalities in Rio de Janeiro State. Data entries of Butantan Institute, in São Paulo, Brazil, from 1998 to 2012 show a declining tendency of snakes brought by donors. In addition, research shows no evidence of Crotalus durissus being an expanding species in the Brazilian territory.

Tissue preservation and cell culture of Przewalskii´s horse (Equus przewalskii): an endangered species / Preservação de tecidos e cultura de células do cavalo de Przewalski (Equus przewalskii): uma espécie em extinção

The Przewalskii´s horse or Mongolian wild horse (Equus przewalskii, Poljakov, 1881) is presently the only species of wild horse in existence. Originally from Asia, it is, classified as in extremely high risk of extinction which puts the species in the seriously threatened category. The aim of this work was the preservation of tissues and the development of cell cultures from tissue samples obtained from a Przewalskii´s horse after its death. Biopsies of skin, skeletal and cardiac muscle, and ear cartilage were removed from a recently dead horse, added to Phosphate Buffer Saline (PBS) and refrigerated until processing. Some of the samples were frozen in liquid nitrogen and the other was grown as explants to generate fibroblast cell monolayers. The cell cultures obtained, were subsequently propagated with low passages, and frozen in liquid nitrogen, thus avoiding genetic and phenotypic alterations. The tissues and cell cultures were thawed to ascertain their viability by checking its progressive grow in a flask. It was not possible to obtain cultures from cardiac muscle. A bank of tissues and cells from the single Przewalskii´s horse that existed in Uruguay was generated, and can be used for scientific purposes and for the conservation of the species in the future

Seasonal flight and resource collection patterns of colonies of the stingless bee Melipona bicolor schencki Gribodo (Apidae, Meliponini) in an Araucaria forest area in southern Brazil / Padrão sazonal de vôo e coleta de recursos em colônias de Melipona bicolor schencki Gribodo (Apidae, Meliponini) em área de Floresta com Araucária no sul do Brasil

Melipona bicolor schencki occurs in southern Brazil and at high elevations in southeastern Brazil. It has potential for use in meliponiculture but this stingless bee species is vulnerable to extinction and we have little knowledge about its ecology. In order to gather essential information for species conservation and management, we made a study of seasonal flight activities in its natural environment. We sampled bees entering the nests with pollen, nectar/water and resin/mud, in five colonies during each season. In parallel, we analyzed the influence of hour of the day and meteorological factors on flight activity. Flights were most intense during spring and summer, with daily mean estimates of 2,100 and 2,333 flights respectively, while in fall and winter the daily flight estimate was reduced to 612 and 1,104 flights, respectively. Nectar and water were the most frequently-collected resources, followed by pollen and building materials. This preference occurred in all seasons, but with variations in intensity. During spring, daily flight activity lasted over 14 hours; this period was reduced in the other seasons, reaching eight hours in winter. Meteorological factors were associated with 40.2 percent of the variation in flight and resource collection activity. Apparently, other factors that we did not measure, such as colony needs and availability of floral resources, also strongly influence the intensity of resource collection.

Melipona bicolor schencki ocorre no Sul e em regiões de altitude elevada no Sudeste do Brasil. Encontra-se vulnerável a extinção no Rio Grande do Sul e possui potencial para meliponicultura, entretanto o conhecimento de sua ecologia é escasso. Desenvolveu-se o estudo sazonal das atividades de vôo de colônias em ambiente natural, com vistas a subsidiar ações conservacionistas e manejo. Amostrou-se o ingresso de pólen, néctar/água e resina/barro em cinco colônias, durante o período de atividades externas, em cada estação do ano. Analisou-se também a influência do horário e de fatores meteorológicos sobre o vôo. Os vôos foram similarmente mais intensos durante a primavera e verão, com estimativa diária de 2100 e 2333, enquanto no outono e inverno reduziram-se respectivamente para 612 e 1104. O transporte de néctar/água foi maior, seguido de cargas de pólen e de materiais de construção. Esta situação ocorreu similarmente nas quatro estações, porém com variações de intensidade. A amplitude diária de vôo foi de 14 horas na primavera, reduzindo-se nas demais estações e atingindo 8 horas no inverno. Os fatores meteorológicos exerceram influência de 40,2 por cento no vôo das abelhas. Este resultado indica que outros fatores, não mensurados neste estudo, como as necessidades das colônias determinadas por fatores fisiológicos e a disponibilidade de recursos florais, exercem forte influência sobre a intensidade de coleta de recursos.