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Toxicidad aguda y crónica del lindano sobre Ceriodaphnia cornuta (Cladocera: Daphniidae) Acute and chronic toxicity of lindane on Ceriodaphnia cornuta (Cladocera: Daphniidae)  [cached]
Jorgelina Juárez,Alcira Villagra de Gamundi
Revista Peruana de Biología , 2011,
Abstract: El lindano es un plaguicida organoclorado cuya toxicidad produce efectos nocivos en la salud humana y la biota. El objetivo de este estudio fue evaluar la toxicidad aguda y crónica del lindano sobre el microcrustáceo Ceriodaphnia cornuta. Para las pruebas agudas se empleó un dise o estático, usando 10 neonatos ≤ 24 horas de edad para el control y para cada concentración de lindano (5, 10, 15, 20 y 25 mg/L). Se realizaron tres réplicas de cada tratamiento. Se controló la inmovilización de los individuos a las 48 hs y se calcularon los valores de CL50. Los bioensayos crónicos consistieron en un dise o semi-estático, utilizando 10 neonatos menores de 24 horas de edad (uno por recipiente) para el control y para cada concentración subletal del tóxico (0,1; 0,15; 0,2; 0,25 y 0,3 mg/L). Se evaluaron los efectos sobre la supervivencia y reproducción durante 21 días. El valor obtenido de CL50 48 horas fue de 5,293 ± 0,7 mg/L. Los parámetros reproductivos (neonatos por hembra, tama o de la camada e índice de incremento natural) disminuyeron al aumentar la concentración del tóxico evaluado, mientras que el inicio de la madurez sexual se retrasó, demostrando la sensibilidad de los organismos prueba al lindano. Lindane is an organochlorine pesticide toxicity which produces harmful effects on human health and biota. The aim of this study was to evaluate the acute and chronic toxicity of Lindane on microcrustaceans Ceriodaphnia cornuta. For acute tests used a static design, using 10 infants ≤ 24 hours of age for control and each concen- tration of lindane (5, 10, 15, 20 and 25 mg/L). There were three replicates of each treatment. Monitored the detention of individuals at 48 am and calculated LC50 values. Chronic Bioassays consisted of a semi-static design, using 10 infants ≤ 24 hours of age (one per vessel) for the control and each of the toxic sublethal concentration (0.1, 0.15, 0.2, 0.25 and 0.3 mg/L). The effects on survival and reproduction over 21 days. The LC50 value of 48 hours was 5.293 ± 0.7 mg/L. Reproductive parameters (neonates per female, litter size and rate of natural increase) decreased with increasing concentration of toxic evaluated, while the onset of sexual maturity is delayed, thus demonstrating the sensitivity of test organisms to lindane.
The use of PCR-RFLP to genetically distinguish the morphologically close species: Ceriodaphnia dubia Richard, 1894 and Ceriodaphnia silvestrii Daday, 1902 (Crustacea Cladocera)
Abreu, MJ.;Santos-Wisniewski, MJ.;Rocha, O.;Orlando, TC.;
Brazilian Journal of Biology , 2010, DOI: 10.1590/S1519-69842010000100016
Abstract: the cladocerans are important components of planktonic and benthic freshwater and good indicators of the trophic state of water bodies. the morphological taxonomy of many species of cladocera is considered complex with minor differences separating some species. nowadays, molecular techniques provide a powerful tool to identify and classify different taxonomical levels, using mainly ribosomal rna genes (rrna) as molecular markers. in the present work we performed pcr-rflp to separate ceriodaphnia dubia, an exotic species in brazil and the native species ceriodaphnia silvestrii, widely distributed in brazilian freshwater. the rflp analysis of the its1-5.8s-its2 region of rrna genes showed to be different between c. dubia and c. silvestrii when using enzymes ecori, apai and sali. thus, the its1-5.8s-its2 region proved to be a useful molecular marker to differentiate the studied ceriodaphnia species, which makes the task easier of telling apart species that are morphologically very similar. also, this methodology might be interesting in determining the distribution of the exotic species c. dubia in brazilian freshwaters, particularly in cases when c. dubia occurs in the absence of c. silvestrii, a particularly difficult task for ecologists who are not taxonomy specialists.
The influence of algal densities on the toxicity of chromium for Ceriodaphnia dubia Richard (Cladocera, Crustacea)
Rodgher, S.;Espíndola, ELG.;
Brazilian Journal of Biology , 2008, DOI: 10.1590/S1519-69842008000200015
Abstract: food availability may affect metal toxicity for aquatic organisms. in the present study, the influence of high, medium and low densities of the algae pseudokirchneriella subcapitata (106, 105 and 104 cells.ml-1, respectively) on the chronic toxicity of chromium to the cladoceran ceriodaphnia dubia was investigated. c. dubia was exposed to a range of chromium concentration from 2.71 to 34.04 μg.l-1 and fed with algae at various densities. in another experiment, the green alga was exposed to chromium concentrations (94 to 774 μg.l-1) and supplied as food in different densities to zooplankton. the survival and reproduction of the cladoceran were measured in these toxicity tests. the ic50 for cr to p. subcapitata and metal accumulated by algal cells were determined. the results of a bifactorial analysis (metal versus algal densities) showed that metal toxicity to zooplankton was dependent on algal densities. significant toxic effects on the reproduction and survival of c. dubia were observed at 8.73, 18.22 and 34.04 μg.l-1 cr when the test organisms were fed with 106 cells.ml-1 of p. subcapitata. although the chlorophyta retain low chromium content, a decrease in the reproduction and survival of c. dubia occurred when they were fed with high algal density contaminated with 774 μg.l-1 cr. it was concluded that high algal density have an appreciable influence on chromium toxicity to daphnids.
Efectos del efluente de curtiembre sobre ceriodaphnia dubia (crustacea, cladocera) en condiciones experimentales
Ceresoli,Natalia; Gagneten,Ana María;
Interciencia , 2003,
Abstract: the aim of this study was to assess empirically the effects of several concentrations of tannery waste water with a high content of cr and sulphide on the life history attributes and population parameters of ceriodaphnia dubia richard 1894 (crustacea, cladocera) in chronic bioessays. the effluent significantly affected survival, fecundity, number of molts and broods of c. dubia. the time between broods and the age of the first reproduction was delayed by the increase of the effluent concentration, producing no broods in concentrations >1ml·l-1. r0 was <1 in effluent concentrations >0.6ml·l-1, which defined the highest limiting concentration that allows the establishment and development of zooplankton populations in the environment. the importance of the use of species with broad distribution and the use of integrative population parameters in ecotoxicological surveys are pointed out. the importance of the development of bioessays with complex effluents is discussed.
Conducta alimentaria de Daphnia ambigua Scourfield 1947, Moina micrura Kurz 1874 y Ceriodaphnia dubia Richard 1895 (Cladocera) frente a un gradiente de concentración de alimento
MARTINEZ,GINGER;
Revista chilena de historia natural , 2000, DOI: 10.4067/S0716-078X2000000100006
Abstract: because cladocera is the most abundant group of filter-feeders in the freshwater zooplankton and their populations are usually found under limited resources conditions, the individual response under a resources concentration gradient has important consequences on the population and community patterns. feeding behavior of moina micrura, ceriodaphnia dubia and daphnia ambigua (cladocera) on the microalgae chlorella sp. and oocystis sp. (chlorophyceae) was compared by using the following parameters: maximum ingestion rate (imax), incipient limiting concentration (ilc) and consumption efficiency (b), which were obtained through a model of functional response. results indicated that d. ambigua showed the highest imax and ilc on both resources, however, this specie presented the lowest b. whereas, d. ambigua did not show differences in b on chlorella sp. or oocystis sp., m. micrura showed a higher b on chlorella sp. and c. dubia on oocystis sp. these results reveal significant interspecific differences in the feeding response of cladocera, which showed a complex behavior exposed to variations in the availability of food resources
Conducta alimentaria de Daphnia ambigua Scourfield 1947, Moina micrura Kurz 1874 y Ceriodaphnia dubia Richard 1895 (Cladocera) frente a un gradiente de concentración de alimento Feeding behaviour of Daphnia ambigua Scourfield 1947, Moina micrura Kurz 1874 and Ceriodaphnia dubia Richard 1895 (Cladocera) under a food concentration gradient  [cached]
GINGER MARTINEZ
Revista chilena de historia natural , 2000,
Abstract: Debido a que Cladocera es el grupo de microfiltradores más abundante del zooplancton límnico y cuyas poblaciones se encuentran usualmente limitadas por alimento, la respuesta de los individuos frente a un gradiente de concentración de recursos tendría significativas implicancias sobre los patrones poblacionales y comunitarios. Se comparó la conducta alimentaria de Moina micrura, Ceriodaphnia dubia y Daphnia ambigua (Cladocera) frente a las microalgas Chlorella sp. y Oocystis sp. (Chlorophyceae) mediante los siguientes parámetros: Tasa de Ingesta Máxima (Imax), Concentración Limitante Incipiente (CLI) y Eficiencia de Consumo (b), los cuales fueron obtenidos a través de un modelo de respuesta funcional. Los resultados mostraron que D. ambigua presentó las mayores Imax y CLI sobre ambos recursos, sin embargo, esta especie presentó la menor b. Mientras que D. ambigua no presentó diferencias en b sobre Chlorella sp. y Oocystis sp., M. micrura presentó una mayor b sobre Chlorella sp. y C. dubia sobre Oocystis sp. Estos resultados revelan significativas diferencias interespecíficas en la respuesta alimentaria de Cladocera, grupo que presentó un complejo comportamiento frente a variaciones en la disponibilidad de recursos alimentarios Because Cladocera is the most abundant group of filter-feeders in the freshwater zooplankton and their populations are usually found under limited resources conditions, the individual response under a resources concentration gradient has important consequences on the population and community patterns. Feeding behavior of Moina micrura, Ceriodaphnia dubia and Daphnia ambigua (Cladocera) on the microalgae Chlorella sp. and Oocystis sp. (Chlorophyceae) was compared by using the following parameters: Maximum Ingestion Rate (Imax), Incipient Limiting Concentration (ILC) and Consumption Efficiency (b), which were obtained through a model of functional response. Results indicated that D. ambigua showed the highest Imax and ILC on both resources, however, this specie presented the lowest b. Whereas, D. ambigua did not show differences in b on Chlorella sp. or Oocystis sp., M. micrura showed a higher b on Chlorella sp. and C. dubia on Oocystis sp. These results reveal significant interspecific differences in the feeding response of Cladocera, which showed a complex behavior exposed to variations in the availability of food resources
Crescimento populacional e análise isotópica de Diaphanosoma spinolosum e Ceriodaphnia cornuta (Crustacea: Cladocera), alimentadas com diferentes fra es de seston natural = Population growth and stable isotope analyses of Diaphanosoma spinolosum and Ceriodaphnia cornuta (Crustacea: Cladocera) fed with different seston size fractions
Pedro Caraballo,Andrés Felipe Sanchez-Caraballo,Bruce Forsberg,Rosseval Leite
Acta Scientiarum : Biological Sciences , 2011,
Abstract: Para definir o efeito do seston como fonte de alimento para Ceriodaphnia cornuta e Diaphanosoma spinolosum durante a enchente no lago Catalao (Amazonia Central) foram desenvolvidos experimentos gin situ h, utilizando a variacao natural de 13C e 15N comotracadores de alimento. As duas especies tiveram acesso a tres diferentes fracoes de seston (< 10, < 30 e < 60 êm) sendo mantidas em garrafas plasticas de 1,1 L submersas, durante nove dias. As atividades foram iniciadas com uma populacao de dez individuos em cada frasco, com tres frascos por cada fracao e quatro intervalos de tempo, para um total de 27 frascos por especie. A cada tres dias, foram coletados tres frascos e os organismos foram fixados para contagem e observacao de parametros populacionais. Os organismos nos ultimos tres frascos de cada fracao foram fixados com formalina e usados para analise de isotopos estaveis de carbono e nitrogenio. As duas especies cresceram em todas as fracoes de alimento, sendo melhor seu desempenho populacional na fracao < 30 êm. D. spinolosum e C. cornuta apresentaram enriquecimento nos valores de 13C e 15N, sendo maior na fracao < 10 êm. Estes resultados sugerem que as fracoes do seston testadas produzem diferentes taxas de crescimento populacional e assinaturas isotopicas nos cladoceros. In order to define the effect of seston size fraction as a food source for Ceriodaphnia cornuta and Diaphanosoma spinolosum, in situ experiments using natural abundance of 13C and 15N were carried out during the rising water period in Catalao Lake. Both species werefed with three different fractions of seston from the lake (< 10, < 30 and < 60 êm) and maintained in submerged 1.1 L plastic bottles for nine days. Ten individuals were put in each flask, maintaining three flasks for each fraction, for a total of 27 flasks per species. Every three days we collected three flasks and fixed the individuals for subsequent counting and observation of demographic population parameters. The organisms in the last three flasks of each fractionwere fixed for stable isotope analysis of 13C and 15N. Both species grew in all of the food fractions, with the best the performance coming in the < 30 êm fraction. D. spinolosum and C. cornuta showed enrichment in 13C and 15N, which was highest in the < 10 êm fraction for both species. These results show that the seston size fractions tested produce different population growth rates and isotopic signatures in cladocerans.
Macrothrix flabelligera, a newly-recorded Cladocera Macrothricidae in Brazilian freshwaters
Güntzel, A. M.;Matsumura-Tundisi, T.;Rocha, O.;
Brazilian Journal of Biology , 2004, DOI: 10.1590/S1519-69842004000200006
Abstract: a short characterization of macrothrix flabelligera smirnov, 1992 (cladocera, macrothricidae) is presented, following a recent record of this species in brazil. general aspects and morphological details of the body of parthenogenetic and ephippial females, as well as of males, are described and illustrated.
Estudios sobre la biología y ecología de Ceriodaphnia cornuta SARS: UNA REVISIóN
Villalobos?,Mariela J; González,Ernesto J;
Interciencia , 2006,
Abstract: ceriodaphnia cornuta sars is one out of three most abundant cladocerans in tropical freshwaters, and the only one belonging to the daphniidae family. this crustacean can tolerate low concentrations of dissolved oxygen and high temperature variations, two features that allow it to be widely distributed in the tropical freshwaters. concerning feeding habits, c. cornuta prefers diatoms and green algae. this cladoceran maintains high growth rates under good-quality food conditions as well as in low-quality ones, consuming, in the last case, blue green algae. c. cornuta shows a short embryonary development, high growing rates of juveniles and early sexual maturity; it has low fecundity and high longevity. predation by fish and chaoborus sp. is an interspecific interaction that has inspired very extensive studies about this crustacean. these studies have shown important effects of predation on its abundance and distribution in freshwaters. c. cornuta may show a series of defense mechanisms as a response to predators, among which polymorphism, changes in some life-history parameters and vertical migration are well documented. all of these aspects justify the importance of c. cornuta as a key organism to obtain a better understanding of dynamics and energy transfer in tropical freshwaters.
A cladistic analysis of the genera of Macrothricidae Norman & Brady (Crustacea, Cladocera, Radopoda)
Elmoor-Loureiro, Lourdes M. A.;
Revista Brasileira de Zoologia , 2005, DOI: 10.1590/S0101-81752005000300034
Abstract: a cladistic analysis of the genera of the macrothricidae (crustacea, cladocera, radopoda) was performed based on 36 morphological characters, and including 15 terminal taxa (three as outgroups). the single tree obtained from this analysis supported the monophyly of macrothricidae and macrothricinae. the group called as "non-macrothricinae" was indicated as paraphyletic. neothricidae was also not supported.
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