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Bioassay using Daphnia magna Straus, 1820 to evaluate the sediment of Caí River (Rio Grande do Sul, Brazil)
Terra, Nara Regina;Feiden, Ilda Rosa;Lucheta, Fabiane;Gon?alves, Silvana Pereira;Gularte, Juliana Schons;
Acta Limnologica Brasiliensia , 2010, DOI: 10.4322/actalb.2011.008
Abstract: aim: the caí river is one of the five that form the guaiba lake hydrographic basin. it is used for public water supply in the capital of rio grande do sul; methods: sediment samples for toxicity test (21 days) with daphnia magna were taken from four sites between the middle and upper reaches in this river from mar./05 to june/09. their quality is described based on the survival and reproduction responses of 440 test-organisms from the beginning of their lives (2-26 hours). percentage survival, mean and total reproduction were calculated for this evaluation. spearman correlation and duncan test were used to compare reproduction between sites and variation of this parameter statistically over time. bacteriological, physical and chemical parameters in water samples collected during the period of the study were considered; results: acute toxicity was observed in 18% of the samples and chronic toxicity in 95%, indicating the presence of small doses of environmental aggressors. mortality and reproduction did not always follow the same trend, and it became clear that the reproductive activity was more sensitive when compared using contaminated samples. duncan test showed up to four clusters at sites ca070, ca092 and ca245, indicating reproduction variation. a pattern of monthly rainfall distribution was not observed, nor was there a correlation between survival, reproduction and rainfall; conclusions: presence of low concentrations of xenobiotics was confirmed by physical, chemical, bacteriological and metal responses in water samples, besides a small effect on survival and constant change in reproductive activity in the organisms exposed to sediment samples. long duration assays are more appropriate to evaluate environmental samples, since usually changes in ecosystem quality are tenuous and not detected by short tests. caí river quality has improved, but further studies are needed to confirm this trend, and to follow the history of the area with a more detailed definitio
Toxic effects of Pseudanabaena tenuis (Cyanobacteria) on the cladocerans Daphnia magna and Ceriodaphnia dubia
Olvera-Ramírez, Roxana;Centeno-Ramos, Carla;Martínez-Jerónimo, Fernando;
Hidrobiológica , 2010,
Abstract: some cyanobacteria can produce toxins that affect the aquatic biota and represent a human health risk. the cyanobacterium pseudanabaena tenuis was isolated from the valle de bravo dam, and cultured in the laboratory under controlled conditions. we determined the acute toxic effects and performed a chronic (consumption) test in the cladocerans daphnia magna (a reference test organism) and ceriodaphnia dubia (a cosmopolitan species). to determine acute toxicity, three exposure ways were assayed: a) cell-free culture medium, b) crude cell extracts of the cyanobacterium after lysing, and c) aqueous extracts of p. tenuis phycobiliproteins. on the other hand, both cladocerans were fed p. tenuis, assessing the effects on survival and reproduction. for comparison, a control culture of both cladocerans was fed the green microalga pseudokirchneriella subcapitata. exposure to the cell-free culture medium did not produce any mortality in either cladoceran, but the aqueous and crude extracts generated acute toxicity. d. magna and c. dubia were negatively affected when fed p. tenuis, since their survival, total progeny, average number of neonates per clutch, and the number of clutches decreased. c. dubia was more sensitive than d. magna, both in the acute toxicity tests and to the effects of p. tenuis consumption. although most of the blooms around the world are dominated by cyanobacteria of the genus microcystis, attention should be given to other species, such as p. tenuis, because, frequently, it is not recognized that smaller cyanobacteria could exceed the larger species in terms of biomass, and produce noxious biological effects.
New records of Parvalona parva (Crustacea: Anomopoda: Chydoridae) from Brazil, with first description of the male
Elmoor-Loureiro, Lourdes M.A.;Santos-Wisniewski, Maria J. dos;Rocha, Odete;
Zoologia (Curitiba) , 2009, DOI: 10.1590/S1984-46702009000200022
Abstract: the neotropical species parvalona parva (daday, 1905) was previously reported only from two localities (northern argentina and len?óis maranhenses, brazil). in the present paper, seven new records of p. parva from brazil are presented. the specimens were collected from small waterbodies located in the federal district and the states of s?o paulo, pará, and pernambuco. these new records suggest that this species is not as rare as previously believed. the male, sexual female, and the lateral head pores of parthenogenetic females are described and illustrated for the first time.
Evaluation of the Gravataí River sediment quality (Rio Grande do Sul- Brazil) using Daphnia magna (Straus, 1820) as the test-organism for toxicity assays
Lucheta, Fabiane;Feiden, Ilda Rosa;Gon?alves, Silvana Pereira;Gularte, Juliana Schons;Terra, Nara Regina;
Acta Limnologica Brasiliensia , 2010, DOI: 10.4322/actalb.2011.002
Abstract: aim: persistent pollutants released to riverbeds return to the trophic system, damaging living organisms thereof. ecotoxicological assays express the effect of environmental interactions with organisms found there. assays were performed with microcrustacean daphnia magna (straus, 1820) in sediment samples, from the headwaters to the mouth, in order to evaluate the gravataí river quality; methods: bottom sediment was used to evaluate the responses of cladocerans to environmental changes in 15 samples collected between jan./06 and may/09. the microcrustaceans were submitted to stress for 21 days from birth (2-26 hours old). duncan test, percentage survival, reproduction and spearman correlation were used to evaluate the quality of the sites; results: duncan test showed a significant difference (p < 0.05) in reproduction in 14 of the 15 samplings, and chronic action was more constant (88%) than the acute one (23%). changes in survival and reproduction related to season or rainfall regime were only observed on a few occasions. the two sites located close to the mouth presented a spearman correlation (p < 0.01) for survival and reproduction. there were changes in some samplings in the headwaters as a result of sewage discharges in the area; conclusions: fluctuating responses were observed in this river due to anthropic contaminants, slow flux and current reflux.
Length-weight relationships for five cladoceran species in an Amazonian lake
Maia-Barbosa, Paulina Maria;Bozelli, Reinaldo Luiz;
Brazilian Archives of Biology and Technology , 2005, DOI: 10.1590/S1516-89132005000200018
Abstract: this work shows the length-weight regressions established for the five most frequent and abundant cladoceran species (bosmina hagmanni, bosminopsis deitersi, ceriodaphnia cornuta, diaphanosoma birgei, and moina minuta) in two stations at lake batata. this lake has received for 10 years very fine bauxite processing tailings, which is responsible for the thick layer over the natural sediment still observed in its western section (impacted station). the individuals were separated into size classes, the dry weight values were determined for each class and were used for establishing weight-length equations. bosminopsis deitersi and ceriodaphnia cornuta were the species showing the smallest size in the two sampled areas (0.152 to 0.322 mm) and diaphanosoma birgei was the largest (0.284 to 0.722 mm). in the natural station, moina minuta and bosminopsis deitersi were the lightest species (0.174 to 0.334 and 0.074 to 0.278 μg, respectively) and in the impacted station, bosmina hagmanni and moina minuta were the lightest (0.248 to 1.555 and 0.210 to 0.566 μg, respectively). in general, individuals from the impacted station exhibited smaller body sizes (0.152- 0.684 mm) and higher weight (0.208 - 1.983 mm), which can be explained by the ingestion of tailing particles. the equations established were shown to be adequate for weight estimates of the analyzed species since the differences found between the observed and estimated weights values were not statistically significant.
A study on environmental changes based upon cladoceran assemblages from the core sediments in Chen Co, southern Tibet
Liping Zhu,Junbo Wang,Anton Brancelj
Chinese Science Bulletin , 2005, DOI: 10.1360/982005-124
Abstract: A consecutive sediment core (CC2) was drilled in Chen Co (lake) of southern Tibet using a PISTON sampler in 1998 AD. Cladoceran remains including their species, amount richness and ecological features are analyzed for the top 117 cm sections of the core, upon which 5 cladoceran assemblages are distinguished. CL0 is an assemblage without any cladocera in the depth between 117–105 cm. CL1 assemblage (depths between 101–77 cm, ca. 1407–1533 AD) possesses total 9 cladoceran species that appear in the core, and performs the greatest richness in the whole sequence. This assemblage reflected that there was plenty of exotic cold water and organic debrises inputing to the sedimentary site under the warmer conditions. The lake was wide and shallow that satisfied the big hydrophyte living. Cladoceran species and richnesses of CL2 assemblage (depths between 77–29 cm, ca. 1533–1831 AD) perform much more decreasing than those of CL1. There was only less Chydorus sphaericus which was acclimatized to wide environmental ranges. This implied that the sedimentary environment is so execrable that most of cladoceran lost their living abilities. Compared with CL1 assemblage, CL3 assemblage (depths between 29–10 cm, ca. 1831–1941 AD) possesses nearly the same dominant species but lower richnesses. Especially, the cladoceran preferring organic debris also decrease in their amounts. This meant that the surface vegetation in the drainage basin was still poor though the environment turned to be better. Except the 2 Zooplankton species, the other 7 species of cladoceran in this core are found in CL4 assemblage (depths between 10-0 cm, ca. 1941–1998 AD), in which the eurythermal species had not performed their competition ability comparing with narrow-temperatures adapted species. It implied that water temperatures were stable and much more influenced by air temperatures under the shallow-water conditions. The environmental features reflected by cladocera assemblages of CC2 core are fully supported by the evidences from ostracoda assemblages, diatom-salinity transfunction, environmental magnetism and relative proxies of the parallel CC1 core. Cladoceran assemblages in the lake sediments of Tibetan Plateau are sensitive to sedimentary environment and very significant to the studies of environmental changes.
Transfer and metabolism of paralytic shellfish poisoning from Alexandrium tamarense to Moina mongolica and to Sciaenops ocellatus
塔玛亚历山大藻经蒙古裸腹溞至美国红鱼鱼苗的麻痹性贝类毒素传递与代谢研究

XU Yixiao,JIANG Tianjiu,
徐轶肖
,江天久

环境科学学报 , 2006,
Abstract: 首次采用枝角类作为麻痹性贝类毒素(Paralytic Shellfish Poisoning,PSP)海洋食物链传递的媒介,实验研究了PSP从甲藻塔玛亚历山大藻(Alexandrium tamarense)经枝角类蒙古裸腹溞(Moina mongolica)至美国红鱼(Sciaenops ocellatus)鱼苗的动态传递与代谢过程.结果表明,塔玛亚历山大藻为550~4900个·mL-1时,蒙古裸腹潘体内可以检测到麻痹性贝类毒素(PSP),美国红鱼鱼苗因摄入含PSP的蒙古裸腹溞而染毒.整个实验过程中,塔玛亚历山大藻、蒙古裸腹溞、美国红鱼消化腺均含有N-磺酰氨甲酰基类毒素C1 2,后者还检测到新生成的氨基甲酸酯类毒素neoSTX.毒素传递给蒙古裸腹溞时,C1 2中β型毒素C2的比例增大,传递给鱼苗时,则α型毒素C1的比例增加.毒素净化期间,鱼苗体内的C1、C2含量基本呈下降趋势,但neoSTX未呈现特定规律性;总毒素含量除藻密度550个·mL-1实验外,随净化时间的推移而下降.
Toxic effects of Pseudanabaena tenuis (Cyanobacteria) on the cladocerans Daphnia magna and Ceriodaphnia dubia Efectos tóxicos de Pseudanabaena tenuis (Cyanobacteria) en los cladóceros Daphnia magna y Ceriodaphnia dubia
Roxana Olvera-Ramírez,Carla Centeno-Ramos,Fernando Martínez-Jerónimo
Hidrobiológica , 2010,
Abstract: Some cyanobacteria can produce toxins that affect the aquatic biota and represent a human health risk. The cyanobacterium Pseudanabaena tenuis was isolated from the Valle de Bravo dam, and cultured in the laboratory under controlled conditions. We determined the acute toxic effects and performed a chronic (consumption) test in the cladocerans Daphnia magna (a reference test organism) and Ceriodaphnia dubia (a cosmopolitan species). To determine acute toxicity, three exposure ways were assayed: a) cell-free culture medium, b) crude cell extracts of the cyanobacterium after lysing, and c) aqueous extracts of P. tenuis phycobiliproteins. On the other hand, both cladocerans were fed P. tenuis, assessing the effects on survival and reproduction. For comparison, a control culture of both cladocerans was fed the green microalga Pseudokirchneriella subcapitata. Exposure to the cell-free culture medium did not produce any mortality in either cladoceran, but the aqueous and crude extracts generated acute toxicity. D. magna and C. dubia were negatively affected when fed P. tenuis, since their survival, total progeny, average number of neonates per clutch, and the number of clutches decreased. C. dubia was more sensitive than D. magna, both in the acute toxicity tests and to the effects of P. tenuis consumption. Although most of the blooms around the world are dominated by cyanobacteria of the genus Microcystis, attention should be given to other species, such as P. tenuis, because, frequently, it is not recognized that smaller cyanobacteria could exceed the larger species in terms of biomass, and produce noxious biological effects. Algunas cianobacterias producen toxinas que afectan la biota acuática y representan un riesgo para la salud humana. La cianobacteria Pseudanabaena tenuis fue aislada del embalse Valle de Bravo y cultivada en el laboratorio. Se determinaron los efectos tóxicos agudos (por exposición) y se evaluó la toxicidad crónica (por consumo), empleando los cladóceros Daphnia magna (organismo de referencia) y Ceriodaphnia dubia (especie cosmopolita). Para determinar la toxicidad aguda se ensayaron tres formas de exposición: a) medio de cultivo libre de células, b) extractos crudos de la cianobacteria después del lisado de las células, y c) extractos acuosos de las ficobiliproteínas. Por otra parte, ambos cladóceros fueron alimentados con P. tenuis, evaluando los efectos sobre la sobrevivencia y la reproducción; como comparación se utilizaron cultivos control alimentados con la microalga verde Pseudokirchneriella subcapitata. La exposición al medio de
Variation of cladocerans from Maoping to Guizhou in the Three Gorges Reservoir before and after impoundment
三峡水库坝前段蓄水前后枝角类的周年变化

XUE Jun-Zeng,YE Lin,CAI Qing-Hua,LIU Jian-Kang,
薛俊增
,叶 麟,蔡庆华,刘建康

水生生物学报 , 2006,
Abstract: The Three Gorges Reservoir was filled at 1 Jun.,2003.The water level of the reservoir rose up to 135m.The lotic river ecosystem evolved into relative lentic reservoir ceosystem before the dam.The community composition of aquatic life changed with the environmental variation.We sampled the cladocerans at 5 sites from Maoping to Guizhou every month during June,2003 to July,2004.There only 2 species were sampled before impoundment at the 5 sites in the reservoir.This result showed the lotic ecosystem(didn't) suit for inhabit for cladocerans.There 20 species were sampled after impoundment at the 5 sites in the reservoir during the first year.The reservoir ecosystem supplied habitat for the water flea.The cladoceran composition changed with season and distribution after impoundment in the reservoir.The species except Bosmina coregoni and B.fatalis varied with season and showed different in composition.The species enriched at the first month(June,2003)after impoundment and in the spring(April,2004).Six species(D.brachyurum,Daphnia cucullata,Bosmina coregoni,B.fatalis,Bosminopsis deitersi and Alona guttata) distributed in five sampling sites.The others species distributed in part sampling sites.
Seasonal variation and longitudinal distribution characters of cladocerans in the Three Gorges Reservoir
三峡水库初次蓄水后干流库区枝角类的空间分布与季节变化

Huixian Wu,Jianliang Yao,Yan Liu,Junzeng Xue,Qinghua Cai,Jiankang Liu,
吴惠仙
,姚建良,刘艳,薛俊增,蔡庆华,刘建康

生物多样性 , 2009,
Abstract: To reveal patterns of longitudinal distribution, seasonal variation, and ecological succession in cladocerans communities in the Three Gorges Reservoir, ten sites were used to sample cladoceran communities across a longitudinal gradient from April, 2004 to January, 2005. Nine cladoceran species were collected throughout the year. Species richness was highest in spring (8 species), lower in summer (5 species) and winter (3 species), and lowest in autumn (2 species). Cladoceran species composition varied across sampling sites. Four species were collected from river sampling sites and seven species from reservoir sampling sites. Cladoceran species richness decreased gradually with increasing distance to the dam within the reservoir area. Cladoceran density and biomass varied among seasons (P <0.01) and sampling sites (P <0.01), and both were highest in spring. Density and biomass of cladocerans in river areas were lower than in the reservoir area. Density and biomass of cladoceran in up area of reservoir was lower than that in down area of reservoir. The cladoceran communities of the Three Gorges Reservoir showed distinct patterns in both longitudinal distribution and seasonal variation.
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