Rapid toxicity assessment using an in vivo enzyme test for Brachionus plicatilis (Rotifera).

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Moffat, B D; Snell, T W

1995-02-01

A 1-hr in vivo enzyme inhibition assay based on esterase activity has good potential for marine toxicity assessment. A test was developed for the rotifer Brachionus plicatilis based on the nonfluorescent substrate fluorescein diacetate (FDA), which is metabolized by esterases to a fluorescent product. Enzyme inhibition, as determined by reduced fluorescence, can be scored visually or quantified using a fluorometer. Quantification of fluorescence permits the calculation of NOEC, LOEC, chronic value, and IC20. The 1-hr esterase inhibition test has sensitivity comparable to that of 24-hr rotifer acute tests for several compounds. The toxicity of six compounds was examined using the quantified assay. The resulting IC20s were within a factor of 3 of the 24-hour LC50s. IC20 values ranged from 0.017 mg/l for tributyltin to 3.1 mg/l for zinc, with an average coefficient of variation of 17.8%. Electrophoretic analysis of rotifer homogenates suggested that a single C esterase (acetylesterase) was responsible for FDA metabolism in B. plicatilis. Several other aquatic species are capable of metabolizing FDA, including Brachionus calyciflorus, Mysidopsis bahia, Menidia beryllina, Pimephales promelas, Ceriodaphnia dubia, Daphnia pulex, Artemia salina, and Ophryotrocha sp. The esterase inhibition test is an attractive tool for assessing aquatic toxicity because of its speed, simplicity, sensitivity, and applicability to a broad range of aquatic species.

[Effects of Alexandrium tamarense and Prorocentrum donghaiense on rotifer Brachionus plicatilis population].

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Wang, Liping; Yan, Tian; Tan, Zhijun; Zhou, Mingjiang

2003-07-01

The effects of Prorocentrum donghaiense and Alexandrium sp., causative species of harmful algal bloom of East China Sea in May 2002, on rotifer Brachionus plicatilis population were studied in the laboratory. The results showed that Alexandrium tamarense (ATHK) had a lethal effect on B. plicatilis and the 48hLC50 was about 1300 cell.ml-1. The toxin comparison of different fractions showed that the algal culture and re-suspended algal cells had the adverse effects, and the alga at earlier growth phases showed a stronger impact, indicating that the inhibitory effect was related with the activity of the living algal cells. P. donghaiense at high densities (4 x 10(4), 5 x 10(4) and 10 x 10(4) cell.ml-1) had an adverse effect on B. plicatilis population, while at low densities (1 x 10(4), 2 x 10(4) and 3 x 10(4) cell.ml-1), the alga could be used as food for rotifer population. When the two algae were mixed, the lethal effect of A. tamarense could be decreased by P. donghaiense. The results indicated that the above HAB event could affect the micro-zooplankton population in the occurrence area of East China Sea.

Pastas de Rhodomonas salina (Cryptophyta como alimento para Brachionus plicatilis (Rotifera

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Miguel Guevara

2011-12-01

Full Text Available Pastas de Rhodomonas salina, obtenidas mediante centrifugación y floculación con quitosano y preservadas con o sin vitamina C, a -20°C fueron evaluadas bioquímicamente y proporcionadas como alimento al rotífero Brachionus plicatilis. Las pastas microalgales: (1 centrifugada y con vitamina C (CV, (2 centrifugada y sin vitamina C (C, (3 floculada y con vitamina C (FV y (4 floculada y sin adición de vitamina C (F; mantuvieron sus contenidos de proteínas y lípidos totales similares al cultivo control, con valores de 40.0±2.32% y 12.0±1.45%, respectivamente. La relación feofitina a/clorofila a fue similar (0.09-0.11 entre las pastas centrifugadas y el cultivo control, pero mayor en las pastas floculadas (1.28-1.48. Las pastas centrifugadas presentaron porcentajes de PUFAs totales, EPA y DHA similares al cultivo control (PUFAs: 47%, EPA: 4% y DHA: 4.7% y superiores al de las pastas floculadas. Las pastas obtenidas por centrifugación indujeron un crecimiento del rotífero igual al obtenido con el alimento control (densidad máxima: 320rotíferos/mL; tasa instantánea de crecimiento: 0.23rotíferos/día, fecundidad: 1.49huevos/ hembra y productividad: 43x103rotíferos/L/día. Se concluye que la pasta de R. salina centrifugada y congelada a -20°C, durante cuatro semanas, sin adición de vitamina C, mantiene su calidad nutricional similar a la del alga fresca y puede ser usada como alimento de Brachionus plicatilis.

The nucleotide sequences of 5S rRNAs from a rotifer, Brachionus plicatilis, and two nematodes, Rhabditis tokai and Caenorhabditis elegans.

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Kumazaki, T; Hori, H; Osawa, S; Ishii, N; Suzuki, K

1982-11-11

The nucleotide sequences of 5S rRNAs from a rotifer, Brachionus plicatilis, and two nematodes, Rhabditis tokai and Caenorhabditis elegans have been determined. The rotifer has two 5S rRNA species that are composed of 120 and 121 nucleotides, respectively. The sequences of these two 5S rRNAs are the same except that the latter has an additional base at its 3'-terminus. The 5S rRNAs from the two nematode species are both 119 nucleotides long. The sequence similarity percents are 79% (Brachionus/Rhabditis), 80% (Brachionus/Caenorhabditis), and 95% (Rhabditis/Caenorhabditis) among these three species. Brachionus revealed the highest similarity to Lingula (89%), but not to the nematodes (79%).

Two circular chromosomes of unequal copy number make up the mitochondrial genome of the rotifer Brachionus plicatilis.

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Suga, Koushirou; Mark Welch, David B; Tanaka, Yukari; Sakakura, Yoshitaka; Hagiwara, Atsushi

2008-06-01

The monogonont rotifer Brachionus plicatilis is an emerging model system for a diverse array of questions in limnological ecosystem dynamics, the evolution of sexual recombination, cryptic speciation, and the phylogeny of basal metazoans. We sequenced the complete mitochondrial genome of B. plicatilis sensu strictu NH1L and found that it is composed of 2 circular chromosomes, designated mtDNA-I (11,153 bp) and mtDNA-II (12,672 bp). Hybridization to DNA isolated from mitochondria demonstrated that mtDNA-I is present at 4 times the copy number of mtDNA-II. The only nucleotide similarity between the 2 chromosomes is a 4.9-kbp region of 99.5% identity including a transfer RNA (tRNA) gene and an extensive noncoding region that contains putative D-loop and control sequence. The mtDNA-I chromosome encodes 4 proteins (ATP6, COB, NAD1, and NAD2), 13 tRNAs, and the large and small subunit ribosomal RNAs; mtDNA-II encodes 8 proteins (COX1-3, NAD3-6, and NAD4L) and 9 tRNAs. Gene order is not conserved between B. plicatilis and its closest relative with a sequenced mitochondrial genome, the acanthocephalan Leptorhynchoides thecatus, or other sequenced mitochondrial genomes. Polymerase chain reaction assays and Southern hybridization to DNA from 18 strains of Brachionus suggest that the 2-chromosome structure has been stable for millions of years. The novel organization of the B. plicatilis mitochondrial genome into 2 nearly equal chromosomes of 4-fold different copy number may provide insight into the evolution of metazoan mitochondria and the phylogenetics of rotifers and other basal animal phyla.

Isolation and purification of glutathione S-transferases from Brachionus plicatilis and B. calyciflorus (Rotifera).

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Bowman, B P; Snell, T W; Cochrane, B J

1990-01-01

1. The enzyme glutathione S-transferase (GST), a critical element in xenobiotic metabolism, was isolated from the marine rotifer Brachionus plicatilis and its freshwater congener B. calyciflorus. 2. In B. plicatilis, GST comprised 4.2% of cytosolic protein and was present as three separate isozymes with mol. wts 30,000, 31,400 and 33,700. Specific activity of crude homogenates was 56 nmol min-1 mg-1 protein, while that of affinity chromatography purified GST was 1850. 3. In B. calyciflorus, GST was present as two isozymes with mol. wts of 26,300 and 28,500, representing 1.0% of cytosolic protein. Crude GST specific activity was 1750 nmol min-1 mg-1 protein and purified was 72,400. 4. Rotifer GSTs are unusual because they are monomers whereas all other animals thus far investigated posses dimeric GSTs.

Comparative ecotoxicity of interstitial waters in littoral ecosystems using Microtox{reg_sign} and the rotifer Brachionus plicatilis

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Valls, T.A. Del; Forja, J.M. [Univ. de Cadiz (Spain). Dpto. de Quimica Fisica; Lubian, L.M.; Gomez-Parra, A. [C.S.I.C., Cadiz (Spain). Inst. de Ciencias Marinas de Andalucia

1997-11-01

The toxic effects of sediment interstitial waters collected from seven littoral sites in the Gulf of Cadiz were tested with the Microtox assay and a 7-d Brachionus plicatilis (Rotifera) decline test. Dissolved organic carbon (DOC), nutrients (ammonia, phosphate, nitrate, nitrite, and silicate), the heavy metals (Fe, Mn, Zn, Cu, Pb, Cr, and Cd), and the linear alkylbenzensulfonate (LAS) concentrations in the interstitial water were measured. The results of assays were compared in a dose-response relationship between sites. This comparison has demonstrated a general agreement between toxicity values determined by Brachionus plicatilis and Photobacterium phosphoreum, except in the case of interstitial water toxicity from mixtures of heavy metals. Data derived from interstitial water chemistry and bioassays were assembled by multivariate statistical techniques (principal components analysis). Positive prevalence of these components in cases studied was used to establish those ranges in chemical concentrations associated with adverse effects. The interstitial water guidelines, in terms of concentrations at or below which biological effects have been shown to be minimal (mg/L), are: DOC, 12.8; phosphate, 0.28; LAS, 80.4; ammonia, 12.1: chromium, 0.0045.

Reproductive Effects of Two Polybrominated Diphenyl Ethers on the Rotifer Brachionus plicatilis.

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Zhang, Jing; Wang, You; Zhou, Bin; Sun, Kai-Ming; Tang, Xuexi

2016-08-01

The effects of two polybrominated diphenyl ethers (PBDEs) on the reproduction of the rotifer Brachionus plicatilis were investigated. Results showed that sexual maturation was promoted by tetra-brominated diphenyl ether-47 (BDE-47) and deca-brominated diphenyl ether-209 (BDE-209), whereas fecundity was inhibited by BDE-47, but promoted by BDE-209. Additionally, both PBDEs affected the expression of two genes, vasa and nanos mRNA, related to rotifer reproduction. This suggests a possible regulatory molecular mechanism at the transcriptional level. Our research extends the current knowledge of the ecotoxicological mechanism induced by PBDEs and provides further essential information for assessing the risks of PBDE contamination in marine ecosystems.

Methods for culturing saltwater rotifers (Brachionus plicatilis) for rearing larval zebrafish.

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Lawrence, Christian; Sanders, Erik; Henry, Eric

2012-09-01

The saltwater rotifer, Brachionus plicatilis, is widely used in the aquaculture industry as a prey item for first-feeding fishes due to its ease of culture, small size, rapid reproductive rate, and amenability to enrichment with nutrients. Despite the distinct advantages of this approach, rotifers have only been sporadically utilized for rearing larval zebrafish, primarily because of the common misconception that maintaining cultures of rotifers is difficult and excessively time-consuming. Here we present simple methods for maintaining continuous cultures of rotifers capable of supporting even the very largest zebrafish aquaculture facility, with minimal investments in materials, time, labor, and space. Examples of the methods' application in one large, existing facility is provided, and troubleshooting of common problems is discussed.

Use of flubendazole as a therapeutic agent against rotifers (Brachionus plicatilis) in intensive cultures of the harpacticoid copepod Tisbe holothuriae

DEFF Research Database (Denmark)

Steenfeldt, Svend Jørgen; Nielsen, Johan W.

2010-01-01

down production and subsequently use a therapeutic agent to eliminate all zooplankton in the system before restart with a stock culture free of rotifers. We tested flubendazole as a mean of controlling rotifers (Brachionus plicatilis) in intensive laboratory cultures of the harpacticoid copepod (Tisbe...... holothuria). Flubendazole was lethal to rotifers in concentrations as low as 0.05 mg L−1. There was no significant effect on the concentration of copepods, even at the highest concentration tested, i.e. 5.0 mg L−1 flubendazole. We conclude that flubendazole is an effective drug for control of B. plicatilis...

Effects of salinity and pH on the activity and oxygen consumption of Brachionus plicatilis (rotatoria)

Energy Technology Data Exchange (ETDEWEB)

Epp, R.W.; Winston, P.W.

1978-01-01

Activity and respiratory rates of the rotifer, Brachionus plicatilis, were determined following exposure to pH values of 6.5, 7.5 and 8.5 and to concentrations of 10, 50 and 100 mosm. Changes in the hydrogen-ion concentration had no detectable effect on either activity or metabolism. Acute reduction in osmolarity of the medium resulted in a reduction in oxygen consumption and activity. Both activity and oxygen consumption increased upon acclimatization to osmolarities of 50 and 100 mosm.

Whole-mount in situ hybridization in the rotifer Brachionus plicatilis representing a basal branch of lophotrochozoans.

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Boell, Louis A; Bucher, Gregor

2008-08-01

In order to broaden the comparative scope of evolutionary developmental biology and to refine our picture of animal macroevolution, it is necessary to establish new model organisms, especially from previously underrepresented groups, like the Lophotrochozoa. We have established the culture and protocols for molecular developmental biology in the rotifer species Brachionus plicatilis Müller (Rotifera, Monogononta). Rotifers are nonsegmented animals with enigmatic basal position within the lophotrochozoans and marked by several evolutionary novelties like the wheel organ (corona), the median eye, and the nonpaired posterior foot. The expression of Bp-Pax-6 is shown using whole-mount in situ hybridization. The inexpensive easy culture and experimental tractability of Brachionus as well as the range of interesting questions to which it holds the key make it a promising addition to the "zoo" of evo-devo model organisms.

Efficacy of a commercial probiotic relative to oxytetracycline as Gram-negative bacterial control agents in a rotifer (Brachionus plicatilis) batch culture

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Two trials were conducted to evaluate two gram-negative bacterial control strategies in batch cultures of the rotifer Brachionus plicatilis. In the first trial, rotifers at an initial density of 47/mL were cultured for 5 d and dosed with a 10-mg/L solution of either oxytetracycline or a commercial p...

[Effect of suspended silt from dredging at Yangtze estuary on Brachionus plicatilis].

Science.gov (United States)

Wang, Jinqui; Xu, Zhaoli; Shi, Chun; Chen, Yaqu

2002-07-01

The effect of suspended silt from dredging at Yangtze estuary on Brachionus plicatilis was investigated by clonal culture (to construct life table) and population accumulative culture. The intrinsic increasing rate of the rotifer population was greatly reduced under different concentrations (1, 3, 5, 7 and 9 mg.ml-1) of silt, from 29.6% to 64.1%, and to a maximum of 130.0%. The suspended silt affected population survival rate, rather than its reproduction rate. In accumulative culture, the densities of female, males, parthenogenetic eggs, and resting eggs in the population were not affected by silt. It was concluded that the presence of suspended silt should have a certain negative influence on the rotifer population in dredging Yangtze estuary.

Specific toxic effect of dinoflagellate Heterocapsa circularisquama on the rotifer Brachionus plicatilis.

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Kim, D; Sato, Y; Oda, T; Muramatsu, T; Matsuyama, Y; Honjo, T

2000-12-01

Heterocapsa circularisquama (Dinophyceae), a noxious red tide dinoflagellate, is known to have a specifically lethal effect on shellfish, especially bivalves such as pearl oyster (Pinctada fucata), but no detrimental effects of this alga on fishes have not been observed so far. In this study, we found that H. circularisquama was toxic to a microzooplankton, a rotifer (Brachionus plicatilis) in a cell concentration-dependent manner, while the cultured supernatant or ultrasonic ruptured H. circularisquama had no significant toxic effect on the rotifer. Since no such toxic effects on the rotifer were observed in Chattonella marina, Heterosigma akashiwo, or Cochlodinium polykrikoides, other species of harmful red tide plankton, H. circularisquama may have a strictly specific toxic mechanism against the rotifer as well as bivalves.

Combined effects of Corexit EC 9500A with secondary abiotic and biotic factors in the rotifer Brachionus plicatilis.

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Williams, Michael B; Powell, Mickie L; Watts, Stephen A

2016-10-01

We examined lethality and behavioral effects of Corexit EC 9500A (C-9500A) exposure on the model marine zooplankton Brachionus plicatilis singularly and in combination with abiotic and biotic factors. C-9500A exposure at standard husbandry conditions (17.5ppt, 24°C, 200 rotifer*mL(-1) density) identified the 24h median lethal concentration, by Probit analysis, to be 107ppm for cultured B. plicatilis. Rotifers surviving exposure to higher concentrations (100 and 150ppm) exhibited a decreased swimming velocity and a reduced net to gross movement ratio. Significant interaction between C-9500A exposure and temperature or salinity was observed. Upper thermal range was reduced and maximal salinity stress was seen as ca. 25ppt. Increased or decreased nutritional availability over the exposure period did not significantly alter mortality of B. plicatilis populations at the concentrations tested. Results from this study may be useful for predicting possible outcomes on marine zooplankton following dispersant application under diverse natural conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

The hard parts (trophi) of the rotifer mastax do contain chitin: evidence from studies on Brachionus plicatilis.

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Klusemann, J; Kleinow, W; Peters, W

1990-01-01

The jaws (trophi) of the rotifer Brachionus plicatilis are soluble in strong acids but are resistant to long treatments by strong alkali. They show the same buoyant density as chitin and also as the chitin-containing layers of rotifer egg-shells. The presence of chitin in these structures was confirmed using the following techniques: chitosan-tests, thin-layer chromatography of trophi-hydrolysates which revealed glucosamine, by dissolving trophi with chitinase and electron microscopic WGA/gold-labelling. The content of chitin in the trophi was estimated by two different methods to be approx. 64% (50-75%).

Responses of the rotifer Brachionus plicatilis to flame retardant (BDE-47) stress.

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Jian, Xiaoyang; Tang, Xuexi; Xu, Ningning; Sha, Jingjing; Wang, You

2017-03-15

A series of short-term toxicological tests were conducted on the rotifer Brachionus plicatilis to assess the toxicity of the flame retardant 2,2',4,4'-tetrabrominated biphenyl ether (BDE-47). BDE-47 increased mortality, morphological damage, and altered population dynamics and fecundity of rotifer. Antioxidant enzymes were differentially changed to maintain the balance between antioxidant and pro-oxidant activity. However, with increases in the concentration of BDE-47, the metabolic and antioxidant activity decreased. Moreover, the reactive oxygen species (ROS) and malondialdehyde contents increased and the ratio between glutathione and glutathione-SH decreased, indicating oxidative stress. The addition of the ROS-inhibitor N-acetylcysteine alleviated the degree of damage and stimulated the activity of xenobiotic-metabolizing and antioxidant system, which suggested that ROS were the most important loop in the stress response. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of the rotifer Brachionus plicatilis (Ploimida: Brachionidae) in a Brazilian coastal lagoon.

Science.gov (United States)

Castilho, M S; Arcifa, M S

2000-12-01

Secondary production, density and biomass fluctuations, and some reproductive aspects of the rotifer Brachionus plicatilis were studied weekly for two years in a Brazilian coastal lagoon. Food (and secondarily temperature) seemed to be the main factor involved in the summer increments. In the first summer, a mass mortality of fish caused changes in the phytoplankton, which switched from the dominance of Cyanophyceae to Chlorophyceae and other groups. For two months, production, density and biomass were relatively high until the recovery of the Cyanophyceae dominance. In the second summer, peaks of shorter duration and higher values of production, in comparison to the first one, were found. The contribution of resting eggs hatching, in the first summer, and the increment in parthenogenetic reproduction, in the second summer, would account for the population increases observed. Males and mictic females occurred when densities were high.

Substituição de Artemia sp. pelo rotífero Brachionus plicatilis na larvicultura do camarão-d'água-doce (Macrobrachium rosenbergii De Man, 1879 Replacement of the Artemia sp. for the rotifer Brachionus plicatilis in the hatchering of the freshwater prawn (Macrobrachium rosenbergii De Man, 1879

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Luciana Almada Thomaz

2004-12-01

Full Text Available Conduziu-se o presente trabalho com o objetivo de avaliar o efeito da substituição dos náuplios de Artemia sp. pelo rotífero enriquecido e congelado (Brachionus plicatilis, O.F. Müller, 1786 sobre a sobrevivência e peso seco das larvas. O experimento foi conduzido em blocos casualizados, sendo testados quatro regimes alimentares na larvicultura do camarão M. rosenbergii, com quatro repetições por tratamento. Nos regimes alimentares, realizaram-se substituições progressivas de náuplios de Artemia sp. (nas pelo rotífero Brachionus plicatilis (rots e testaram-se os seguintes tratamentos: 100% B. plicatilis (30 rots/mL (T1; 100% Artemia sp. (5 nas/mL (T2, 60% Artemia sp. (3 nas/mL + 40% B. plicatilis (12 rots/mL (T3 e 40% Artemia sp. (2 nas/mL + 60% B. plicatilis (18 rots/mL (T4, adicionando-se a estes tratamentos ração úmida. Os resultados da sobrevivência final em pós-larvas foram analisados pelo teste do X² e demonstraram não haver diferenças significativas do tratamento T2 (68,36% sobre os tratamentos T3 (68,76% e T4 (64,60%. O tratamento T1 (100% B. plicatilis apresentou mortalidade total no 14º dia do experimento. O peso seco médio das pós-larvas foi analisado estatisticamente pela ANOVA, não apresentando diferenças significativas entre os valores de 3,29 mg (T2, 3,08 mg (T3 e 3,38 mg (T4. A taxa de mortalidade baseada no número de larvas encontradas mortas diariamente, em relação ao número de larvas estocadas inicialmente, foi maior para todos os tratamentos nos primeiros 15 dias do experimento. Portanto, os resultados demonstraram que a substituição total de rotíferos enriquecidos e congelados acarretou a mortalidade total das larvas, mas a substituição parcial de 40% e 60% dos náuplios de Artemia sp. pelo B. plicatilis foi viável, não apresentando prejuízos significativos em termos de sobrevivência e peso seco das pós-larvas.This work was carried out to identify the replacement of the nauplii Artemia

Analysis of expressed sequence tags of the cyclically parthenogenetic rotifer Brachionus plicatilis.

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Koushirou Suga

Full Text Available BACKGROUND: Rotifers are among the most common non-arthropod animals and are the most experimentally tractable members of the basal assemblage of metazoan phyla known as Gnathifera. The monogonont rotifer Brachionus plicatilis is a developing model system for ecotoxicology, aquatic ecology, cryptic speciation, and the evolution of sex, and is an important food source for finfish aquaculture. However, basic knowledge of the genome and transcriptome of any rotifer species has been lacking. METHODOLOGY/PRINCIPAL FINDINGS: We generated and partially sequenced a cDNA library from B. plicatilis and constructed a database of over 2300 expressed sequence tags corresponding to more than 450 transcripts. About 20% of the transcripts had no significant similarity to database sequences by BLAST; most of these contained open reading frames of significant length but few had recognized Pfam motifs. Sixteen transcripts accounted for 25% of the ESTs; four of these had no significant similarity to BLAST or Pfam databases. Putative up- and downstream untranslated regions are relatively short and AT rich. In contrast to bdelloid rotifers, there was no evidence of a conserved trans-spliced leader sequence among the transcripts and most genes were single-copy. CONCLUSIONS/SIGNIFICANCE: Despite the small size of this EST project it revealed several important features of the rotifer transcriptome and of individual monogonont genes. Because there is little genomic data for Gnathifera, the transcripts we found with no known function may represent genes that are species-, class-, phylum- or even superphylum-specific; the fact that some are among the most highly expressed indicates their importance. The absence of trans-spliced leader exons in this monogonont species contrasts with their abundance in bdelloid rotifers and indicates that the presence of this phenomenon can vary at the subphylum level. Our EST database provides a relatively large quantity of transcript

Analysis of expressed sequence tags of the cyclically parthenogenetic rotifer Brachionus plicatilis.

Science.gov (United States)

Suga, Koushirou; Welch, David Mark; Tanaka, Yukari; Sakakura, Yoshitaka; Hagiwara, Atsushi

2007-08-01

Rotifers are among the most common non-arthropod animals and are the most experimentally tractable members of the basal assemblage of metazoan phyla known as Gnathifera. The monogonont rotifer Brachionus plicatilis is a developing model system for ecotoxicology, aquatic ecology, cryptic speciation, and the evolution of sex, and is an important food source for finfish aquaculture. However, basic knowledge of the genome and transcriptome of any rotifer species has been lacking. We generated and partially sequenced a cDNA library from B. plicatilis and constructed a database of over 2300 expressed sequence tags corresponding to more than 450 transcripts. About 20% of the transcripts had no significant similarity to database sequences by BLAST; most of these contained open reading frames of significant length but few had recognized Pfam motifs. Sixteen transcripts accounted for 25% of the ESTs; four of these had no significant similarity to BLAST or Pfam databases. Putative up- and downstream untranslated regions are relatively short and AT rich. In contrast to bdelloid rotifers, there was no evidence of a conserved trans-spliced leader sequence among the transcripts and most genes were single-copy. Despite the small size of this EST project it revealed several important features of the rotifer transcriptome and of individual monogonont genes. Because there is little genomic data for Gnathifera, the transcripts we found with no known function may represent genes that are species-, class-, phylum- or even superphylum-specific; the fact that some are among the most highly expressed indicates their importance. The absence of trans-spliced leader exons in this monogonont species contrasts with their abundance in bdelloid rotifers and indicates that the presence of this phenomenon can vary at the subphylum level. Our EST database provides a relatively large quantity of transcript-level data for B. plicatilis, and more generally of rotifers and other gnathiferan phyla, and

Evaluating the toxic effects of three priority hazardous and noxious substances (HNS) to rotifer Brachionus plicatilis.

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Zheng, Lei; Pan, Luqing; Lin, Pengfei; Miao, Jingjing; Wang, Xiufen; Lin, Yufei; Wu, Jiangyue

2017-12-01

Hazardous and noxious substances (HNS) spill in the marine environment is an issue of growing concern, and it will mostly continue to do so in the future owing to the increase of high chemical traffic. Nevertheless, the effects of HNS spill on marine environment, especially on aquatic organisms are unclear. Consequently, it is emergent to provide valuable information for the toxicities to marine biota caused by HNS spill. Accordingly, the acute toxicity of three preferential HNS and sub-lethal effects of acrylonitrile on Brachionus plicatilis were evaluated. The median lethal concentration (LC 50 ) at 24 h were 47.2 mg acrylonitrile L -1 , 276.9 mg styrene L -1 , and 488.3 mg p-xylene L -1 , respectively. Sub-lethal toxicity effects of acrylonitrile on feeding behavior, development, and reproduction parameters of B. plicatilis were also evaluated. Results demonstrated that rates of filtration and ingestion were significantly reduced at 2.0, 4.0, and 8.0 mg L -1 of acrylonitrile. Additionally, reproductive period, fecundity, and life span were significantly decreased at high acrylonitrile concentrations. Conversely, juvenile period was significantly increased at the highest two doses and no effects were observed on embryonic development and post-reproductive period. Meanwhile, we found that ingestion rate decline could be a good predictor of reproduction toxicity in B. plicatilis and ecologically relevant endpoint for toxicity assessment. These data will be useful to assess and deal with marine HNS spillages.

Swimming speed alteration of Artemia sp. and Brachionus plicatilis as a sub-lethal behavioural end-point for ecotoxicological surveys.

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Garaventa, Francesca; Gambardella, Chiara; Di Fino, Alessio; Pittore, Massimiliano; Faimali, Marco

2010-03-01

In this study, we investigated the possibility to improve a new behavioural bioassay (Swimming Speed Alteration test-SSA test) using larvae of marine cyst-forming organisms: e.g. the brine shrimp Artemia sp. and the rotifer Brachionus plicatilis. Swimming speed was investigated as a behavioural end-point for application in ecotoxicology studies. A first experiment to analyse the linear swimming speed of the two organisms was performed to verify the applicability of the video-camera tracking system, here referred to as Swimming Behavioural Recorder (SBR). A second experiment was performed, exposing organisms to different toxic compounds (zinc pyrithione, Macrotrol MT-200, and Eserine). Swimming speed alteration was analyzed together with mortality. The results of the first experiment indicate that SBR is a suitable tool to detect linear swimming speed of the two organisms, since the values have been obtained in accordance with other studies using the same organisms (3.05 mm s(-1) for Artemia sp. and 0.62 mm s(-1) for B. plicatilis). Toxicity test results clearly indicate that swimming speed of Artemia sp. and B. plicatilis is a valid behavioural end-point to detect stress at sub-lethal toxic substance concentrations. Indeed, alterations in swimming speed have been detected at toxic compound concentrations as low as less then 0.1-5% of their LC(50) values. In conclusion, the SSA test with B. plicatilis and Artemia sp. can be a good behavioural integrated output for application in marine ecotoxicology and environmental monitoring programs.

Production of the rotifer Brachionus plicatilis (Ploimida: Brachionidae in a Brazilian coastal lagoon

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Maria Stela Maioli Castilho

2000-12-01

Full Text Available Secondary production, density and biomass fluctuations, and some reproductive aspects of the rotifer Brachionus plicatilis were studied weekly for two years in a Brazilian coastal lagoon. Food (and secondarily temperature seemed to be the main factor involved in the summer increments. In the first summer, a mass mortality of fish caused changes in the phytoplankton, which switched from the dominance of Cyanophyceae to Chlorophyceae and other groups. For two months, production, density and biomass were relatively high until the recovery of the Cyanophyceae dominance. In the second summer, peaks of shorter duration and higher values of production, in comparison to the first one, were found. The contribution of resting eggs hatching, in the first summer, and the increment in parthenogenetic reproduction, in the second summer, would account for the population increases observed. Males and mictic females occurred when densities were high.

Speciation in ancient cryptic species complexes: evidence from the molecular phylogeny of Brachionus plicatilis (Rotifera).

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Gómez, Africa; Serra, Manuel; Carvalho, Gary R; Lunt, David H

2002-07-01

Continental lake-dwelling zooplanktonic organisms have long been considered cosmopolitan species with little geographic variation in spite of the isolation of their habitats. Evidence of morphological cohesiveness and high dispersal capabilities support this interpretation. However, this view has been challenged recently as many such species have been shown either to comprise cryptic species complexes or to exhibit marked population genetic differentiation and strong phylogeographic structuring at a regional scale. Here we investigate the molecular phylogeny of the cosmopolitan passively dispersing rotifer Brachionus plicatilis (Rotifera: Monogononta) species complex using nucleotide sequence variation from both nuclear (ribosomal internal transcribed spacer 1, ITS1) and mitochondrial (cytochrome c oxidase subunit I, COI) genes. Analysis of rotifer resting eggs from 27 salt lakes in the Iberian Peninsula plus lakes from four continents revealed nine genetically divergent lineages. The high level of sequence divergence, absence of hybridization, and extensive sympatry observed support the specific status of these lineages. Sequence divergence estimates indicate that the B. plicatilis complex began diversifying many millions of years ago, yet has showed relatively high levels of morphological stasis. We discuss these results in relation to the ecology and genetics of aquatic invertebrates possessing dispersive resting propagules and address the apparent contradiction between zooplanktonic population structure and their morphological stasis.

Effects of diet on population development of the rotifer Brachionus plicatilis in culture

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Planas, M.; Estévez, A.

1989-06-01

Experiments were conducted in order to observe the effect of five diets on the population development of the rotifer Brachionus plicatilis Müller under laboratory conditions. Diets were based on baker’s yeast ( Saccharomyces cerevisiae) and the algae Tetraselmis suecica and Isochrysis galbana, mixed, or as simple diets. Growth rates, fecundity and biometric parameters were studied for 15 days. The cultures were divided in a logarithmic phase and a harvesting phase. Rotifers fed on Tetraselmis, alone or mixed with yeast or Isochrysis, gave good performances with the best results in all the parameters studied. Average growth rates in all diets were similar during the exponential phase, with values ranging from 0.72 ( Tetraselmis and Tetraselmis + yeast) to 0.47 (yeast). During the harvesting phase there were high differences between diets, with rates highly reduced in the yeast-group (0.17) and good rates when Tetraselmis was ingested (0.65 0.51). This alga had a positive influence on the rotifers, increasing individual growth and fecundity.

Bacterial diversity associated with the rotifer Brachionus plicatilis sp. complex determined by culture-dependent and -independent methods.

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Ishino, Ryota; Iehata, Shunpei; Nakano, Miyo; Tanaka, Reiji; Yoshimatsu, Takao; Maeda, Hiroto

2012-03-01

The bacterial communities associated with rotifers (Brachionus plicatilis sp. complex) and their culture water were determined using culture-dependent and -independent methods (16S rRNA gene clone library). The bacterial communities determined by the culture-independent method were more diverse than those determined by the culture-dependent method. Although the culture-dependent method indicated the bacterial community of rotifers was relatively similar to that of the culture water, 16S rRNA gene clone library analyses revealed a great difference between the two microbiotas. Our results suggest that most bacteria associated with rotifers are not easily cultured using conventional methods, and that the microbiota of rotifers do not correspond with that of the culture water completely.

Synergistic toxicity of Macondo crude oil and dispersant Corexit 9500A(®) to the Brachionus plicatilis species complex (Rotifera).

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Rico-Martínez, Roberto; Snell, Terry W; Shearer, Tonya L

2013-02-01

Using the marine rotifer Brachionus plicatilis acute toxicity tests, we estimated the toxicity of Corexit 9500A(®), propylene glycol, and Macondo oil. Ratios of 1:10, 1:50 and 1:130 for Corexit 9500A(®):Macondo oil mixture represent: maximum exposure concentrations, recommended ratios for deploying Corexit (1:10-1:50), 1:130 the actual dispersant:oil ratio used in the Deep Water Horizon spill. Corexit 9500A(®) and oil are similar in their toxicity. However, when Corexit 9500A(®) and oil are mixed, toxicity to B. manjavacas increases up to 52-fold. Extrapolating these results to the oil released by the Macondo well, suggests underestimation of increased toxicity from Corexit application. We found small differences in sensitivity among species of the B. plicatilis species complex, likely reflecting phylogenetic similarity. Just 2.6% of the water-accommodated fraction of oil inhibited rotifer cyst hatching by 50%, an ecologically significant result because rotifer cyst in sediments are critical resources for the recolonization of populations each Spring. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of nutritional state on Hsp60 levels in the rotifer Brachionus plicatilis following toxicant exposure.

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Wheelock, C E; Baumgartner, T A; Newman, J W; Wolfe, M F; Tjeerdema, R S

2002-11-13

The nutritional state of an organism can affect the results of toxicity testing. Here we exemplified this fact by examining the effect of nutritional deprivation on heat shock protein 60 (hsp60) production in the rotifer Brachionus plicatilis following exposure to two proven inducers of hsp60, a water-accommodated fraction of crude oil (WAF) and a dispersed oil preparation (DO). Both DO and WAF exposures of unfed rotifers resulted in significantly greater hsp60 levels than that of fed DO and WAF exposed rotifers at 8 h: 870 and 3100% of control, respectively. Results clearly demonstrate that a poor nutritional state potentiates stress protein induction upon exposure to water-soluble petroleum products. It is therefore critical to define the organismal nutritional status when reporting toxic responses. Copyright 2002 Elsevier Science B.V.

The mate recognition protein gene mediates reproductive isolation and speciation in the Brachionus plicatilis cryptic species complex.

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Gribble, Kristin E; Mark Welch, David B

2012-08-01

Chemically mediated prezygotic barriers to reproduction likely play an important role in speciation. In facultatively sexual monogonont rotifers from the Brachionus plicatilis cryptic species complex, mate recognition of females by males is mediated by the Mate Recognition Protein (MRP), a globular glycoprotein on the surface of females, encoded by the mmr-b gene family. In this study, we sequenced mmr-b copies from 27 isolates representing 11 phylotypes of the B. plicatilis species complex, examined the mode of evolution and selection of mmr-b, and determined the relationship between mmr-b genetic distance and mate recognition among isolates. Isolates of the B. plicatilis species complex have 1-4 copies of mmr-b, each composed of 2-9 nearly identical tandem repeats. The repeats within a gene copy are generally more similar than are gene copies among phylotypes, suggesting concerted evolution. Compared to housekeeping genes from the same isolates, mmr-b has accumulated only half as many synonymous differences but twice as many non-synonymous differences. Most of the amino acid differences between repeats appear to occur on the outer face of the protein, and these often result in changes in predicted patterns of phosphorylation. However, we found no evidence of positive selection driving these differences. Isolates with the most divergent copies were unable to mate with other isolates and rarely self-crossed. Overall the degree of mate recognition was significantly correlated with the genetic distance of mmr-b. Discrimination of compatible mates in the B. plicatilis species complex is determined by proteins encoded by closely related copies of a single gene, mmr-b. While concerted evolution of the tandem repeats in mmr-b may function to maintain identity, it can also lead to the rapid spread of a mutation through all copies in the genome and thus to reproductive isolation. The mmr-b gene is evolving rapidly, and novel alleles may be maintained and increase in

The mate recognition protein gene mediates reproductive isolation and speciation in the Brachionus plicatilis cryptic species complex

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Gribble Kristin E

2012-08-01

Full Text Available Abstract Background Chemically mediated prezygotic barriers to reproduction likely play an important role in speciation. In facultatively sexual monogonont rotifers from the Brachionus plicatilis cryptic species complex, mate recognition of females by males is mediated by the Mate Recognition Protein (MRP, a globular glycoprotein on the surface of females, encoded by the mmr-b gene family. In this study, we sequenced mmr-b copies from 27 isolates representing 11 phylotypes of the B. plicatilis species complex, examined the mode of evolution and selection of mmr-b, and determined the relationship between mmr-b genetic distance and mate recognition among isolates. Results Isolates of the B. plicatilis species complex have 1–4 copies of mmr-b, each composed of 2–9 nearly identical tandem repeats. The repeats within a gene copy are generally more similar than are gene copies among phylotypes, suggesting concerted evolution. Compared to housekeeping genes from the same isolates, mmr-b has accumulated only half as many synonymous differences but twice as many non-synonymous differences. Most of the amino acid differences between repeats appear to occur on the outer face of the protein, and these often result in changes in predicted patterns of phosphorylation. However, we found no evidence of positive selection driving these differences. Isolates with the most divergent copies were unable to mate with other isolates and rarely self-crossed. Overall the degree of mate recognition was significantly correlated with the genetic distance of mmr-b. Conclusions Discrimination of compatible mates in the B. plicatilis species complex is determined by proteins encoded by closely related copies of a single gene, mmr-b. While concerted evolution of the tandem repeats in mmr-b may function to maintain identity, it can also lead to the rapid spread of a mutation through all copies in the genome and thus to reproductive isolation. The mmr-b gene is evolving

Discovering genes associated with dormancy in the monogonont rotifer Brachionus plicatilis.

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Denekamp, Nadav Y; Thorne, Michael A S; Clark, Melody S; Kube, Michael; Reinhardt, Richard; Lubzens, Esther

2009-03-13

Microscopic monogonont rotifers, including the euryhaline species Brachionus plicatilis, are typically found in water bodies where environmental factors restrict population growth to short periods lasting days or months. The survival of the population is ensured via the production of resting eggs that show a remarkable tolerance to unfavorable conditions and remain viable for decades. The aim of this study was to generate Expressed Sequence Tags (ESTs) for molecular characterisation of processes associated with the formation of resting eggs, their survival during dormancy and hatching. Four normalized and four subtractive libraries were constructed to provide a resource for rotifer transcriptomics associated with resting-egg formation, storage and hatching. A total of 47,926 sequences were assembled into 18,000 putative transcripts and analyzed using both Blast and GO annotation. About 28-55% (depending on the library) of the clones produced significant matches against the Swissprot and Trembl databases. Genes known to be associated with desiccation tolerance during dormancy in other organisms were identified in the EST libraries. These included genes associated with antioxidant activity, low molecular weight heat shock proteins and Late Embryonic Abundant (LEA) proteins. Real-time PCR confirmed that LEA transcripts, small heat-shock proteins and some antioxidant genes were upregulated in resting eggs, therefore suggesting that desiccation tolerance is a characteristic feature of resting eggs even though they do not necessarily fully desiccate during dormancy. The role of trehalose in resting-egg formation and survival remains unclear since there was no significant difference between resting-egg producing females and amictic females in the expression of the tps-1 gene. In view of the absence of vitellogenin transcripts, matches to lipoprotein lipase proteins suggest that, similar to the situation in dipterans, these proteins may serve as the yolk proteins in

NMDA receptor expression and C terminus structure in the rotifer Brachionus plicatilis and long-term potentiation across the Metazoa.

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Kenny, Nathan J; Dearden, Peter K

2013-12-01

The C termini of N-methyl-D-aspartate (NMDA) receptor NR2 subunits are thought to play a major role in the molecular establishment of memory across the Bilateria, via the phenomenon known as long-term potentiation (LTP). Despite their long history of use as models in the study of memory, the expression and structure of the NR2 subunit in the Lophotrochozoa has remained uncategorized. Here, we report the phylogenic relationships of NR subunits across the Bilateria, and the cloning and in situ analysis of expression of NMDA NR1 and NR2 subunits in the monogont rotifer Brachionus plicatilis. RNA in situ hybridization suggests expression of NMDA receptor subunits in B. plicatilis is neural, consistent with expression observed in other species, and ours is the first report confirming NR2 expression in the lophotrochozoan clade. However, the single NR2 subunit identified in B. plicatilis was found to lack the long C terminal domain found in vertebrates, which is believed to modulate LTP. Further investigation revealed that mollusc and annelid NR2 subunits possess long intracellular C terminal domains. As data from molluscs (and particularly Aplysia californica) are the basis for much of our understanding of LTP, understanding how these diverse lophotrochozoan C termini function in vivo will have many implications for how we consider the evolution of the molecular control of learning and memory across the Metazoa as a whole and interpret the results of experiments into this vital component of cognition.

Copper accumulation and transport in a marine food chain composed of Platymonas subcordiformis, brachionus plicatilis and Penaeus monodon

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Cai, A.-Gen; Chen, Wei-Qi; Li, Wen-Quan

1997-09-01

Accumulation, transport and toxicity of Cu in the food chain consisting of Platymonas subcordiformis, Brachionus plicatilis and Penaeus monodon were studied. Effects of Cu on the growth of organisms in the food chain were investigated and the inhibiting effect concentration (EC50) of Cu was then determined according to the dynamics of the relative number of cells or total individuals of organisms, expressed in percentages with reference to the controlled system, under different culture conditions. On the basis of the variations in accumulation and percentages of accumulation of Cu in the biological phase, the relationship between the accumulation of Cu in organisms and its toxicity was analyzed and the main approach for determining the transport of Cu in the food chain was then discussed.

Postembryonic development of hard jaws (trophi) in a species belonging to the Brachionus plicatilis complex (Rotifera, Monogononta): a morphometric analysis.

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Fontaneto, Diego; Melone, Giulio

2006-04-01

The presence of hard jaws (trophi), with species-specific shape and size, is a taxonomic feature of Rotifera, a group of microscopic metazoans. Since trophi are used to discriminate among species, it is important to know whether these structures change in taxonomically important ways during postembryonic development. Using both SEM and optical images, we analyzed more than 100 individuals of a single clonal lineage of a monogonont rotifer, Brachionus plicatilis, in order to describe body and trophi development after hatching. Body size, expressed as lorica width and length, was isometrically related to age of the animals only during preadult stages. Trophi size, expressed as length of the different parts, was unrelated to either age or body size. Therefore, trophi elements do not grow after hatching in B. plicatilis. Despite the dimensional invariance with age, some differences in trophi size among individuals of the same clone were recorded. No difference in left-right asymmetry of the trophi was shown; the asymmetric elements of the trophi named rami consistently had the right ramus longer than the left. This constancy is in contrast to the reported trophi asymmetries in bdelloid rotifers, in which left-right asymmetries are not constant within clonal lineages. In conclusion, we suggest that also trophi size, constant within the analyzed clone, may be used as an additional taxonomic feature to help in the discrimination of taxa within the B. plicatilis complex of cryptic species. Copyright (c) 2006 Wiley-Liss, Inc.

Effects of copper and tributyltin on stress protein abundance in the rotifer Brachionus plicatilis.

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Cochrane, B J; Irby, R B; Snell, T W

1991-01-01

1. Exposure of the rotifer Brachionus plicatilis to elevated temperature resulted in the synthesis of a number of proteins, including a prominent one of 58,000 Da (SP58). 2. This protein is immunologically crossreactive with the 65,000 Da heat shock protein of the moth Heliothis virescens, which is a member of a highly conserved family of mitochondrial proteins. 3. Exposure of rotifers to sublethal doses of CuSO4 leads to a 4-5-fold increase in abundance of SP58, with maximum increase occurring at a dose that is approximately 5% of the LC50 for that compound. 4. A similar response was seen with tributyl tin (TBT). Kinetics of induction were sigmoidal, with induction occurring in the range of 20-30 micrograms/l. 5. No response was observed when rotifers were exposed to aluminum chloride, mercury chloride, pentachlorophenol, sodium arsenite, sodium azide, sodium dodecyl sulfate, or zinc chloride. 6. These results indicate that changes in stress protein abundance may prove useful as a biomarker of exposure to particular toxicants.

Discovering genes associated with dormancy in the monogonont rotifer Brachionus plicatilis

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Kube Michael

2009-03-01

Full Text Available Abstract Background Microscopic monogonont rotifers, including the euryhaline species Brachionus plicatilis, are typically found in water bodies where environmental factors restrict population growth to short periods lasting days or months. The survival of the population is ensured via the production of resting eggs that show a remarkable tolerance to unfavorable conditions and remain viable for decades. The aim of this study was to generate Expressed Sequence Tags (ESTs for molecular characterisation of processes associated with the formation of resting eggs, their survival during dormancy and hatching. Results Four normalized and four subtractive libraries were constructed to provide a resource for rotifer transcriptomics associated with resting-egg formation, storage and hatching. A total of 47,926 sequences were assembled into 18,000 putative transcripts and analyzed using both Blast and GO annotation. About 28–55% (depending on the library of the clones produced significant matches against the Swissprot and Trembl databases. Genes known to be associated with desiccation tolerance during dormancy in other organisms were identified in the EST libraries. These included genes associated with antioxidant activity, low molecular weight heat shock proteins and Late Embryonic Abundant (LEA proteins. Real-time PCR confirmed that LEA transcripts, small heat-shock proteins and some antioxidant genes were upregulated in resting eggs, therefore suggesting that desiccation tolerance is a characteristic feature of resting eggs even though they do not necessarily fully desiccate during dormancy. The role of trehalose in resting-egg formation and survival remains unclear since there was no significant difference between resting-egg producing females and amictic females in the expression of the tps-1 gene. In view of the absence of vitellogenin transcripts, matches to lipoprotein lipase proteins suggest that, similar to the situation in dipterans, these

Using population demographic parameters to assess impacts of two polybrominated diphenyl ethers (BDE-47, BDE-209) on the rotifer Brachionus plicatilis.

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Sha, Jingjing; Wang, You; Chen, Hongmei; Wang, Ming; Wang, Hong; Li, Xiaohong; Qi, Lei; Tang, Xuexi

2015-09-01

Polybrominated diphenyl ethers (PBDEs) are highly persistent anthropogenic contaminants found in the environment, posing a risk to aquatic ecosystems, whereas there is a lack of data concerning their impacts on marine invertebrates. The objective of this study was to assess the relative lethal and sublethal aquatic toxicity effects of two PBDEs, BDE-47 and BDE-209 congeners, on marine zooplankton rotifer Brachionus plicatilis associated with PBDE concentrations and time of exposure. Gas chromatography-mass spectrometry (GC-MS) analyses were performed to determine actual PBDE concentrations. Rotifer population demographic parameters from life tables, including age-specific survivorship (lx), age-specific fecundity (mx), net reproductive rate (R0), intrinsic rate of increase (rm), finite rate of increase (λ), life expectancy (E0) and generation time (T), were used as measures of treatment effects. Results from this study have revealed increasingly intense negative effects on many of the rotifer demographic parameters with elevated PBDE concentrations. The population growth curves of B. plicatilis showed almost no lag phase and reached peak abundances within 11 days, while B. plicatilis exposed to BDE-209 had a lag phase of about 5 days. In addition, increased PBDE levels reduced the population abundances and peak population densities of B. plicatilis. The two PBDEs have caused the carrying capacity (K) suppressed and the negative influence turned more serious as the concentration rose. Results also revealed that the time to reach growth curve inflection point (Tp) was shortened by PBDEs to different degrees. This study not only indicated that life table demography and population growth curve studies were two important aspects used to evaluate toxicant PBDE effects, but also compared the two PBDE disruptions to the population growth and reproduction of the rotifer. Copyright © 2015 Elsevier Inc. All rights reserved.

Study on mixis potential of rotifer resting eggs ( Brachionus plicatilis) with different collection times and different preservation periods

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Zhou, Li; Zheng, Yan; Xiang, Jian-Hai

2001-09-01

The present study investigated the possible changes in the mixis potential of rotifer resting eggs produced by a single stock of Brachionus plicatilis and collected and preserved annually from 1985 1998. Several clones derived from each batch of resting eggs were cultured under the same conditions for 21 days. The percentage of clones appearing resting eggs and the average yield of resting eggs produced from each clone were recorded and statistically analyzed to find the differences between the mixis potential of those resting egg batches. Results showed that different batches of resting eggs had different mictic levels among their descendent clones; but no regular relationship was found between the mixis potential of resting eggs and their collection times/preservation periods. Several internal and external factors that might affect the mixis potential of resting eggs were discussed.

Induction of hsp60 in the rotifer, Brachionus plicatilis exposed to dispersed and undispersed crude oil

International Nuclear Information System (INIS)

Wheelock, C.; Tjeerdema, R.; Wolfe, M.

1995-01-01

The use of chemical dispersants to treat oil spills remains a controversial area. Questions arise as to whether the dispersed oil is in fact more toxic than the original spill, potentially increasing the exposure of organisms in the water column to the dispersed components. Stress proteins, including hsp60, are a group of highly conserved proteins that are induced in response to a wide variety of environmental agents, including UV light, heavy metals, and xenobiotics. They are constitutively expressed, but Brachionus plicatilis has been used to document increased hsp60 levels in response to different environmental stresses. Hsp60 was therefore selected as a sublethal endpoint for B. plicatilis exposed to a range of concentrations of a water accommodated fraction (WAF) of Prudhoe Bay Crude Oil (PBCO), a PCBO/dispersant (Corexit 9527) fraction and a mixture of Corexit 9527 alone. All exposures were done at concentrations below the no observable effect level (NOEL) and at two different salinities, 22 ppt and 34 ppt. Laemmli SDS-PAGE techniques followed by Western Blotting using hsp60 specific antibodies and chemiluminescent detection were used to isolate, identify and measure induced hsp60 as a percentage of control values. Hsp60 induction exhibited a biphasic response with maximal induction occurring at lower concentrations of all three different mixtures, WAF, PBCO/Corexit 9527, and Corexit 9527 alone. Preliminary data found that the dispersed oil is indeed more toxic in terms of hsp60 induction than both the undispersed oil and the dispersing agent alone

Induction of hsp60 in the rotifer, Brachionus plicatilis exposed to dispersed and undispersed crude oil

Energy Technology Data Exchange (ETDEWEB)

Wheelock, C.; Tjeerdema, R.; Wolfe, M. [Univ. of California, Santa Cruz, CA (United States). Dept. of Chemistry and Biochemistry

1995-12-31

The use of chemical dispersants to treat oil spills remains a controversial area. Questions arise as to whether the dispersed oil is in fact more toxic than the original spill, potentially increasing the exposure of organisms in the water column to the dispersed components. Stress proteins, including hsp60, are a group of highly conserved proteins that are induced in response to a wide variety of environmental agents, including UV light, heavy metals, and xenobiotics. They are constitutively expressed, but Brachionus plicatilis has been used to document increased hsp60 levels in response to different environmental stresses. Hsp60 was therefore selected as a sublethal endpoint for B. plicatilis exposed to a range of concentrations of a water accommodated fraction (WAF) of Prudhoe Bay Crude Oil (PBCO), a PCBO/dispersant (Corexit 9527) fraction and a mixture of Corexit 9527 alone. All exposures were done at concentrations below the no observable effect level (NOEL) and at two different salinities, 22 ppt and 34 ppt. Laemmli SDS-PAGE techniques followed by Western Blotting using hsp60 specific antibodies and chemiluminescent detection were used to isolate, identify and measure induced hsp60 as a percentage of control values. Hsp60 induction exhibited a biphasic response with maximal induction occurring at lower concentrations of all three different mixtures, WAF, PBCO/Corexit 9527, and Corexit 9527 alone. Preliminary data found that the dispersed oil is indeed more toxic in terms of hsp60 induction than both the undispersed oil and the dispersing agent alone.

Identification of genes differentially expressed by calorie restriction in the rotifer (Brachionus plicatilis).

Science.gov (United States)

Oo, Aung Kyaw Swar; Kaneko, Gen; Hirayama, Makoto; Kinoshita, Shigeharu; Watabe, Shugo

2010-01-01

A monogonont rotifer Brachionus plicatilis has been widely used as a model organism for physiological, ecological studies and for ecotoxicology. Because of the availability of parthenogenetic mode of reproduction as well as its versatility to be used as live food in aquaculture, the population dynamic studies using the rotifer have become more important and acquired the priority over those using other species. Although many studies have been conducted to identify environmental factors that influence rotifer populations, the molecular mechanisms involved still remain to be elucidated. In this study, gene(s) differentially expressed by calorie restriction in the rotifer was analyzed, where a calorie-restricted group was fed 3 h day(-1) and a well-fed group fed ad libitum. A subtracted cDNA library from the calorie-restricted rotifer was constructed using suppression subtractive hybridization (SSH). One hundred sixty-three expressed sequence tags (ESTs) were identified, which included 109 putative genes with a high identity to known genes in the publicly available database as well as 54 unknown ESTs. After assembling, a total of 38 different genes were obtained among 109 ESTs. Further validation of expression by semi-quantitative reverse transcription-PCR showed that 29 out of the 38 genes obtained by SSH were up regulated by calorie restriction.

Identification of 28 cytochrome P450 genes from the transcriptome of the marine rotifer Brachionus plicatilis and analysis of their expression.

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Kim, Hui-Su; Han, Jeonghoon; Kim, Hee-Jin; Hagiwara, Atsushi; Lee, Jae-Seong

2017-09-01

Whole transcriptomes of the rotifer Brachionus plicatilis were analyzed using an Illumina sequencer. De novo assembly was performed with 49,122,780 raw reads using Trinity software. Among the assembled 42,820 contigs, 27,437 putative open reading frame contigs were identified (average length 1235bp; N50=1707bp). Functional gene annotation with Gene Ontology and InterProScan, in addition to Kyoto Encyclopedia of Genes and Genomes pathway analysis, highlighted the metabolism of xenobiotics by cytochrome P450 (CYP). In addition, 28 CYP genes were identified, and their transcriptional responses to benzo[α]pyrene (B[α]P) were investigated. Most of the CYPs were significantly upregulated or downregulated (Pplicatilis in response to exposure to various chemicals. Copyright © 2017 Elsevier Inc. All rights reserved.

A study of oxidative stress induced by two polybrominated diphenyl ethers in the rotifer Brachionus plicatilis.

Science.gov (United States)

Zhang, Jing; Wang, You; Sun, Kai-Ming; Fang, Kuan; Tang, Xuexi

2016-12-15

Polybrominated diphenyl ethers (PBDEs) are widely dispersed persistent organic pollutants in the marine ecosystem. However, their toxic mechanisms in marine organisms, especially invertebrates, remain poorly understood. Two common congeners of PBDEs, tetrabrominated diphenyl ether-47 (BDE-47) and decabrominated diphenyl ether-209 (BDE-209), were investigated. Their toxic mechanisms, with a focus on oxidative stress, were examined in rotifer Brachionus plicatilis. Overproduction of reactive oxygen species (ROS) was induced by two PBDEs. The expression of superoxide dismutase (SOD) mRNA was increased, suggesting SOD play a main role in ROS-scavenging. The intercellular concentrations of calcium ([Ca 2+ ] in ) and the expression of calmodulin (CaM) mRNA were increased. This indicates the calcium ion (Ca 2+ ) signaling channel is involved in PBDEs stress. Further analysis showed that the reproductive system might be the target site for toxicity of PBDEs. Moreover, high value of detection indexes in BDE-47 experimental groups suggested BDE-47 might cause higher oxidative damage than BDE-209 in rotifers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Combined effects of temperature and salinity on the demographic response of Proales similis (Beauchamp, 1907) and Brachionus plicatilis (Müller, 1786) (Rotifera) to mercury.

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Rebolledo, Uriel Arreguin; Nandini, S; Sánchez, Ofelia Escobar; Sarma, S S S

2018-07-01

The demographic response of the brackish-water rotifers Proales similis and Brachionus plicatilis to mercury (0.5, 2, 8 and 32 μg L -1 of HgCl 2 ) at different salinity levels (10 and 20‰) and two temperature (25 °C and 32 °C) regimes were evaluated. Median lethal concentration (LC 50 ) for P. similis and B. plicatilis was 10 and 16 μg L -1 , respectively, showing that Proales similis was more sensitive to mercury than B. plicatilis. The rate of population increase (r) for both species was greater at 10‰ salinity and 32 °C (ranged from 0.6 to 0.95 d -1 ). The r-value decreased as the concentration of mercury in the medium increased. Regardless of the temperature, at lower salinity and higher mercury concentration (32 μg L -1 ), P. similis died within six days. The survivorship of P. similis and B. plicatilis was higher at 25 °C than at 32 °C (ranged from 5 to 8 and 7-13 d, respectively). Fecundity was higher at 32 °C than at 25 °C for both rotifers species. There was a significant effect of the interaction among salinity, temperature, and mercury in both species on the reproductive variables such as net and gross reproductive rates, generation time and the rate of population increase. Considering the sensitivity of P. similis, we suggest that this species be included in the list of marine bioassay organisms. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Effects of Microalgae as Live Food for Brachionus plicatilis (Rotifer) in Intensive Culture System.

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Rahman, Abdull Razak Abd; Cob, Zaidi Che; Jamari, Zainoddin; Mohamed, Abdul Majid; Toda, Tatsuki; Ross, Othman Haji

2018-03-01

Brachionus plicatilis is used to feed fish and crustacean larvae in the aquaculture industry. It is well established that the type of microalgae may influence rotifer production. This experiment was conducted to determine the effect of five different locally available microalgae species at Fisheries Research Institute (FRI), Kampung Pulau Sayak, Kedah, Malaysia on the instantaneous growth rate (μ) of rotifer. Nannochloris sp., Tetraselmis sp., Isochrysis sp., Chlorella sp., and Nannochloropsis sp. were used as feed at different algae densities (0.1, 0.3, 0.7 and 1.5 × 10 6 cells/ml) and culture volumes (20, 70 and 210 ml). At algae densities ranging from 0.3 to 1.5 × 10 6 cells/ml, an average μ value of more than 0.90 per day were recorded for all algae species. However, at density of 0.1 × 10 6 cells/ml, only Tetraselmis sp. resulted in the significantly highest μ value compared with others ( p < 0.05). In terms of volume, smaller culture volume of Tetraselmis sp. (20 ml) showed significantly higher μ compared with higher volume (70 and 210 ml cultures).

Treatment of fish-processing wastewater by co-culture of Candida rugopelliculosa and Brachionus plicatilis.

Science.gov (United States)

Lim, Joontaek; Kim, Taeyun; Hwang, Seokhwan

2003-05-01

This research was conducted as a part of the continuous development of a novel technique for managing fish-processing wastewater by cultivating proteolytic yeast, Candida rugopelliculosa, as possible diet of the rotifer, Brachionus plicatilis. It was feasible to use Alaska Pollack processing wastewater as a growth medium for C. rugopelliculosa, which was stimulatory for growth of the rotifer by 18.3% over the commercial diet of Saccharomyces cerevisiae. Maximum growth of C. rugopelliculosa and reduction of influent soluble chemical oxygen demand (SCOD) concentration were respectively (6.09+/-0.04)x10(6) cells/ml and 70.0% at 6.3h hydraulic retention time (HRT). Method of 4th order Runge-Kutta approximation was successfully applied to determine the Monod kinetics of C. rugopelliculosa by using unsteady state data from only one continuous unsteady state operation at a fixed HRT. The maximum microbial growth rates, mu(max), and half saturation coefficient, K(s), were determined to be 0.82+/-0.22 h(-1) and 690+/-220 mg SCOD/L, respectively. The microbial yield coefficient, Y, and microbial decay rate coefficient, k(d), were determined to be (1.39+/-0.22)x10(4) cells/mg SCOD and 0.06+/-0.01 h(-1), respectively.

Long-term survival of hydrated resting eggs from Brachionus plicatilis.

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Clark, Melody S; Denekamp, Nadav Y; Thorne, Michael A S; Reinhardt, Richard; Drungowski, Mario; Albrecht, Marcus W; Klages, Sven; Beck, Alfred; Kube, Michael; Lubzens, Esther

2012-01-01

Several organisms display dormancy and developmental arrest at embryonic stages. Long-term survival in the dormant form is usually associated with desiccation, orthodox plant seeds and Artemia cysts being well documented examples. Several aquatic invertebrates display dormancy during embryonic development and survive for tens or even hundreds of years in a hydrated form, raising the question of whether survival in the non-desiccated form of embryonic development depends on pathways similar to those occurring in desiccation tolerant forms. To address this question, Illumina short read sequencing was used to generate transcription profiles from the resting and amictic eggs of an aquatic invertebrate, the rotifer, Brachionus plicatilis. These two types of egg have very different life histories, with the dormant or diapausing resting eggs, the result of the sexual cycle and amictic eggs, the non-dormant products of the asexual cycle. Significant transcriptional differences were found between the two types of egg, with amictic eggs rich in genes involved in the morphological development into a juvenile rotifer. In contrast, representatives of classical "stress" proteins: a small heat shock protein, ferritin and Late Embryogenesis Abundant (LEA) proteins were identified in resting eggs. More importantly however, was the identification of transcripts for messenger ribonucleoprotein particles which stabilise RNA. These inhibit translation and provide a valuable source of useful RNAs which can be rapidly activated on the exit from dormancy. Apoptotic genes were also present. Although apoptosis is inconsistent with maintenance of prolonged dormancy, an altered apoptotic pathway has been proposed for Artemia, and this may be the case with the rotifer. These data represent the first transcriptional profiling of molecular processes associated with dormancy in a non-desiccated form and indicate important similarities in the molecular pathways activated in resting eggs compared

Long-term survival of hydrated resting eggs from Brachionus plicatilis.

Directory of Open Access Journals (Sweden)

Melody S Clark

Full Text Available Several organisms display dormancy and developmental arrest at embryonic stages. Long-term survival in the dormant form is usually associated with desiccation, orthodox plant seeds and Artemia cysts being well documented examples. Several aquatic invertebrates display dormancy during embryonic development and survive for tens or even hundreds of years in a hydrated form, raising the question of whether survival in the non-desiccated form of embryonic development depends on pathways similar to those occurring in desiccation tolerant forms.To address this question, Illumina short read sequencing was used to generate transcription profiles from the resting and amictic eggs of an aquatic invertebrate, the rotifer, Brachionus plicatilis. These two types of egg have very different life histories, with the dormant or diapausing resting eggs, the result of the sexual cycle and amictic eggs, the non-dormant products of the asexual cycle. Significant transcriptional differences were found between the two types of egg, with amictic eggs rich in genes involved in the morphological development into a juvenile rotifer. In contrast, representatives of classical "stress" proteins: a small heat shock protein, ferritin and Late Embryogenesis Abundant (LEA proteins were identified in resting eggs. More importantly however, was the identification of transcripts for messenger ribonucleoprotein particles which stabilise RNA. These inhibit translation and provide a valuable source of useful RNAs which can be rapidly activated on the exit from dormancy. Apoptotic genes were also present. Although apoptosis is inconsistent with maintenance of prolonged dormancy, an altered apoptotic pathway has been proposed for Artemia, and this may be the case with the rotifer.These data represent the first transcriptional profiling of molecular processes associated with dormancy in a non-desiccated form and indicate important similarities in the molecular pathways activated in

Temperature-dependent elimination efficiency on Phaeocystis globosa by different initial population sizes of rotifer Brachionus plicatilis.

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Sun, Yunfei; Wang, Yuanyuan; Lei, Jin; Qian, Chenchen; Zhu, Xuexia; Akbar, Siddiq; Huang, Yuan; Yang, Zhou

2018-07-01

Due to sea water eutrophication and global warming, the harmful Phaeocystis blooms outbreak frequently in coastal waters, which cause a serious threat to marine ecosystem. The application of rotifer to control the harmful alga is a promising way. To investigate the influence of initial rotifer density and temperature on the ability of rotifer Brachionus plicatilis to eliminate Phaeocystis globosa population, we cultured P. globosa with different initial rotifer densities (1, 3, 5 inds mL -1 ) at 19, 22, 25, 28, and 31 °C for 9-16 d. Results showed that the population of rotifer feeding on Phaeocystis increased rapidly and higher temperatures favored the growth of P. globosa and B. plicatilis. With increased initial rotifer density and temperature, both the clearance rate of rotifer and the reduction rate of P. globosa increased, and thus P. globosa were eliminated earlier. Both temperature and initial rotifer density had significant effects on clearance rate of rotifer and the time to Phaeocystis extinction, and there was a significant interaction between the two factors on the two parameters, i.e., the effect of initial rotifer density on eliminating Phaeocystis decreased with increasing temperature. The rotifer in 5 inds mL -1 at 28 °C eliminated P. globosa in 4 d, whereas the rotifer in 1 ind mL -1 at 19 °C spent about 16 d on eliminating P. globosa. In conclusion, higher temperature and bigger initial rotifer density promote rotifer to eliminate the harmful P. globosa, and the optimal temperature for rotifer to clear P. globosa is 28 °C. Copyright © 2018 Elsevier Ltd. All rights reserved.

The significance of some methodological effects on filtration and ingestion rates of the rotifer Brachionus plicatilis

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Schlosser, H. J.; Anger, K.

1982-06-01

Filtration rate (F) and ingestion rate (I) were measured in the rotifer Brachionus plicatilis feeding on the flagellate Dunaliella spec. and on yeast cells (Saccharomyces cerevisiae). 60-min experiments in rotating bottles served as a standard for testing methodological effects on levels of F and I. A lack of rotation reduced F values by 40 %, and a rise in temperature from 18° to 23.5 °C increased them by 42 %. Ingestion rates increased significantly up to a particle (yeast) concentration of ca. 600-800 cells · μl-1; then they remained constant, whereas filtration rates decreased beyond this threshold. Rotifer density (up to 1000 ind · ml-1) and previous starvation (up to 40 h) did not significantly influence food uptake rates. The duration of the experiment proved to have the most significant effect on F and I values: in 240-min experiments, these values were on the average more than 90 % lower than in 15-min experiments. From this finding it is concluded that ingestion rates obtained from short-term experiments (60 min or less) cannot be used in energy budgets, because they severely overestimate the actual long-term feeding capacity of the rotifers. At the lower end of the particle size spectrum (2 to 3 µm) there are not only food cells, but apparently also contaminating faecal particles. Their number increased with increasing duration of experiments and lead to an underestimation of F and I. Elemental analyses of rotifers and their food suggest that B. plicatilis can ingest up to 0.6 mJ or ca. 14 % of its own body carbon within 15 min. The long term average was estimated as 3.4 mJ · ind-1 · d-1 or ca. 75 % of body carbon · d-1.

Application of rotifer Brachionus plicatilis in detecting the toxicity of harmful algae

Science.gov (United States)

Yan, Tian; Wang, Yunfeng; Wang, Liping; Chen, Yang; Han, Gang; Zhou, Mingjiang

2009-05-01

The toxicity of seven major HAB (harmful algal bloom) species/strains, Prorocentrum donghaiense, Phaeocystis globosa, Prorocentrum micans, Alexandrium tamarense (AT-6, non-PSP producer), Alexandrium lusitanicum, Alexandrum tamarense (ATHK) and Heterosigma akashiwo were studied against rotifer Brachionus plicatilis under laboratory conditions. The results show that P. donghaiense, P. globosa, P. micans, A. tamarense (AT-6), or A. lusitanicum could maintain the individual survival and reproduction, as well as the population increase of the rotifer, but the individual reproduction would decrease when exposed to these five algae at higher densities for nine days; H. akashiwo could decrease the individual survival and reproduction, as well as population increase of the rotifer, which is similar to that of the starvation group, indicating that starvation might be its one lethal factor except for the algal toxins; A. tamarense (ATHK) has strong lethal effect on the rotifer with 48h LC50 at 800 cells/mL. The experiment on ingestion ability indicated by gut pigment change shows that P. donghaiense, P. globosa, P. micans, A. tamarense (AT-6) and A. lusitanicum can be taken by the rotifers as food, but A. tamarense (ATHK) or H. akashiwo can be ingested by the rotifers. The results indicate that all the indexes of individual survival and reproduction, population increase, gut pigment change of the rotifers are good and convenient to be used to reflect the toxicities of HAB species. Therefore, rotifer is suggested as one of the toxicity testing organisms in detecting the toxicity of harmful algae.

Effect of temperature and viscosity on swimming velocity of the copepod Acartia tonsa, brine shrimp Artemia salina and rotifer Brachionus plicatilis

DEFF Research Database (Denmark)

Larsen, Poul Scheel; Madsen, C.V.; Riisgard, H.U.

2008-01-01

Beating cilia are important organelles for swimming in many zooplanktonic aquatic organisms, including many invertebrate larvae, rotifers and ciliates, but other planktonic organisms, such as copepods and brine shrimps, use muscle-powered swimming appendages. In recent studies we found...... of swimming velocity for a 10 degrees C temperature reduction) that is found to be largest for the brine shrimp Artemia salina nauplius (37 %) and the rotifer Brachionus plicatilis (26%), but negligible for the copepod Acartia tonsa (4%). We suggest that experimental data on change in swimming velocity (V......) due to change in kinematic viscosity (v) be correlated in terms of a power law, V proportional to v(-m). The present data on swimming velocity of copepods, brine shrimps and rotifers show values of exponent m approximate to 1.5 to 3, with a trend of decreasing values for increasing size of species...

Trade-off between reproduction and lifespan of the rotifer Brachionus plicatilis under different food conditions.

Science.gov (United States)

Sun, Yunfei; Hou, Xinying; Xue, Xiaofeng; Zhang, Lu; Zhu, Xuexia; Huang, Yuan; Chen, Yafen; Yang, Zhou

2017-11-13

Phaeocystis globosa, one of the most typical red tide-forming species, is usually mixed in the food composition of rotifers. To explore how rotifers respond by adjusting life history strategy when feeding on different quality foods, we exposed the rotifer Brachionus plicatilis to cultures with 100% Chlorella, a mixture of 50% P. globosa and 50% Chlorella, or 100% P. globosa. Results showed that rotifers exposed to 100% Chlorella or to mixed diets produced more total offspring and had higher age-specific fecundity than those exposed to 100% P. globosa. Food combination significantly affected the net reproduction rates of rotifers. By contrast, rotifers that fed on 100% P. globosa or on mixed diets had a longer lifespan than those fed on 100% Chlorella. The overall performances (combining reproduction and lifespan together) of rotifers cultured in 100% Chlorella or mixed diets were significantly higher than those cultured in 100% P. globosa. In general, Chlorella favors rotifers reproduction at the cost of shorter lifespan, whereas P. globosa tends to extend the lifespan of rotifers with lower fecundity, indicating that trade-off exists between reproduction and lifespan under different food conditions. The present study also suggests that rotifers may have the potential to control harmful P. globosa.

Brachionus plicatilis (Rotifer'in Farklı Besin Ortamlarında Büyümesi.

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Bircan Özbaş

2015-12-01

Full Text Available Farklı besin diyetlerinin rotifer (Brachionus plicatilis kültürlerinin büyümesi üzerindeki etkilerinin araştırıldığı bu çalışmada, rotiferler Nannochloropsis sp., ekmek mayası (Saccharomyces cerevisiae ve kurutulmuş Spirulina tozu ile beslendi. İlk denemede, optimum Spirulina konsantrasyonu günde 0.01 g / 106 rotifer olarak bulundu. Deneme gruplarında alg, alg+maya, alg+Spirulina, maya+Spirulina ve maya/2+Spirulina olmak üzere 5 deneme grubu oluşturuldu. Mikroskobik gözlemlerde, Spirulina partikülleri havanda ezilmiş olmasına rağmen rotiferler tarafından tüketilemeyecek boyutta idi. Sonuç olarak, alg içeren grupların en iyi büyümeyi gösterdiği tespit edildi. Spirulina ise partikül büyüklüğünden dolayı rotiferler tarafından alınamadı. Maya hücreleri ise rotifer hücreleri için optimum büyüklükte olmasına rağmen, ortam kirliliğine neden olması bakımından alg ile beslenen gruplara göre daha düşük bir büyüme gösterdi

Effects of two polybrominated diphenyl ethers (BDE-47, BDE-209) on the swimming behavior, population growth and reproduction of the rotifer Brachionus plicatilis.

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Sha, Jingjing; Wang, You; Lv, Jianxia; Wang, Hong; Chen, Hongmei; Qi, Leilei; Tang, Xuexi

2015-02-01

Polybrominated diphenyl ethers (PBDEs) are new kinds of persistent organic pollutants (POPs) and their potential threats to the equilibrium and sustainability of marine ecosystems have raised worldwide concerns. Here, two kinds of PBDEs, tetra-BDE (BDE-47) and deca-BDE (BDE-209) were applied, and their toxic effects on the swimming behavior, population growth and reproduction of Brachionus plicatilis were investigated. The results showed that: (1) The actual concentrations of BDE-47 and -209 in the seawater phase measured by GC-MS (Gas Chromatography-Mass Spectrometer) were much lower than their nominal concentrations. (2) In accordance with the 24-hr acute tests, BDE-209 did not show any obvious swimming inhibition to rotifers, but a good correlation did exist between the swimming inhibition rate and BDE-47 concentration suggesting that BDE-47 is more toxic than BDE-209. (3) Both BDE-47 and -209 had a significant influence on the population growth and reproduction parameters of B. plicatilis including the population growth rate, the ratio of ovigerous females/non-ovigerous females (OF/NOF), the ratio of mictic females/amictic females (MF/AF), resting egg production and the mictic rate, which indicate that these parameters in B. plicatilis population were suitable for monitoring and assessing PBDEs. Our results suggest that BDE-47 and -209 are not acute lethal toxicants and may pose a low risk to marine rotifers at environmental concentrations for short-term exposure. They also accumulate differently into rotifers. Further research data are needed to understand the mechanisms responsible for the effects caused by PBDEs and to assess their risks accurately. Copyright © 2014. Published by Elsevier B.V.

A multiplex PCR method for rapid identification of Brachionus rotifers.

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Vasileiadou, Kalliopi; Papakostas, Spiros; Triantafyllidis, Alexander; Kappas, Ilias; Abatzopoulos, Theodore J

2009-01-01

Cryptic species are increasingly being recognized in many organisms. In Brachionus rotifers, many morphologically similar yet genetically distinct species/biotypes have been described. A number of Brachionus cryptic species have been recognized among hatchery strains. In this study, we present a simple, one-step genetic method to detect the presence of those Brachionus sp. rotifers that have been found in hatcheries. With the proposed technique, each of the B. plicatilis sensu stricto, B. ibericus, Brachionus sp. Nevada, Brachionus sp. Austria, Brachionus sp. Manjavacas, and Brachionus sp. Cayman species and/or biotypes can be identified with polymerase chain reaction (PCR) analysis. Based on 233 cytochrome c oxidase subunit I sequences, we reviewed all the available cryptic Brachionus sp. genetic polymorphisms, and we designed six nested primers. With these primers, a specific amplicon of distinct size is produced for every one of the involved species/biotypes. Two highly sensitive protocols were developed for using the primers. Many of the primers can be combined in the same PCR. The proposed method has been found to be an effective and practical tool to investigate the presence of the above six cryptic species/biotypes in both individual and communal (bulk) rotifer deoxyribonucleic acid extractions from hatcheries. With this technique, hatchery managers could easily determine their rotifer composition at the level of cryptic species and monitor their cultures more efficiently.

A novel method for rearing first-feeding larval zebrafish: polyculture with Type L saltwater rotifers (Brachionus plicatilis).

Science.gov (United States)

Best, Jason; Adatto, Isaac; Cockington, Jason; James, Althea; Lawrence, Christian

2010-09-01

Promoting high rates of growth and survival can be a major challenge in zebrafish culture, especially during the first-feeding stage. Here we describe a new rearing technique in which zebrafish larvae are polycultured in static tanks with Type "L" saltwater rotifers (Brachionus plicatilis) for the first 5 days of feeding (days 5-9 postfertilization). To demonstrate the effectiveness of this technique, we conducted rearing trials using fish from two different strains: AB and nacre. Growth, survival, water quality, and rotifer density were assayed daily through the polyculture phase (days 5-9), and during the transition to standard rearing conditions (days 10-12). After that point, once the fish were fully integrated onto recirculating systems, parameters were measured once per week out to day 30. In all trials, the fish displayed high rates of growth and survival throughout the three phases (polyculture, transition, and recirculating flow), indicating that this method may be employed during the critical first-feeding stage to help improve rearing performance in zebrafish facilities. Additionally, water quality parameters observed during the polyculture phase of the trials reveal that early zebrafish larvae are much more tolerant of elevated levels of ammonia and salinity than previously believed.

Improvement of the nutritional value and growth of rotifer (Brachionus plicatilis by different enrichment period with Bacillus sp.

Directory of Open Access Journals (Sweden)

Sutia Budi

2011-01-01

Full Text Available Brachionus plicatilis is a widely used as natural feed in hatchery. Characteristics of rotifers as biocapsule can improve the quality of rotifers in a practical way. Bacillus sp. is capable of improving the nutrition rotifers to produce vitamins, food detoxication or through enzymatic activity such as protease, lipase, and amylase. This research aimed at observing the influence of the enrichment length of Bacillus sp. on the quality of nutrition and growth of rotifers. The research container was a polyearbonate vessel of one ton volume which contained Nannochloropsis sp. with the density of 105 cell/mL, it was then scattered with rotifer with the density of 1,000 ind./mL. The types of bacteria used were Bacillus subtilis, B. pumilus and B. licheformis with the density of 2x1010 cfu/g. The experiments tried with different enrichment length were A = 0 hour, B = 5 hours, C = 10 hours and D = 10 hours with triplicate. As the comparing data, rotifer culture experiment was carried out with Nannochlorophsis sp.as the control. The number of containers were 24 which consists of 12 for threatment and 12 pieces as control. Variables measured were proximate to each treatment and the growth of rotifers. The result of the research revealed the enrichment length of rotifers with Bacillus sp. has significantly (P Key words: rotifers, Bacillus, enrichment period, proximate   ABSTRAK Brachionus plicatilis merupakan pakan alami yang banyak digunakan dalam pembenihan. Karakteristik rotifer sebagai biokapsul secara praktis dapat meningkatkan kualitas rotifer. Bacillus sp. mampu memperbaiki nutrisi rotifer dengan memproduksi vitamin, detoksikasi pangan maupun melalui aktivitas enzimatis seperti protease, lipase, dan amilase. Penelitian ini bertujuan untuk melihat pengaruh pengkayaan Bacillus sp. terhadap kualitas nutrisi dan pertumbuhan rotifer. Wadah penelitian menggunakan bak fiber volume 1 ton yang berisikan Nannochloropsis sp. dengan kepadatan 105 cell

Impact of several harmful algal bloom (HAB) causing species, on life history characteristics of rotifer Brachionus plicatilis Müller

Science.gov (United States)

Lin, Jianing; Yan, Tian; Zhang, Qingchun; Zhou, Mingjiang

2016-07-01

In recent years, harmful algal blooms (HABs) have occurred frequently along the coast of China, and have been exhibiting succession from diatom- to dinoflagellate-dominated blooms. To examine the effects of different diatom and dinoflagellate HABs, the life history parameters of rotifers ( Brachionus plicatilis Müller) were measured after exposure to different concentrations of HAB species. The HAB species examined included a diatom ( Skeletonema costatum) and four dinoflagellates ( Prorocentrum donghaiense, Alexandrium catenella, Prorocentrum lima and Karlodinium veneficum). Compared with the control treatment (CT), the diatom S. costatum showed no adverse impacts on rotifers. Exposure to dinoflagellates at densities equivalent to those measured in the field resulted in a reduction in all the life history parameters measured. This included a reduction in: lifetime egg production (CT: 20.34 eggs/ind.) reduced to 10.11, 3.22, 4.17, 7.16 eggs/ind., life span (CT: 394.53 h) reduced to 261.11, 162.90, 203.67, 196 h, net reproductive rate (CT: 19.51/ind.) reduced to 3.01, 1.26, 3.53, 5.96/ind., finite rate of increase (CT: 1.47/d) reduced to 1.16, 1.03, 1.33, 1.38/d, and intrinsic rate of population increase (CT: 0.39/d) reduced to 0.15, 0.03, 0.28, 0.32/d, for the dinoflagellates P. donghaiense, A. catenella, P. lima and K. veneficum, respectively. The results showed that the diatom S. costatum had no detrimental consequences on the reproduction and growth of B. plicatilis, however, the four dinoflagellates tested did show adverse effects. This suggests that dinoflagellate HABs may suppress microzooplankton, resulting in an increase in algal numbers.

Genome size evolution at the speciation level: the cryptic species complex Brachionus plicatilis (Rotifera).

Science.gov (United States)

Stelzer, Claus-Peter; Riss, Simone; Stadler, Peter

2011-04-07

Studies on genome size variation in animals are rarely done at lower taxonomic levels, e.g., slightly above/below the species level. Yet, such variation might provide important clues on the tempo and mode of genome size evolution. In this study we used the flow-cytometry method to study the evolution of genome size in the rotifer Brachionus plicatilis, a cryptic species complex consisting of at least 14 closely related species. We found an unexpectedly high variation in this species complex, with genome sizes ranging approximately seven-fold (haploid '1C' genome sizes: 0.056-0.416 pg). Most of this variation (67%) could be ascribed to the major clades of the species complex, i.e. clades that are well separated according to most species definitions. However, we also found substantial variation (32%) at lower taxonomic levels--within and among genealogical species--and, interestingly, among species pairs that are not completely reproductively isolated. In one genealogical species, called B. 'Austria', we found greatly enlarged genome sizes that could roughly be approximated as multiples of the genomes of its closest relatives, which suggests that whole-genome duplications have occurred early during separation of this lineage. Overall, genome size was significantly correlated to egg size and body size, even though the latter became non-significant after controlling for phylogenetic non-independence. Our study suggests that substantial genome size variation can build up early during speciation, potentially even among isolated populations. An alternative, but not mutually exclusive interpretation might be that reproductive isolation tends to build up unusually slow in this species complex.

Hsp60-induced tolerance in the rotifer Brachionus plicatilis exposed to multiple environmental contaminants.

Science.gov (United States)

Wheelock, C E; Wolfe, M F; Olsen, H; Tjeerdema, R S; Sowby, M L

1999-04-01

Hsp60 induction was selected as a sublethal endpoint of toxicity for Brachionus plicatilis exposed to a water accommodated fraction (WAF) of Prudhoe Bay crude oil (PBCO), a PBCO/dispersant (Corexit 9527(R)) fraction and Corexit 9527(R) alone. To examine the effect of multiple stressors, exposures modeled San Francisco Bay, where copper levels are approximately 5 microgram/L, salinity is 22 per thousand, significant oil transport and refining occurs, and petroleum releases have occurred historically. Rotifers were exposed to copper at 5 microgram/L for 24 h, followed by one of the oil/dispersant preparations for 24 h. Batch-cultured rotifers were used in this study to model wild populations instead of cysts. SDS-PAGE with Western Blotting using hsp60-specific antibodies and chemiluminescent detection were used to isolate, identify, and measure induced hsp60 as a percentage of control values. Both PBCO/dispersant and dispersant alone preparations induced significant levels of hsp60. However, hsp60 expression was reduced to that of controls at high WAF concentrations, suggesting interference with protein synthesis. Rotifers that had been preexposed to copper maintained elevated levels of hsp60 upon treatment with WAF at all concentrations. Results suggest that induction of hsp60 by chronic low-level exposure may serve as a protective mechanism against subsequent or multiple stressors and that hsp60 levels are not additive for the toxicants tested in this study, giving no dose-response relationship. The methods employed in this study could be useful for quantifying hsp60 levels in wild rotifer populations.

Successful Replacement of Artemia salina nauplii with Marine Rotifers (Brachionus plicatilis) in the Diet of Preadult Zebrafish (Danio rerio).

Science.gov (United States)

Lawrence, Christian; James, Althea; Mobley, Scottie

2015-10-01

Previously established rearing protocols for zebrafish begin feeding with marine rotifers (Brachionus plicatilis), followed by Artemia nauplii until the fish reach subadult stage, the developmental time point at which they can be most easily transitioned onto a processed diet. However, the inclusion of Artemia is less than ideal, given its fluctuating availability and high costs. We tested whether or not we could replace Artemia with rotifers during our normal rearing sequence and still meet published performance standards for (i) weaning fish onto a processed diet by 25 days postfertilization (dpf) and (ii) successful breeding by 60 dpf. Here, we present the results of trials where wild-type and casper zebrafish were fed exclusively with rotifers (R) or rotifers followed by Artemia (RA) for the first 25 dpf after which point all fish were transitioned to a processed diet (Gemma Micro 300). We measured growth and survival at days 25 and 60, and tested for reproductive capability at 60 dpf. While growth performance was significantly better in the RA groups, we were still able to meet goals for both weaning and generation time in the R groups without compromising survival or sex ratios.

Persistent genetic signatures of colonization in Brachionus manjavacas rotifers in the Iberian Peninsula.

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Gómez, Africa; Montero-Pau, Javier; Lunt, David H; Serra, Manuel; Campillo, Sergi

2007-08-01

Recent phylogeographical assessments have consistently shown that continental zooplankton display high levels of population subdivision, despite the high dispersal capacity of their diapausing propagules. As such, there is an apparent paradox between observed cosmopolitanism in the zooplankton that is associated with long-distance dispersal, and strong phylogeographical structures at a regional scale. Such population dynamics, far from migration-drift equilibrium, have been shown in the rotifer species complex Brachionus plicatilis, a group of over a dozen species inhabiting salt lakes and coastal lagoons worldwide. Here we present the mitochondrial DNA phylogeography of one of these species, Brachionus manjavacas, in the Iberian Peninsula, where it often co-occurs with the morphologically similar species B. plicatilis sensu stricto. We obtained sequences from 233 individuals from diapausing eggs and clonal cultures from 16 lakes in the Iberian Peninsula, and a Tunisian lake. Two strongly supported deep mitochondrial DNA clades were found (A and B). Phylogenetic and nested clade analysis showed that clade A has a strong phylogeographical structure, with a strong similarity of phylogeographical patterns between B. manjavacas clade A and B. plicatilis s.s. These include (i) signatures of allopatric fragmentation between central and southern populations, and (ii) range expansions in the Iberian Peninsula, both likely to have occurred during the Pleistocene. We find evidence for a glacial refugium in the Guadiana basin. Clades A and B co-occurred in several of these lakes because of range expansion and secondary contact between both clades. The co-occurrence between B. plicatilis s.s. and B. manjavacas is not recent, and both species might have experienced similar environmental challenges during the Pleistocene. The strong correlation of genetic and geographical distance found suggests that historical events can lead to such correlation, mirroring the effects of

Genome size evolution at the speciation level: The cryptic species complex Brachionus plicatilis (Rotifera

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Riss Simone

2011-04-01

Full Text Available Abstract Background Studies on genome size variation in animals are rarely done at lower taxonomic levels, e.g., slightly above/below the species level. Yet, such variation might provide important clues on the tempo and mode of genome size evolution. In this study we used the flow-cytometry method to study the evolution of genome size in the rotifer Brachionus plicatilis, a cryptic species complex consisting of at least 14 closely related species. Results We found an unexpectedly high variation in this species complex, with genome sizes ranging approximately seven-fold (haploid '1C' genome sizes: 0.056-0.416 pg. Most of this variation (67% could be ascribed to the major clades of the species complex, i.e. clades that are well separated according to most species definitions. However, we also found substantial variation (32% at lower taxonomic levels - within and among genealogical species - and, interestingly, among species pairs that are not completely reproductively isolated. In one genealogical species, called B. 'Austria', we found greatly enlarged genome sizes that could roughly be approximated as multiples of the genomes of its closest relatives, which suggests that whole-genome duplications have occurred early during separation of this lineage. Overall, genome size was significantly correlated to egg size and body size, even though the latter became non-significant after controlling for phylogenetic non-independence. Conclusions Our study suggests that substantial genome size variation can build up early during speciation, potentially even among isolated populations. An alternative, but not mutually exclusive interpretation might be that reproductive isolation tends to build up unusually slow in this species complex.

Influence of salinity and dissolved organic carbon on acute Cu toxicity to the rotifer Brachionus plicatilis.

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Cooper, Christopher A; Tait, Tara; Gray, Holly; Cimprich, Giselle; Santore, Robert C; McGeer, James C; Wood, Christopher M; Smith, D Scott

2014-01-21

Acute copper (Cu) toxicity tests (48-h LC50) using the euryhaline rotifer Brachionus plicatilis were performed to assess the effects of salinity (3, 16, 30 ppt) and dissolved organic carbon (DOC, ∼ 1.1, ∼ 3.1, ∼ 4.9, ∼ 13.6 mg C L(-1)) on Cu bioavailability. Total Cu was measured using anodic stripping voltammetry, and free Cu(2+) was measured using ion-selective electrodes. There was a protective effect of salinity observed in all but the highest DOC concentrations; at all other DOC concentrations the LC50 value was significantly higher at 30 ppt than at 3 ppt. At all salinities, DOC complexation significantly reduced Cu toxicity. At higher concentrations of DOC the protective effect increased, but the increase was less than expected from a linear extrapolation of the trend observed at lower concentrations, and the deviation from linearity was greatest at the highest salinity. Light-scattering data indicated that salt induced colloid formation of DOC could be occurring under these conditions, thereby decreasing the number of available reactive sites to complex Cu. When measurements of free Cu across DOC concentrations at each individual salinity were compared, values were very similar, even though the total Cu LC50 values and DOC concentrations varied considerably. Furthermore, measured free Cu values and predicted model values were comparable, highlighting the important link between the concentration of bioavailable free Cu and Cu toxicity.

Acute and chronic toxicity of copper to the euryhaline rotifer, Brachionus plicatilis ("L" strain).

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Arnold, W R; Diamond, R L; Smith, D S

2011-02-01

This article presents data from original research, intended for the use in the development of copper (Cu) criteria for the protection of estuarine and marine organisms and their uses in the United States. Two 48-h static-acute toxicity tests-one with and one without added food-and a 96-h static multigeneration life-cycle test (P1-F2 generations) were performed concurrently using the euryhaline rotifer Brachionus plicatilis ("L" strain) to develop a Cu acute-to-chronic ratio (ACR) for this species. Tests were performed at 15 g/L salinity, at 25°C, and the exposure concentrations of dissolved Cu were verified. Supplemental chemical analyses were performed and reported for the development of a Cu-saltwater biotic ligand model (BLM). Supplemental analyses included alkalinity, calcium, chloride, dissolved organic carbon (DOC), hardness, magnesium, potassium, sodium, and temperature. The acute toxicity test measurement end points were the dissolved Cu median lethal concentration (LC₅₀) values based on rotifer survival. The chronic measurement end points were the dissolved Cu no-observed-effect concentration (NOEC), lowest-observed-effect concentration (LOEC), EC₂₅, EC₂₀, and EC₁₀ based on the intrinsic rate of rotifer population increase (r). The 48-h LC₅₀(Fed), 48-h LC₅₀(Unfed), 96-h NOEC, 96-h LOEC, EC₂₅, EC₂₀, and EC₁₀ were 20.8, 13.4, 6.1, 10.3, 11.7, 10.9, and 8.8 μg Cu/L, respectively. The ACRs were calculated as ratios of each 48-h LC₅₀ value [fed and unfed) and each of the 96-h chronic values (ChV; geometric mean of NOEC and LOEC)], EC₁₀, EC₂₀, and EC₂₅. The ACRs ranged from 1.15 to 2.63.

Effect of periodical starvation on the life history of Brachionus plicatilis O.F. Müller (Rotifera): a possible strategy for population stability.

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Yoshinaga; Hagiwara; Tsukamoto

2000-10-25

To estimate the changes in the life history of the rotifer Brachionus plicatilis O.F. Müller under starvation, we carried out an individual culture and determined the effects of periodical food deprivation on its asexual reproductive characteristics such as lifespan, reproductive period, age at first egg and offspring production, and lifetime fecundity (total number of offspring produced in her lifetime). Rotifers were fed for 1-3 h daily, and were then starved until the next day. Control animals were fed throughout their lifespan. Starved rotifers matured and produced their first offspring at an older age than the control animals. The periodical starvation resulted in a decrease in the lifetime fecundity to less than half that of the non-starved control. The reproductive period and lifespan were 2-3 times longer in the starved animals than in the control animals. The negative relationship between lifespan and lifetime fecundity is interpreted as a trade-off in an alternative life-history strategy of rotifers under starved conditions. The great decrease in fecundity and extension of lifespan enables rotifers to compensate to keep the population in equilibrium.

A novel adhering junction in the apical ciliary apparatus of the rotifer Brachionus plicatilis (Rotifera, Monogononta).

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Dallai, R; Lupetti, P; Lane, N J

1996-10-01

Cultures of the rotifer Brachionus plicatilis were examined with regard to their interepithelial junctions after infiltration with the extracellular tracer lanthanum, freeze-fracturing or quick-freeze deep-etching. The lateral borders between ciliated cells have an unusual apical adhering junction. This apical part of their intercellular cleft looks desmosome-like, but it is characterized by unusual intramembranous E-face clusters of particles. Deep-etching reveals that these are packed together in short rows which lie parallel to one another in orderly arrays. The true membrane surface in these areas features filaments in the form of short ribbons; these are produced by projections, possibly part of the glycocalyx, emerging from the membranes, between which the electron-dense tracer lanthanum permeates. These projections appear to overlap with each other in the centre of the intercellular cleft; this would provide a particularly flexible adaptation to maintain cell-cell contact and coordination as a consequence. The filamentous ribbons may be held in position by the intramembranous particle arrays since both have a similar size and distribution. These contacts are quite different from desmosomes and appear to represent a distinct new category of adhesive cell-cell junction. Beneath these novel structures, conventional pleated septate junctions are found, exhibiting the undulating intercellular ribbons typical of this junctional type, as well as the usual parallel alignments of intramembranous rows of EF grooves and PF particles. Below these are found gap junctions as close-packed plaques of intramembranous particles on either the P-face or E-face. After freeze-fracturing, the complementary fracture face to the particles shows pits, usually on the P-face, arrayed with a very precise hexagonal pattern.

Widespread secondary contact and new glacial refugia in the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula.

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Campillo, Sergi; Serra, Manuel; Carmona, María José; Gómez, Africa

2011-01-01

Small aquatic organisms harbour deep phylogeographic patterns and highly structured populations even at local scales. These patterns indicate restricted gene flow, despite these organisms' high dispersal abilities, and have been explained by a combination of (1) strong founder effects due to rapidly growing populations and very large population sizes, and (2) the development of diapausing egg banks and local adaptation, resulting in low effective gene flow, what is known as the Monopolization hypothesis. In this study, we build up on our understanding of the mitochondrial phylogeography of the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula by both increasing the number of sampled ponds in areas where secondary contact is likely and doubling sample sizes. We analyzed partial mitochondrial sequences of 252 individuals. We found two deep mitochondrial DNA lineages differing in both their genetic diversity and the complexity of their phylogeographic structure. Our analyses suggest that several events of secondary contact between clades occurred after their expansion from glacial refugia. We found a pattern of isolation-by-distance, which we interpret as being the result of historical colonization events. We propose the existence of at least one glacial refugium in the SE of the Iberian Peninsula. Our findings challenge predictions of the Monopolization hypothesis, since coexistence (i.e., secondary contact) of divergent lineages in some ponds in the Iberian Peninsula is common. Our results indicate that phylogeographic structures in small organisms can be very complex and that gene flow between diverse lineages after population establishment can indeed occur.

Widespread secondary contact and new glacial refugia in the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula.

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Sergi Campillo

Full Text Available Small aquatic organisms harbour deep phylogeographic patterns and highly structured populations even at local scales. These patterns indicate restricted gene flow, despite these organisms' high dispersal abilities, and have been explained by a combination of (1 strong founder effects due to rapidly growing populations and very large population sizes, and (2 the development of diapausing egg banks and local adaptation, resulting in low effective gene flow, what is known as the Monopolization hypothesis. In this study, we build up on our understanding of the mitochondrial phylogeography of the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula by both increasing the number of sampled ponds in areas where secondary contact is likely and doubling sample sizes. We analyzed partial mitochondrial sequences of 252 individuals. We found two deep mitochondrial DNA lineages differing in both their genetic diversity and the complexity of their phylogeographic structure. Our analyses suggest that several events of secondary contact between clades occurred after their expansion from glacial refugia. We found a pattern of isolation-by-distance, which we interpret as being the result of historical colonization events. We propose the existence of at least one glacial refugium in the SE of the Iberian Peninsula. Our findings challenge predictions of the Monopolization hypothesis, since coexistence (i.e., secondary contact of divergent lineages in some ponds in the Iberian Peninsula is common. Our results indicate that phylogeographic structures in small organisms can be very complex and that gene flow between diverse lineages after population establishment can indeed occur.

Effect of juvenile hormone and serotonin (5-HT) on mixis induction of the rotifer Brachionus plicatilis Muller.

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Gallardo; Hagiwara; Snell

2000-09-05

Juvenile hormone (JH) and serotonin (5-HT) were previously shown to enhance mictic (sexual) female production of the rotifer Brachionus plicatilis in batch cultures. To explore the basis of these effects, experiments were conducted on isolated individuals. JH treatment of maternal rotifers with 5 and 50 µgml(-1) (18.8 and 187.7 µM) resulted in significantly higher (P<0.05) mictic female production in the second (F(2)) and third (F(3)) generations. JH treatment was effective even at a lower food concentration of 7x10(5) cellsml(-1), but it was not effective when free ammonia was added at 2.4 and 3.1 µgml(-1). Mictic female production was not increased with exposure to 5-HT up to 50 µgml(-1) (129.1 µM) concentrations. When food level was reduced to 7x10(5) cellsml(-1), however, 5-HT-treated rotifers produced significantly (P<0.05) more mictic females than the control, particularly in F(3) generation. Mictic female production of 5-HT-treated rotifers did not differ from that of the control with or without free ammonia, but the intrinsic rate of natural increase (r) of 5-HT-treated rotifers at 3.1 µgml(-1) free ammonia was significantly higher than the control. These results show that juvenile hormone increases mictic female production under optimum and sub-optimum food levels, whereas 5-HT increases both mictic female production at low food level and population growth rate at high free ammonia concentrations. These compounds could be used to manage rotifer cultures and probe the mechanisms controlling the rotifer life cycle as it switches to mictic reproduction.

An analysis of species boundaries and biogeographic patterns in a cryptic species complex: the rotifer--Brachionus plicatilis.

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Suatoni, Elizabeth; Vicario, Saverio; Rice, Sean; Snell, Terry; Caccone, Adalgisa

2006-10-01

Since the advent of molecular phylogenetics, there is increasing evidence that many small aquatic and marine invertebrates--once believed to be single, cosmopolitan species--are in fact cryptic species complexes. Although the application of the biological species concept is central to the identification of species boundaries in these cryptic complexes, tests of reproductive isolation do not frequently accompany phylogenetic studies. Because different species concepts generally identify different boundaries in cryptic complexes, studies that apply multiple species concepts are needed to gain a more detailed understanding of patterns of diversification in these taxa. Here we explore different methods of empirically delimiting species boundaries in the salt water rotifer Brachionus plicatilis by comparing reproductive data (i.e., the traditional biological species concept) to phylogenetic data (the genealogical species concept). Based on a high degree of molecular sequence divergence and largely concordant genetic patterns in COI and ITS1, the genealogical species hypothesis indicates the existence of at least 14 species--the highest estimate for the group thus far. A test of the genealogical species concept with biological crosses shows a fairly high level of concordance, depending on the degree of reproductive success used to draw boundaries. The convergence of species concepts in this group suggests that many of the species within the group may be old. Although the diversity of the group is higher than previously understood, geographic distributions remain broad. Efficient passive dispersal has resulted in global distributions for many species with some evidence of isolation by distance over large geographic scales. These patterns concur with expectations that micro-meiofauna (0.1-1mm) have biogeographies intermediate to microbial organisms and large vertebrates. Sympatry of genetically distant strains is common.

The effects of salinity, pH, and dissolved organic matter on acute copper toxicity to the rotifer, Brachionus plicatilis ("L" strain).

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Arnold, W R; Diamond, R L; Smith, D S

2010-08-01

This paper presents data from original research for use in the development of a marine biotic ligand model and, ultimately, copper criteria for the protection of estuarine and marine organisms and their uses. Ten 48-h static acute (unfed) copper toxicity tests using the euryhaline rotifer Brachionus plicatilis ("L" strain) were performed to assess the effects of salinity, pH, and dissolved organic matter (measured as dissolved organic carbon; DOC) on median lethal dissolved copper concentrations (LC50). Reconstituted and natural saltwater samples were tested at seven salinities (6, 11, 13, 15, 20, 24, and 29 g/L), over a pH range of 6.8-8.6 and a range of dissolved organic carbon of <0.5-4.1 mg C/L. Water chemistry analyses (alkalinity, calcium, chloride, DOC, hardness, magnesium, potassium, sodium, salinity, and temperature) are presented for input parameters to the biotic ligand model. In stepwise multiple regression analysis of experimental results where salinity, pH, and DOC concentrations varied, copper toxicity was significantly related only to the dissolved organic matter content (pH and salinity not statistically retained; alpha=0.05). The relationship of the 48-h dissolved copper LC50 values and dissolved organic carbon concentrations was LC50 (microg Cu/L)=27.1xDOC (mg C/L)1.25; r2=0.94.

Influence of the age of algae fed to rotifers (Brachionus plicatilis O.F. Müller) on the expression of mixis in their progenies.

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Lubzens, E; Minkoff, G

1988-04-01

The sequence of the appearance of mixis in the rotifer Brachionus plicatilis was followed among the descendents of amictic rotifers transferred from a high salinity media (40 S) to a low one (9 S). All the neonates that hatched from the amictic eggs, after being transferred to a low salinity, were amictic. Each one of these neonates was cultured individually and its offspring removed periodically every 8-10 h. It was observed that throughout their reproductive phase, these parental females retained their potential to produce either mictic or amictic offspring. All the first produced neonates developed into amictic females, but among those produced later, three patterns were prevalent. The prevalent pattern (type A) was one in which the probability of a neonate being mictic increased towards the middle of the parents' reproductive phase and was followed by a slow decline. In the second pattern (type B), the probability of a daughter being mictic was constant throughout the parents' reproductive phase. It is suspected that the quality of food supplied to the rotifers determines the appearance of patterns, A, B or C. It is postulated that the innate capacity of rotifers to undergo mixis is genetically controlled, while its expression is modulated by environmental conditions.

Comparative ecotoxicity of polystyrene nanoparticles in natural seawater and reconstituted seawater using the rotifer Brachionus plicatilis.

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Manfra, L; Rotini, A; Bergami, E; Grassi, G; Faleri, C; Corsi, I

2017-11-01

The impact of nanoplastics using model polystyrene nanoparticles (PS NPs), anionic (PS-COOH) and cationic (PS-NH 2 ), has been investigated on the marine rotifer Brachionus plicatilis, a major component of marine zooplanktonic species. The role of different surface charges in affecting PS NP behaviour and toxicity has been considered in high ionic strength media. To this aim, the selected media were standardized reconstituted seawater (RSW) and natural sea water (NSW), the latter resembling more natural exposure scenarios. Hatched rotifer larvae were exposed for 24h and 48h to both PS NPs in the range of 0.5-50μg/ml using PS NP suspensions made in RSW and NSW. No effects on lethality upon exposure to anionic NPs were observed despite a clear gut retention was evident in all exposed rotifers. On the contrary, cationic NPs caused lethality to rotifer larvae but LC 50 values resulted lower in rotifers exposed in RSW (LC 50 =2.75±0.67µg/ml) compared to those exposed in NSW (LC 50 =6.62±0.87µg/ml). PS NPs showed similar pattern of aggregation in both high ionic strength media (RSW and NSW) but while anionic NPs resulted in large microscale aggregates (Z-average 1109 ± 128nm and 998±67nm respectively), cationic NP aggregates were still in nano-size forms (93.99 ± 11.22nm and 108.3 ± 12.79nm). Both PDI and Z-potential of PS NPs slightly differed in the two media suggesting a role of their different surface charges in affecting their behaviour and stability. Our findings confirm the role of surface charges in nanoplastic behaviour in salt water media and provide a first evidence of a different toxicity in rotifers using artificial media (RSW) compared to natural one (NSW). Such evidence poses the question on how to select the best medium in standardized ecotoxicity assays in order to properly assess their hazard to marine life in natural environmental scenarios. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of the nutritional status of semi-continuous microalgal cultures on the productivity and biochemical composition of Brachionus plicatilis.

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Ferreira, Martiña; Seixas, Pedro; Coutinho, Paula; Fábregas, Jaime; Otero, Ana

2011-12-01

The rotifer Brachionus plicatilis was cultured using the microalga Isochrysis aff. galbana clone T-ISO as feed. T-ISO was cultured semi-continuously with daily renewal rates of 10%, 20%, 30%, 40%, and 50% of the volume of cultures. The increase of renewal rate led to increasing nutrient and light availability in microalgal cultures, which caused differences in the biochemical composition of microalgal biomass. Growth rate, individual dry weight, organic content, and biomass productivity of rotifer cultures increased in response to higher growth rate in T-ISO cultures. Rotifer growth rate showed a strong negative correlation (R² = 0.90) with the C/N ratio of microalgal biomass. Rotifer dry weight was also affected by nutrient availability of T-ISO cultures, increasing up to 50% from nutrient-limited to nutrient-sufficient conditions. Consequently, biomass productivity of rotifer cultures increased more than twofold with the increase of renewal rate of T-ISO cultures. Rotifer organic content underwent the same trend of total dry weight. Maximum content of polyunsaturated fatty acids was reached in rotifers fed T-ISO from the renewal rate of 40%, with percentages of docosahexaenoic acid (22:6ω-3, DHA) and eicosapentaenoic acid (20:5ω-3, EPA) of 11% and 5% of total fatty acids, respectively. Selecting the most appropriate conditions for microalgal culture can therefore enhance the nutritive quality of microalgal biomass, resulting in a better performance of filter feeders and their nutrient content, and may constitute a useful tool to improve the rearing of fish larvae and other aquaculture organisms that require live feed in some or all the stages of their life cycle.

Is it photosensitization or photodegradation when UV-B irradiation is combined with BDE-47? Evidence from the growth and reproduction changes of rotifer Brachionus plicatilis.

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Liu, Chunchen; Tang, Xuexi; Zhou, Bin; Jiang, Yongshun; Lv, Mengchen; Zang, Yu; Wang, You

2018-07-01

Ecotoxicological methods were applied in the present study, and the marine rotifer Brachionus plicatilis was used as the toxic endpoint to depict what occurred when 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) was combined with solar ultraviolet-B radiation (UV-B). B. plicatilis was exposed to three different combination methods of BDE-47 and UV-B at an equal toxicity ratio, including normal rotifer co-cultured with UV-B-irradiated BDE-47 (known as Method I), UV-B-irradiated rotifer co-cultured with BDE-47 exposure (known as Method II) and normal rotifer co-cultured with the simultaneous addition of BDE-47 and UV-B irradiation (known as Method III). Acute and chronic experiments were preformed to determine the toxicity differentiation according to the growth and reproduction changes in the rotifer. Twenty-four-hour acute experiments showed that the modes of three combined methods changed from antagonism to additive, to synergistic with the concentration/dose increment, and the contribution rates of Method I and Method II to Method III were calculated by approximately 40.4% and 59.6%, respectively. Chronic exposure to either the single stressor or the combination of stressors inhibited the growth and reproduction of the rotifer, demonstrating the inhibition of the population growth rate and the decrease in the larvae production. Three combined groups presented more serious damages compared to groups with single stress exposure, and the ascending sequence of toxicity was Method I

Effects of commercial enrichment products on fatty acid components ...

African Journals Online (AJOL)

ajl yemi

2011-10-26

Oct 26, 2011 ... 3050 (ZB) and Spresso (ZC) on fatty acid compositions in rotifers (Brachionus plicatilis) which were intensively ... docosahexaenoic acid (DHA) and the ratio of n–3/n–6 in enriched rotifers groups were higher (p < 0.05). The level of ...... acid profiles and bacterial load in cultured rotifers (Brachionus plicatilis ...

Genome-wide identification of 31 cytochrome P450 (CYP) genes in the freshwater rotifer Brachionus calyciflorus and analysis of their benzo[α]pyrene-induced expression patterns.

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Han, Jeonghoon; Kim, Duck-Hyun; Kim, Hui-Su; Kim, Hee-Jin; Declerck, Steven A J; Hagiwara, Atsushi; Lee, Jae-Seong

2018-03-01

While marine invertebrate cytochrome P450 (CYP) genes and their roles in detoxification mechanisms have been studied, little information is available regarding freshwater rotifer CYPs and their functions. Here, we used genomic sequences and RNA-seq databases to identify 31 CYP genes in the freshwater rotifer Brachionus calyciflorus. The 31 Bc-CYP genes with a few tandem duplications were clustered into CYP 2, 3, 4, mitochondrial, and 46 clans with two marine rotifers Brachionus plicatilis and Brachionus koreanus. To understand the molecular responses of these 31 Bc-CYP genes, we also examined their expression patterns in response to benzo[α]pyrene (B[α]P). Three Bc-CYP genes (Bc-CYP3044B3, Bc-CYP3049B4, Bc-CYP3049B6) were significantly upregulated (P<0.05) in response to B[α]P, suggesting that these CYP genes can be involved in detoxification in response to B[α]P exposure. These genes might be useful as biomarkers of B[α]P exposure in B. calyciflorus. Overall, our findings expand the repertoire of known CYPs and shed light on their potential roles in xenobiotic detoxification in rotifers. Copyright © 2017 Elsevier Inc. All rights reserved.

Desempenho larval do camarão-d'água-doce (Macrobrachium rosenbergii De Man, 1879 submetido a diferentes regimes alimentares Larval performance of the freshwater prawn (Macrobrachium rosenbergii De Man, 1879 submitted to different feeding systems

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Luciana Almada Thomaz

2004-12-01

Full Text Available O desempenho das larvas de Macrobrachium rosenbergii submetidas a quatro diferentes regimes alimentares foi verificado utilizando a observação diária dos subestádios larvais e as primeiras metamorfoses. As larvas foram estocadas em densidade de aproximadamente 100 larvas.l-1, em 16 tanques retangulares, com capacidade de 33 litros. O experimento foi dividido em quatro unidades experimentais (blocos, nos quais foram testados quatro regimes alimentares na larvicultura em circuito aberto, com quatro repetições por tratamento. Os regimes alimentares substituindo progressivamente náuplio de Artemia sp. (nas pelo rotífero Brachionus plicatilis (rots foram os seguintes tratamentos: 100% Brachionus plicatilis (30 rots/mL (T1; 100% Artemia (5 nas/ mL (T2, 60% Artemia (3 nas/mL + 40% Brachionus plicatilis (12 rots/ mL (T3 e 40% Artemia (2 nas/mL + 60% Brachionus plicatilis (18 rots/ mL (T4, sendo adicionada a estes tratamentos ração úmida. Os resultados da mudança dos subestádios larvais demonstraram que não houve diferença significativa entre os tratamentos T2, T3 e T4. No tratamento T1 (100% Brachionus plicatilis houve mortalidade total no 14º dia do experimento. O efeito da ocorrência das primeiras metamorfoses para pós-larvas, ocorreu ao 27º dia nos tratamentos T2, T3 e T4. Conseqüentemente, o ciclo de larvicultura até a metamorfose de 90% para pós-larva (PL1 foi o mesmo nos tratamentos (35 dias. Portanto, a utilização do rotífero enriquecido e congelado no regime alimentar das larvas permitiu desempenho satisfatório em termos de desenvolvimento larval de M. rosenbergii até a passagem para o estádio de pós-larva.The feeding is one of the most important factors to larval development and the sucess of the commercial cultivation of decapod crustacean larvae depends on the efficient and economic utilization of the available food. The performance of Macrobrachium rosenbergii larva submitted to four different feeding systems was

Measurement of Survival Time in Brachionus Rotifers: Synchronization of Maternal Conditions.

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Kaneko, Gen; Yoshinaga, Tatsuki; Gribble, Kristin E; Welch, David M; Ushio, Hideki

2016-07-22

Rotifers are microscopic cosmopolitan zooplankton used as models in ecotoxicological and aging studies due to their several advantages such as short lifespan, ease of culture, and parthenogenesis that enables clonal culture. However, caution is required when measuring their survival time as it is affected by maternal age and maternal feeding conditions. Here we provide a protocol for powerful and reproducible measurement of the survival time in Brachionus rotifers following a careful synchronization of culture conditions over several generations. Empirically, poor synchronization results in early mortality and a gradual decrease in survival rate, thus resulting in weak statistical power. Indeed, under such conditions, calorie restriction (CR) failed to significantly extend the lifespan of B. plicatilis although CR-induced longevity has been demonstrated with well-synchronized rotifer samples in past and present studies. This protocol is probably useful for other invertebrate models, including the fruitfly Drosophila melanogaster and the nematode Caenorhabditis elegans, because maternal age effects have also been reported in these species.

Complete mitochondrial genome of the monogonont rotifer, Brachionus koreanus (Rotifera, Brachionidae).

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Hwang, Dae-Sik; Suga, Koushirou; Sakakura, Yoshitaka; Park, Heum Gi; Hagiwara, Atsushi; Rhee, Jae-Sung; Lee, Jae-Seong

2014-02-01

The complete mitochondrial genome was obtained from the assembled genome data sequenced by next generation sequencing (NGS) technology from the monogonont rotifer Brachionus koreanus. The mitochondrial genome of B. koreanus was composed of two circular chromosomes designated as mtDNA-I (10,421 bp) and mtDNA-II (11,923 bp). The gene contents of B. koreanus were identical with previously reported B. plicatilis mitochondrial genomes. However, gene orders of B. koreanus showed one rearrangement between the two species. Of 12 protein-coding genes (PCGs), 3 genes (ATP6, ND1, and ND3) had an incomplete stop codon. The A + T base composition of B. koreanus mitochondrial genome was high (68.81%). They also showed anti-G bias (12.03% and 10.97%) on the second and third position of PCGs as well as slight anti-C bias (15.96% and 14.31%) on the first and third position of PCGs.

Use of Probiotic Bacillus spp. in Rotifer (Brachionus plicatilis) and Artemia (Artemia urmiana) Enrichment: Effects on Growth and Survival of Pacific White Shrimp, Litopenaeus vannamei, Larvae.

Science.gov (United States)

Jamali, Hadi; Imani, Ahmad; Abdollahi, Daruosh; Roozbehfar, Reza; Isari, Amin

2015-06-01

This study was to evaluate the effect of a preparation of Bacillus probiotic (Bacillus licheniformis and B. subtilis, 1:1) on growth and survival rate of Pacific white shrimp, Litopenaeus vannamei larvae. The larvae were fed on Artemia urmiana nauplii and Brachionus plicatilis enriched with the probiotic preparation at 1 × 10(6) CFU mL(-1) rate. The experimental setup was completely randomized design comprised of six treatments, namely solo Artemia nauplii (A) or rotifer (R), Artemia nauplii and rotifer without any enrichment (A + R), Artemia nauplii enrichment with probiotic bacilli (Bacillus licheniformis and B. subtilis) (A + B), rotifer enrichment with probiotic bacilli (R + B) and enriched Artemia nauplii and rotifer (A + R + B). All treatments were performed in triplicate. Chemical parameters of rearing water viz. pH, salinity and temperature were 7.5-8, 30-31 ppt and 31-32 °C, respectively. Photoperiod was 16L:8D. Shrimp larvae were fed Artemia nauplii and rotifers at 5-20 and 10-40 individuals per shrimp larvae four times a day, respectively. Growth and survival rate of larvae were determined at MII, MIII, PL1, PL4, PL7 and PL10 stages. Larvae in A + R + B treatment showed the highest total length (10.89 ± 0.51 mm), weight (674 ± 73 μg) and survival rate (65% ± 3.5). Lowest total length, weight and survival rate (7.96 ± 0.63 mm, 493 ± 52 μg and 24.5 ± 2.4%, respectively) were recorded in treatment B larvae. We concluded that Bacillus probiotic can improve growth and survival rate of Pacific white shrimp larvae without conceivably undesirable effects.

The changes in the biochemical compositions and enzymatic activities of rotifer (Brachionus plicatilis, Müller) and Artemia during the enrichment and starvation periods.

Science.gov (United States)

Naz, Mehmet

2008-12-01

The changes in the biochemical compositions and enzymatic activities of rotifer (Brachionus plicatilis) and Artemia, enriched and stored at 4 degrees C temperature, were determined. The total starvation period was 16 h and samples were taken at the end of the 8th and 16th hours. In present study, the rotifer and nauplii catabolized a large proportion of the protein during the enrichment period. Lipid contents of both live preys increased during the enrichment period and decreased in nauplii and metanauplii throughout the starvation period but lipid content of the rotifer remained relatively constant during the starvation period. The changes observed in the amino acid compositions of Artemia and the rotifer were statistically significant (P < 0.05). The conspicuous decline the essential amino acid (EAA) and nonessential amino acid (NEAA) content of the rotifer was observed during the enrichment period. However, the essential amino acid (EAA) and nonessential amino acid (NEAA) contents of Artemia nauplii increased during the enrichment period. The unenriched and enriched rotifers contained more monounsaturated fatty acid (MUFAs) than polyunsaturated fatty acid (PUFAs) and saturated fatty acids (SFA). However, Artemia contained more PUFAs than MUFAs and SFA during the experimental period. A sharp increase in the amounts of docosahexaenoic acid (DHA) during the enrichment of the rotifer and Artemia nauplii was observed. However, the amount of DHA throughout the starvation period decreased in Artemia metanauplii but not in Artemia nauplii. Significant differences in tryptic, leucine aminopeptidase N (LAP), and alkaline phosphatase (AP) enzyme activities of Artemia and rotifer were observed during the enrichment and starvation period (P < 0.05). The digestive enzymes derived from live food to fish larvae provided the highest contribution at the end of the enrichment period. In conclusion, the results of the study provide important contributions to determine the most

Study on kinetics of glucose uptake by some species of plankton

Science.gov (United States)

Li, Wenquan; Wang, Xian; Zhang, Yaohua

1993-03-01

The rates of glucose uptake by some species of plankton were determined by3H-glucose tracer method. Experimental results indicated that the observed glucose uptake at natural seawater concentrations by Platymonas subcordiformis and Brachionus plicatilis was principally a metabolic process fitted with the Michaelis-Menten equation in the range of adaptive temperatures. Heterotrophic uptake by Platymonas subcordiformis was mainly dependent on diffusion at high glucose levels. The uptake by Brachionus plicatilis showed active transport even at high glucose levels, indicating its high heterotrophic activity. The uptake rate by Artemia salina was lower, and its V m/K ratio was lower than those of the other two species of plankton.

Molecular and expression analysis of manganese superoxide dismutase (Mn-SOD) gene under temperature and starvation stress in rotifer Brachionus calyciflorus.

Science.gov (United States)

Yang, Jianghua; Dong, Siming; Zhu, Huanxi; Jiang, Qichen; Yang, Jiaxin

2013-04-01

Superoxide dismutase (SOD) is an important antioxidant enzyme that protects organs from damage by reactive oxygen species. We cloned cDNA encoding SOD activated with manganese (Mn-SOD) from the rotifer Brachionus calyciflorus Pallas. The full-length cDNA of Mn-SOD was 1,016 bp and had a 669 bp open reading frame encoding 222 amino acids. The deduced amino acid sequence of B. calyciflorus Mn-SOD showed 89.1, 71.3, and 62.1 % similarity with the Mn-SOD of the marine rotifer Brachionus plicatilis, the nematode Caenorhabditis elegans, and the fruit fly Drosophila melanogaster, respectively. The phylogenetic tree constructed based on the amino acid sequences of Mn-SODs from B. calyciflorus and other organisms revealed that this rotifer is closely related to nematodes. Analysis of the mRNA expression of Mn-SOD under different conditions revealed that expression was enhanced 5.6-fold (p 0.05). Moderate starvation promoted Mn-SOD mRNA expression (p 12 < 0.01, p 36 < 0.05), which reached a maximum value (15.3 times higher than control, p 24 < 0.01) at 24 h. SOD and CAT activities also elevated at the 12 h-starved group. These results indicate that induction of Mn-SOD expression by stressors likely plays an important role in aging of B. calyciflorus.

Intracellular haemolytic agents of Heterocapsa circularisquama exhibit toxic effects on H. circularisquama cells themselves and suppress both cell-mediated haemolytic activity and toxicity to rotifers (Brachionus plicatilis).

Science.gov (United States)

Nishiguchi, Tomoki; Cho, Kichul; Yasutomi, Masumi; Ueno, Mikinori; Yamaguchi, Kenichi; Basti, Leila; Yamasaki, Yasuhiro; Takeshita, Satoshi; Kim, Daekyung; Oda, Tatsuya

2016-10-01

A harmful dinoflagellate, Heterocapsa circularisquama, is highly toxic to shellfish and the zooplankton rotifer Brachionus plicatilis. A previous study found that H. circularisquama has both light-dependent and -independent haemolytic agents, which might be responsible for its toxicity. Detailed analysis of the haemolytic activity of H. circularisquama suggested that light-independent haemolytic activity was mediated mainly through intact cells, whereas light-dependent haemolytic activity was mediated by intracellular agents which can be discharged from ruptured cells. Because H. circularisquama showed similar toxicity to rotifers regardless of the light conditions, and because ultrasonic ruptured H. circularisquama cells showed no significant toxicity to rotifers, it was suggested that live cell-mediated light-independent haemolytic activity is a major factor responsible for the observed toxicity to rotifers. Interestingly, the ultrasonic-ruptured cells of H. circularisquama suppressed their own lethal effect on the rotifers. Analysis of samples of the cell contents (supernatant) and cell fragments (precipitate) prepared from the ruptured H. circularisquama cells indicated that the cell contents contain inhibitors for the light-independent cell-mediated haemolytic activity, toxins affecting H. circularisquama cells themselves, as well as light-dependent haemolytic agents. Ethanol extract prepared from H. circularisquama, which is supposed to contain a porphyrin derivative that displays photosensitising haemolytic activity, showed potent toxicity to Chattonella marina, Chattonella antiqua, and Karenia mikimotoi, as well as to H. circularisquama at the concentration range at which no significant toxicity to rotifers was observed. Analysis on a column of Sephadex LH-20 revealed that light-dependent haemolytic activity and inhibitory activity on cell-mediated light-independent haemolytic activity existed in two separate fractions (f-2 and f-3), suggesting that both

N-acyl homoserine lactone-degrading microbial enrichment cultures isolated from Penaeus vannamei shrimp gut and their probiotic properties in Brachionus plicatilis cultures.

Science.gov (United States)

Tinh, Nguyen Thi Ngoc; Asanka Gunasekara, R A Y S; Boon, Nico; Dierckens, Kristof; Sorgeloos, Patrick; Bossier, Peter

2007-10-01

Three bacterial enrichment cultures (ECs) were isolated from the digestive tract of Pacific white shrimp Penaeus vannamei, by growing the shrimp microbial communities in a mixture of N-acyl homoserine lactone (AHL) molecules. The ECs, characterized by denaturing gradient gel electrophoresis analysis and subsequent rRNA sequencing, degraded AHL molecules in the degradation assays. Apparently, the resting cells of the ECs also degraded one of the three types of quorum-sensing signal molecules produced by Vibrio harveyi in vitro [i.e. harveyi autoinducer 1 (HAI-1)]. The most efficient AHL-degrading ECs, EC5, was tested in Brachionus experiments. EC5 degraded the V. harveyi HAI-1 autoinducer in vivo, neutralizing the negative effect of V. harveyi autoinducer 2 (AI-2) mutant, in which only the HAI-1- and CAI-1-mediated components of the quorum-sensing system are functional on the growth of Brachionus. This suggests that EC5 interferes with HAI-1-regulated metabolism in V. harveyi. These AHL-degrading ECs need to be tested in other aquatic systems for their probiotic properties, preferably in combination with specific AI-2-degrading bacteria.

Acute toxicity tests using rotifers. 4. Effects of cyst age, temperature, and salinity on the sensitivity of Brachionus calyciflorus

Energy Technology Data Exchange (ETDEWEB)

Snell, T.W.; Moffat, B.D.; Janssen, C.; Persoone, G. (University of Tampa, Florida (USA))

1991-06-01

Several aspects of the response to toxicants using a standardized toxicity test with the freshwater rotifer Brachionus calyciflorus are described. Test animals are obtained by hatching cysts which produce animals of similar age and physiological condition. The acute toxicity of 28 compounds is described with 24-hr LC50's. The LC50's span five orders of magnitude, from silver at 0.008 mg.liter-1 to benzene at more than 1000 mg.liter-1. Control mortality in 84 tests averaged 2% with a standard deviation of 3%, indicating very consistent test sensitivity. Only once in 84 trials did a test fail because of excessive control mortality, yielding a failure rate of 1.2%. Cyst age from 0 to 18 months had no effect on the sensitivity of neonates to reference toxicants. Both high and low temperatures increased rotifer sensitivity to reference toxicants. Copper sensitivity was greater at 10, 25, and 30 degrees C compared with results at 20 degrees C. Likewise, sodium pentachlorophenol toxicity was greater at 10 and 30 degrees C compared with results at 20 degrees C. Survivorship curves at 25 degrees C of neonates under control conditions indicated that mortality begins at about 30 hr. This places a practical limit on toxicant exposure for the assay of 24 hr. B. calyciflorus cysts hatch at salinities up to 5 ppt and acute toxicity tests using pentachlorophenol at this salinity yielded LC50's about one-half those of standard freshwater. B. calyciflorus is preferred over Brachionus plicatilis for toxicity tests in salinities up to 5 ppt because it is consistently more sensitive.

First feeding of Eugerres brasilianus (Carapeva larvae with Acartia tonsa (Copepod nauplii increases survival and resistance to acute stress

Directory of Open Access Journals (Sweden)

Wanessa de Melo Costa

2016-01-01

Full Text Available The rotifer Brachionus sp. is commonly used for larval feeding in marine fish hatcheries. The aim of this study was to evaluate whether the inclusion of Acartia tonsa nauplii in the initial diet of carapeva larvae improves their survival, growth and resistance to stress when compared to the regimen containing only rotifers. Adult copepods were collected in the wild and cultured with the microalgae Chaetoceros muelleri, Isochrysis galbana and Nannochloropsis oculata to obtain nauplii. Carapeva larvae were grown for 15 days using four treatments and three replicates: 1 Brachionus plicatilis rotifers (10 to 15/mL; 2 A. tonsa nauplii (0.25 to 0.5/mL; 3 Brachionus plicatilis rotifers (5 to 7.5/mL + A. tonsa nauplii (0.12 to 0.25/mL, and 4 no supply of live feed. After 15 days, the carapeva larvae were subjected to stress by exposure to air for 10 seconds and then returned to the source tank to evaluate survival after 24 h. Survival and stress resistance were higher in carapeva larvae fed B. plicatilis + A. tonsa nauplii (P<0.05, 20.9 ± 11.2% and 88.9%, respectively. These results confirm the positive effect of the inclusion of copepod nauplii in the diet of fish larvae. However, more research is needed to validate these results.

Marine microalgae flocculation using plant: the case of Nannochloropsis oculata and Moringa oleifera

International Nuclear Information System (INIS)

Baharuddin, N.; Aziz, N. S.; Sohif, H. N.; Basiran, M. N.

2016-01-01

Marine microalgae have been commercially used as live feed for aquaculture and nutritional supplements. However, harvesting of marine microalgae is a major obstacle for industrial scale and one of the promising harvesting techniques is bio-flocculation. Nannochloropsis oculata from the culture broth was investigated. The potential of Moringa oleifera as a flocculant has been evaluated using jar test experiments. Moringa oleifera after oil extraction (MOAE) and with non-extracted Moringa oleifera (MOWE) have been studied and compared to chemical flocculant, aluminium sulphate. Three parameters involved: pH, settling time and flocculant dosage. When MOAE and MOWE were used as flocculants, the highest flocculation efficiency of Nannochloropsis oculata was observed at 93.77 percent (pH 7, 150 minutes, 5000 mg/L) and 70.56 percent (pH 7, 90 minutes, 4000 mg/L) respectively. Harvesting efficiency of 99.98 percent with short settling time, 30 minutes and 2000 mg/L of flocculant dosage at pH 6 was achieved using aluminium sulphate. The concentrated of Nannochloropsis oculata was then fed to the Brachionus plicatilis (rotifers) to observe the growth characteristics in 12 days period. Concentrates of MOWE gave better growth of Brachionus plicatilis than growth in concentrates of MOAE and live Nannochloropsis oculata. In contrast, growth of Brachionus plicatilis in aluminium sulphate was tremendously decline. In Conclusion, bio-flocculation using Moringa oleifera was rapid, inexpensive and eco-friendly technology as no addition of chemical flocculants was required. (author)

Real-time PCR detection and quantification of fish probiotic Phaeobacter strain 27-4 and fish pathogenic Vibrio in microalgae, rotifer, Artemia and first feeding turbot (Psetta maxima) larvae

DEFF Research Database (Denmark)

Prol, M.J.; Bruhn, Jesper Bartholin; Pintado, J.

2009-01-01

and in presence of microalgae (Isochrysis galbana), rotifers (Brachionus plicatilis), Artemia nauplii or turbot (Psetta maxima) larvae by real-time PCR based on primers directed at genetic loci coding for antagonistic and virulence-related functions respectively. The optimized protocol was used to study...

Phaeobacter gallaeciensis Reduces Vibrio anguillarum in Cultures of Microalgae and Rotifers, and Prevents Vibriosis in Cod Larvae

DEFF Research Database (Denmark)

D'Alvise, Paul; Lillebø, Siril; Prol García, María Jesús

2012-01-01

-antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 10(7) cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio...

African Journal of Aquatic Science - Vol 37, No 1 (2012)

African Journals Online (AJOL)

An experimental study on food and salinity preferences of two Brachionus plicatilis rotifer strains from Iran · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. R Malekzadeh Viayeh, H Mohammadi. http://dx.doi.org/10.2989/16085914.2012.666379 ...

An experimental study on food and salinity preferences of two ...

African Journals Online (AJOL)

Effects of feeding on four algal species (Chlorella vulgaris, Nannochloropsis oculata, Isochrysis galbana and Scenedesmus obliques) at salinities of 5, 15 and 25 on the population growth parameters of two Iranian strains of the widespread rotifer species Brachionus plicatilis were examined. Maximum specific growth rate of ...

Experimental and mathematical model of the interactions in the mixed culture of links in the "producer-consumer" cycle

Science.gov (United States)

Pisman, T. I.; Galayda, Ya. V.

The paper presents experimental and mathematical model of interactions between invertebrates the ciliates Paramecium caudatum and the rotifers Brachionus plicatilis and algae Chlorella vulgaris and Scenedesmus quadricauda in the producer -- consumer aquatic biotic cycle with spatially separated components The model describes the dynamics of the mixed culture of ciliates and rotifers in the consumer component feeding on the mixed algal culture of the producer component It has been found that metabolites of the algae Scenedesmus produce an adverse effect on the reproduction of the ciliates P caudatum Taking into account this effect the results of investigation of the mathematical model were in qualitative agreement with the experimental results In the producer -- consumer biotic cycle it was shown that coexistence is impossible in the mixed algal culture of the producer component and in the mixed culture of invertebrates of the consumer component The ciliates P caudatum are driven out by the rotifers Brachionus plicatilis

Isolation and characterisation of photoactive haemolytic toxin from ...

African Journals Online (AJOL)

We found that cell-free methanol extract from H. circularisquama caused haemolysis of rabbit erythrocytes and showed cytotoxic effects on HeLa cells and on the rotifer Brachionus plicatilis in a dose- and time-dependent manner. Interestingly, the haemolytic activity and cytotoxic effects of the extract were completely ...

Journal of Aquatic Sciences - Vol 20, No 2 (2005)

African Journals Online (AJOL)

Morphometry of brachionus plicatilis (Plioma:Brachionidae) used in larval rearing · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. GA Akin-Oriola, A Boura, V Kostopoulou, G Verriopoulos, 107-112. http://dx.doi.org/10.4314/jas.v20i2.20048 ...

Browse Title Index

African Journals Online (AJOL)

Items 251 - 300 of 390 ... Vol 20, No 2 (2005), Morphometry of brachionus plicatilis (Plioma:Brachionidae) used in larval rearing, Abstract. GA Akin-Oriola, A Boura, V Kostopoulou, G Verriopoulos. Vol 21, No 1 (2006), Muscle lipid content and lipase activity in the liver and digestive tract of some freshwater fishes (Pisces: ...

587-IJBCS-Article-Agadjihouede Hyppolite

African Journals Online (AJOL)

DR GATSING

Production de proies vivantes Brachionus plicatilis et. Artemia salina. Ifremer, station Merea, 83. 84. Shep H. 1994. Comparaison des capacities de développement et des processus de régulation en élevage monospécifique de triostypes de proies planctoniques d'intérêt aquacole : Moina micrura,. Diaphanosoma excisum.

make up.contents pg

African Journals Online (AJOL)

spamer

supplied was the rotifer Brachionus plicatilis; the water in the aquarium was maintained a light green colour from an outdoor culture of Chlorella sp. Later, rotifers were supplemented with newly hatched nauplii of Artemia sp. and copepods from plankton hauls at sea. At Sea World, 75- and 110-l aquaria were used.

Author Details

African Journals Online (AJOL)

Akin-Oriola, GA. Vol 20, No 2 (2005) - Articles Morphometry of brachionus plicatilis (Plioma:Brachionidae) used in larval rearing. Abstract. ISSN: 0189-8779. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions ...

Patterns and processes in the genetic differentiation of the Brachionus calyciflorus complex, a passively dispersing freshwater zooplankton.

Science.gov (United States)

Xiang, Xian-ling; Xi, Yi-long; Wen, Xin-li; Zhang, Gen; Wang, Jin-xia; Hu, Ke

2011-05-01

Elucidating the evolutionary patterns and processes of extant species is an important objective of any research program that seeks to understand population divergence and, ultimately, speciation. The island-like nature and temporal fluctuation of limnetic habitats create opportunities for genetic differentiation in rotifers through space and time. To gain further understanding of spatio-temporal patterns of genetic differentiation in rotifers other than the well-studied Brachionus plicatilis complex in brackish water, a total of 318 nrDNA ITS sequences from the B. calyciflorus complex in freshwater were analysed using phylogenetic and phylogeographic methods. DNA taxonomy conducted by both the sequence divergence and the GMYC model suggested the occurrence of six potential cryptic species, supported also by reproductive isolation among the tested lineages. The significant genetic differentiation and non-significant correlation between geographic and genetic distances existed in the most abundant cryptic species, BcI-W and Bc-SW. The large proportion of genetic variability for cryptic species Bc-SW was due to differences between sampling localities within seasons, rather than between different seasons. Nested Clade Analysis suggested allopatric or past fragmentation, contiguous range expansion and long-distance colonization possibly coupled with subsequent fragmentation as the probable main forces shaping the present-day phylogeographic structure of the B. calyciflorus species complex. Copyright © 2011 Elsevier Inc. All rights reserved.

Effects of commercial enrichment products on fatty acid components ...

African Journals Online (AJOL)

This study was undertaken to test the effects of enrichment products. Red pepper paste (ZA), AlgaMac 3050 (ZB) and Spresso (ZC) on fatty acid compositions in rotifers (Brachionus plicatilis) which were intensively cultured on a mixture of ω3 algae and ω3 yeast. Enriched rotifers were seen to have higher level of ...

Assessment of the toxicity of the solid coating PV1 in a marine invironment, using biotests with algae, a rotifer and a bacteria

NARCIS (Netherlands)

Foekema, E.M.; Sneekes, A.C.

2007-01-01

The toxic potential of substances that may leach from the solid coating PV1 was tested using • the marine bacteria Vibrio fisheri in the Microtox® Basic test • the marine algae Skeletonema costatum in a 72h algal growth inhibition test • the marine rotifer Brachionus plicatilis in the 24 h ROTOX®

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African Journals Online (AJOL)

Items 3601 - 3650 of 11090 ... P Mwaura, T Dubois, T Losenge, D Coyne, E Kahangi. Vol 11, No 2 (2012), Effect of enriched Brachionus plicatilis and Artemia salina nauplii by microalga Tetraselmis chuii (Bütcher) grown on four different culture media on the growth and survival of Sparus aurata larvae, Abstract PDF. HM Khairy ...

Comparative study on growth and survival of larval and juvenile ...

African Journals Online (AJOL)

The total fatty acid and total unsaturated fatty acid in the algae significantly increased (P < 0.001) for ch1, D1, N1 and T1 taking into consideration that the state of C22:6 significantly increased. The ch1 gave better growth and survival percentage followed by D1 for enrich Brachionus plicatilis and newly hatched Artemia.

Genome-wide identification of nuclear receptor (NR) genes and the evolutionary significance of the NR1O subfamily in the monogonont rotifer Brachionus spp.

Science.gov (United States)

Kim, Duck-Hyun; Kim, Hui-Su; Hwang, Dae-Sik; Kim, Hee-Jin; Hagiwara, Atsushi; Lee, Jae-Seong; Jeong, Chang-Bum

2017-10-01

Nuclear receptors (NRs) are a large family of transcription factors that are involved in many fundamental biological processes. NRs are considered to have originated from a common ancestor, and are highly conserved throughout the whole animal taxa. Therefore, the genome-wide identification of NR genes in an animal taxon can provide insight into the evolutionary tendencies of NRs. Here, we identified all the NR genes in the monogonont rotifer Brachionus spp., which are considered an ecologically key species due to their abundance and world-wide distribution. The NR family was composed of 40, 32, 29, and 32 genes in the genomes of the rotifers B. calyciflorus, B. koreanus, B. plicatilis, and B. rotundiformis, respectively, which were classified into seven distinct subfamilies. The composition of each subfamily was highly conserved between species, except for NR1O genes, suggesting that they have undergone sporadic evolutionary processes for adaptation to their different environmental pressures. In addition, despite the dynamics of NR evolution, the significance of the conserved endocrine system, particularly for estrogen receptor (ER)-signaling, in rotifers was discussed on the basis of phylogenetic analyses. The results of this study may help provide a better understanding the evolution of NRs, and expand our knowledge of rotifer endocrine systems. Copyright © 2017 Elsevier Inc. All rights reserved.

Use of rotifers for the maintenance of monoalgal mass cultures of Spirulina

Energy Technology Data Exchange (ETDEWEB)

Mitchell, S.A.; Richmond, A.

1987-01-01

Zooplankton was successfully used for the biological control of unicellular algal contaminants in Spirulina mass cultures even under conditions adverse to the growth of Spirulina (maximal winter daily temperature of approximately 10 degrees C and very low bicarbonate concentration). Brachionus plicatilis (Rotifera) was the most successful species of zooplankton used. The interrelationships between Spirulina, green unicellular contaminant, and B. plicatilis were studied under various conditions. Two species of unicellular contaminant were used; Monoraphidium minutum was isolated from local cultures and Chlorella vulgaris, obtained from contaminated Spirulina cultures in Israel. The rotifer B. plicatilis successfully controlled the population size of both contaminants whether they were introduced in a single addition or as a daily dose. The biological control of the unicellular contaminants allows Spirulina to be cultured in a medium low in bicarbonate, thereby reducing the cost of the medium and increasing the quantity of CO2 that may be freely absorbed from the atmosphere at the optimal pH for Spirulina cultivation. (Refs. 9).

Effects of selected pharmaceuticals (ibuprofen and amoxicillin on the demography of Brachionus calyciflorus and Brachionus havanaensis (Rotifera

Directory of Open Access Journals (Sweden)

Brenda Karen González-Pérez

2016-09-01

Full Text Available The levels of emerging chemicals have increased dramatically during the last two decades posing problems for human and environmental health. Pain-killers such as ibuprofen and antibiotics such as amoxicillin are generally consumed together and hence are discharged into waterbodies as effluents. The lack of a rigorous control of pharmaceutical discharges into natural waterbodies is a concern for limnologists and ecotoxicologists because of their possible effects on non-target organisms. Rotifers, due to their sensitivity, short generation time and high reproductive rates, are widely used as bioassay organisms in testing the effects of different substances including pharmaceuticals. Here we quantified the demographic responses of Brachionus calyciflorus and Brachionus havanaensis exposed to three sublethal concentrations of ibuprofen (25, 12.5 and 6.25 mg L−1 and amoxicillin (200, 100 and 50 μg L−1. Our data showed that both survivorship- and reproduction-related variables were negatively affected with increasing concentrations of both pharmaceuticals. The rate of population increase of B. calyciflorus (0.63–0.72 d−1 was not affected by amoxicillin or by ibuprofen but for B. havanaensis, it was decreased significantly (from 0.89 to 0.38 d−1. Compared to ibuprofen, amoxicillin had more adverse effects on both the rotifer species.

Species-specific separation of lake plankton reveals divergent food assimilation patterns in rotifers.

Science.gov (United States)

Burian, Alfred; Kainz, Martin J; Schagerl, Michael; Yasindi, Andrew

2014-06-01

1. The analysis of functional groups with a resolution to the individual species level is a basic requirement to better understand complex interactions in aquatic food webs. Species-specific stable isotope analyses are currently applied to analyse the trophic role of large zooplankton or fish species, but technical constraints complicate their application to smaller-sized plankton. 2. We investigated rotifer food assimilation during a short-term microzooplankton bloom in the East African soda lake Nakuru by developing a method for species-specific sampling of rotifers. 3. The two dominant rotifers, Brachionus plicatilis and Brachionus dimidiatus , were separated to single-species samples (purity >95%) and significantly differed in their isotopic values (4.1‰ in δ 13 C and 1.5‰ in δ 15 N). Bayesian mixing models indicated that isotopic differences were caused by different assimilation of filamentous cyanobacteria and particles plicatilis (48%), whereas it was hardly ingested by B. dimidiatus . Overall, A . fusiformis was, relative to its biomass, assimilated to small extents, demonstrating a high grazing resistance of this species. 5. In combination with high population densities, these results demonstrate a strong potential of rotifer blooms to shape phytoplankton communities and are the first in situ demonstration of a quantitatively important direct trophic link between rotifers and filamentous cyanobacteria.

Effects of sexual reproduction of the inferior competitor Brachionus calyciflorus on its fitness against Brachionus angularis

Science.gov (United States)

Li, Chen; Niu, Cuijuan

2015-03-01

Sexual reproduction adversely affects the population growth of cyclic parthenogenetic animals. The density-dependent sexual reproduction of a superior competitor could mediate the coexistence. However, the cost of sex may make the inferior competitor more vulnerable. To investigate the effect of sexual reproduction on the inferior competitor, we experimentally paired the competition of one Brachionus angularis clone against three Brachionus calyciflorus clones. One of the B. calyciflorus clones showed a low propensity for sexual reproduction, while the other two showed high propensities. The results show that all B. calyciflorus clones were excluded in the competition for resources at low food level. The increased food level promoted the competition persistence, but the clones did not show a clear pattern. Both the cumulative population density and resting egg production increased with the food level. The cumulative population density decreased with the mixis investment, while the resting egg production increased with the mixis investment. A trade-off between the population growth and sexual reproduction was observed in this research. The results indicate that although higher mixis investment resulted in a lower population density, it would not determinately accelerate the exclusion process of the inferior competitor. On the contrary, higher mixis investment promoted resting egg production before being excluded and thus promised a long-term benefit. In conclusion, our results suggest that mixis investment, to some extent, favored the excluded inferior competitor under fierce competition or some other adverse conditions.

Effect of the addition of Lactobacillus delbrueckii subsp. delbrueckii on the gut microbiota composition and contribution to the well-being of European sea bass (Dicentrarchus labrax, L.)

OpenAIRE

Silvi, Stefania; Nardi, Miria; Sulpizio, Roberto; Orpianesi, Carla; Caggiano, Massimo; Carnevali, Oliana; Cresci, Alberto

2011-01-01

The present study aimed to test the effects of probiotic treatment on gut microbiota and the contribution to the well-being of European sea bass (Dicentrarchus labrax, L.). A bacterial strain of Lactobacillus delbrueckii subsp. delbrueckii (AS13B), isolated from adult European sea bass gut, was administered during sea bass development using Brachionus plicatilis and/or Artemia salina as carriers. The effective strain colonization and modulation of the gut microbiota, the mortality and the cor...

Experimental and mathematical model of the interactions in the mixed culture of links in the “producer-consumer” cycle

Science.gov (United States)

Pisman, T. I.

2009-07-01

The paper presents a experimental and mathematical model of interactions between invertebrates (the ciliates Paramecium caudatum and the rotifers Brachionus plicatilis) in the "producer-consumer" aquatic biotic cycle with spatially separated components. The model describes the dynamics of the mixed culture of ciliates and rotifers in the "consumer" component, feeding on the mixed algal culture of the "producer" component. It has been found that metabolites of the algae Scenedesmus produce an adverse effect on the reproduction of the ciliates P. caudatum. Taking into account this effect, the results of investigation of the mathematical model were in qualitative agreement with the experimental results. In the "producer-consumer" biotic cycle it was shown that coexistence is impossible in the mixed culture of invertebrates of the "consumer" component. The ciliates P. caudatum are driven out by the rotifers B. plicatilis.

An integrated fish-plankton aquaculture system in brackish water.

Science.gov (United States)

Gilles, S; Fargier, L; Lazzaro, X; Baras, E; De Wilde, N; Drakidès, C; Amiel, C; Rispal, B; Blancheton, J-P

2013-02-01

Integrated Multi-Trophic Aquaculture takes advantage of the mutualism between some detritivorous fish and phytoplankton. The fish recycle nutrients by consuming live (and dead) algae and provide the inorganic carbon to fuel the growth of live algae. In the meanwhile, algae purify the water and generate the oxygen required by fishes. Such mechanism stabilizes the functioning of an artificially recycling ecosystem, as exemplified by combining the euryhaline tilapia Sarotherodon melanotheron heudelotii and the unicellular alga Chlorella sp. Feed addition in this ecosystem results in faster fish growth but also in an increase in phytoplankton biomass, which must be limited. In the prototype described here, the algal population control is exerted by herbivorous zooplankton growing in a separate pond connected in parallel to the fish-algae ecosystem. The zooplankton production is then consumed by tilapia, particularly by the fry and juveniles, when water is returned to the main circuit. Chlorella sp. and Brachionus plicatilis are two planktonic species that have spontaneously colonized the brackish water of the prototype, which was set-up in Senegal along the Atlantic Ocean shoreline. In our system, water was entirely recycled and only evaporation was compensated (1.5% volume/day). Sediment, which accumulated in the zooplankton pond, was the only trophic cul-de-sac. The system was temporarily destabilized following an accidental rotifer invasion in the main circuit. This caused Chlorella disappearance and replacement by opportunist algae, not consumed by Brachionus. Following the entire consumption of the Brachionus population by tilapias, Chlorella predominated again. Our artificial ecosystem combining S. m. heudelotii, Chlorella and B. plicatilis thus appeared to be resilient. This farming system was operated over one year with a fish productivity of 1.85 kg/m2 per year during the cold season (January to April).

Man-induced hydrological changes, metazooplankton communities and invasive species in the Berre Lagoon (Mediterranean Sea, France)

International Nuclear Information System (INIS)

Delpy, Floriane; Pagano, Marc; Blanchot, Jean; Carlotti, François; Thibault-Botha, Delphine

2012-01-01

The Berre Lagoon has been under strong anthropogenic pressure since the early 1950s. The opening of the hydroelectric EDF power plant in 1966 led to large salinity drops. The zooplankton community was mainly composed of two common brackish species: Acartia tonsa and Brachionus plicatilis. Since 2006, European litigation has strongly constrained the input of freshwater, maintaining the salinity above 15. A study was performed between 2008 and 2010 to evaluate how these modifications have impacted the zooplankton community. Our results show that the community is more diverse and contains several coastal marine species (i.e., Centropages typicus, Paracalanus parvus and Acartia clausi). A. tonsa is still present but is less abundant, whereas B. plicatilis has completely disappeared. Strong predatory marine species, such as chaetognaths, the large conspicuous autochtonous jellyfish Aurelia aurita and the invasive ctenophore Mnemiopsis leidyi, are now very common as either seasonal or permanent features of the lagoon.

Genetic determinants of mate recognition in Brachionus manjavacas (Rotifera).

Science.gov (United States)

Snell, Terry W; Shearer, Tonya L; Smith, Hilary A; Kubanek, Julia; Gribble, Kristin E; Welch, David B Mark

2009-09-09

repeats are kept nearly identical through a process of concerted evolution. Information-rich molecules like surface glycoproteins are well adapted for chemical communication and aquatic animals may have evolved signaling systems based on these compounds, whereas insects use cuticular hydrocarbons. Owing to its critical role in mating, the mate recognition pheromone gene will be a useful molecular marker for exploring the mechanisms and rates of selection and the evolution of reproductive isolation and speciation using rotifers as a model system. The phylogenetic variation in the mate recognition pheromone gene can now be studied in conjunction with the large amount of ecological and population genetic data being gathered for the Brachionus plicatilis species complex to understand better the evolutionary drivers of cryptic speciation.

Comparison of the radiosensitivity of dry dormant eggs, gemmules, and statoblasts of three invertebrate forms

International Nuclear Information System (INIS)

Shimada, Atsuko; Egami, Nobuo

1985-01-01

Radiosensitivities of the special structures (reproductive organs) of various invertebrate animals were examined. The doses of 50 % hatch were about 5 kR for staboblasts of the bryozoa, Pectinatella magnifica; 70 kR for gemmules of the freshwater sponge, Eunapius fragilis; 130 kR for gemmuls of the freshwater sponge, Ephydatia fluviatilis; 180 kR for dry eggs of the rotifer, Brachionus plicatilis, and 350 kR for dry eggs of Artemia salina. The results showed that Artemia eggs were the most radioresistant reproductive organ among the materials examined. (author)

Genetic determinants of mate recognition in Brachionus manjavacas (Rotifera

Directory of Open Access Journals (Sweden)

Kubanek Julia

2009-09-01

, even at synonymous positions, suggests that the repeats are kept nearly identical through a process of concerted evolution. Information-rich molecules like surface glycoproteins are well adapted for chemical communication and aquatic animals may have evolved signaling systems based on these compounds, whereas insects use cuticular hydrocarbons. Conclusion Owing to its critical role in mating, the mate recognition pheromone gene will be a useful molecular marker for exploring the mechanisms and rates of selection and the evolution of reproductive isolation and speciation using rotifers as a model system. The phylogenetic variation in the mate recognition pheromone gene can now be studied in conjunction with the large amount of ecological and population genetic data being gathered for the Brachionus plicatilis species complex to understand better the evolutionary drivers of cryptic speciation.

Diet quality impact on growth, reproduction, and digestive activity in .i.Brachionus calyciflorus./i

Czech Academy of Sciences Publication Activity Database

Štrojsová, Martina; Nedoma, Jiří; Seďa, Jaromír; Vrba, Jaroslav

2008-01-01

Roč. 30, č. 10 (2008), s. 1123-1131 ISSN 0142-7873 R&D Projects: GA AV ČR(CZ) IAA600170602 Institutional research plan: CEZ:AV0Z60170517 Keywords : Brachionus * phosphorus limitation * growth * reproduction * phosphatase Subject RIV: EG - Zoology Impact factor: 1.707, year: 2008

Potential use of an ultrasound antifouling technology as a ballast water treatment system

Science.gov (United States)

Estévez-Calvar, Noelia; Gambardella, Chiara; Miraglia, Francesco; Pavanello, Giovanni; Greco, Giuliano; Faimali, Marco; Garaventa, Francesca

2018-03-01

The aim of this study was to investigate, at a laboratory scale, the potentialities of an ultrasound-based treatment initially designed to eliminate fouling, as a ballast water treatment system. Therefore, early life stages of three different zooplanktonic species (Amphibalanus amphitrite, Brachionus plicatilis and Artemia salina) were exposed to ultrasound waves (20-22 kHz). The experimental set up included static assays with variations of time exposure (30 s, 60 s and 30 s on/60 s off/30 s on), material of tanks (stainless steel, galvanized steel and plastic) and position of the ultrasound source. Results showed that the treatment efficacy increased from 30 to 60 s and no differences were registered between 60 s-continuous exposure and pulse exposure. The highest efficacy was observed in Experiment I (metal-to-metal contact assay) with a mortality value of 93-95% for B. plicatilis and A. salina. It consisted of organisms located inside stainless steel tubes that were located in direct contact with the ultrasound source and treated for 60 s. Further, we found that, generally, A. amphitrite and B. plicatilis were the most resistant species to the ultrasound treatment whereas A. salina was the most sensitive. We further discuss that US may unlikely be used for commercial vessels, but may be used to treat ballast water in smaller ballast tanks as on board of mega yachts.

Adverse effects of the SSRI antidepressant sertraline on early life stages of marine invertebrates.

Science.gov (United States)

Estévez-Calvar, Noelia; Canesi, Laura; Montagna, Michele; Faimali, Marco; Piazza, Veronica; Garaventa, Francesca

2017-07-01

Widespread contamination of coastal environments by emerging compounds includes low concentrations of pharmaceuticals. These pollutants are not currently incorporated in monitoring programs despite their effects on non-target organisms are very little documented. Among the selective serotonin reuptake inhibitor (SSRI) antidepressants, sertraline (SRT) is one of the most prescribed globally. In this work, earlier life stages of Amphibalanus amphitrite, Brachionus plicatilis and Mytilus galloprovincialis were exposed to environmental concentrations of SRT in order to study both sub-lethal and lethal responses in 24/48 h-tests. Low concentrations of SRT altered significantly swimming behavior in A. amphitrite and B. plicatilis giving 48 h-EC 50 (μg/L) of 113.88 and 282.23, respectively whereas higher values were observed for mortality and immobilization. EC 50 embryotoxicity with M. galloprovincialis was 206.80 μg/L. This work add new data about SRT ecotoxicity on marine invertebrates and confirms the applicability of behavioral endpoints to evaluate the environmental impact of antidepressants in marine organisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of enriched Brachionus plicatilis and Artemia salina nauplii by ...

African Journals Online (AJOL)

AJL

2012-01-05

Jan 5, 2012 ... medium, especially the short chain fatty acids (C16:0, C18:0 and ... constituted 22.3% of the total fatty acids, due to the presence of DHA ...... to influence tissue fatty acid composition of Atlantic salmon, Salmo salar L., parr.

Acute toxicity of toluene, hexane, xylene, and benzene to the rotifers Brachionus calyciflorus and Brachionus plicatilis

Energy Technology Data Exchange (ETDEWEB)

Ferrando, M.D.; Andreu-Moliner, E. (Univ. of Valencia (Spain))

1992-08-01

A large number of studies on the biological effects of oil pollution in the aquatic environment deal with the effects of whole crude or refined oils or their water-soluble fractions. However, low boiling, aromatic hydrocarbons, which are probably the most toxic constituents of oil, have until now not been examined in sufficient detail. Toluene, benzene and xylene, constitute a major component of various oils. They may be readily lost by weathering but are toxic in waters that are relatively stagnant and are chronically polluted. Korn et al. have stated that toluene is more toxic than many other hydrocarbons such as benzene, though the latter are more water-soluble. Report of the effects of exposure to organic solvents like hexane or toluene are still limited although organic solvents are a well-known group of neurointoxicants. Various benzene derivates continue to be used as chemical intermediates, solvents, pesticides, so on, in spite of incomplete knowledge of their chronic toxicity. The majority of toxicity studies about the effects of pollution on aquatic organisms under controlled conditions have used either fish or the cladoceran Daphnia magna and there are few studies reported using rotifers. The effects of herbicides on population variables of laboratory rotifer cultures have been investigated. Rotifers are one of the main sources of zooplankton production and they have an important ecological significance in the aquatic environment. The present work was designed to investigate the effect of short-term exposure to some petroleum derivates which might be expected to occur immediately under an oil-slick, on freshwater and brackish environment rotifers. 18 refs., 1 tab.

Population density, sexual reproduction and diapause in monogonont rotifers: new data for Brachionus and a review

Directory of Open Access Journals (Sweden)

John J. GILBERT

2004-09-01

Full Text Available Diapausing, fertilized eggs in monogonont rotifers typically are formed after an environmental signal induces amictic females to produce mictic daughters. Mictic females lay haploid eggs that may develop parthenogenetically into males, or that may be fertilized and develop into diapausing, female embryos called resting eggs. Laboratory experiments demonstrate that crowding is the signal for production of mictic females in strains of Brachionus calyciflorus from Texas, Spain and Germany, and in a strain of Brachionus variabilis from Spain. In these experiments, newborn amictic females were cultured singly in large and small volumes to give lowand high-density treatments. Therefore, the induction of mictic females is due exclusively to population density and cannot be attributed to a grouping effect involving some interaction among individuals. B. variabilis is very sensitive to population density; females had to be cultured in 30 ml to prevent appreciable production of mictic daughters. Crowding is now known to be the signal for initiation of sexuality and diapause in four species of Brachionus, two species of Epiphanes, and Rhinoglena frontalis. The chemical that mediates this response somehow influences oocytes in the maternal body cavity to differentiate into mictic females. Aggregation of individuals in natural systems may facilitate the production of mictic females. In some of these rotifers, the response to crowding is suppressed in early generations from the resting egg, assuring that clonal populations will attain higher population densities before committing to sexual reproduction. Fitness benefits of the mictic-female response to crowding, and to other environmental signals in other rotifers (dietary tocopherol, long photoperiod, are discussed.

Degradation models and ecotoxicity in marine waters of two antifouling compounds: sodium hypochlorite and an alkylamine surfactant.

Science.gov (United States)

López-Galindo, Cristina; Garrido, M Carmen; Casanueva, José F; Nebot, Enrique

2010-03-15

Industrial wastes have a substantial impact on coastal environments. Therefore, to evaluate the impact of cooling water discharges from coastal power plants, we studied the kinetics of the degradative processes and the ecotoxicity of two antifouling products: (1) a classic antifouling product; sodium hypochlorite (NaClO) and (2) an alternative one; aliphatic amines (commercial under the registered trade mark Mexel432). To assess the persistence of both compounds the decay of sodium hypochlorite and the primary biodegradation rate of Mexel432 were determined in natural seawater at 20 degrees C. The results indicated a more rapid decay of NaClO than Mexel432. The degradation behavior of both chemicals was described following a logistic model, which permitted calculating kinetic parameters such as t(50) or t(90). The t(50) was 1h and 2d for NaClO and Mexel432, respectively. To evaluate the potential risks of the aforementioned treatments to marine organisms, the acute toxicity of both antifouling products was studied on the microalgae Isochrysis galbana and Dunaliella salina, and on the invertebrate Brachionus plicatilis, using growth inhibition and death tests as toxic response, respectively. For I. galbana, the 96-h EC(50) values were 2.91+/-0.15mg/L of NaClO and 4.55+/-0.11mg/L of Mexel432. D. salina showed values of 96-h EC(50) of 1.73+/-0.16mg/L of NaClO and 7.21+/-0.1mg/L of Mexel432. Brachionus plicatilis showed a 24-h LC(50) of 1.23+/-0.1mg/L of NaClO and 3.62+/-0.37mg/L of Mexel432. Acute toxicity was highly dependent on the chemical and species tested. NaClO presented more toxic effects than Mexel432, also B. plicatilis was the most sensitive species in both cases. The lowest NOECs obtained, 0.25mg/L for NaClO and 2.12mg/L for Mexel432, were similar to the theoretical residual concentrations of these biocides in cooling water discharges. Therefore, these discharges can cause undesirable negative effects upon the aquatic organisms present.

Toxicity of algal-derived aldehydes to two invertebrate species: Do heavy metal pollutants have a synergistic effect?

Energy Technology Data Exchange (ETDEWEB)

Taylor, Rebecca L. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)]. E-mail: r.l.taylor@ncl.ac.uk; Caldwell, Gary S. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom); Bentley, Matthew G. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)

2005-08-15

The recent discovery of the production of anti-proliferative aldehydes in a variety of microalgal species has lead to considerable investigation into the effects of these toxins on aquatic invertebrates. Studies have, however, rarely considered the impact pollutants may have on grazer responses to algal toxins. In this study, the acute toxicities of five aldehydes to the rotifer Brachionus plicatilis and nauplii of the brine shrimp Artemia salina are examined using immersion assays. In addition, the effect of a representative of these aldehydes in the presence of sub-lethal levels of heavy metals was examined. B. plicatilis generally showed greater sensitivity to the aldehydes than A. salina. The polyunsaturated 2-trans,4-trans-decadienal was the most toxic to both species having 24 h LD{sub 50} values of 7 and 20 {mu}M for B. plicatilis and A. salina, respectively. The remaining aldehydes had different orders of toxicity for the two species with a stronger relationship observed between mortality and aldehyde carbon-chain length for A. salina whereas B. plicatilis mortality showed a stronger dependence on the presence of carbon-carbon double bonds in the aldehydes. The presence of 1 {mu}M of copper sulphate in solutions of decadienal resulted in the reduction of the 24 h LD{sub 50} of decadienal by approximately a third for both species. 1 {mu}M of copper chloride in solutions of decadienal reduced the 24 h LD{sub 50} of decadienal to A. salina nauplii by approximately 11% and 1 {mu}M zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 {mu}M copper sulphate had no significant impact on their subsequent mortality in decadienal. The ecological implications and the possible mechanisms for the action of copper sulphate on the response of organisms to decadienal are discussed.

Long-term competitive dynamics of two cryptic rotifer species: diapause and fluctuating conditions.

Directory of Open Access Journals (Sweden)

Carmen Gabaldón

Full Text Available Life-history traits may have an important role in promoting species coexistence. However, the complexity of certain life cycles makes it difficult to draw conclusions about the conditions for coexistence or exclusion based on the study of short-term competitive dynamics. Brachionus plicatilis and B. manjavacasare two cryptic rotifer species co-occurring in many lakes on the Iberian Peninsula. They have a complex life cycle in which cyclical parthenogenesis occurs with diapausing stages being the result of sexual reproduction. B. plicatilis and B. manjavacasare identical in morphology and size, their biotic niches are broadly overlapping, and they have similar competitive abilities. However, the species differ in life-history traits involving sexual reproduction and diapause, and respond differently to salinity and temperature. As in the case of certain other species that are extremely similar in morphology, a fluctuating environment are considered to be important for their coexistence. We studied the long-term competitive dynamics of B. plicatilis and B. manjavacas under different salinity regimes (constant and fluctuating. Moreover, we focused on the dynamics of the diapausing egg bank to explore how the outcome of the entire life cycle of these rotifers can work to mediate stable coexistence. We demonstrated that these species do not coexist under constant-salinity environment, as the outcome of competition is affected by the level of salinity-at low salinity, B. plicatilis excluded B. manjavacas, and the opposite outcome occurred at high salinity. Competitive dynamics under fluctuating salinity showed that the dominance of one species over the other also tended to fluctuate. The duration of co-occurrence of these species was favoured by salinity fluctuation and perhaps by the existence of a diapausing egg bank. Stable coexistence was not found in our system, which suggests that other factors or other salinity fluctuation patterns might act as

Long-term competitive dynamics of two cryptic rotifer species: diapause and fluctuating conditions.

Science.gov (United States)

Gabaldón, Carmen; Carmona, María José; Montero-Pau, Javier; Serra, Manuel

2015-01-01

Life-history traits may have an important role in promoting species coexistence. However, the complexity of certain life cycles makes it difficult to draw conclusions about the conditions for coexistence or exclusion based on the study of short-term competitive dynamics. Brachionus plicatilis and B. manjavacasare two cryptic rotifer species co-occurring in many lakes on the Iberian Peninsula. They have a complex life cycle in which cyclical parthenogenesis occurs with diapausing stages being the result of sexual reproduction. B. plicatilis and B. manjavacasare identical in morphology and size, their biotic niches are broadly overlapping, and they have similar competitive abilities. However, the species differ in life-history traits involving sexual reproduction and diapause, and respond differently to salinity and temperature. As in the case of certain other species that are extremely similar in morphology, a fluctuating environment are considered to be important for their coexistence. We studied the long-term competitive dynamics of B. plicatilis and B. manjavacas under different salinity regimes (constant and fluctuating). Moreover, we focused on the dynamics of the diapausing egg bank to explore how the outcome of the entire life cycle of these rotifers can work to mediate stable coexistence. We demonstrated that these species do not coexist under constant-salinity environment, as the outcome of competition is affected by the level of salinity-at low salinity, B. plicatilis excluded B. manjavacas, and the opposite outcome occurred at high salinity. Competitive dynamics under fluctuating salinity showed that the dominance of one species over the other also tended to fluctuate. The duration of co-occurrence of these species was favoured by salinity fluctuation and perhaps by the existence of a diapausing egg bank. Stable coexistence was not found in our system, which suggests that other factors or other salinity fluctuation patterns might act as stabilizing

Toxicity of algal-derived aldehydes to two invertebrate species: Do heavy metal pollutants have a synergistic effect?

International Nuclear Information System (INIS)

Taylor, Rebecca L.; Caldwell, Gary S.; Bentley, Matthew G.

2005-01-01

The recent discovery of the production of anti-proliferative aldehydes in a variety of microalgal species has lead to considerable investigation into the effects of these toxins on aquatic invertebrates. Studies have, however, rarely considered the impact pollutants may have on grazer responses to algal toxins. In this study, the acute toxicities of five aldehydes to the rotifer Brachionus plicatilis and nauplii of the brine shrimp Artemia salina are examined using immersion assays. In addition, the effect of a representative of these aldehydes in the presence of sub-lethal levels of heavy metals was examined. B. plicatilis generally showed greater sensitivity to the aldehydes than A. salina. The polyunsaturated 2-trans,4-trans-decadienal was the most toxic to both species having 24 h LD 50 values of 7 and 20 μM for B. plicatilis and A. salina, respectively. The remaining aldehydes had different orders of toxicity for the two species with a stronger relationship observed between mortality and aldehyde carbon-chain length for A. salina whereas B. plicatilis mortality showed a stronger dependence on the presence of carbon-carbon double bonds in the aldehydes. The presence of 1 μM of copper sulphate in solutions of decadienal resulted in the reduction of the 24 h LD 50 of decadienal by approximately a third for both species. 1 μM of copper chloride in solutions of decadienal reduced the 24 h LD 50 of decadienal to A. salina nauplii by approximately 11% and 1 μM zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 μM copper sulphate had no significant impact on their subsequent mortality in decadienal. The ecological implications and the possible mechanisms for the action of copper sulphate on the response of organisms to decadienal are discussed

Inclusion of copepod Acartia tonsa nauplii in the feeding of Centropomus undecimalis larvae increases stress resistance

Directory of Open Access Journals (Sweden)

Wanessa de Melo-Costa

2015-09-01

Full Text Available This research represents the first result of studies of the common snook Centropomus undecimalis larvae from broodstock matured in captivity in Brazil. The aim of this study was to evaluate if the inclusion of Acartia tonsa nauplii improves stress resistance of common snook larvae. The larvae were fed with: rotifers Brachionus plicatilis (10 to 15 mL-1; A. tonsa nauplii (0.25 to 0.5 mL-1 and rotifers (5 to 7.5 mL-1, and A. tonsa nauplii (0.12 to 0.25 mL-1. The average percentage of survival of the treatments was 11.9%. At 20 days of age, larvae were subjected to thermal stress. Subsequently, the stress resistance was evaluated. Common snook larvae fed B. plicatilis+A. tonsa reached a higher weight and length (7.5 ± 0.00 mg and 9.1 ± 0.23 mm, respectively and resisted more heat stress (87.4% than larvae fed other foods, indicating that the feed mixture is satisfactory as a starter diet for larvae of common snook. However, more research is needed to confirm these results.

Zooplankton responses to sandbar opening in a tropical eutrophic coastal lagoon

Science.gov (United States)

Santangelo, Jayme M.; de M. Rocha, Adriana; Bozelli, Reinaldo L.; Carneiro, Luciana S.; de A. Esteves, Francisco

2007-02-01

The effects of a disturbance by sandbar opening on the zooplankton community were evaluated through a long-term study in an eutrophic and oligohaline system, Imboassica Lagoon, Rio de Janeiro, Brazil. Zooplankton samples and limnological data were collected monthly from March 2000 to February 2003. Before the sandbar was opened in February 2001, the lagoon showed eutrophic conditions, with high mean nutrient concentrations and low salinity (total nitrogen - TN = 190.28 μM, chlorophyll a content - Chl. a = 104.60 μg/L and salinity = 0.87'). During this period, the zooplankton species present, such as the rotifers Brachionus calyciflorus and Brachionus havanaensis, were typical of freshwater to oligohaline and eutrophic environments. After the sandbar opening, the lagoon changed to a lower trophic status and increased salinity (TN = 55.11 μM, Chl. a = 27.56 μg/L and salinity = 19.64'). As a result, the zooplankton community came to consist largely of the rotifer Brachionus plicatilis, marine copepods and meroplanktonic larvae, mainly Gastropoda. Salinity was the main force structuring the zooplankton community after the sandbar opening. Two years after this episode, the prior zooplankton community had not reestablished itself, indicating a low resilience to this disturbance. The conditions developed prior to a sandbar opening can be crucial to the community responses in the face of this disturbance and for the capacity of the original zooplankton community to re-establish itself.

The diversity of Indian Brachionidae (Rotifera: Eurotatoria: Monogononta and their distribution

Directory of Open Access Journals (Sweden)

B.K. Sharma

2014-11-01

Full Text Available We evaluate diversity status of the Brachionidae of India and present an annotated checklist of 46 species excluding dubious and unconfirmed reports. These merit biodiversity value as ~27% of the global diversity of the taxon and ~81% of its Oriental species. We observed two Australasian elements, two Oriental endemics, one Indian endemic, one paleotropical and one cosmo (sub tropical species. The cold-water Keratella serrulata and Notholca squamula are new records from eastern Himalayas. Maximum brachionid diversity (32 species from Assam state of northeast India (NEI is followed by the reports of 27 and 26 species from Tamil Nadu and West Bengal, respectively; 25 species each from Tripura and Maharashtra; and 24 species from Jammu & Kashmir. Brachionus, the most diverse brachionid genus, is widely distributed in India with low richness in hill states of NEI and coastal waters in particular. The Indian brachionid taxonomy is confounded with unconfirmed reports, misidentifications, invalid taxa, and inconsistent treatment of morphological variants, while analysis of cryptic diversity in Brachionus calyciflorus, B. caudatus, B. forficula, B. plicatilis, B. quadridentatus, B. urceolaris, Keratella cochlearis and K. quadrata species-groups awaits attention.

Toxicity of two imidazolium ionic liquids, [bmim][BF4] and [omim][BF4], to standard aquatic test organisms: Role of acetone in the induced toxicity.

Science.gov (United States)

Tsarpali, Vasiliki; Dailianis, Stefanos

2015-07-01

The main goal of this study was to investigate the toxicity of the imidazolium-based ionic liquids (ILs), [bmim][BF4] (1-butyl-3-methylimidazolium tetrafluoroborate) and [omim][BF4] (1-octyl-3-methylimidazolium tetrafluoroborate), in battery of standard aquatic toxicity test organisms. Specifically, exposure of the algae Scenedesmus rubescens, crustaceans Thamnocephalus platyurus and Artemia franciscana, rotifers Brachionus calyciflorus and Brachionus plicatilis and bivalve Mytilus galloprovincialis to different concentrations of [bmim][BF4], [omim][BF4] and/or a binary mixture of [bmim][BF4]-[omim][BF4] (1:1) with or without acetone (carrier solvent), revealed that solvent can differentially mediate ILs' toxic profile. Acetone's ability to differentially affect ILs' cation's alkyl chain length, as well as the hydrolysis of [BF4(-)] anions was evident. Given that the toxic potency of the tested ILs seemed to be equal or even higher (in some cases) than those of conventional organic solvents, the present study revealed that the characterization of imidazolium-based ILs as "green solvents" should not be generalized, at least in case of their natural occurrence in mixtures with organic solvents, such as acetone. Copyright © 2015 Elsevier Inc. All rights reserved.

Morphology and ultrastructure of the freshwater rotifer Brachionus bidentatus (Monogononta: Brachionidae) using scanning and transmission electron microscopy.

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Guerrero-Jiménez, Gerardo; Zavala-Padilla, Guadalupe; Silva-Briano, Marcelo; Rico-Martínez, Roberto

2013-12-01

The study of sexual reproductive behavior supported by ultrastructural evidence is important in rotifers to describe differences among potential cryptic species. In this research, the morphology of the rotifer Brachionus bidentatus is described at the ultrastructural level, using electronic microscopy, together with a brief description and discussion of its sexual reproductive behavior. The characteristics of the (a) male, (b) the female, (c) the sexual egg or cyst, (d) the partenogenic egg, (e) the no-fecundated sexual egg (male egg), and (f) the trophi, were described. Another part of this research is dedicated to the ultrastructure of the sex cells of the male rotifer B. bidentatus. Samples were obtained from La Punta pond in Cosio, Aguascalientes, Mexico (22 degrees 08' N - 102 degrees 24' W), and a culture was maintained in the laboratory. Fifty organisms, from different stages of the rotifer Brachionus bidentatus, were fixed in Formol at 4% and then prepared; besides, for the trophi, 25 female rotifer Brachionus bidentatus were prepared for observation in a JEOL 5900 LV scanning electronic microscope. In addition, for the observation of male sex cells, 500 males of Brachionus bidentatus were isolated, fixed and observed in a JEOL 1010 transmission microscope. Females of B. bidentatus in laboratory cultures had a lifespan of five days (mean+one SD = 4.69 +/- 0.48; N=13), and produced 4.5 +/- 3.67 (N=6) parthenogenetic eggs during such lifespan. In the case of non-fertilized sexual eggs, they produced up to 18 eggs (mean+one SD = 13 +/- 4.93; N=7). Sexual females produced a single cyst on average (mean +/- one SD = I +/- 0; N=20). For the sexual cycle, the time of copulation between male and female ranged from 10 to 40 seconds (mean +/- one SD = 17.33 +/- 10.55, N=7). The spermatozoa are composed of a celular body and a flagellum, the size of the body is of 300 nm while the flagellum measures 1 700nm. The rods have a double membrane. Their mean length is almost

Effect of different densities of live and dead Chlorella vulgaris on the population growth of rotifers Brachionus calyciflorus and Brachionus patulus (Rotifera

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E. Lucía-Pavón

2001-12-01

Full Text Available In order to maintain rotifer populations during periods of low algal production, it is necessary to offer alternate diets, some of which include forms of preserved algae. The present work is based on the effect of live and dead Chlorella vulgaris on the population growth of Brachionus calyciflorus and Brachionus patulus. The experimental design consisted of 3 algal levels (0.5x10(6, 1.5x10(6 and 4.5x10(6 cells ml-1 offered in 3 forms (living, frozen and heat-killed. The maximal population density values for B. calyciflorus ranged from 55±1 ind. ml-1 (at 0.5x10(6 cells ml-1 to 471±72 ind. ml-1 (at 4.5x10(6 cells ml-1 with live Chlorella, but was much lower (6±1 to 26±6 ind. ml-1 with frozen or heat-killed alga under comparable food levels. However, the maximum population density of B. patulus under live or or heat-killed Chlorella was similar at comparable algal levels but when offered frozen algae it was four times less. The highest mean peak population density was 1227±83 ind. ml-1 under 4.5x10(6 cells ml-1. The rate of population increase for B. calyciflorus varied from 0.50 to 0.79 using live Chlorella, but under comparable conditions, this range was lower (0.21 to 0.31 for B. patulus. Results have been discussed in light of possible application for aquaculturePara mantener poblaciones de rotíferos durante periodos con escasez de microalgas, es necesario ofrecer dietas alternativas, incluyendo algunas formas de microalgas preservadas. El presente trabajo analiza el efecto de Chlorella vulgaris viva y muerta sobre el crecimiento poblacional de Brachionus calyciflorus y Brachonus patulus. El diseño experimental consistió en tres niveles de algas (0.5x10(6, 1.5x10(6 y 4.5x10(6 células ml-1 ofrecidas en tres formas (viva, congelada y muerta con agua caliente. Las abundancias máximas de población de B. calyciflorus variaron desde 55±1 ind. ml-1 (en 0.5x10(6 células ml-1 a 471±72 ind. ml-1 (en 4.5x10(6 células ml-1 con Chlorella viva

Global isolation by distance despite strong regional phylogeography in a small metazoan

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Mills Scott

2007-11-01

Full Text Available Abstract Background Small vagile eukaryotic organisms, which comprise a large proportion of the Earth's biodiversity, have traditionally been thought to lack the extent of population structuring and geographic speciation observed in larger taxa. Here we investigate the patterns of genetic diversity, amongst populations of the salt lake microscopic metazoan Brachionus plicatilis s. s. (sensu stricto (Rotifera: Monogononta on a global scale. We examine the phylogenetic relationships of geographic isolates from four continents using a 603 bp fragment of the mitochondrial COI gene to investigate patterns of phylogeographic subdivision in this species. In addition we investigate the relationship between genetic and geographic distances on a global scale to try and reconcile the paradox between the high vagility of this species and the previously reported patterns of restricted gene flow, even over local spatial scales. Results Analysis of global sequence diversity of B. plicatilis s. s. reveals the presence of four allopatric genetic lineages: North American-Far East Asian, Western Mediterranean, Australian, and an Eastern Mediterranean lineage represented by a single isolate. Geographically orientated substructure is also apparent within the three best sampled lineages. Surprisingly, given this strong phylogeographic structure, B. plicatilis s. s. shows a significant correlation between geographic and genetic distance on a global scale ('isolation by distance' – IBD. Conclusion Despite its cosmopolitan distribution and potential for high gene flow, B. plicatilis s. s. is strongly structured at a global scale. IBD patterns have traditionally been interpreted to indicate migration-drift equilibrium, although in this system equilibrium conditions are incompatible with the observed genetic structure. Instead, we suggest the pattern may have arisen through persistent founder effects, acting in a similar fashion to geographic barriers for larger

Global isolation by distance despite strong regional phylogeography in a small metazoan

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Mills, Scott; Lunt, David H; Gómez, Africa

2007-01-01

Background Small vagile eukaryotic organisms, which comprise a large proportion of the Earth's biodiversity, have traditionally been thought to lack the extent of population structuring and geographic speciation observed in larger taxa. Here we investigate the patterns of genetic diversity, amongst populations of the salt lake microscopic metazoan Brachionus plicatilis s. s. (sensu stricto) (Rotifera: Monogononta) on a global scale. We examine the phylogenetic relationships of geographic isolates from four continents using a 603 bp fragment of the mitochondrial COI gene to investigate patterns of phylogeographic subdivision in this species. In addition we investigate the relationship between genetic and geographic distances on a global scale to try and reconcile the paradox between the high vagility of this species and the previously reported patterns of restricted gene flow, even over local spatial scales. Results Analysis of global sequence diversity of B. plicatilis s. s. reveals the presence of four allopatric genetic lineages: North American-Far East Asian, Western Mediterranean, Australian, and an Eastern Mediterranean lineage represented by a single isolate. Geographically orientated substructure is also apparent within the three best sampled lineages. Surprisingly, given this strong phylogeographic structure, B. plicatilis s. s. shows a significant correlation between geographic and genetic distance on a global scale ('isolation by distance' – IBD). Conclusion Despite its cosmopolitan distribution and potential for high gene flow, B. plicatilis s. s. is strongly structured at a global scale. IBD patterns have traditionally been interpreted to indicate migration-drift equilibrium, although in this system equilibrium conditions are incompatible with the observed genetic structure. Instead, we suggest the pattern may have arisen through persistent founder effects, acting in a similar fashion to geographic barriers for larger organisms. Our data indicates

Plankton community and the relationship with the environment in saline lakes of Onon-Torey plain, Northeastern Mongolia.

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Afonina, Ekaterina Yu; Tashlykova, Natalya A

2018-02-01

The plankton community of sixteen saline lakes located on Onon-Torey plain (Northeastern Mongolia) during the filling phase and the raising of the water level was investigated in July 2011. Thirty-five taxa of phytoplankton and thirty-one species of zooplankton were found. For phytoplankton, blue-green algae ( Merismopedia elegans , Anabaenopsis elenkinii , Arthrospora fusiformis , Spirulina major , Lyngbya sp., Oscillatoria sp.) and green algae ( Monoraphidium minutum , Tetrastrum komarekii , Ankyra ocellata , Oocystis sp.) were dominant. For zooplankton, Filinia longiseta, Brachionus plicatilis , B. variabilis , Hexarthra mira (Rotifera), Daphnia magna , Moina brachiata , M. mongolica (Cladocera), Arctodiaptomus bacillifer , Mixodiaptomus incrassatus , Metadiaptomus asiaticus (Copepoda) dominated. Mineralization, active hydrogen ratio, dissolved oxygen and water temperature were the main factors influencing the diversity, structure and distribution of plankton organisms in the steppe lakes during low water level. The RDA analysis for phytoplankton and zooplankton from different lakes was carried out for selected two groups which included lakes and a subset related species. The first group is of oligohaline and mesohaline lakes in which mostly green algae, rotifers and copepods inhabit. The second group is of mesohaline and polyhaline lakes with mainly blue-green algae , some crustaceans and rotifers inhabiting. High abundance and biomass of Spirulina major , Oscillatoria sp. and Brachionus variabilis were observed in lakes with high mineralization, pH and temperature.

Vibrio rotiferianus sp. nov., isolated from cultures of the rotifer Brachionus plicatilis.

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Gomez-Gil, B; Thompson, F L; Thompson, C C; Swings, J

2003-01-01

Five Gram-negative bacterial strains, oxidase-positive, motile by means of more than one polar flagella, facultative anaerobe, arginine dihydrolase-negative, lysine- and omithine decarboxylase-positive, sensitive to the vibriostatic agent O/129, were isolated from a flow-through rotifer culture system in Gent, Belgium, and previously characterized by fluorescent amplified fragment length polymorphism. Comparison of the 16S rDNA sequence of strain LMG 21460T indicated close relationships (approximately 99% similarity) to Vibrio campbellii, Vibrio harveyi, Vibrio alginolyticus and Vibrio parahaemolyticus. However, DNA hybridization experiments revealed similarity values below 70% with its closest species V. campbellii and V. harveyi. Additionally, the analysed strains differ from related Vibrio species by the utilization of melibiose and production of acid from L-arabinose and amygdalin. Among the strains analysed, differences were observed in some phenotypic characters, particularly susceptibility to ampicillin, polymyxin B and amikacin, and urease activity. The major fatty acids identified were 16:0, 18:1 omega7c, 14:0, 12:0 3-OH and 18:0. Vibrio rotiferianus sp. nov. is proposed, with type strain LMG 21460T (=CAIM 577T); it has a DNA G+C content of 44.5 +/- 0.01 mol%.

Zooplâncton do estuário do Pina (Recife-Pernambuco-Brasil: composição e distribuição temporal

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Eneida Maria Eskinazi-Sant'Anna

1996-01-01

Full Text Available Estudos sobre a composição e variação diurna do zooplâncton do estuário do Pina (PE foram reali;r.ados, baseando-se em 200 litros de água superficial, coletada e filtrada em uma rede com malha de 69 11m de abertura, durante os períodos seco Uaneiro e fevereiro/91 e chuvoso Uunho e julho/91, em um ciclo diurno de 12 h. Paralelamente, foram coletados dados hidrolÓgicos. O zooplâncton esteve representado por 19 taxa, além do meroplâncton. Destacaram-se Favella ehrenbergi, Brachionus plicatilis, Copepoda nauplii e Oithona osvaldocnlzi (♀. Valores quantitativos mais altos foram registrados no peJíodo seco. O máximo registrado foi de 411.7490rg.m-3 e o mínimo 2.6230rg.m-3 .As correntes de marés foram as principais responsáveis pela variação espacial do zooplâncton. A diversidade específica foi baixa, evidenciando processos seletivos no estuário.Composieionand daily variation of zooplankton in the estuary of Pina (Brazil- PE was studied based on 200L of water filtered at surface through a net mesh size of 69 Jlm, during the dry (January-February/91 and the rainy (June-July/91 seasons. The samplcs were collected with time interval of three hours, during a daylight period. Concurrent hydrological data were obtained. Nineteen taxon of zooplankton were registered, including meroplankton, of which the most abundant was Favella ehrenbergi, followed by Brachionus plicatilis, Copepoda nauplii and Oithona osvaldocnlzi (♀. Higher quantitatives values occured in the dry reason. The maximum registered was 411,7490rg.m-3 and the minimum 2,6230rg.m-3 . The tidal currents were the main factor influencing the zooplankton spacial variation. Specific diversity was low, highlighting selcctive processes in the Pina estuary.

Population dynamics of Brachionus calyciflorus (Rotifera: Brachionidae) in waste water from food-processing industry in Mexico

OpenAIRE

Arévalo Stevenson, Raymundo Alfredo; Sarma, S.S.S.; Nandini, S.

1998-01-01

Waste water from Mexico's largest food processing industrial sector (based on maize, nejayote water) was used for growing Brachionus calyciflorus isolated from Lake Chapultepec in the Federal District of Mexico (D.F.). Nejayote water was collected from Colonia Providencia, D.F. Experiments were conducted at 25°C in 25 ml capacity vials with 20 ml of medium into which we introduced B. calyciflorus at an initial density of 1 ind ml-1. The experimental design consisted a total of 33 test vessels...

Shifts in rotifer life history in response to stable isotope enrichment: testing theories of isotope effects on organismal growth

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2017-01-01

In ecology, stable isotope labelling is commonly used for tracing material transfer in trophic interactions, nutrient budgets and biogeochemical processes. The main assumption in this approach is that the enrichment with a heavy isotope has no effect on the organism growth and metabolism. This assumption is, however, challenged by theoretical considerations and experimental studies on kinetic isotope effects in vivo. Here, I demonstrate profound changes in life histories of the rotifer Brachionus plicatilis fed 15N-enriched algae (0.4–5.0 at%); i.e. at the enrichment levels commonly used in ecological studies. These findings support theoretically predicted effects of heavy isotope enrichment on growth, metabolism and ageing in biological systems and underline the importance of accounting for such effects when using stable isotope labelling in experimental studies. PMID:28405367

Interspecies Interactions Reverse the Hazard of Antibiotics Exposure: A Plankton Community Study on Responses to Ciprofloxacin hydrochloride.

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Wang, Changyou; Wang, Ziyang; Zhang, Yong; Su, Rongguo

2017-05-24

The ecotoxicological effects of Ciprofloxacin hydrochloride (CIP) were tested on population densities of plankton assemblages consisting of two algae (Isochrysis galbana and Platymonas subcordiformis) and a rotifer (Brachionus plicatilis). The I. galbana showed a significant decrease in densities when concentrations of CIP were above 2.0 mg L -1 in single-species tests, while P. subcordiformis and B. plicatilis were stable in densities when CIP were less than10.0 mg L -1 . The equilibrium densities of I. galbana in community test increased with CIP concentrations after falling to a trough at 5.0 mg L -1 , showed a completely different pattern of P. subcordiformis which decreased with CIP concentrations after reaching a peak at 30.0 mg L -1 . The observed beneficial effect was a result of interspecies interactions of trophic cascade that buffered for more severe direct effects of toxicants. The community test-based NOEC of CIP (2.0 mg L -1 ), embodying the indirect effects, was different from the extrapolated one derived by single-species tests (0.5 mg L -1 ), but all lacked confidence interval. A CIP threshold concentration of obvious relevance to ecological interaction was calculated with a simplified plankton ecological model, achieving a value of 1.26 mg L -1 with a 95% bootstrapping confidence interval from 1.18 to 1.31 mg L -1 .

The ecological competition and grazing reverse the effects of sulfamethoxazole on plankton: a case study on characterizing community-level effect.

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Wang, Changyou; Liang, Shengkang; Zhang, Yong

2018-04-12

The toxic effects of sulfamethoxazole (SMX) on densities of two algae, Platymonas helgolandica var. tsingtaoensis, Isochrysis galbana, and of a rotifer, Brachionus plicatilis, were tested by the population and community experiments. Two endpoints, the carrying capacity and the densities array of community in steady state (DACS), were used to characterize the toxic effects at a population level and a community one, respectively. The results showed that the carrying capacity of P. helgolandica var. tsingtaoensis and B. plicatilis did not decline significantly in population test when the concentration of SMX was lower than 6.0 mg L -1 and 12.0 mg L -1 , respectively. However, I. galbana was sensitive to SMX and had presented toxic effect at 3.0 mg L -1 . By extrapolation of toxic effect at a population level to a community one, a derived community-NOEC was 3.0 mg L -1 , representing an inference from data of toxic effects at population level. In community experiment, when the customized community was in steady state, the density of I. galbana increased as a whole with SMX concentration in the range of tested concentration (0-144 mg L -1 ), while that of P. helgolandica var. tsingtaoensis assumed the trend of a reversed "v" in this range. Only the density of B. plicatilis decreased with SMX concentration. With the DACS as endpoint, a NOEC for the customized community was determined to be 6.0 mg L -1 . This indicates that interspecific interactions can reverse the toxic effects of SMX on phytoplankton. The DACS was reliable and stable, serving as the endpoints in assessment of the effects of the pollutants on the ecosystems.

Cultivation of Arthrospira (Spirulina platensis using confectionary wastes for aquaculture feeding

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Hala Y. El-Kassas

2015-12-01

Full Text Available The microalga biomass production from confectionary effluent is a possible solution for the urgent need for a live food in aquaculture. Arthrospira (Spirulina platensis was the dominant alga in effluent of “Biscomisr a confectionary factory”, in Alexandria–Egypt. Therefore, it was isolated from the effluent samples and used throughout the study. The cyanobacterium, A. platensis was grown on the effluent using 22 Central Composite Design (22 CCD. This work addresses the best effluent dilution (WC, % as well as sodium bicarbonate concentration (SBC on the alga growth and biochemical composition. Total protein, carbohydrate, lipid contents and fatty acid profiles of the produced algal biomass were highly improved. The statistical analyses suggested that the main effect of (WC, % is significant negative influences on the algal contents of proteins, lipids and carbohydrates (p > 0.01. Although it had a significant positive influence on chlorophyll (p > 0.01, no significant effect on algal β carotenes (p > 0.05 had been reported. The inter action effect of SBC together with WC, % exerted a significant negative influence on the algal proteins (p > 0.01 and no significant effect on the other responses (p > 0.05. The produced alga biomass was used for feeding the rotifer, Brachionus plicatilis for further application in aquaculture. Growth rate, reproductive rate and fecundity attributes, fatty acid content of B. plicatilis were amended. The Pearson correlation test indicated that β carotenes displayed a highly positive significant correlation with the growth rate of B. plicatilis (r = 0.733, p < 0.01 and the carbohydrates showed significant positive correlations with Egg % (r = 0.657, p < 0.05.

Morphological similarity and ecological overlap in two rotifer species.

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Gabaldón, Carmen; Montero-Pau, Javier; Serra, Manuel; Carmona, María José

2013-01-01

Co-occurrence of cryptic species raises theoretically relevant questions regarding their coexistence and ecological similarity. Given their great morphological similitude and close phylogenetic relationship (i.e., niche retention), these species will have similar ecological requirements and are expected to have strong competitive interactions. This raises the problem of finding the mechanisms that may explain the coexistence of cryptic species and challenges the conventional view of coexistence based on niche differentiation. The cryptic species complex of the rotifer Brachionus plicatilis is an excellent model to study these questions and to test hypotheses regarding ecological differentiation. Rotifer species within this complex are filtering zooplankters commonly found inhabiting the same ponds across the Iberian Peninsula and exhibit an extremely similar morphology-some of them being even virtually identical. Here, we explore whether subtle differences in body size and morphology translate into ecological differentiation by comparing two extremely morphologically similar species belonging to this complex: B. plicatilis and B. manjavacas. We focus on three key ecological features related to body size: (1) functional response, expressed by clearance rates; (2) tolerance to starvation, measured by growth and reproduction; and (3) vulnerability to copepod predation, measured by the number of preyed upon neonates. No major differences between B. plicatilis and B. manjavacas were found in the response to these features. Our results demonstrate the existence of a substantial niche overlap, suggesting that the subtle size differences between these two cryptic species are not sufficient to explain their coexistence. This lack of evidence for ecological differentiation in the studied biotic niche features is in agreement with the phylogenetic limiting similarity hypothesis but requires a mechanistic explanation of the coexistence of these species not based on

Morphological similarity and ecological overlap in two rotifer species.

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Carmen Gabaldón

Full Text Available Co-occurrence of cryptic species raises theoretically relevant questions regarding their coexistence and ecological similarity. Given their great morphological similitude and close phylogenetic relationship (i.e., niche retention, these species will have similar ecological requirements and are expected to have strong competitive interactions. This raises the problem of finding the mechanisms that may explain the coexistence of cryptic species and challenges the conventional view of coexistence based on niche differentiation. The cryptic species complex of the rotifer Brachionus plicatilis is an excellent model to study these questions and to test hypotheses regarding ecological differentiation. Rotifer species within this complex are filtering zooplankters commonly found inhabiting the same ponds across the Iberian Peninsula and exhibit an extremely similar morphology-some of them being even virtually identical. Here, we explore whether subtle differences in body size and morphology translate into ecological differentiation by comparing two extremely morphologically similar species belonging to this complex: B. plicatilis and B. manjavacas. We focus on three key ecological features related to body size: (1 functional response, expressed by clearance rates; (2 tolerance to starvation, measured by growth and reproduction; and (3 vulnerability to copepod predation, measured by the number of preyed upon neonates. No major differences between B. plicatilis and B. manjavacas were found in the response to these features. Our results demonstrate the existence of a substantial niche overlap, suggesting that the subtle size differences between these two cryptic species are not sufficient to explain their coexistence. This lack of evidence for ecological differentiation in the studied biotic niche features is in agreement with the phylogenetic limiting similarity hypothesis but requires a mechanistic explanation of the coexistence of these species not

Plankton community and the relationship with the environment in saline lakes of Onon-Torey plain, Northeastern Mongolia

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Ekaterina Yu. Afonina

2018-02-01

Full Text Available The plankton community of sixteen saline lakes located on Onon-Torey plain (Northeastern Mongolia during the filling phase and the raising of the water level was investigated in July 2011. Thirty-five taxa of phytoplankton and thirty-one species of zooplankton were found. For phytoplankton, blue-green algae (Merismopedia elegans, Anabaenopsis elenkinii, Arthrospora fusiformis, Spirulina major, Lyngbya sp., Oscillatoria sp. and green algae (Monoraphidium minutum, Tetrastrum komarekii, Ankyra ocellata, Oocystis sp. were dominant. For zooplankton, Filinia longiseta, Brachionus plicatilis, B. variabilis, Hexarthra mira (Rotifera, Daphnia magna, Moina brachiata, M. mongolica (Cladocera, Arctodiaptomus bacillifer, Mixodiaptomus incrassatus, Metadiaptomus asiaticus (Copepoda dominated. Mineralization, active hydrogen ratio, dissolved oxygen and water temperature were the main factors influencing the diversity, structure and distribution of plankton organisms in the steppe lakes during low water level. The RDA analysis for phytoplankton and zooplankton from different lakes was carried out for selected two groups which included lakes and a subset related species. The first group is of oligohaline and mesohaline lakes in which mostly green algae, rotifers and copepods inhabit. The second group is of mesohaline and polyhaline lakes with mainly blue-green algae, some crustaceans and rotifers inhabiting. High abundance and biomass of Spirulina major, Oscillatoria sp. and Brachionus variabilis were observed in lakes with high mineralization, pH and temperature.

Brachionidae (Rotifera: Monogononta de la albufera El Paraíso y el reporte de Brachionus ibericusen el Perú

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Emily Toscano

2013-12-01

Full Text Available En este trabajo se reportan las especies de Brachionidae reconocidos en las muestras recogidas en octubre de 2010 en la albufera Laguna El Paraiso, Huacho (11°13' −11° 10'S, 77° 35' −77°40'W. Cinco especies fueron determinadas: Keratella tropica, Brachionus quadridentatus, B. urceolaris, B. angularis y B. ibericusCiros-Pérez 2001. Este último es un nuevo reporte para el Perú y amplía su distribución a nivel mundial.

Ovarian development and early larval survival of Stenopus zanzibaricus (Bruce, 1976

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Daniel Marques

2014-06-01

Full Text Available Despite economically valuable, ornamental shrimps are poorly studied and there is a lack of protocols for their captive breeding. Stenopus is one of the most important genera of ornamental shrimps, being Stenopus zanzibaricus one of the species with less information about captive breeding and larviculture. For a better knowledge of its reproductive cycle, we evaluated morphological and color changes during ovarian development of adult females through daily photographs taken during all the cycle. The effect of three diets (Brachionus plicatilis + Tetraselmis chuii; newly artemia nauplii + Tetraselmis chuii; newly artemia nauplii and two different temperatures (25ºC and 27ºC on early larval development were also evaluated. With this study, it was expected to obtain some insight about Stenopus zanzibaricus reproductive cycle and early larval development, in order to develop captive breeding and larval rearing protocols for this economic valuable species.

Two-dimensional micro-beam imaging of trace elements in a single plankton measured by a synchrotron radiation X-ray fluorescence analysis

International Nuclear Information System (INIS)

Ezoe, Masako; Sasaki, Miho; Hokura, Akiko; Nakai, Izumi; Terada, Yasuko; Yoshinaga, Tatsuki; Tukamoto, Katsumi; Hagiwara, Atsushi

2002-01-01

Two-dimensional imaging and a quantitative analysis of trace elements in rotifer, Brachionus plicatilis, belonging to zooplankton, were carried out by a synchrotron radiation X-ray fluorescence analysis (SR-XRF). The XRF imaging revealed that female rotifers accumulated Fe and Zn in the digestive organ and Fe, Zn, Cu, and Ca in the sexual organs, while the Mn level was high in the head. From a quantitative analysis by inductively coupled plasma mass spectrometry (ICP-MS), we found that rotifers eat the chlorella and accumulate the above elements in the body. The result of quantitative analyses of Mn, Cu, and Zn by SR-XRF in a single sample is in fair agreement with the average values determined by ICP-MS analyses, which were obtained by measuring a large number of rotifers, digested by nitric acid. The present study has demonstrated that SR-XRF is an effective tool for the trace element analysis of a single individual of rotifer. (author)

Two-dimensional micro-beam imaging of trace elements in a single plankton measured by a synchrotron radiation X-ray fluorescence analysis

Energy Technology Data Exchange (ETDEWEB)

Ezoe, Masako; Sasaki, Miho; Hokura, Akiko; Nakai, Izumi [Tokyo Univ. of Science, Faculty of Science, Tokyo (Japan); Terada, Yasuko [Japan Synchrotron Radiation Research Inst., Mikazuki, Hyogo (Japan); Yoshinaga, Tatsuki; Tukamoto, Katsumi [Tokyo Univ., Ocean Research Inst., Tokyo (Japan); Hagiwara, Atsushi [Nagasaki Univ., Graduate School of Science and Technology, Bunkyou, Nagasaki (Japan)

2002-10-01

Two-dimensional imaging and a quantitative analysis of trace elements in rotifer, Brachionus plicatilis, belonging to zooplankton, were carried out by a synchrotron radiation X-ray fluorescence analysis (SR-XRF). The XRF imaging revealed that female rotifers accumulated Fe and Zn in the digestive organ and Fe, Zn, Cu, and Ca in the sexual organs, while the Mn level was high in the head. From a quantitative analysis by inductively coupled plasma mass spectrometry (ICP-MS), we found that rotifers eat the chlorella and accumulate the above elements in the body. The result of quantitative analyses of Mn, Cu, and Zn by SR-XRF in a single sample is in fair agreement with the average values determined by ICP-MS analyses, which were obtained by measuring a large number of rotifers, digested by nitric acid. The present study has demonstrated that SR-XRF is an effective tool for the trace element analysis of a single individual of rotifer. (author)

Decoloration and detoxification of effluents by ionizing radiation

Science.gov (United States)

Borrely, Sueli I.; Morais, Aline V.; Rosa, Jorge M.; Badaró-Pedroso, Cintia; da Conceição Pereira, Maria; Higa, Marcela C.

2016-07-01

Three distinct textile samples were investigated for color and toxicity (S1-chemical/textile industry; S2-final textile effluent; S3 - standard textile produced effluent-untreated blue). Radiation processing of these samples were carried out at Dynamitron Electron Beam Accelerator and color and toxicity removal were determined: color removal by radiation was 96% (40 kGy, S1); 55% (2.5 kGy, S2) and 90% (2.5 kGy, S3). Concerning toxicity assays, Vibrio fischeri luminescent bacteria demonstrated higher reduction after radiation than the other systems: removal efficiencies were 33% (20 kGy, S1); 55% (2.5 kGy, S2) and 33% (2.5 kGy, S3). Daphnia similis and Brachionus plicatilis fitted well for S3 effluents. Hard toxic volumes into biological treatment plant may be avoided if radiation would be previously applied in a real plant. Results reveled how indispensable is to run toxicity to more than one living-organism.

Free ammonia offers algal crop protection from predators in dairy wastewater and ammonium-rich media.

Science.gov (United States)

Thomas, Patrick K; Dunn, Gary P; Passero, Maxine; Feris, Kevin P

2017-11-01

Cost-effective methods for protecting crops from grazing organisms like rotifers are needed to reduce the risk of pond crashes in mass algal cultures. We present a novel strategy to optimize the exposure time to free ammonia, via control of media pH, in both defined media and dairy anaerobic digester effluent to suppress rotifers and maintain algal productivity. We tested five different free ammonia exposure times (0, 1, 2, 6, and 12h) and found a significant nonlinear effect of exposure time (p0.9) on rotifer survival. In both media types, 6-12h of elevated free ammonia significantly reduced Brachionus plicatilis rotifer survival with no negative effects on Nannochloropsis oculata, while shorter exposure times were insufficient to inhibit rotifers, leading to severe algal culture crashes. These results suggest that algal crops can be protected from rotifers, without productivity loss, by elevating free ammonia for 6 or more hours. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bioconcentration and localization of lead in the freshwater rotifer Brachionus calyciflorus Pallas 1677 (Rotifera: Monogononta)

International Nuclear Information System (INIS)

Alvarado-Flores, Jesús; Rico-Martínez, Roberto; Ventura-Juárez, Javier; Silva-Briano, Marcelo; Rubio-Franchini, Isidoro

2012-01-01

We studied how lead is bioconcentrated and distributed in the rotifer Brachionus calyciflorus using metal histochemistry to locate lead granules, Leadmium Green ® analysis to establish the route of uptake, atomic absorption to determined the bioconcentration factor (BCF), and detected the presence of microelements in the cuticle by X-ray microanalysis with scanning electron microscopy. Our results indicate: (a) the digestive system is the main route of lead uptake in the rotifer B. calyciflorus, (b) after 24-h lead is deposited in granules in the mastax and vitellarium, (c) our energy-dispersive X-ray microanalysis indicates decalcification taking place in the cuticle of the rotifer after a 24-h lead exposure, and (d) we determined a BCF = 115 for lead after a 24 h exposure. However, the route of mobilization and storage of intracellular lead are still not fully understood in B. calyciflorus.

Bioconcentration and localization of lead in the freshwater rotifer Brachionus calyciflorus Pallas 1677 (Rotifera: Monogononta)

Energy Technology Data Exchange (ETDEWEB)

Alvarado-Flores, Jesus, E-mail: jalvaflo@hotmail.com [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Quimica, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Rico-Martinez, Roberto, E-mail: rrico@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Quimica, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Ventura-Juarez, Javier, E-mail: jventur@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Morfologia, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Silva-Briano, Marcelo, E-mail: msilva@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Biologia, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Rubio-Franchini, Isidoro, E-mail: rubio_reyes@hotmail.com [Instituto de Servicios de Salud del Estado de Aguascalientes, Laboratorio Estatal de Salud Publica, Av. Siglo XXI 105, Ciudad Satelite Morelos, C.P. 20270, Aguascalientes, Ags. (Mexico)

2012-03-15

We studied how lead is bioconcentrated and distributed in the rotifer Brachionus calyciflorus using metal histochemistry to locate lead granules, Leadmium Green{sup Registered-Sign} analysis to establish the route of uptake, atomic absorption to determined the bioconcentration factor (BCF), and detected the presence of microelements in the cuticle by X-ray microanalysis with scanning electron microscopy. Our results indicate: (a) the digestive system is the main route of lead uptake in the rotifer B. calyciflorus, (b) after 24-h lead is deposited in granules in the mastax and vitellarium, (c) our energy-dispersive X-ray microanalysis indicates decalcification taking place in the cuticle of the rotifer after a 24-h lead exposure, and (d) we determined a BCF = 115 for lead after a 24 h exposure. However, the route of mobilization and storage of intracellular lead are still not fully understood in B. calyciflorus.

PENYIMPANAN ROTIFERA INSTAN (Brachionus rotundiformis PADA SUHU YANG BERBEDA DENGAN PEMBERIAN PAKAN MIKROALGA KONSENTRAT

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Erlania Erlania

2016-11-01

Full Text Available Keberhasilan kegiatan budidaya perikanan harus ditunjang dengan ketersediaan benih yang berkesinambungan. Oleh karena itu, diperlukan juga ketersediaan pakan alami larva berupa rotifera (Brachionus rotundiformis. Desain percobaan berupa rancangan faktorial dengan dua faktor dan lima ulangan diaplikasikan dalam penelitian ini. Sebagai perlakuan berupa suhu ruang penyimpanan (suhu kamar, suhu ruang AC, dan suhu refrigerator/lemari es dan pakan mikroalga konsentrat (monospesies dan multispesies. Bakteri probiotik juga digunakan sebagai pengontrol kualitas air. Spesies mikroalga yang digunakan adalah Nannochloropsis sp., Dunaliella sp., Isochrysis sp., dan Pavlova sp. Parameter yang diukur adalah kelimpahan rotifera dan parameter kualitas air media kultur (pH, salinitas, DO, dan NH3. Analisis data terdiri atas analisis regresi, analisis ragam, dan uji keparalelan. Hasil pengukuran parameter kualitas air selama penyimpanan menunjukkan kondisi media yang relatif stabil dan merupakan kisaran optimum bagi pertumbuhan B. rotundiformis. Kelimpahan maksimum tertinggi dari B. rotundiformis baik pada perlakuan pakan monospesies maupun multispesies alga adalah pada suhu kamar. Dari interaksi kedua perlakuan, diperoleh kelimpahan akhir tertinggi pada suhu ruang AC–pakan multispesies. Hal ini menunjukkan bahwa rotifera dapat disimpan lebih lama pada suhu ruang AC dengan pemberian pakan multispesies alga. The success of any aquaculture practices should be supported by sustainable supply of fish fry. Therefore, the availability of rotifers (Brachionus rotundiformis as natural feed for fish larvae is required. The research was arranged in factorial design with two treatments and five replications. Treatments consisted of different room storage temperatures (refrigerator, room temperature, and room with air conditioner/AC and microalgae concentrate added as rotifer feed (monospecies and multispecies algae. Probiotic bacteria was used to control water quality

Réflexions sur les rotifères en tant qu'indicateurs biologiques

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POURRIOT R.

1976-01-01

Full Text Available Quelques espèces de Rotifères fournissent un bon exemple d'indicateurs écologiques pour un facteur limitant : Synchaeta lakowitziana, Conochitoides natans, Notholca spp (température, Brachionus plicatilis (salinité. Le système d'indexation des espèces à la qualité des eaux est discuté. Les espèces strictement édaphiques (non aquatiques, les espèces rares appartenant à des genres où la variabilité est grande et les espèces euryoecques, peu caractéristiques, devraient être exclues des listes d'indicateurs établies par SLADECEK (1973, car elles ne facilitent pas l'application de ce système. Il s'avère nécessaire d'améliorer le poids indicatif et la valeur de saprobité des espèces, de ne conserver que les plus caractéristiques par leur constance et leur fidélité. Il serait, de plus, intéressant de se référer à des index plus dynamiques que statiques.

Differentiation between activity of digestive enzymes of Brachionus calyciflorus and extracellular enzymes of its epizooic bacteria

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Wilko H. AHLRICHS

2009-08-01

Full Text Available The rotifer Brachionus calyciflorus was examined by scanning electron microscopy (SEM for surface-attached, i.e. epizootic, bacteria to ascertain their specific localization and thus find out if we could discern between rotifer and bacterial enzyme activity. The lorica of B. calyciflorus was colonized by one distinct type of bacteria, which originated from the algal culture used for rotifer feeding. The corona, posterior epidermis and foot of all inspected individuals were always without attached bacteria. The density of the attached bacteria was higher with the increasing age of B. calyciflorus: while young individuals were colonized by ~ tens of bacterial cells, older ones had on average hundreds to thousands of attached bacteria. We hypothesize that epizooic bacteria may produce the ectoenzymes phosphatases and β-N-acetylhexosaminidases on the lorica, but not on the corona of B. calyciflorus. Since enzyme activities of epizooic bacteria may influence the values and interpretation of bulk rotifer enzyme activities, we should take the bacterial contribution into account.

Reduced expression of exocytotic proteins caused by anti-cholinesterase pesticides in Brachionus calyciflorus (Rotifera: Monogononta

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IA Pérez-Legaspi

Full Text Available AbstractThe organophosphate and carbamate pesticides methyl-parathion and carbaryl have a common action mechanism: they inhibit acetylcholinesterase enzyme by blocking the transmission of nerve impulses. However, they can alter the expression of exocytotic membrane proteins (SNARE, by modifying release of neurotransmitters and other substances. This study evaluated the adverse effects of the pesticides methyl-parathion and carbaryl on expression of SNARE proteins: Syntaxin-1, Syntaxin-4 and SNAP-23 in freshwater rotifer Brachionus calyciflorus. Protein expression of these three proteins was analyzed before and after exposure to these two pesticides by Western Blot. The expression of Syntaxin-1, Syntaxin-4 and SNAP-23 proteins in B. calyciflorussignificantly decreases with increasing concentration of either pesticides. This suggests that organophosphates and carbamates have adverse effects on expression of membrane proteins of exocytosis by altering the recognition, docking and fusion of presynaptic and vesicular membranes involved in exocytosis of neurotransmitters. Our results demonstrate that the neurotoxic effect of anticholinesterase pesticides influences the interaction of syntaxins and SNAP-25 and the proper assembly of the SNARE complex.

Population dynamics of Brachionus calyciflorus (Rotifera: Brachionidae in waste water from food-processing industry in Mexico

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Raymundo Alfredo Arévalo Stevenson

1998-09-01

Full Text Available Waste water from Mexico's largest food processing industrial sector (based on maize, nejayote water was used for growing Brachionus calyciflorus isolated from Lake Chapultepec in the Federal District of Mexico (D.F.. Nejayote water was collected from Colonia Providencia, D.F. Experiments were conducted at 25°C in 25 ml capacity vials with 20 ml of medium into which we introduced B. calyciflorus at an initial density of 1 ind ml-1. The experimental design consisted a total of 33 test vessels (2 food combinations X 5 densities X 3 replicates = 30 plus 3 replicates as controls that contained only algae. Experiments were terminated after day 16. Waste water in original concentration did nt rotifes. However, when diluted to 5 oncentrations (ranging from 2% to 32% and pH adjusted to 7.0, rotifer density increased with increasing concentration of waste water. Green algae (at constant density of 2 X 10 6 cells-1 of Chlorella in combination with waste water resulted in a higher abundance of rotifers only at higher concentration (above 8 % of waste water. The maximum peak density of rotifers (238-50 ind ml -1 was obtained at 16% dilution of waste water nd with addition of Chlorella. The rate of population increase per day ® (mean-SD varied from 0.355-0.059 to 0.457-0.048 depending on food combination and concetration.Se usó aguas de desecho de la industria de la masa y la tortilla (aguas de nixtamal o nejayote para crecer rotíferos de agua dulce, Brachionus calyciflorus. El nejayote sin dilución no permitió el desarrollo del rotífero. Sin embargo, cuando se diluyó, B. calyciflorus aprovechó la materia orgánica. El agua de desecho por sí misma (sin alimento algal adicional fue comparable al agua con densidades del alga Chlorella de 2 X 10(6 células ml-1. Concentraciones de nejayote por encima del 8% no permitieron el crecimiento poblacional. Sin embargo, la presencia de alga permitió el desarrollo del rotífero a concentraciones de 8% y 16

Effects of chlorpyrifos on life cycle parameters, cytochrome P450S expression, and antioxidant systems in the monogonont rotifer Brachionus koreanus.

Science.gov (United States)

Kim, Ryeo-Ok; Kim, Bo-Mi; Jeong, Chang-Bum; Lee, Jae-Seong; Rhee, Jae-Sung

2016-06-01

Chlorpyrifos is a widely used organophosphorus insecticide for controlling diverse insect pests of crops. In the monogonont rotifer Brachionus koreanus, population growth retardation with the inhibition of lifespan, fecundity, and individual body size of ovigerous females was shown over 10 d in response to chlorpyrifos exposure. At the molecular and biochemical levels, the rotifer B. koreanus defensome, composed of cytochrome P450 complements, heat shock protein 70, and antioxidant enzymatic systems (i.e., glutathione, glutathione peroxidase, glutathione reductase, and glutathione S-transferase), was significantly induced in response to different concentrations of chlorpyrifos. Thus, chlorpyrifos strongly induced a defensome system to mitigate the deleterious effects of chlorpyrifos at in vivo and in vitro levels as a trade-off in fitness costs. Environ Toxicol Chem 2016;35:1449-1457. © 2015 SETAC. © 2015 SETAC.

Order-sorted Algebraic Specifications with Higher-order Functions

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth

1995-01-01

This paper gives a proposal for how order-sorted algebraic specification languages can be extended with higher-order functions. The approach taken is a generalisation to the order-sorted case of an approach given by Mller, Tarlecki and Wirsing for the many-sorted case. The main idea in the proposal...

The use of morphological and histological features as nutritional condition indices of Pagrus pagrus larvae

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Marina Vera Diaz

Full Text Available Morphometrical and histological techniques were employed to characterize Pagrus pagrus larvae nutritional condition. Larvae were reared in laboratory under controlled conditions with the main objective of testing whether these methodologies allowed finding differences between larvae from different feeding treatments. Once yolk was consumed (three days after hatching larvae were assigned to a feeding treatment: starved during the whole experiment; delayed feeding, starved during three days; fed during the entire experiment. Algae (Nannochloropsis oculata and rotifers (Brachionus plicatilis were provided to larvae for feed treatments. Larvae were fixed daily; for morphometrical purposes in 5% formaldehyde solution, and in Bouin for histological sections. Results herein obtained showed that both methodologies are sensitive enough to distinguish larvae characterized by different nutritional condition states obtained from the feeding treatments. Consequently, these methodologies could be employed in wild red porgy larvae in order to asses their nutritional condition. These techniques could also be employed to check larval quality obtained with aquaculture purposes to estimate the effects of changes in rearing protocols or kind of food supply and thus, to guaranty a higher survival of early developmental stages of reared larvae.

Combined toxicity effects of chlorine, ammonia, and temperature on marine plankton. Progress report, September 16, 1975--September 30, 1976

Energy Technology Data Exchange (ETDEWEB)

Goldman, J. C.; Ryther, J. H.

1976-10-01

Research on the combined effects of chlorine, ammmonia and temperature on marine plankton have been carried out for 20 months. To date continuous-flow bioassays have been conducted on lobster larvae (Homarus americanus), oyster larvae (Crassostrea virginica), copepods (Acartia tonsa), rotifers (Brachionus plicatilis), three juvenile and larval fish, killifish (Fundulus heteroclitus), scup (Stenotomus versicolor), and winter flounder (Pseudopleuronectes americanus), and phytoplankton (the diatom Phaeodactylum tricornutum). In addition, studies on zooplankton metabolism, filtration rates, and growth were carried out on exposed organisms. In general, the responses of invertebrates were distinctly different than those of fish: increasing mortality with increasing chlorine dose and greater sensitivity to chloramines than free chlorine in the former, and a threshold level of chlorine and greater sensitivity to free chlorine in the latter. Phytoplankton responses indicate that chlorine effects on primary producers are minimal compared to the serious effects on zooplankton, particularly larval forms that spawn intermittently. The overall conclusion of our studies is that chlorine application at power plants must be carried out with extreme caution and that serious consideration should be given to applying dechlorination at all coastal cooling systems.

In vitro populations of rotifer Brachionus plicatilis Müller demonstrate inhibition when fed with copper-preaccumulating microalgae.

Science.gov (United States)

Moreno-Garrido, I; Lubián, L M; Soares, A M

1999-10-01

Four marine microalgal species (Chlorella autotrophyca, Nannochloropsis gaditana, Tetraiselmis chuii, and Isochrysis aff. galbana) were exposed for 24 h to 1 mg L(-1) dissolved copper and then transferred to fresh medium. After that, a group of 10 neonate rotifers were fed with these four microalgal species. The levels of accumulated copper in cellular concentrations of the microalgae were checked, with the result of around 40% of original concentration, with the exception of I. aff. galbana (25% of original concentration). In all cases, cells with preaccumulated metal caused a delay of 1 or 2 days in populational development of rotifers (increase in "lag phase"). The microalgae that were not fed to rotifers (disposed in parallel series) did not significantly transfer metal to the medium after the first day.

Morphological alterations in the freshwater rotifer Brachionus calyciflorus Pallas 1766 (Rotifera: Monogononta) caused by vinclozolin chronic exposure.

Science.gov (United States)

Alvarado-Flores, Jesús; Rico-Martínez, Roberto; Adabache-Ortíz, Araceli; Silva-Briano, Marcelo

2015-05-01

Vinclozolin (VZ) is a dicarboximide fungicide widely used on fruits, vegetables and wines, effective against fungi plagues. In this study we characterized the effects of VZ using a 4-day reproductive chronic assay with the freshwater rotifer Brachionus calyciflorus. The assay included observations of several features of asexual and sexual reproduction. Our results indicate that VZ: (a) increased asexual and sexual reproduction, (b) caused severe abnormality in females and (c) these abnormalities were inherited by sexual and asexual reproduction. At 1.2 mg/L three abnormal females were found out of 457 total females (0.66 %). This low percentage is consistent and reproducible according to further analysis, where we increased the number of replicates and total females exposed to 1.2 mg/L of VZ, and found 18 abnormal females out of 2868 total females (0.63 % abnormality). Interestingly, abnormal females found at 5.6 mg/L VZ exposure, were able to show mating behavior. Our results suggest that VZ behaves as a strong endocrine disruptor whose effects show the characteristic inverted-U-shape exposure concentration response curve regarding the intrinsic population increase and the percentage of abnormalities as endpoints.

Optofluidic technology for monitoring rotifer Brachionus calyciflorus responses to regular light pulses

Science.gov (United States)

Cartlidge, Rhys; Campana, Olivia; Nugegoda, Dayanthi; Wlodkowic, Donald

2016-12-01

Behavioural alterations can occur as a result of a toxicant exposure at concentrations significantly lower than lethal effects that are commonly measured in acute toxicity testing. The use of alternating light and dark photoperiods to test phototactic responses of aquatic invertebrates in the presence of environmental contaminants provides an attractive analytical avenue. Quantification of phototactic responses represents a sublethal endpoint that can be employed as an early warning signal. Despite the benefits associated with the assessment of these endpoints, there is currently a lack of automated and miniaturized bioanalytical technologies to implement the development of toxicity testing with small aquatic species. In this study we present a proof-of-concept microfluidic Lab-on-a-Chip (LOC) platform for the assessment of rotifer swimming behavior in the presence of the toxicant copper sulfate. The device was designed to assess impact of toxicants at sub-lethal concentrations on freshwater crustacean Brachionus calyciflorus, testing behavioral endpoints such as animal swimming distance, speed and acceleration. The LOC device presented in this work enabled straightforward caging of microscopic crustaceans as well as non-invasive analysis of rapidly swimming animals in a focal plane of a video-microscopy system. The chip-based technology was fabricated using a new photolithography method that enabled formation of thick photoresist layers with minimal distortion. Photoresist molds were then employed for replica molding of LOC devices with poly(dimethylsiloxane) (PDMS) elastomer. The complete bioanalytical system consisted of: (i) microfluidic PDMS chip-based device; (ii) peristaltic microperfusion pumping manifold; (iii) miniaturized CMOS camera for video data acquisition; and (iv) video analysis software algorithms for quantification of changes in swimming behaviour of B. calyciflorus in response to reference toxicants.

Kweekopzet van de Brachionus plicatilis op basis van kunstmatige voeders: Algenconcentraten en Rotimac als fast-food voor voedseldiertjes

NARCIS (Netherlands)

Vin, de C.M.

2003-01-01

De aquacultuursector is de snelst groeiende voedselproducerende sector ter wereld. De grootste producent is China, gevolgd door India en Japan. Binnen de Europese Unie is Spanje koploper, gevolgd door Frankrijk en Italië. Nederland komt op de vijfde plaats. Nederland heeft een aquacultuur productie

EST based phylogenomics of Syndermata questions monophyly of Eurotatoria

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Bucher Gregor

2008-12-01

Full Text Available Abstract Background The metazoan taxon Syndermata comprising Rotifera (in the classical sense of Monogononta+Bdelloidea+Seisonidea and Acanthocephala has raised several hypotheses connected to the phylogeny of these animal groups and the included subtaxa. While the monophyletic origin of Syndermata and Acanthocephala is well established based on morphological and molecular data, the phylogenetic position of Syndermata within Spiralia, the monophyletic origin of Monogononta, Bdelloidea, and Seisonidea and the acanthocephalan sister group are still a matter of debate. The comparison of the alternative hypotheses suggests that testing the phylogenetic validity of Eurotatoria (Monogononta+Bdelloidea is the key to unravel the phylogenetic relations within Syndermata. The syndermatan phylogeny in turn is a prerequisite for reconstructing the evolution of the acanthocephalan endoparasitism. Results Here we present our results from a phylogenomic approach studying i the phylogenetic position of Syndermata within Spiralia, ii the monophyletic origin of monogononts and bdelloids and iii the phylogenetic relations of the latter two taxa to acanthocephalans. For this analysis we have generated EST libraries of Pomphorhynchus laevis, Echinorhynchus truttae (Acanthocephala and Brachionus plicatilis (Monogononta. By extending these data with database entries of B. plicatilis, Philodina roseola (Bdelloidea and 25 additional metazoan species, we conducted phylogenetic reconstructions based on 79 ribosomal proteins using maximum likelihood and bayesian approaches. Our findings suggest that the phylogenetic position of Syndermata within Spiralia is close to Platyhelminthes, that Eurotatoria are not monophyletic and that bdelloids are more closely related to acanthocephalans than monogononts. Conclusion Mapping morphological character evolution onto molecular phylogeny suggests the (partial or complete reduction of the corona and the emergence of a retractable

Decoloration and detoxification of effluents by ionizing radiation

International Nuclear Information System (INIS)

Borrely, Sueli I.; Morais, Aline V.; Rosa, Jorge M.; Badaró-Pedroso, Cintia; Conceição Pereira, Maria da; Higa, Marcela C.

2016-01-01

Three distinct textile samples were investigated for color and toxicity (S1–chemical/textile industry; S2–final textile effluent; S3 - standard textile produced effluent–untreated blue). Radiation processing of these samples were carried out at Dynamitron Electron Beam Accelerator and color and toxicity removal were determined: color removal by radiation was 96% (40 kGy, S1); 55% (2.5 kGy, S2) and 90% (2.5 kGy, S3). Concerning toxicity assays, Vibrio fischeri luminescent bacteria demonstrated higher reduction after radiation than the other systems: removal efficiencies were 33% (20 kGy, S1); 55% (2.5 kGy, S2) and 33% (2.5 kGy, S3). Daphnia similis and Brachionus plicatilis fitted well for S3 effluents. Hard toxic volumes into biological treatment plant may be avoided if radiation would be previously applied in a real plant. Results reveled how indispensable is to run toxicity to more than one living-organism. - Highlights: • 2.5 kGy was enough for decoloration and detoxification of S2 and S3. • S1 effluents were very toxic and required at least 20 kGy for detoxification. • Radiation processing reduced toxicity for 100% of treated samples. • V. fischeri was the best tool for toxicity measurements.

Rearing larvae of dusky grouper, Epinephelus marginatus (Lowe, 1834, (Pisces: Serranidae in a semi-extensive mesocosm

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Maria Emília Cunha

2009-10-01

Full Text Available One of the major obstacles to propagating dusky grouper, Epinephelus marginatus, is the difficulty of rearing the early larvae. We have successfully raised dusky grouper larvae in mesocosms using a mixed diet of endogenous plankton grown in the rearing tank and an exogenous supply of Brachionus plicatilis and Artemia sp. Newly hatched larvae at an initial density of 1.3 ind.l-1 were stocked in partially shaded 3 m3 circular outdoor tanks during the summers of 2007 and 2008. Before introducing newly hatched larvae, the water was left for six days to promote plankton growth. Larval growth occurred at two different rates: i a faster rate from first feeding to the beginning of metamorphosis, and ii a slower rate at transformation. Survival at the beginning of metamorphosis was less than 10% (33 DPH in 2007 and between 25 and 50% (25 DPH in 2008. High mortalities were observed during larval transformation. The estimated minimum food requirement per grouper larvae increased more than 300% from the beginning of the notochord flexion to the beginning of metamorphosis. To meet such a high feeding requirement the number of larger prey organisms/copepods in the mesocosm should be eight times higher during this time period.

Influence of dispersants on trophic transfer of petroleum hydrocarbons in a marine food chain

Energy Technology Data Exchange (ETDEWEB)

Wolfe, M.; Tjeerdema, R. [Univ. of California, Santa Cruz, CA (United States). Dept. of Chemistry and Biochemistry; Sowby, M. [California Dept. of Fish and Game, Sacramento, CA (United States)

1995-12-31

When crude oil is accidentally released into the ocean, it threatens many levels of marine life. Intervention, in the form of chemical dispersing agents, alters the normal behavior of petroleum hydrocarbons (PH) by increasing their functional water solubility and the extent of their exposure to sub-surface organisms. Dispersing agents may modify bioavailability as a result of altered interactions between dispersed PH droplets and organismal cell membranes.The objective of this research was to determine the impact of dispersing agents on PH bioavailability and trophic transfer in primary levels of a marine food chain. Uptake, bioaccumulation, depuration, and metabolic transformation of a model PH, {sup 14}C-naphthalene, were measured and compared for Prudhoe Bay Crude Oil (PBCO) dispersed with Corexit 9527 and undispersed preparations of the water-accommodated fractions (WAF) of PBCO at two salinities and temperatures. The model food chain consisted of Isochrysis galbana and Brachionus plicatilis. Direct aqueous exposure was compared with combined aqueous and dietary exposure. Fractionation and identification of metabolites was done by HPLC co-chromatography with analytical standards, and quantitation was done by liquid scintillation counting. GC-FID characterization of WAF and dispersed oil (DO) preparations shows higher concentrations of petroleum hydrocarbons and a greater number of individual constituents in the dispersed oil preparations.

Influence of dispersants on trophic transfer of petroleum hydrocarbons in a marine food chain

International Nuclear Information System (INIS)

Wolfe, M.; Tjeerdema, R.

1995-01-01

When crude oil is accidentally released into the ocean, it threatens many levels of marine life. Intervention, in the form of chemical dispersing agents, alters the normal behavior of petroleum hydrocarbons (PH) by increasing their functional water solubility and the extent of their exposure to sub-surface organisms. Dispersing agents may modify bioavailability as a result of altered interactions between dispersed PH droplets and organismal cell membranes.The objective of this research was to determine the impact of dispersing agents on PH bioavailability and trophic transfer in primary levels of a marine food chain. Uptake, bioaccumulation, depuration, and metabolic transformation of a model PH, 14 C-naphthalene, were measured and compared for Prudhoe Bay Crude Oil (PBCO) dispersed with Corexit 9527 and undispersed preparations of the water-accommodated fractions (WAF) of PBCO at two salinities and temperatures. The model food chain consisted of Isochrysis galbana and Brachionus plicatilis. Direct aqueous exposure was compared with combined aqueous and dietary exposure. Fractionation and identification of metabolites was done by HPLC co-chromatography with analytical standards, and quantitation was done by liquid scintillation counting. GC-FID characterization of WAF and dispersed oil (DO) preparations shows higher concentrations of petroleum hydrocarbons and a greater number of individual constituents in the dispersed oil preparations

Methodical aspects of rearing decapod larvae, Pagurus bernhardus (Paguridae) and Carcinus maenas (Portunidae)

Science.gov (United States)

Dawirs, R. R.

1982-12-01

Improved methods for experimental rearing of Pagurus bernhardus and Carcinus maenas larvae are presented. Isolated maintenance was found essential for reliable statistical evaluation of results obtained from stages older than zoea-1. Only by isolated rearing is it possible to calculate mean values ±95% confidence intervals of stage duration. Mean values (without confidence intervals) can only be given for group-reared larvae if mortality is zero. Compared to group rearing, isolated rearing led to better survival, shorter periods of development and stimulated growth. Due to different swimming behavior P. bernhardus zoeae needed larger water volumes than Carcinus maenas larvae. P. bernhardus zoeae were reared with best results when isolated in Petri dishes (ca. 50 ml). They fed on newly hatched brine shrimp nauplii ( Artemia spp.). P. bernhardus megalopa did not require any gastropod shell or substratum; it developed best in glass vials without any food. C. maenas larvae could be reared most sucessfully in glass vials (ca 20 ml) under a simulated day-night regime (LD 16:8); constant darkness had a detrimental effect on development, leading to prolonged stage-duration times. C. maenas larvae were fed a mixture of newly hatched brine shrimp naupli and rotifers ( Brachionus plicatilis).

Differential evolution of asexual and sexual females in a benign culture environment

Science.gov (United States)

Snell, Terry W.

2013-01-01

Here we report one of the first investigations of evolvability of lifespan and reproduction in metazoans, examining both extrinsic and intrinsic factors. We tested effects on senescence of an environmental variable (simulated lake hydroperiod, the length of time an aquatic habitat is inundated), female reproductive physiology (asexual females that reproduce by ameiosis, versus sexual females reproducing by meiosis), and time in a benign culture environment (minimal, if any, external mortality factors). To do this we established chemostat cultures of the rotifer Brachionus plicatilis s.s., and maintained the cultures for 385 d. Hydroperiod alone or in interaction with the effects of time in the benign environment (season) or reproductive physiology had no significant effect on the net reproductive rate, generation time, or rate of aging. Yet combining animals from both ephemeral and permanent hydroperiods revealed a 26% increase in asexual female lifespan across seasons (23% decrease in the rate of aging) and a 56% increase in asexual fecundity, suggesting that maintenance in benign laboratory conditions leads to slower aging. The relative stasis of traits for sexual females implies an impact of reproductive physiology on evolvability. In addition we found a positive correlation between fecundity and lifespan, suggesting an absence of trade-offs in life history traits in the benign laboratory environment. PMID:24795527

Isolation mediates persistent founder effects on zooplankton colonisation in new temporary ponds

Science.gov (United States)

Badosa, Anna; Frisch, Dagmar; Green, Andy J.; Rico, Ciro; Gómez, Africa

2017-03-01

Understanding the colonisation process in zooplankton is crucial for successful restoration of aquatic ecosystems. Here, we analyzed the clonal and genetic structure of the cyclical parthenogenetic rotifer Brachionus plicatilis by following populations established in new temporary ponds during the first three hydroperiods. Rotifer populations established rapidly after first flooding, although colonisation was ongoing throughout the study. Multilocus genotypes from 7 microsatellite loci suggested that most populations (10 of 14) were founded by few clones. The exception was one of the four populations that persisted throughout the studied hydroperiods, where high genetic diversity in the first hydroperiod suggested colonisation from a historical egg bank, and no increase in allelic diversity was detected with time. In contrast, in another of these four populations, we observed a progressive increase of allelic diversity. This population became less differentiated from the other populations suggesting effective gene flow soon after its foundation. Allelic diversity and richness remained low in the remaining two, more isolated, populations, suggesting little gene flow. Our results highlight the complexity of colonisation dynamics, with evidence for persistent founder effects in some ponds, but not in others, and with early immigration both from external source populations, and from residual, historical diapausing egg banks.

Dissolution of coccolithophorid calcite by microzooplankton and copepod grazing

Science.gov (United States)

Antia, A. N.; Suffrian, K.; Holste, L.; Müller, M. N.; Nejstgaard, J. C.; Simonelli, P.; Carotenuto, Y.; Putzeys, S.

2008-01-01

Independent of the ongoing acidification of surface seawater, the majority of the calcium carbonate produced in the pelagial is dissolved by natural processes above the lysocline. We investigate to what extent grazing and passage of coccolithophorids through the guts of copepods and the food vacuoles of microzooplankton contribute to calcite dissolution. In laboratory experiments where the coccolithophorid Emiliania huxleyi was fed to the rotifer Brachionus plicatilis, the heterotrophic flagellate Oxyrrhis marina and the copepod Acartia tonsa, calcite dissolution rates of 45-55%, 37-53% and 5-22% of ingested calcite were found. We ascribe higher loss rates in microzooplankton food vacuoles as compared to copepod guts to the strongly acidic digestion and the individual packaging of algal cells. In further experiments, specific rates of calcification and calcite dissolution were also measured in natural populations during the PeECE III mesocosm study under differing ambient pCO2 concentrations. Microzooplankton grazing accounted for between 27 and 70% of the dynamic calcite stock being lost per day, with no measurable effect of CO2 treatment. These measured calcite dissolution rates indicate that dissolution of calcite in the guts of microzooplankton and copepods can account for the calcite losses calculated for the global ocean using budget and model estimates.

Insights into the CuO nanoparticle ecotoxicity with suitable marine model species.

Science.gov (United States)

Rotini, A; Gallo, A; Parlapiano, I; Berducci, M T; Boni, R; Tosti, E; Prato, E; Maggi, C; Cicero, A M; Migliore, L; Manfra, L

2018-01-01

Metal oxide nanoparticles, among them copper oxide nanoparticles (CuO NPs), are widely used in different applications (e.g. batteries, gas sensors, superconductors, plastics and metallic coatings), increasing their potential release in the environment. In aquatic matrix, the behavior of CuO NPs may strongly change, depending on their surface charge and some physical-chemical characteristics of the medium (e.g. ionic strength, salinity, pH and natural organic matter content). Ecotoxicity of CuO NPs to aquatic organisms was mainly studied on freshwater species, few tests being performed on marine biota. The aim of this study was to assess the toxicity of CuO NPs on suitable indicator species, belonging to the ecologically relevant level of consumers. The selected bioassays use reference protocols to identify Effect/Lethal Concentrations (E(L)C), by assessing lethal and sub-lethal endpoints. Mortality tests were performed on rotifer (Brachionus plicatilis), shrimp (Artemia franciscana) and copepod (Tigriopus fulvus). While moult release failure and fertilization rate were studied, as sub-lethal endpoints, on T. fulvus and sea urchin (Paracentrotus lividus), respectively. The size distribution and sedimentation rates of CuO NPs, together with the copper dissolution, were also analyzed in the exposure media. The CuO NP ecotoxicity assessment showed a concentration-dependent response for all species, indicating similar mortality for B. plicatilis (48hLC 50 = 16.94 ± 2.68mg/l) and T. fulvus (96hLC 50 = 12.35 ± 0.48mg/l), followed by A. franciscana (48hLC 50 = 64.55 ± 3.54mg/l). Comparable EC 50 values were also obtained for the sub-lethal endpoints in P. lividus (EC 50 = 2.28 ± 0.06mg/l) and T. fulvus (EC 50 = 2.38 ± 0.20mg/l). Copper salts showed higher toxicity than CuO NPs for all species, with common sensitivity trend as follows: P. lividus ≥ T. fulvus (sublethal endpoint) ≥ B. plicatilis >T. fulvus (lethal endpoint) >A. franciscana. CuO NP micrometric

Buried in time: Culturable fungi in a deep-sea sediment core from the Chagos Trench, Indian Ocean

Digital Repository Service at National Institute of Oceanography (India)

Raghukumar, C.; Raghukumar, S.; Sheelu, G.; Gupta, S.M.; Nath, B.N.; Rao, B.R.

of sediments was determined by the ?Karbonat-Bombe? method (M?ller and Gastner, 1971). The DBD is one among the several physical properties of sediment including porosity and is inversely related to porosity as shown by the equation of Garg (1987... Karbonat-Bombe?, a simple device for the determination of carbonate content in sediments, soils and other material. Neues Jahrbuch Minearalogie, 10, 466-469. Mueller, V., Sengbusch, P. V., 1983. Visualization of aquatic fungi (Chytridiales...

2015 annual report of the research project with NIRS electrostatic accelerators

International Nuclear Information System (INIS)

2016-12-01

This paper compiled 27 reports on the results in FY2015 of the shared facilities such as PIXE analysis system and tandem accelerator (PASTA), single particle irradiation system to cell (SPICE), and neutron exposure accelerator system for biological effect experiments (NASBEE), which are under jurisdiction of the National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Sciences and Technology. There are following reports. (1) Study on the quantification of ultra-trace multielement simultaneous analysis based on PIXE method of atmospheric aerosol (characteristics of atmospheric particles adhering to Ginkgo biloba in the symbol area of a large city). (2) Technological development on standard samples for micro PIXE analysis (upgrading of application technology of micro PIXE analysis method). (3) Study on analysis of body element distribution of aquatic organisms using PIXE analysis method (1)-(5). (4) Investigation on the effects of neutron exposure on carcinogenesis and its protective methods. (5) Intracellular oxidative stress change due to neutron irradiation (active oxygen expression due to NASBEE neutron irradiation in SK-N-SH cells). (6) Study on correlation between the distribution of trace metal elements in oral mucosa / jawbone and the disease conditions. In the micro PIXE analysis method of (2), standard substances for bio-related elements had been prepared so far, but this time the abundance of elements in micro-organism (Brachionus plicatilis) and micro-regions of plant lichens was measured. (A.O.)

Polymerase chain reaction as a tool for developing stress protein probes

Energy Technology Data Exchange (ETDEWEB)

Cochrane, B.J.; Mattley, Y.D. (Univ. of South Florida, Tampa, FL (United States). Dept. of Biology); Snell, T.W. (Georgia Inst. of Tech., Atlanta, GA (United States). Div. of Biology)

1994-08-01

Because of the high degree of evolutionary conservation of stress proteins, potential exists for the development of nucleic acid probes from particular species that could be used to monitor stress-related changes in mRNA abundance. The polymerase chain reaction (PCR) is a powerful tool that can be applied to the generation of these probes, provided that primer sequences can be identified that specifically amplify sequences of interest from a wide variety of organisms. The authors identified such sequences from multiple alignments of published chaperonin and stress-70 sequences, and tested their ability to amplify appropriately sized fragments from genomic DNA from a variety of vertebrates and invertebrates. Although no primer pair could be used successfully with all species, the authors were able to derive specific products from most species by testing different pairs. One primer pair for chaperonin proved particularly useful. Products were obtained from all tested species, and with a single exception (human), these primers appeared to amplify a single copy sequence. The authors determined the nucleotide sequence of the product obtained from the rotifer Brachionus plicatilis and determined by phylogenetic analysis of the inferred protein product that the product obtained is most likely derived from a rotifer DNA template. Finally, the authors show that this product can be used to detect changes in abundance of homologous mRNA in heat-stressed rotifers.

Patterns of intraspecific variability in the response to caloric restriction

Science.gov (United States)

Gribble, Kristin E.; Kaido, Oksana; Jarvis, George; Mark Welch, David B.

2014-01-01

Caloric restriction (CR) is cited as the most robust means of increasing lifespan across a range of taxa, yet there is a high degree of variability in the response to CR, both within and between species. To examine the intraspecific evolutionary conservation of lifespan extension by CR, we tested the effects of chronic caloric restriction (CCR) at multiple food levels and of intermittent fasting (IF) in twelve isolates from the Brachionus plicatilis species complex of monogonont rotifers. While CCR generally increased or did not change lifespan and total fecundity, IF caused increased, unchanged, or decreased lifespan, depending upon the isolate, and decreased total fecundity in all but one isolate. Lifespan under ad libitum (AL) feeding varied among isolates and predicted the lifespan response to CR: longer-lived isolates under AL were less likely to have a significant increase in lifespan under CCR and were more likely to have a significantly shortened lifespan under IF. Lifespan under AL conditions and the response to CR were not correlated with hydroperiodicity of native habitat or with time in culture. Lack of trade-off between lifespan and fecundity under CCR, and differences in lifespan and fecundity under CCR and IF, even when average food intake was similar, suggest that longevity changes are not always directly determined by energy intake and that CCR and IF regimens extend lifespan through diverse genetic mechanisms. PMID:24384399

Effects of wood preservative leachates from docks

Energy Technology Data Exchange (ETDEWEB)

Wendt, P.H.; Van Dolah, R.F.; Bobo, M.Y.; Mathews, T.D. [South Carolina Marine Resources Research Inst., Charleston, SC (United States)

1994-12-31

Recent evidence indicates that the wood preservative commonly used in dock pilings (chromated copper arsenate or CCA) is highly toxic to several estuarine organisms in laboratory experiments. Increasing demand for residential docks prompted a field study intended to complement these earlier laboratory investigations. Objectives of the study were to: (1) examine concentrations of Cu, Cr, and As in sediments and oysters from intertidal locations in several creeks with and without high densities of docks; (2) examine the bioaccumulation of wood preservative leachates by laboratory-reared oysters transferred to field sites near and distant from newly constructed docks; and (3) investigate the acute toxicity of wood preservative leachates for several species of estuarine fishes and invertebrates exposed to these compounds in the field. Preliminary results indicate that sediment concentrations of all three metals were well below ER-L levels reported by Long and Morgan at all but one dock site. In an ancillary study, 24h LC{sub 50} bioassays were performed using rotifers (Brachionus plicatilis) which were exposed to pore water from sediments in creeks with and without docks. Toxicities of bulk sediments from the same sites were examined using Microtox which measures decreases in bioluminescence of marine bacteria (Photobacterium phosphoreum) as a function of sediment concentration. Neither the rotifer nor the Microtox bioassays showed any significant differences in toxicity between creeks with and without docks.

Proceedings of the Frontiers of Retrovirology Conference 2016

OpenAIRE

Zurnic, Irena; H?tter, Sylvia; Lehmann, Ute; Stanke, Nicole; Reh, Juliane; Kern, Tobias; Lindel, Fabian; Gerresheim, Gesche; Hamann, Martin; M?llers, Erik; Lesbats, Paul; Cherepanov, Peter; Serrao, Erik; Engelman, Alan; Lindemann, Dirk

2016-01-01

Table of contents Oral presentations Session 1: Entry & uncoating O1 Host cell polo-like kinases (PLKs) promote early prototype foamy virus (PFV) replication Irena Zurnic, Sylvia H?tter, Ute Lehmann, Nicole Stanke, Juliane Reh, Tobias Kern, Fabian Lindel, Gesche Gerresheim, Martin Hamann, Erik M?llers, Paul Lesbats, Peter Cherepanov, Erik Serrao, Alan Engelman, Dirk Lindemann O2 A novel entry/uncoating assay reveals the presence of at least two species of viral capsids during synchronized HIV...

Effects of bisphenol A and its analogs bisphenol F and S on life parameters, antioxidant system, and response of defensome in the marine rotifer Brachionus koreanus.

Science.gov (United States)

Park, Jun Chul; Lee, Min-Chul; Yoon, Deok-Seo; Han, Jeonghoon; Kim, Moonkoo; Hwang, Un-Ki; Jung, Jee-Hyun; Lee, Jae-Seong

2018-06-01

To understand the adverse outcome in response to bisphenol A and its analogs bisphenol F and S (BPA, BPF, and BPS), we examined acute toxicity, life parameter, and defensome in the marine rotifer Brachionus koreanus. Among the bisphenol analogs, BPA showed the highest acute toxicity and then BPF and BPS, accordingly in the view of descending magnitude of toxicity. In life parameters including life span and reproduction, BPA, BPF, and BPS were found to cause adverse effect. Both intracellular ROS level and GST activity were significantly increased (P bisphenol analogs exposures. In response to bisphenol analogs, defensomes of phase I, II, and III detoxification mechanism demonstrated inverse relationship between the lipophilicity of bisphenol analogs and the expression patterns of defensomes. BPA and BPF were found to have significant modulation (P bisphenol A and its analogs F and S demonstrated specific detoxification mechanism in rotifer. Copyright © 2018 Elsevier B.V. All rights reserved.

Demography of zooplankton (Anuraeopsis fissa, Brachionus rubens and Moina macrocopa fed Chlorella vulgaris and Scenedesmus acutus cultured on different media

Directory of Open Access Journals (Sweden)

Jesús Morales-Ventura

2012-09-01

Full Text Available Generally zooplankton growth is often limited by the quality of their algal diet. A cheaper common practice in aquaculture, is to culture algae with fertilizers; however, the demography of zooplankton when fed these algae has not yet been evaluated. We studied the population growth and life table demography of the rotifers Anuraeopsis fissa and Brachionus rubens, and the cladoceran Moina macrocopa. For this, the algae Scenedesmus acutus or Chlorella vulgaris were cultured on defined (Bold’s basal medium or the commercial liquid fertilizer (Bayfolan. Experiments were conducted at one algal concentration 1.0x10(6cells/mL of C. vulgaris or its equivalent dry weight of 0.5x10(6cells/mL of S. acutus. The population dynamics were tested at 23±1ºC in 100mL transparent jars, each with 50mL of the test medium, with an initial density of 0.5indiv/mL, for a total of 48 test jars (3 zooplankton 2 algal species x 2 culture media x 4 replicates. For the life table experiments with M. macrocopa, we introduced 10 neonates (Generalmente el crecimiento del zooplancton está a menudo limitado por la calidad de su dieta de algas. La demografía del zooplancton durante la alimentación con algas no ha sido estudiada, a pesar de que el cultivo de algas con fertilizantes es una práctica económica común en acuacultura. Se analizó la demografía de Anuraeopsis fissa y Brachionus rubens (rotíferos y Moina macrocopa (cladóceros, alimentados con las algas verdes Scenedesmus acutus o Chlorella vulgaris cultivadas en medio Bold o fertilizante líquido comercial (Bayfolan, de Bayer. En los rotíferos no se observaron diferencias significativas en el promedio de vida, sin embargo, este parámetro en M. macrocopa con S. acutus cultivada en Medio Bold, fue significativamente menor que en otras dietas. Las tasas de reproducción bruta y neta de A. fissa fueron significativamente mayores con C. vulgaris cultivada en medio Bold, que con el fertilizante; estas tasas en B

Indicadores de condición larvaria aplicados al camarón de río del norte Cryphiops caementarius (Molina, 1782, en condiciones de cultivo controlado Larval condition indicators applied to the northern river shrimp Cryphiops caementarius (Molina, 1782, under condition of controlled cultivation

Directory of Open Access Journals (Sweden)

María C Morales

2012-09-01

Full Text Available Se estudia el desarrollo larvario del camarón de río del norte de Chile, Cryphiops caementarius, desde el estado de zoea 1 hasta el primer juvenil, caracterizando y analizando criterios que verificaron la aplicación de indicadores de tipo morfológico y de comportamiento para la evaluación de la condición larvaria de la especie, en condiciones de cultivo. Las larvas, se mantuvieron en cultivo, en un tanque de 250 L con agua a 20 psu y temperatura de 25 ± 1°C, controlada con termostato y con un recambio del 100% diariamente. La alimentación consistió en microalgas (Nannochloris sp. e Isochrysis sp., rotíferos (Brachionus plicatilis, nauplios de Artemia franciscana y alimento formulado. Se utilizaron cinco indicadores de carácter morfológico y de comportamiento aplicados a las larvas de C. caementarius: llenado intestinal, estado de la glándula digestiva, desarrollo branquial, comportamiento natatorio y respuesta fototáctica. Estos indicadores, permitieron determinar el estado de condición y calidad de las larvas de C. caementarius, logrando un efectivo seguimiento y asociación de cada uno de ellos, con cada estado de desarrollo larvario, estandarizando características deseables en las larvas y evidenciando resultados verificables, que permitan establecer un adecuado plan de seguimiento del cultivo, optimizar los protocolos de manejo y de alimentación de las larvas. Además de cada indicador, fue posible desglosar una amplia gama de potenciales estudios a realizar, basados en las relaciones que la morfología y el comportamiento larvario mantienen con las capacidades fisiológicas de las larvas en desarrollo.The larval development of the Chilean northern river shrimp Cryphiops caementarius was studied, from the condition of zoea 1 up to the condition of juvenile stage, analyzing and characterizing diverse criteria that allowed checking the application of morphological and behavioral indicators for the evaluation of the larval

Fecundity, growth, and survival of the angelfish Pterophyllum scalare (Perciformes: Cichlidae under laboratory conditions

Directory of Open Access Journals (Sweden)

Armando A Ortega-Salas

2009-09-01

Full Text Available The freshwater angelfishes (Pterophyllum are South American cichlids that have become very popular among aquarists, yet scarce information on their culture and aquarium husbandry exists. We studied Pterophyllum scalare to analyze dietary effects on fecundity, growth, and survival of eggs and larvae during 135 days. Three diets were used: A decapsulated cysts of Artemia, B commercial dry fish food, and C a mix diet of the rotifer Brachionus plicatilis and the cladoceran Daphnia magna. The initial larval density was 100 organisms in each 40L aquarium. With diet A, larvae reached a maximum weight of 3.80g, a total length of 6.3 cm, and a height of 5.8cm; with diet B: 2.80g, 4.81cm, and 4.79cm, and with diet C: 3.00g, 5.15cm, and 5.10cm, respectively. Significant differences were observed between diet A, and diet B and C, but no significantly differences were observed between diets B and C. Fecundity varied from 234 to 1 082 eggs in 20 and 50g females, respectively. Egg survival ranged from 87.4% up to 100%, and larvae survival (80 larvae/40L aquarium from 50% to 66.3% using diet B and A, respectively. Live food was better for growing fish than the commercial balanced food diet. Fecundity and survival are important factors in planning a good production of angelfish. Rev. Biol. Trop. 57 (3: 741-747. Epub 2009 September 30.Se realizaron estudios de cultivo en laboratorio del pez ángel, Pterophyllum scalare, para analizar los efectos de su dieta en la fecundidad, crecimiento y sobrevivencia en huevos y larvas por un período 135 días. Tres dietas diferentes se utilizaron A quistes decapsulados de Artemia, B comida comercial seca para pez, C una mezcla de rotíferos, Brachionus plicatilis y el cladocero, Daphnia magna. La densidad inicial de larvas en acuarios de 40L fue de 100 organismos. Utilizando la dieta A, las larvas alcanzaron un peso máximo de 3.80g, una longitud total de 6.3cm y una altura de 5.8cm; utilizando la dieta B, fue de 2.80g, 4

Genome-wide transcriptomics of aging in the rotifer Brachionus manjavacas, an emerging model system.

Science.gov (United States)

Gribble, Kristin E; Mark Welch, David B

2017-03-01

Understanding gene expression changes over lifespan in diverse animal species will lead to insights to conserved processes in the biology of aging and allow development of interventions to improve health. Rotifers are small aquatic invertebrates that have been used in aging studies for nearly 100 years and are now re-emerging as a modern model system. To provide a baseline to evaluate genetic responses to interventions that change health throughout lifespan and a framework for new hypotheses about the molecular genetic mechanisms of aging, we examined the transcriptome of an asexual female lineage of the rotifer Brachionus manjavacas at five life stages: eggs, neonates, and early-, late-, and post-reproductive adults. There are widespread shifts in gene expression over the lifespan of B. manjavacas; the largest change occurs between neonates and early reproductive adults and is characterized by down-regulation of developmental genes and up-regulation of genes involved in reproduction. The expression profile of post-reproductive adults was distinct from that of other life stages. While few genes were significantly differentially expressed in the late- to post-reproductive transition, gene set enrichment analysis revealed multiple down-regulated pathways in metabolism, maintenance and repair, and proteostasis, united by genes involved in mitochondrial function and oxidative phosphorylation. This study provides the first examination of changes in gene expression over lifespan in rotifers. We detected differential expression of many genes with human orthologs that are absent in Drosophila and C. elegans, highlighting the potential of the rotifer model in aging studies. Our findings suggest that small but coordinated changes in expression of many genes in pathways that integrate diverse functions drive the aging process. The observation of simultaneous declines in expression of genes in multiple pathways may have consequences for health and longevity not detected by

Metal stress in zooplankton diapause production: post-hatching response.

Science.gov (United States)

Aránguiz-Acuña, Adriana; Pérez-Portilla, Pablo

2017-04-01

Aquatic organisms commonly respond to harsh conditions by forming diapausing stages, which enable populations to survive adverse periods forming egg banks. Production of diapausing eggs is frequently observed in monogonont rotifers, previously changing from asexual to partial sexual reproduction (mixis). In despite that zooplankton are frequently used in ecotoxicological assessment because of their sensitivity to various toxicants and their important role in the ecosystems, toxicity evaluations often consider the directly exposed population produced by parthenogenetic reproduction, exclusively. We assessed experimentally effects of exposure to metals on mixis delay and fitness of hatchlings of the rotifer Brachionus plicatilis obtained from a brackish water lagoon with high metal content, especially copper. We show that sub-lethal concentrations of copper affected traits related to sexual reproduction and diapausing egg production in the rotifer. Copper addition did not delay the start of mixis, suggesting that rapid initiation of mixis is promoted in risky environments, according to the hypothesis of mixis as an escape strategy. Higher investment in mixis was obtained when individuals were exposed to metal. Addition of copper negatively affected the hatching success of diapausing eggs and performance of hatchlings. Nevertheless, these effects were greater for individuals formed in non-metal conditions, suggesting an adaptive advantage of populations from natural sediments exposed to copper. These results highlight the ecological and evolutionary consequences of the presence of metals in freshwater environments by modulating diapause adaptive efficacy and the selective process in egg banks.

Evaluation of toxicity and removal of color in textile effluent treated with electron beam; Avaliacao da toxicidade e remocao da cor de um efluente textil tratado com feixe de eletrons

Energy Technology Data Exchange (ETDEWEB)

Morais, Aline Viana de

2015-07-01

The textile industry is among the main activities Brazil, being relevant in number of jobs, quantity and diversity of products and mainly by the volume of water used in industrial processes and effluent generation. These effluents are complex mixtures which are characterized by the presence of dyes, surfactants, metal sequestering agents, salts and other potentially toxic chemicals for the aquatic biota. Considering the lack of adequate waste management to these treatments, new technologies are essential in highlighting the advanced oxidation processes such as ionizing radiation electron beam. This study includes the preparation of a standard textile effluent chemical laboratory and its treatment by electron beam from electron accelerator in order to reduce the toxicity and intense staining resulting from Cl. Blue 222 dye. The treatment caused a reduction in toxicity to exposed organisms with 34.55% efficiency for the Daphnia similis micro crustacean and 47.83% for Brachionus plicatilis rotifer at a dose of 2.5 kGy. The Vibrio fischeri bacteria obtained better results after treatment with a dose of 5 kGy showing 57.29% efficiency. Color reduction was greater than 90% at a dose of 2.5 kGy. This experiment has also carried out some preliminary tests on the sensitivity of the D. similis and V. fischeri organisms to exposure of some of the products used in this bleaching and dyeing and two water reuse simulations in new textile processing after the treating the effluent with electron beam. (author)

Evaluation of toxicity and removal of color in textile effluent treated with electron beam

International Nuclear Information System (INIS)

Morais, Aline Viana de

2015-01-01

The textile industry is among the main activities Brazil, being relevant in number of jobs, quantity and diversity of products and mainly by the volume of water used in industrial processes and effluent generation. These effluents are complex mixtures which are characterized by the presence of dyes, surfactants, metal sequestering agents, salts and other potentially toxic chemicals for the aquatic biota. Considering the lack of adequate waste management to these treatments, new technologies are essential in highlighting the advanced oxidation processes such as ionizing radiation electron beam. This study includes the preparation of a standard textile effluent chemical laboratory and its treatment by electron beam from electron accelerator in order to reduce the toxicity and intense staining resulting from Cl. Blue 222 dye. The treatment caused a reduction in toxicity to exposed organisms with 34.55% efficiency for the Daphnia similis micro crustacean and 47.83% for Brachionus plicatilis rotifer at a dose of 2.5 kGy. The Vibrio fischeri bacteria obtained better results after treatment with a dose of 5 kGy showing 57.29% efficiency. Color reduction was greater than 90% at a dose of 2.5 kGy. This experiment has also carried out some preliminary tests on the sensitivity of the D. similis and V. fischeri organisms to exposure of some of the products used in this bleaching and dyeing and two water reuse simulations in new textile processing after the treating the effluent with electron beam. (author)

Experimental studies on the larval development of the shrimps Crangon crangon and C. allmanni

Science.gov (United States)

Criales, M. M.; Anger, K.

1986-09-01

Larvae of the shrimps Crangon crangon L. and C. allmanni Kinahan were reared in the laboratory from hatching through metamorphosis. Effects of rearing methods (larval density, application of streptomycin, food) and of salinity on larval development were tested only in C. crangon, influence of temperature was studied in both species. Best results were obtained when larvae were reared individually, with a mixture of Artemia sp. and the rotifer Brachionus plicatilis as food. Streptomycin had partly negative effects and was thus not adopted for standard rearing techniques. All factors tested in this study influenced not only the rates of larval survival and moulting, but also morphogenesis. In both species, in particular in C. crangon, a high degree of variability in larval morphology and in developmental pathways was observed. Unsuitable conditions, e.g. crowding in mass culture, application of antibiotics, unsuitable food (rotifers, phytoplankton), extreme temperatures and salinities, tend to increase the number of larval instars and of morphological forms. The frequency of moulting is controlled mainly by temperature. Regression equations describing the relations between the durations of larval instars and temperature are given for both Crangon species. The number of moults is a linear function of larval age and a power function of temperature. There is high variation in growth (measured as carapace length), moulting frequency, morphogenesis, and survival among hatches originating from different females. The interrelations between these different measures of larval development in shrimps and prawns are discussed.

The Complete and Updated "Rotifer Polyculture Method" for Rearing First Feeding Zebrafish

Science.gov (United States)

Lawrence, Christian; Best, Jason; Cockington, Jason; Henry, Eric C.; Hurley, Shane; James, Althea; Lapointe, Christopher; Maloney, Kara; Sanders, Erik

2016-01-01

The zebrafish (Danio rerio) is a model organism of increasing importance in many fields of science. One of the most demanding technical aspects of culture of this species in the laboratory is rearing first-feeding larvae to the juvenile stage with high rates of growth and survival. The central management challenge of this developmental period revolves around delivering highly nutritious feed items to the fish on a nearly continuous basis without compromising water quality. Because larval zebrafish are well-adapted to feed on small zooplankton in the water column, live prey items such as brachionid rotifers, Artemia, and Paramecium are widely recognized as the feeds of choice, at least until the fish reach the juvenile stage and are able to efficiently feed on processed diets. This protocol describes a method whereby newly hatched zebrafish larvae are cultured together with live saltwater rotifers (Brachionus plicatilis) in the same system. This polyculture approach provides fish with an "on-demand", nutrient-rich live food source without producing chemical waste at levels that would otherwise limit performance. Importantly, because the system harnesses both the natural high productivity of the rotifers and the behavioral preferences of the fish, the labor involved with maintenance is low. The following protocol details an updated, step-by-step procedure that incorporates rotifer production (scalable to any desired level) for use in a polyculture of zebrafish larvae and rotifers that promotes maximal performance during the first 5 days of exogenous feeding. PMID:26863035

MORFOMETRI ROTIFER Brachionus rotundiformis STRAIN SS ASAL TAMBAK MINANGA DAN TAMBAK WATULINEY SULAWESI UTARA YANG DIKULTUR PADA SALINITAS YANG BERBEDA

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Inneke Fenny Melke Rumengan

2016-11-01

The rotifers Brachionus rotundiformis were found predominantly in Minanga and Watuliney brackishwater ponds in North Sulawesi. The two ponds are located 7 km apart at south-eastern coast of North Sulawesi facing to Maluku Sea. Morphometry of the two groups may associate with the original salinities of the ponds, 25—33 and 0—3 ppt in Minanga and Watuliney ponds, respectively. The rotifers were cultured at different salinities in laboratory in order to observe the plasticity of their size. Rotifers from Minanga ponds were gradually adapted by lowering salinities from 30 ppt to 25, 20 until 5 ppt. In contrast, Rotifers from Watuliney ponds were adapted gradually by increasing salinities from 5 ppt to 10, 15, 20, 25, and 30 ppt. In each treatment, 5 first laid eggs were put into each test tube containing Nannochloropsi oculata (3x106 cells/mL at 25°C, and after 7 days, the rotifer population remarkably increased due to parthenogenetic reproduction, and then body size of 30 egg-carrying rotifers of each treatment were measured under microscope. Body size of rotifers from Minanga ponds in all treatment was lower than that of rotifers from Watuliney ponds. Statistically, morphometry of the two groups was significantly different. However, there was a tendency for that lorica length of rotifers from Watuliney ponds to increase as the salinity increase, while rotifers from Minanga  ponds did not significantly changed in their sizes as the salinity changed.

Desarrollo embrionariolarval y tiempo de metamorfosis del pez tropical Xenomelaniris brasiliensis (Pisces: Atherinidae

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Veronica del Río

2005-09-01

Full Text Available Se describe el desarrollo embrionario y larval hasta la metamorfosis de Xenomelaniris brasiliensi. Un total de 29 ejemplares sexualmente maduros, 16 hembras (10.86 ± 1.01 cm y 7.63 ± 2.62 g y 13 machos (10.43 ± 0.57 cm y 6.54 ± 1.44 g, liberaron sus productos sexuales mediante masaje abdominal. Los huevos fértiles fueron esféricos de 1.18 ± 0.44 mm de diámetro, verdosos, translúcidos, bentónicos, ricos en vitelo, corion rugoso y estriado, con numerosos filamentos coriónicos, distribuidos aleatoriamente por toda la superficie externa y numerosas gotas lipídicas con un diámetro de 0.11 ± 0.07 mm. El desarrollo embrionario se realizó a 26.36 ± 2.03 ºC, 39.67 ± 0.58 PSU y pH 8.30 ± 0.10 eclosionando larvas de 4.56 ± 0.97 mm a las 143 hrs: 19 min, con vestigios del saco vitelino y una gota lipídica interna. Las larvas fueron alimentadas diariamente con Brachionus plicatilis e Isochrysis galbana, a partir de la segunda semana se incorporó nauplios de Artemia, manteniendo la adición diaria de I. galbana. A los 13 días después de la eclosión de larvas (6.10 ± 1.54 mm se inició la flexión, completándose a los 32 días (11.25 ± 1.87 mm con un complejo hipural completamente desarrollado. Se concluye que X. brasiliensis presentó desarrollo larval directo, iniciándose la metamorfosis de larva (13.08 ± 2.07 a juvenil a los 40 días de edad.Development of the tropical fish Xenomelaniris brasiliensis (Pisces: Atherinidae from embryo to larva and time to metamorphosis. Embryoniclarval development, and metamorphosis larval time, were studied in the tropical fish Xenomelaniris brasiliensis. Twenty nine sexually mature specimens were used, 16 females (10.86 ± 1.01 cm and 7.63 ± 2.62 g and 13 males (10.43 ± 0.57 cm and 6.54 ± 1.44 g which produced gametes through abdominal massage. Fertilized eggs were spherical (1.18 ± 0.44 mm diameter, greenish, transparent, benthonic and vitelusrich; rugose striated chorion with numerous

Effect of crude extracts from cyanobacterial blooms in Lake Texcoco (Mexico) on the population growth of Brachionus calyciflorus (Rotifera).

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Barrios, Cesar Alejandro Zamora; Nandini, S; Sarma, S S S

2017-12-01

Unlike temperate regions, tropical ecosystems are characterized by high temperatures (>18 °C) all year, promoting blooms of cyanobacteria which often produce secondary metabolites toxic to zooplankton. Nabor Carillo and the Recreational Lake are part of the saline, Lake Texcoco, in Central Mexico which is filled nowadays with treated waste water. Both water bodies are dominated by Planktothrix, Anabaenopsis, Spirulina and Microcystis. In this study we present the concentration of microcystins in these waterbodies over an annual cycle. We also evaluated the chronic effects of cyanobacterial crude extracts from both lakes on two clones of the rotifer Brachionus calyciflorus, one from Nabor Carrillo Lake and the other from a canal in the shallow, Lake Xochimilco. The experiments on population growth were performed, beginning with 10 individuals per container for each of the following treatments: control (no crude extract), concentrated crude extract, and diluted crude extract (50:50) with moderately hard water and Chlorella vulgaris in a concentration of 0.5 × 10 6  cells ml -1 . The cyanotoxin levels were measured using an ELISA test and ranged between 0.20 and 2.4 μg L -1 in the lake water. The results showed that the Recreational Lake extracts were more toxic, killing the rotifers in less than five days. The r values ranged from -1.74 to 0.48 in the presence of the crude extracts and 0.16 and 0.24 in the controls. The results have been discussed with emphasis on the importance of conducting regular studies to test ecotoxicological impacts of cyanobacterial blooms in tropical waters. Copyright © 2017 Elsevier Ltd. All rights reserved.

Immunodetection of Luteinizing Hormone (LH, Follicle-Stimulating Hormone (FSH, Thyroid Stimulating Hormone (TSH and Prolactin (PRL in Brachionus calyciflorus (Rotifera: Monogononta

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Jesús Alvarado-Flores

2009-12-01

Full Text Available The endocrine system controls and coordinates behavioral, biochemical, and physiological processes through signal mechanisms using neuropeptides or products of neurosecretory cells. Among invertebrates, this system is poorly studied in rotifers, in which estrogens and androgens significantly affect sexual reproduction. This is the first report of the presence of the Luteinizing Hormone (LH, Follicle-Stimulating Hormone (FSH, Thyroid Stimulating Hormone (TSH and Prolactin (PRL in rotifers. Analyses included the avidin-biotin-peroxidase complex method with primary antibodies LH (Anti-Rat LH serum for RIA, PRL (Anti-Rat PRL serum for RIA, FSH (Anti-Rat FSH serum for RIA and TSH (Anti-Rat TSH serum for RIA. These hormones were found in females, males and parthenogenetic and sexual eggs of the freshwater Brachionus calyciflorus. The immunoreactivity of FSH, LH, TSH and PRL in females was observed in: ovaries, cerebrum, mastax, stomach, lorica, and the stomach gland. However, in males LH was observed only at the trochal disk and cerebrum. The hormones FSH, TSH and PRL, were observed in testicles, contractil vesicles, and cementary gland of males. Regarding amictic or parthenogenetic eggs, the hormones LH, FSH, TSH, and PRL were located mainly in the micromeres, and the staining in the macromeres was weak. On the other hand, in the mictic or sexual eggs the inner shell is stained for the hormones PRL and LH, opposite to the staining of FSH and TSH, located mainly in the embryo. In general, immuno-reactivity was observed in areas important for the reproductive, excretory, digestive and developmental processes. Rev. Biol. Trop. 57 (4: 1049-1058. Epub 2009 December 01.Se logró detectar la presencia de las hormonas: Hormona Luteinizante (LH, Hormona Folículo Estimulante (FSH, Hormona Estimulante de la Tiroides (TSH y Prolactina (PRL en Brachionus calyciflorus siendo el primer reporte de la presencia de dichas hormonas en rotíferos. Estas hormonas fueron

GROWTH AND BEHAVIOR OF LARVAL ZEBRAFISH Danio ...

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Because Zebrafish (Danio rerio) have become a popular and important model for scientific research, the capability to rear larval zebrafish to adulthood is of great importance. Recently research examining the effects of diet (live versus processed) have been published. In the current study we examined whether the larvae can be reared on a processed diet alone, live food alone, or the combination while maintaining normal locomotor behavior, and acceptable survival, length and weight at 14 dpf in a static system. A 14 day feeding trial was conducted in glass crystallizing dishes containing 500 ml of 4 ppt Instant Ocean. On day 0 pdf 450 embryos were selected as potential study subjects and placed in a 26○C incubator on a 14:10 (light:dark) light cycle. At 4 dpf 120 normally developing embryos were selected per treatment and divided into 3 bowls of 40 embryos (for an n=3 per treatment; 9 bowls total). Treatment groups were: G (Gemma Micro 75 only), R (L-type marine rotifers (Brachionus plicatilis) only) or B (Gemma and rotifers). Growth (length), survival, water quality and rotifer density were monitored on days 5-14. On day 14, weight of larva in each bowl was measured and 8 larva per bowl were selected for use in locomotor testing. This behavior paradigm tests individual larval zebrafish under both light and dark conditions in a 24-well plate.After 14 dpf, survival among the groups was not different (92-98%). By days 7 -14 R and B larvae were ~2X longer

Phaeobacter gallaeciensis Reduces Vibrio anguillarum in Cultures of Microalgae and Rotifers, and Prevents Vibriosis in Cod Larvae

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D’Alvise, Paul W.; Lillebø, Siril; Prol-Garcia, Maria J.; Wergeland, Heidrun I.; Nielsen, Kristian F.; Bergh, Øivind; Gram, Lone

2012-01-01

Phaeobacter gallaeciensis can antagonize fish-pathogenic bacteria in vitro, and the purpose of this study was to evaluate the organism as a probiont for marine fish larvae and their feed cultures. An in vivo mechanism of action of the antagonistic probiotic bacterium is suggested using a non-antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 107 cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio anguillarum was significantly reduced by wild-type P. gallaeciensis, when introduced into these cultures. A P. gallaeciensis mutant that did not produce the antibacterial compound tropodithietic acid (TDA) did not reduce V. anguillarum numbers, suggesting that production of the antibacterial compound is important for the antagonistic properties of P. gallaeciensis. The ability of P. gallaeciensis to protect fish larvae from vibriosis was determined in a bath challenge experiment using a multidish system with 1 larva per well. Unchallenged larvae reached 40% accumulated mortality which increased to 100% when infected with V. anguillarum. P. gallaeciensis reduced the mortality of challenged cod larvae (Gadus morhua) to 10%, significantly below the levels of both the challenged and the unchallenged larvae. The TDA mutant reduced mortality of the cod larvae in some of the replicates, although to a much lesser extent than the wild type. It is concluded that P. gallaeciensis is a promising probiont in marine larviculture and that TDA production likely contributes to its probiotic effect. PMID:22928051

Phaeobacter gallaeciensis reduces Vibrio anguillarum in cultures of microalgae and rotifers, and prevents vibriosis in cod larvae.

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Paul W D'Alvise

Full Text Available Phaeobacter gallaeciensis can antagonize fish-pathogenic bacteria in vitro, and the purpose of this study was to evaluate the organism as a probiont for marine fish larvae and their feed cultures. An in vivo mechanism of action of the antagonistic probiotic bacterium is suggested using a non-antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 10(7 cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio anguillarum was significantly reduced by wild-type P. gallaeciensis, when introduced into these cultures. A P. gallaeciensis mutant that did not produce the antibacterial compound tropodithietic acid (TDA did not reduce V. anguillarum numbers, suggesting that production of the antibacterial compound is important for the antagonistic properties of P. gallaeciensis. The ability of P. gallaeciensis to protect fish larvae from vibriosis was determined in a bath challenge experiment using a multidish system with 1 larva per well. Unchallenged larvae reached 40% accumulated mortality which increased to 100% when infected with V. anguillarum. P. gallaeciensis reduced the mortality of challenged cod larvae (Gadus morhua to 10%, significantly below the levels of both the challenged and the unchallenged larvae. The TDA mutant reduced mortality of the cod larvae in some of the replicates, although to a much lesser extent than the wild type. It is concluded that P. gallaeciensis is a promising probiont in marine larviculture and that TDA production likely contributes to its probiotic effect.

A successful microbound diet for the larval culture of Chinese shrimp Fenneropenaeus chinensis

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Wang, Xinxia; Mai, Kangsen

2005-07-01

A 13-day feeding trial was carried out to evaluate the effectiveness of a microbound diet for rearing the larvae of Chinese shrimp Fenneropenaeus chinensis in comparison with the live foods that consist of Isochrysis galbana, Chlorella vulgaris, Tetraselmis chuii, rotifer (Brachionus plicatilis) and Artemia sp. Larvae of 0 to 13d post-hatch (dph) were reared in a temperature-controlled semi-open culture system and stocked at a density of 100 larvae L-1 in tanks, each containing 50 L sterilized seawater with salinity 30 32. Larvae were manually fed either the live foods or the microbound diet 6 times per day. At 13dph, the growth of the larvae fed on the microbound diet was approximately 84% of that fed on the live foods. The survival rate of the larvae fed on the microbound diet was 44.29% at 13 dph, which was not significantly different from that of larvae fed on live foods (63.55% ). The body length and development index (DI) of the larvae fed on the microbound diet were always lower than those of larvae fed on live foods. However, the differences reached significant levels only at 11 and 13dph (P<0.05). The mean dry weight loss of the microbound diet was 9.2% after 90min immersion in seawater, indicating that this diet has a good water stability. The microbound diet contains 5223% crude protein and 10.27% lipid and is easy to prepare. These characteristics of the diet suggest good potentials for its successful use in the larviculture of other penaeid and fish species.

Does haplodiploidy purge inbreeding depression in rotifer populations?

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Ana M Tortajada

2009-12-01

Full Text Available Inbreeding depression is an important evolutionary factor, particularly when new habitats are colonized by few individuals. Then, inbreeding depression by drift could favour the establishment of later immigrants because their hybrid offspring would enjoy higher fitness. Rotifers are the only major zooplanktonic group where information on inbreeding depression is still critically scarce, despite the fact that in cyclical parthenogenetic rotifers males are haploid and could purge deleterious recessive alleles, thereby decreasing inbreeding depression.We studied the effects of inbreeding in two populations of the cyclical parthenogenetic rotifer Brachionus plicatilis. For each population, we compared both the parental fertilization proportion and F1 fitness components from intraclonal (selfed and interclonal (outcrossed crosses. The parental fertilization proportion was similar for both types of crosses, suggesting that there is no mechanism to avoid selfing. In the F1 generation of both populations, we found evidence of inbreeding depression for the fitness components associated with asexual reproduction; whereas inbreeding depression was only found for one of the two sexual reproduction fitness components measured.Our results show that rotifers, like other major zooplanktonic groups, can be affected by inbreeding depression in different stages of their life cycle. These results suggest that haplodiploidy does not purge efficiently deleterious recessive alleles. The inbreeding depression detected here has important implications when a rotifer population is founded and intraclonal crossing is likely to occur. Thus, during the foundation of new populations inbreeding depression may provide opportunities for new immigrants, increasing gene flow between populations, and affecting genetic differentiation.

Zooplankton diversity of a protected and vulnerable wetland system in southern South America (Llancanelo area, Argentina

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D. Sabina D’Ambrosio

2016-02-01

Full Text Available Abstract In arid regions, climatic conditions exert a great control on the aquatic systems present, but recent changes in climate have produced an enhanced salinization of the aquatic environments located there. Consequently, a major reduction in biodiversity would be expected in those wetlands that were originally fresh water. Salinity is a principal cause of reduced biodiversity particularly in zooplankton because few of those species can adapt to the salt pressure of saline environments. Therefore, the aim of this study was to gain essential information on the diversity of aquatic invertebrates in Llancanelo basin by focussing the analysis on the zooplankton community and exploring seasonal and spatial differences in the zooplankton assemblages of this vulnerable wetland system within an arid region of Argentina. Seasonal samples were taken at nine sites in the basin (a shallow lake, 4 springs, streams, and the Malargüe River. A total of 45 species were identified. The zooplankton abundance in the lake displayed a clear seasonal contrast and was higher than that recorded in the springs and lotic environments. Boeckella poopoensis, Fabrea salina, and Brachionus plicatilis predominated in the lake, indicating their halophilia. The presence of the crustaceans Alona sp., Macrocyclops albidus, and Paracyclops fimbriatus was restricted to the springs; whereas Notholca labis and Notholca squamula were found only in running water. The zooplankton species richness in the Llancanelo area is low because of both the salt content in the lake and the irregularity of freshwater entry in all locations during the annual cycle.

Does Haplodiploidy Purge Inbreeding Depression in Rotifer Populations?

Science.gov (United States)

Tortajada, Ana M.; Carmona, María José; Serra, Manuel

2009-01-01

Background Inbreeding depression is an important evolutionary factor, particularly when new habitats are colonized by few individuals. Then, inbreeding depression by drift could favour the establishment of later immigrants because their hybrid offspring would enjoy higher fitness. Rotifers are the only major zooplanktonic group where information on inbreeding depression is still critically scarce, despite the fact that in cyclical parthenogenetic rotifers males are haploid and could purge deleterious recessive alleles, thereby decreasing inbreeding depression. Methodology/Principal Findings We studied the effects of inbreeding in two populations of the cyclical parthenogenetic rotifer Brachionus plicatilis. For each population, we compared both the parental fertilization proportion and F1 fitness components from intraclonal (selfed) and interclonal (outcrossed) crosses. The parental fertilization proportion was similar for both types of crosses, suggesting that there is no mechanism to avoid selfing. In the F1 generation of both populations, we found evidence of inbreeding depression for the fitness components associated with asexual reproduction; whereas inbreeding depression was only found for one of the two sexual reproduction fitness components measured. Conclusions/Significance Our results show that rotifers, like other major zooplanktonic groups, can be affected by inbreeding depression in different stages of their life cycle. These results suggest that haplodiploidy does not purge efficiently deleterious recessive alleles. The inbreeding depression detected here has important implications when a rotifer population is founded and intraclonal crossing is likely to occur. Thus, during the foundation of new populations inbreeding depression may provide opportunities for new immigrants, increasing gene flow between populations, and affecting genetic differentiation. PMID:19997616

Dinámica poblacional del rotífero Brachionus ibericus aislado de estanques para camarón, alimentado con diferentes dietas

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José Cristóbal Román-Reyes

2014-11-01

Full Text Available La producción de microalgas vivas para cultivar rotíferos constituye uno de los mayores costos de operación en la larvicultura de peces, por lo que se están desarrollando sustitutos comerciales de microalgas para la alimentación y producción de rotíferos. Se desconoce el efecto que tienen las formulaciones comerciales sobre la dinámica poblacional de rotíferos nativos del noroeste de México y en este estudio se evaluó el efecto de cuatro dietas comerciales (Espirulina, RotiMac®, Nanno 3600®, RotiGrow-Plus® y la microalga viva Nannochloropsis sp., sobre el crecimiento poblacional y fecundidad del rotífero Brachionus ibericus (GenBank KJ949043, aislado de una granja de camarón blanco (Litopenaeus vannamei. Se realizaron cinco réplicas por tratamiento alimenticio utilizando recipientes con volumen de 12 L de agua, con temperatura de 29 ± 1°C y salinidad de 35 ± 1, respectivamente. Los resultados mostraron que durante los periodos experimentales, las dietas probadas resultaron adecuadas para alimentar a B. ibericus, con tasas de crecimiento, tiempos de duplicación, densidades máximas y fecundidades que fluctuaron entre 0.20 a 0.27 rotíferos día-1, 2.60 a 3.42 días, 215 a 344 rotíferos mL-1 y de 0.16 a 0.39 huevos hembra-1, respectivamente. Las diferencias entre tratamientos fueron significativas (P 0.05 a las obtenidas con Nanno 3600®.

Effect of food quantity and quality on population growth rate and digestive activity in the euryhaline rotifer .i.Brachionus plicatilis./i. Müller

Czech Academy of Sciences Publication Activity Database

Štrojsová, M.; Suga, K.; Hagiwara, A.; Vrba, Jaroslav

2009-01-01

Roč. 94, č. 6 (2009), s. 706-719 ISSN 1434-2944 Institutional research plan: CEZ:AV0Z60170517 Keywords : reproduction * nitrogen limitation * phosphorus limitation * phosphatase activity Subject RIV: EG - Zoology Impact factor: 1.082, year: 2009

Influence of dispersants on petroleum bioavailability in a marine food chain

International Nuclear Information System (INIS)

Wolfe, M.; Tjeerdema, R.

1995-01-01

When crude oil is accidentally released into the ocean it threatens many levels of marine life. Intervention, in the form of chemical dispersing agents, may alter the normal behavior of petroleum hydrocarbons (PH) by increasing their functional water solubility and the extent of their exposure to sub-surface marine organisms. Further, the dispersing agent may modify bioavailability as a result of altered interactions between dispersed PH droplets and organismal cell membranes, To date, little information exists on the sub-lethal effects of dispersants and factors modifying their role in the bioavailability and disposition of PH in marine food chains. The objective of the current research was to determine the impact of dispersing agents on PH bioavailability to primary levels of a marine food chain. Uptake, bioaccumulation, deputation, and metabolic transformation of a model PH, 14 C-naphthalene, were measured and compared for dispersed Prudhoe Bay Crude Oil (PBCO) vs. undispersed preparations of the water-accommodated fractions (WAF) of PBCO at two salinities (22 and 34 ppt) employing Isochrysis galbana, a primary producer, and Brachionus plicatilis, a primary consumer. Fractionation and identification of metabolites was done by HPLC co-chromatography with analytical standards, and quantitation was done by liquid scintillation counting. GC-FID characterization of WAF and dispersed oil preparations shows higher concentrations of petroleum hydrocarbons and a greater number of individual constituents in the dispersed oil preparations. However, short term (eight hour) and long term (two week) static exposure studies indicate the uptake of 14 C-naphthalene from WAF preparations is inhibited by up to 50% from dispersed oil preparations. Results of comparative static and flow-through chamber exposure studies will be presented

Toxic effect of a marine bacterium on aquatic organisms and its algicidal substances against Phaeocystis globosa.

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Qiuchan Yang

Full Text Available Harmful algal blooms have caused enormous damage to the marine ecosystem and the coastal economy in China. In this paper, a bacterial strain B1, which had strong algicidal activity against Phaeocystis globosa, was isolated from the coastal waters of Zhuhai in China. The strain B1 was identified as Bacillus sp. on the basis of 16S rDNA gene sequence and morphological characteristics. To evaluate the ecological safety of the algicidal substances produced by strain B1, their toxic effects on marine organisms were tested. Results showed that there were no adverse effects observed in the growth of Chlorella vulgaris, Chaetoceros muelleri, and Isochrystis galbana after exposure to the algicidal substances at a concentration of 1.0% (v/v for 96 h. The 48h LC50 values for Brachionus plicatilis, Moina mongolica Daday and Paralichthys olivaceus were 5.7, 9.0 and 12.1% (v/v, respectively. Subsequently, the algicidal substances from strain B1 culture were isolated and purified by silica gel column, Sephadex G-15 column and high-performance liquid chromatography. Based on quadrupole time-of-flight mass spectrometry and PeakView Software, the purified substances were identified as prolyl-methionine and hypoxanthine. Algicidal mechanism indicated that prolyl-methionine and hypoxanthine inhibited the growth of P. globosa by disrupting the antioxidant systems. In the acute toxicity assessment using M. mongolica, 24h LC50 values of prolyl-methionine and hypoxanthine were 7.0 and 13.8 g/L, respectively. The active substances produced by strain B1 can be considered as ecologically and environmentally biological agents for controlling harmful algal blooms.

The community structure and seasonal dynamics of plankton in Bange Lake, northern Tibet, China

Science.gov (United States)

Zhao, Wen; Zhao, Yuanyi; Wang, Qiaohan; Zheng, Mianping; Wei, Jie; Wang, Shan

2016-11-01

The seasonal variations in biomass, abundance, and species composition of plankton in relation to hydrography were studied in the saline Bange Lake, northern Tibet, China. Sampling was carried out between one to three times per month from May 2001 to July 2002. Salinity ranged from 14 to 146. The air and water temperature exhibited a clear seasonal pattern, and mean annual temperatures were approximately 4.8°C and 7.3°C, respectively. The lowest water temperature occurred in winter from December to March at -2°C and the highest in June and July at 17.7°C. Forty-one phytoplankton taxa, 21 zooplankton, and 5 benthic or facultative zooplankton were identified. The predominant phytoplankton species were Gloeothece linearis, Oscillatoria tenuis, Gloeocapsa punctata, Ctenocladus circinnatus, Dunaliella salina, and Spirulina major. The predominant zooplankton species included Holophrya actra, Brachionus plicatilis, Daphniopsis tibetana, Cletocamptus dertersi, and Arctodiaptomus salinus. The mean annual total phytoplankton density and biomass for the entire lake were 4.52×107 cells/L and 1.60 mg/L, respectively. The annual mean zooplankton abundance was 52, 162, 322, and 57, 144 ind./L, in the three sublakes. The annual mean total zooplankton biomass in Lakes 1-3 was 1.23, 9.98, and 2.13 mg/L, respectively. The annual mean tychoplankton abundances in Bg1, 2, and 3 were 47, 67, and 654 ind./L. The annual mean tychoplankton biomass was 2.36, 0.16, and 2.03 mg/L, respectively. The zooplankton biomass (including tychoplankton) in the lake was 9.11 mg/L. The total number of plankton species in the salt lake was significantly negatively correlated with salinity.

Zooplankton of an urban coastal lagoon: composition and association with environmental factors and summer fish kill

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Leonardo C. e Souza

2011-06-01

Full Text Available Zooplankton may be regarded as a sensitive tool for monitoring environmental variations in coastal lagoons due to their ability to immediately react to changes in the water column trophic features and salinity levels. As a coastal lagoon with a broad history of anthropic influence, Rodrigo de Freitas Lagoon (Rio de Janeiro, Brazil is widely used for water sports and artisanal fishing. The present study aimed to expand the knowledge base about zooplankton in the Rodrigo de Freitas Lagoon by assessing the composition and time-spatial distribution of the major zooplankton groups. Samples were collected fortnightly from at four distinct sampling points August 2001 to July 2002. At each point, salinity, temperature, dissolved oxygen and water transparency were measured. During the study period, the lagoon behaved as an spatially homogeneous environment in what regards the abiotic variables. However, all these variables showed significant differences along the time, mainly related to seasonality (air temperature and rainy and dry periods. The zooplankton community showed low taxonomic richness, with the predominance of species commonly found in coastal lagoons, especially with mesohaline conditions, as well as those found in estuaries. An interesting fact was the rise in zooplankton abundance at all sampling points right after a fish kill event. Such increase was caused mainly by the Brachionus plicatilis O.F. Müller 1786 species. Thus, the zooplankton community was affected by physical and chemical factors, mainly by the dissolved oxygen decline event and variations in the influx of seawater into the lagoon. In addition, phytoplankton availability and fish predation pressure were suggested as important regulating factors of the zooplankton community.

Influence of dispersants on petroleum bioavailability in a marine food chain

Energy Technology Data Exchange (ETDEWEB)

Wolfe, M.; Tjeerdema, R. [Univ. of California, Santa Cruz, CA (United States). Dept. of Chemistry and Biochemistry; Sowby, M. [California Dept. of Fish and Game, Sacramento, CA (United States)

1995-12-31

When crude oil is accidentally released into the ocean it threatens many levels of marine life. Intervention, in the form of chemical dispersing agents, may alter the normal behavior of petroleum hydrocarbons (PH) by increasing their functional water solubility and the extent of their exposure to sub-surface marine organisms. Further, the dispersing agent may modify bioavailability as a result of altered interactions between dispersed PH droplets and organismal cell membranes, To date, little information exists on the sub-lethal effects of dispersants and factors modifying their role in the bioavailability and disposition of PH in marine food chains. The objective of the current research was to determine the impact of dispersing agents on PH bioavailability to primary levels of a marine food chain. Uptake, bioaccumulation, deputation, and metabolic transformation of a model PH, {sup 14}C-naphthalene, were measured and compared for dispersed Prudhoe Bay Crude Oil (PBCO) vs. undispersed preparations of the water-accommodated fractions (WAF) of PBCO at two salinities (22 and 34 ppt) employing Isochrysis galbana, a primary producer, and Brachionus plicatilis, a primary consumer. Fractionation and identification of metabolites was done by HPLC co-chromatography with analytical standards, and quantitation was done by liquid scintillation counting. GC-FID characterization of WAF and dispersed oil preparations shows higher concentrations of petroleum hydrocarbons and a greater number of individual constituents in the dispersed oil preparations. However, short term (eight hour) and long term (two week) static exposure studies indicate the uptake of{sup 14}C-naphthalene from WAF preparations is inhibited by up to 50% from dispersed oil preparations. Results of comparative static and flow-through chamber exposure studies will be presented.

Feeding behaviour of the hydromedusa Aequorea vitrina

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Hans Ulrik RiisgÅrd

2007-06-01

Full Text Available The prey-capture mechanism of the hydromedusa Aequorea vitrina was studied by means of laboratory video-microscope observations. In stagnant water A. vitrina remains stationary with its very long (about 4x bell diameter marginal tentacles motionless hanging down in the water, ready for ambush capture of prey organisms that collide with the tentacles. A. vitrina was found to be efficient at capturing brine shrimps (Artemia salina, less efficient at capturing rotifers (Brachionus plicatilis, and very inefficient at capturing copepods (Acartia tonsa. The initial hauling up of an extended marginal tentacle with an adhering prey is fast (>10 mm s-1. Both the bell margin and the mouth move towards each other so that the captured prey can be transferred from the tentacle to the elongated mouth-lips to be further transported into the mouth and stomach. It takes about 20 s from when an Artemia prey organism encounters a tentacle until it is transferred to the mouth-lips. The subsequent digestion in the stomach takes about 30 min. When A. vitrina encounters a jellyfish-prey (a small medusa of Aurelia aurita, it starts to swim in order to adhere the relatively big prey to its mouth-lips. Then A. vitrina opens its mouth wide to swallow the captured medusa, a process which takes about 15 to 20 min. The subsequent digestion takes 2 to 3 h. Field observations of undisturbed A. vitrina made by snorkelling in the Limfjord (Denmark revealed that the feeding behaviour was similar to that observed in the laboratory in stagnant water. It is concluded that A. vitrina is an ambush-predator, and not a cruising-predatory medusa as previously suggested.

Effect of food type and concentration on growth and fatty acid composition of early larvae of the anchovy (Engraulis encrasicolus) reared under laboratory conditions

KAUST Repository

Garrido, Susana

2012-12-01

Experiments were conducted during the summer of 2008 and 2009 to study the growth of early post yolk-sac European anchovy (Engraulis encrasicolus, Linnaeus, 1758) larvae reared under different food regimes. The fatty acid composition was used to assess nutritional condition of the larvae. Prey items used in the experiments were Gymnodinium sanguineum, Brachionus plicatilis and nauplii of the copepods Acartia grani and Euterpina acutifrons. Food type and concentration affected the growth of the larvae. Mixed diets composed of rotifers and copepod nauplii at high concentration resulted in higher anchovy larvae growth rates in comparison with single-prey diets using either rotifers or copepod nauplii. The addition of the dinoflagellate G. sanguineum (25-50cellsml -1) to the prey offered did not enhance significantly larval growth. Highest growth rates of anchovy larvae (0.28mmd -1) were obtained using high concentrations of a mixed diet, particularly the combination of rotifers and A. grani nauplii. Fatty acid composition at hatch was similar to the composition observed in the field, but during larvae ontogeny there was a marked decrease in the contribution of polyunsaturated fatty acids such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Such difference reflects the high requirements of these PUFA for larvae development, and suggests that the food offered failed to fulfill the larvae nutritional requirements. The growth rates obtained in our experiments were, overall, in the lower range of those observed in natural conditions. Taking into considerations the fact that larvae in the field are expected to encounter lower prey concentrations, we discuss the reasons for such disagreement. © 2012 Elsevier B.V.

Effect of food type and concentration on growth and fatty acid composition of early larvae of the anchovy (Engraulis encrasicolus) reared under laboratory conditions

KAUST Repository

Garrido, Susana; Saiz, Enric; Peters, Janna L.; Ré , Pedrobarcia; Á lvarez, Paula; Cotano, Unai; Herrero, D. L.; de Murguí a, Amalia Martí nez; Irigoien, Xabier

2012-01-01

Experiments were conducted during the summer of 2008 and 2009 to study the growth of early post yolk-sac European anchovy (Engraulis encrasicolus, Linnaeus, 1758) larvae reared under different food regimes. The fatty acid composition was used to assess nutritional condition of the larvae. Prey items used in the experiments were Gymnodinium sanguineum, Brachionus plicatilis and nauplii of the copepods Acartia grani and Euterpina acutifrons. Food type and concentration affected the growth of the larvae. Mixed diets composed of rotifers and copepod nauplii at high concentration resulted in higher anchovy larvae growth rates in comparison with single-prey diets using either rotifers or copepod nauplii. The addition of the dinoflagellate G. sanguineum (25-50cellsml -1) to the prey offered did not enhance significantly larval growth. Highest growth rates of anchovy larvae (0.28mmd -1) were obtained using high concentrations of a mixed diet, particularly the combination of rotifers and A. grani nauplii. Fatty acid composition at hatch was similar to the composition observed in the field, but during larvae ontogeny there was a marked decrease in the contribution of polyunsaturated fatty acids such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Such difference reflects the high requirements of these PUFA for larvae development, and suggests that the food offered failed to fulfill the larvae nutritional requirements. The growth rates obtained in our experiments were, overall, in the lower range of those observed in natural conditions. Taking into considerations the fact that larvae in the field are expected to encounter lower prey concentrations, we discuss the reasons for such disagreement. © 2012 Elsevier B.V.

Joint inhibition of TOR and JNK pathways interacts to extend the lifespan of Brachionus manjavacas (Rotifera).

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Snell, Terry W; Johnston, Rachel K; Rabeneck, Brett; Zipperer, Cody; Teat, Stephanie

2014-04-01

The TOR kinase pathway is central in modulating aging in a variety of animal models. The target of rapamycin (TOR) integrates a complex network of signals from growth conditions, nutrient availability, energy status, and physiological stresses and matches an organism's growth rate to the resource environment. Important remaining problems are the identification of the pathways that interact with TOR and their characterization as additive or synergistic. One of the most versatile stress sensors in metazoans is the Jun-N-terminal kinase (JNK) signaling pathway. JNK is an evolutionarily conserved stress-activated protein kinase that is induced by a range of stressors, including UV irradiation, reactive oxygen species, DNA damage, heat, and bacterial antigens. JNK is thought to interact with the TOR pathway, but its effects on TOR are poorly understood. We used the rotifer Brachionus manjavacas as a model animal to probe the regulation of TOR and JNK pathways and explore their interaction. The effect of various chemical inhibitors was examined in life table and stressor challenge experiments. A survey of 12 inhibitors revealed two, rapamycin and JNK inhibitor, that significantly extended lifespan of B. manjavacas. At 1 μM concentration, exposure to rapamycin or JNK inhibitor extended mean rotifer lifespan by 35% and maximum lifespan by 37%. Exposure to both rapamycin and JNK inhibitor simultaneously extended mean rotifer lifespan by 65% more than either alone. Exposure to a combination of rapamycin and JNK inhibitors conveyed greater protection to starvation, UV and osmotic stress than either inhibitor alone. RNAi knockdown of TOR and JNK gene expression was investigated for its ability to extend rotifer lifespan. RNAi knockdown of the TOR gene resulted in 29% extension of the mean lifespan compared to control and knockdown of the JNK gene resulted in 51% mean lifespan extension. In addition to the lifespan, we quantified mitochondria activity using the fluorescent

Dietary β-glucan (MacroGard®) enhances survival of first feeding turbot (Scophthalmus maximus) larvae by altering immunity, metabolism and microbiota.

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Miest, Joanna J; Arndt, Carmen; Adamek, Mikolaj; Steinhagen, Dieter; Reusch, Thorsten B H

2016-01-01

Reflecting the natural biology of mass spawning fish aquaculture production of fish larvae is often hampered by high and unpredictable mortality rates. The present study aimed to enhance larval performance and immunity via the oral administration of an immunomodulator, β-glucan (MacroGard(®)) in turbot (Scophthalmus maximus). Rotifers (Brachionus plicatilis) were incubated with or without yeast β-1,3/1,6-glucan in form of MacroGard(®) at a concentration of 0.5 g/L. Rotifers were fed to first feeding turbot larvae once a day. From day 13 dph onwards all tanks were additionally fed untreated Artemia sp. nauplii (1 nauplius ml/L). Daily mortality was monitored and larvae were sampled at 11 and 24 dph for expression of 30 genes, microbiota analysis, trypsin activity and size measurements. Along with the feeding of β-glucan daily mortality was significantly reduced by ca. 15% and an alteration of the larval microbiota was observed. At 11 dph gene expression of trypsin and chymotrypsin was elevated in the MacroGard(®) fed fish, which resulted in heightened tryptic enzyme activity. No effect on genes encoding antioxidative proteins was observed, whilst the immune response was clearly modulated by β-glucan. At 11 dph complement component c3 was elevated whilst cytokines, antimicrobial peptides, toll like receptor 3 and heat shock protein 70 were not affected. At the later time point (24 dph) an anti-inflammatory effect in form of a down-regulation of hsp 70, tnf-α and il-1β was observed. We conclude that the administration of MacroGard(®) induced an immunomodulatory response and could be used as an effective measure to increase survival in rearing of turbot. Copyright © 2015 Elsevier Ltd. All rights reserved.

Different types of interactions of links in artificial and natural ecosystems under anthropogenic pressure

Science.gov (United States)

Somova, Lydia; Pisman, Tamara; Mikheeva, Galina; Pechurkin, Nickolay

The life of organisms in an ecosystem depends not only on abiotic factors, but also on the interaction of organisms in which they come with each other. The study of mechanisms of the bioregulation based on ecological - biochemical interactions of ecosystem links is necessary to know the ecosystem development, its stability, survival of ecosystem organisms. It is of high importance as for the creation of artificial ecosystems, and also for the study of natural ecosystems under anthropogenic pressure on them. To create well-functioning ecosystems is necessary to study and consider the basic types of relationships between organisms. The basic types of interactions between organisms have been studied with simple terrestrial and water ecosystems. 1. The interaction of microbiocenoses and plants were studied in experiments with agrocenoses. Microbiocenosis proposed for increase of productivity of plants and for obtaining ecologically pure production of plants has been created taking into account mutual relationships between species of microorganisms. 2. The experimental model of the atmosphere closed «autotroph - heterotroph» system in which heterotrophic link was the mixed population of yeasts (Candida utilis and Candida guilliermondii) was studied. The algae Chlorella vulgaris was used as an autotroph link. It was shown, that the competition result for heterotrophic link depended on strategy of populations of yeast in relation to a substrate and oxygen utilization. 3. As a result of experimental and theoretical modelling of a competition of algae Chlorella vulgaris and Scenedesmus quadricauda at continuous cultivation, the impossibility of their coexistence in the conditions of limitation on nitrogen was shown. 4. Pray-predator interactions between algae (Chlorella vulgaris, Scenedesmus quadricauda) and invertebrates (Paramecium caudatum, Brachionus plicatilis) were studied in experimental closed ecosystem. This work was partly supported by the Russian Foundation for

Aeolian transport of biota with dust: A wind tunnel experiment

Science.gov (United States)

Rivas, J. A., Jr.; Gill, T. E.; Van Pelt, R. S.; Walsh, E.

2015-12-01

Ephemeral wetlands are ideal sources for dust emission, as well as repositories for dormant stages of aquatic invertebrates. An important component of invertebrate dispersal and colonization to new areas is the ability to be entrained into the atmosphere. Aquatic invertebrate eggs fall within the size of dust and sand grains (30-600μm), are less dense and aerodynamically shaped. We have shown previously that aquatic invertebrates can be dispersed long distances in dust storms but the extent of transport of taxa based on diapausing egg size/morphology has not been investigated. Here, we control the wind erosion process in a wind tunnel to test entrainment of diapausing stages of brine shrimp, clam shrimp, tadpole shrimp, fairy shrimp, Daphnia, and the rotifers Brachionus plicatilis and B. calyciflorus into the air by saltation. Diapausing eggs were mixed with sterilized wind-erodible soil. The soil/egg mixture was moistened with distilled water and air dried to form a crust. Dust was generated in a wind tunnel by releasing sand grains that act as saltator material similar to wind-entrained natural sands. Maximum wind velocity was 10m/s and entrained particles were sampled through an isokinetic horizontal intake opening. Aeolian sediment was collected from three points in the system; transfer section for coarse sediment, the pan subtending a settling chamber for finer saltation-sized sediment, and two paper filters for suspension-sized sediment. Samples were then passed through 250 and 350 μm sieves to remove abrader sand and rehydrated with various sterile media depending on the type of organism. We retrieved viable brine, fairy, and tadpole shrimp, ostracods, Daphnia, and diapausing eggs of the rotifers after hydration. This experiment demonstrates that resting stages of many invertebrates can be wind-eroded due to size and egg morphology and remain viable under controlled conditions mimicking dust emission.

Does copepods influence dusky grouper (Epinephelus marginatus early development?

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Monica Mateus

2014-06-01

Full Text Available Good knowledge on the development of early life stages is essential for successful conservation programs of threatened fish species. Diet and rearing system affects early life survival and juvenile quality. Copepods are the natural food of fish larvae in the wild possessing high nutritional value, when compared with live feeds used in aquaculture (rotifers and artemia, and a wide range of size classes. Rearing systems with low water column disturbance and low larval densities enhanced the survival of fragile fish larvae. The aim of this work is to evaluate the effect of the introduction of copepods in the diet of early dusky grouper larvae reared in controlled mesocosm systems using larval development and juvenile quality as indicators. Two feeding protocols were tested, one composed only by rotifers (Brachionus plicatilis, brine shrimp (Artemia spp. and dry feed and the other supplemented with copepods (Paracartia grani from mouth opening (2 day after hatching - DAH to 8 DAH. Feeding behavior, growth, survival, skeletal malformations and digestive enzymes activity was assessed at different developmental stages. The addition of copepods to the early larvae diet of dusky grouper resulted in faster development and higher survival rates. Larvae fed with copepods improved their development. At 20 DAH all larvae reared at the mesocosm with copedods were already at the stage of post-flexion while in the system without copepods this stage was attained later. At 25 DAH only 64% of the larvae were in post flexion in the mesoscosm without copepods. At 30 DAH larvae supplemented with copepods attained an acidic digestion (high specific activity of pepsin earlier than at the system without copepods. In this last system alkaline digestion (trypsin specific activity, characteristic of early larval stages, was significantly higher reinforcing the faster development of larvae fed with copepods. In both systems the incidence of skeletal malformations was low.

Demography of zooplankton (Anuraeopsis fissa, Brachionus rubens and Moina macrocopa) fed Chlorella vulgaris and Scenedesmus acutus cultured on different media.

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Morales-Ventura, Jesús; Nandini, S; Sarma, S S S; Castellanos-Páez, Maria Elena

2012-09-01

Generally zooplankton growth is often limited by the quality of their algal diet. A cheaper common practice in aquaculture, is to culture algae with fertilizers; however, the demography of zooplankton when fed these algae has not yet been evaluated. We studied the population growth and life table demography of the rotifers Anuraeopsis fissa and Brachionus rubens, and the cladoceran Moina macrocopa. For this, the algae Scenedesmus acutus or Chlorella vulgaris were cultured on defined (Bold's basal) medium or the commercial liquid fertilizer (Bayfolan). Experiments were conducted at one algal concentration 1.0 x 10(6) cells/mL of C. vulgaris or its equivalent dry weight of 0.5 x 10(6) cells/mL of S. acutus. The population dynamics were tested at 23 +/- 1 degrees C in 100 mL transparent jars, each with 50mL of the test medium, with an initial density of 0.5indiv/mL, for a total of 48 test jars (3 zooplankton 2 algal species x 2 culture media x 4 replicates). For the life table experiments with M. macrocopa, we introduced 10 neonates (vulgaris cultured in Bold medium. Regardless of the culture medium, Chlorella resulted in significantly higher gross and net reproductive rates for B. rubens than S. acutus diets. The reproductive rates of M. macrocopa were significantly higher in all the tested diets except when fed with S. acutus in Bold medium. The population increase rate, derived from growth experiments of A. fissa and B. rubens, ranged from 0.1-0.25/d and were significantly higher on C vulgaris cultured in liquid fertilizer as compared to the other diets. The growth rates of M. macrocopa ranged from 0.1 to 0.38/d, and were highest with diets of C. vulgaris cultured in Bold medium and S. acutus cultured in fertilizer. Thus, regardless of the culture medium used, the growth rates of the evaluated zooplankton species were higher with Chlorella than with Scenedesmus. The peak population density was highest (2 800ind/mL) for A. fissa fed Chlorella that was cultured on

Adverse effects of methylmercury (MeHg) on life parameters, antioxidant systems, and MAPK signaling pathways in the rotifer Brachionus koreanus and the copepod Paracyclopina nana.

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Lee, Young Hwan; Kim, Duck-Hyun; Kang, Hye-Min; Wang, Minghua; Jeong, Chang-Bum; Lee, Jae-Seong

2017-09-01

To evaluate the adverse effects of MeHg on the rotifer Brachionus koreanus and the copepod Paracyclopina nana, we assessed the effects of MeHg toxicity on life parameters (e.g. growth retardation and fecundity), antioxidant systems, and mitogen-activated protein kinase (MAPK) signaling pathways at various concentrations (1ng/L, 10ng/L, 100ng/L, 500ng/L, and 1000ng/L). MeHg exposure resulted in the growth retardation with the increased ROS levels but decreased glutathione (GSH) levels in a dose-dependent manner in both B. koreanus and P. nana. Antioxidant enzymatic activities (e.g. glutathione S-transferase [GST], glutathione reductase [GR], and glutathione peroxidase [GPx]) in B. koreanus showed more positive responses compared the control but in P. nana, those antioxidant enzymatic activities showed subtle changes due to different no observed effect concentration (NOEC) values among the two species. Expression of antioxidant genes (e.g. superoxide dismutase [SOD], GSTs, glutathione peroxidase [GPx], and catalase [CAT]) also demonstrated similar effects as shown in antioxidant enzymatic activities. In B. koreanus, the level of p-ERK was decreased in the presence of 1000ng/L MeHg, while the levels of p-ERK and p-p38 in P. nana were reduced in the presence of 10ng/L MeHg. However, p-JNK levels were not altered by MeHg in B. koreanus and P. nana, compared to the corresponding controls. In summary, life parameters (e.g. reduced fecundity and survival rate) were closely associated with effects on the antioxidant system in response to MeHg. These observations provide a better understanding on the adverse effects of MeHg on in vivo life parameters and molecular defense mechanisms in B. koreanus and P. nana. Copyright © 2017 Elsevier B.V. All rights reserved.

The use of multivariate analysis to link sediment contamination and toxicity data to establish sediment quality guidelines: an example in the Gulf of Cadiz (Spain); El uso del analisis multivariante en la union de datos de toxicidad y contaminacion para establecer guias de calidad de sedimento: Un ejemplo en la Bahia de Cadiz (Espana)

Energy Technology Data Exchange (ETDEWEB)

Del Valls, T. Angel; Forja, Jesus M [Departamento de Quimica Fisica, Facultad de Ciencias del Mar, Universidad de Cadiz, Cadiz, (Spain); Gomez-Parra, Abelardo [Instituto de Ciencias Marinas de Andalucia, CSIC, Puerto Real, Cadiz, (Spain)

1998-03-01

To evaluate marine sediment quality in the Gulf of Cadiz, chemical concentration and toxicity test endpoints from sediments were linked using multivariate analysis. Sediment samples were collected synoptically at seven stations in two littoral ecosystems of the Gulf of Cadiz (five in the Bay of Cadiz and two in the salt marsh of the Barbate River), and subjected to six separate, replicated sediment toxicity tests and comprehensive sediment chemistry analyses. The toxic effects of sediments were tested using three operational sediment phases: whole sediment, using the estuarine amphipod Microdeutopus gryllotalpa (10 d static: survival) and the estuarine clam Ruditapes philippinaru (48 h static: survival) and of the marine fish Sparus aurata (48 h static. Survival); and interstitial water, using populations of the estuarine rotifer Brachionus Plicatilis (7 d static: Population decline) and of the marine bacteria Photobacterium phosphoreum (Microtox ). To evaluate the levels of contamination, the concentrations in the sediments of organic carbon, 14 trace metals (Fe, Mn, Cu, Zn, Pb, Cd, Ag, Hg, As, Sn, V, Ni, Co and Cr) and the surfactant linear alkylbenzenesulphonate (LAS) were measured. The results of the toxicity tests were compared in a dose-response relationship between sites, demonstrating a general agreement between the toxicity values determined by all the tests, except in the case of interstitial water toxicity (principally due to toxic mixtures of trace metals). Data derived from sediment chemistry and bioassays were assembled by multivariate statistical techniques (PCA and factor analysis), showing that the two data types could be represented by only five factors corresponding to five overlapping chemical-biological effect relations. Positive prevalence of these factors in the cases studied was used to establish those ranges in chemical concentrations associated with adverse effects. The sediment quality guidelines, in terms of concentrations at or below

Effects of calanoid copepod Schmackeria poplesia as a live food on the growth, survival and fatty acid composition of larvae and juveniles of Japanese flounder, Paralichthys olivaceus

Science.gov (United States)

Liu, Guangxing; Xu, Donghui

2009-12-01

Zooplankton constitutes a major part of the diet for fish larvae in the marine food web, and it is generally believed that copepods can meet the nutritional requirements of fish larvae. In this study, calanoid copepod Schmackeria poplesia, rotifer Brachionus plicatilis and anostraca crustacean Artemia sp. were analyzed for fatty acid contents, and were used as live food for culturing larval Japanese flounder, Paralichthys olivaceus. The total content of three types of HUFAs (DHA, EPA and ARA) in S. poplesia was significantly higher than that in the other two live foods ( P<0.01). Three live organisms were used for raising larvae and juveniles of Paralichthys olivaceus respectively for 15 and 10 d. Then the growth, survival and fatty acid composition of the larvae and juveniles were investigated. The results showed that the larvae and juveniles fed with copepods ( S. poplesia) had significantly higher growth rate than those fed with the other two organisms ( P<0.01). The survival of the flounder larvae fed with copepods was significantly higher than that of the others ( P<0.01), and the survival of the juvenile fish fed with copepods was higher than that fed with Artemia ( P<0.05). The contents of three types of HUFAs (DHA, EPA and ARA) and the ratio of DHA/EPA in larval and juvenile flounder P. olivaceus were analyzed. The results showed that the contents of DHA, EPA and ARA in the larvae and juveniles fed with S. poplesia were higher than those fed with a mixed diet or Artemia only, and the ratio of EPA/ARA in larvae and juveniles of P. olivaceus fed with S. poplesia was lower than that in the case of feeding with a mixed diet or Artemia only. The present data showed that copepod is the best choice for feeding the larvae and juveniles of fish considering its effects on the survival, growth and nutrition composition of the fish.

Transitioning NWChem to the Next Generation of Manycore Machines

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Bylaska, Eric J.; Apra, Edoardo; Kowalski, Karol; Jacquelin, Mathias; De Jong, Wibe A.; Vishnu, Abhinav; Palmer, Bruce J.; Daily, Jeffrey A.; Straatsma, Tjerk P.; Hammond, Jeff R.; Klemm, Michael

2017-11-09

The NorthWest Chemistry (NWChem) modeling software is a popular molecular chemistry simulation software that was designed from the start to work on massively parallel processing supercomputers[6, 28, 49]. It contains an umbrella of modules that today includes Self Consistent Field (SCF), second order Mller-Plesset perturbation theory (MP2), Coupled Cluster, multi-conguration selfconsistent eld (MCSCF), selected conguration interaction (CI), tensor contraction engine (TCE) many body methods, density functional theory (DFT), time-dependent density functional theory (TDDFT), real time time-dependent density functional theory, pseudopotential plane-wave density functional theory (PSPW), band structure (BAND), ab initio molecular dynamics, Car-Parrinello molecular dynamics, classical molecular dynamics (MD), QM/MM, AIMD/MM, GIAO NMR, COSMO, COSMO-SMD, and RISM solvation models, free energy simulations, reaction path optimization, parallel in time, among other capabilities[ 22]. Moreover new capabilities continue to be added with each new release.

Demography of zooplankton (Anuraeopsis fissa, Brachionus rubens and Moina macrocopa fed Chlorella vulgaris and Scenedesmus acutus cultured on different media

Directory of Open Access Journals (Sweden)

Jesús Morales-Ventura

2012-09-01

Full Text Available Generally zooplankton growth is often limited by the quality of their algal diet. A cheaper common practice in aquaculture, is to culture algae with fertilizers; however, the demography of zooplankton when fed these algae has not yet been evaluated. We studied the population growth and life table demography of the rotifers Anuraeopsis fissa and Brachionus rubens, and the cladoceran Moina macrocopa. For this, the algae Scenedesmus acutus or Chlorella vulgaris were cultured on defined (Bold’s basal medium or the commercial liquid fertilizer (Bayfolan. Experiments were conducted at one algal concentration 1.0x10(6cells/mL of C. vulgaris or its equivalent dry weight of 0.5x10(6cells/mL of S. acutus. The population dynamics were tested at 23±1ºC in 100mL transparent jars, each with 50mL of the test medium, with an initial density of 0.5indiv/mL, for a total of 48 test jars (3 zooplankton 2 algal species x 2 culture media x 4 replicates. For the life table experiments with M. macrocopa, we introduced 10 neonates (<24h old into each test jar containing the specific algal type and concentration. For the rotifer experiments, we set 5mL tubes with one neonate each and 10 replicates for each algal species and culture medium. We found that the average rotifer life span was not influenced by the diet, but for M. macrocopa fed S. acutus cultured in Bold’s medium, the average lifespan was significantly lower than with the other diets. The gross and net reproductive rates of A. fissa (ranging from 18-36 offspring per female were significantly higher for C. vulgaris cultured in Bold medium. Regardless of the culture medium, Chlorella resulted in significantly higher gross and net reproductive rates for B. rubens than S. acutus diets. The reproductive rates of M. macrocopa were significantly higher in all the tested diets except when fed with S. acutus in Bold medium. The population increase rate, derived from growth experiments of A. fissa and B. rubens

L'élevage larvaire des poissons marins : chaînes alimentaires et aliments composés

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GIRIN M.

1977-01-01

Full Text Available L'approvisionnement quotidien en nourriture est, en règle générale, le principal facteur limitant de productions à grande échelle de jeunes poissons marins.La pêche de plancton dans la nature a été, et reste, le moyen d'expérimentation le plus immédiat, et le plus satisfaisant sur le plan qualitatif. Mais la récolte des quantités nécessaires, au moment voulu, devient très délicate dès que l'on dépasse l'échelle de l'aquarium. Le développement, ces dernières décennies, de techniques de production en masse d'animaux-proies a permis le lancement d'élevages à grande échelle. Parmi ces proies, le Branchiopode Artemia salina et le Rotifère Brachionus plicatilis dominent incontestablement ; tandis que l'élevage des Copépodes, part la plus intéressante du plancton naturel, reste encore mal maîtrisé. Cependant , l'élevage et l'emploi de proies vivantes, quelles qu'elles soient, imposent la réalisation d'installations coûteuses et l'emploi d'un abondant personnel qualifié. Il en est résulté récemment un important effort de recherche en direction de nourritures inertes, broyats , poudres et aliments composés, généralement abandonnés après les échecs enregistrés pendant les premières années du siècle. Quelques résultats encourageants ont été obtenus, mais ils restent limités et soulèvent de délicats problèmes d'hygiène des bacs d'élevage. L'emploi de proies vivantes , au moins pendant le premier mois des élevages , reste donc encore une obligation. Dans ce contexte, l'essentiel de l'effort actuel tend , d'une part à réduire leur durée d'emploi au minimum possible et, d'autre part, à rendre leur production plus rationnelle , en recherchant des méthodes qui évitent, pour leur alimentation , de faire appel à des algues planctoniques vivantes.

Effects of population outcrossing on rotifer fitness

Science.gov (United States)

2010-01-01

Background Outcrossing between populations can exert either positive or negative effects on offspring fitness. Cyclically parthenogenetic rotifers, like other continental zooplankters, show high genetic differentiation despite their high potential for passive dispersal. Within this context, the effects of outcrossing may be relevant in modulating gene flow between populations through selection for or against interpopulation hybrids. Nevertheless, these effects remain practically unexplored in rotifers. Here, the consequences of outcrossing on the rotifer Brachionus plicatilis were investigated. Cross-mating experiments were performed between a reference population and three alternative populations that differed in their genetic distance with regard to the former. Two offspring generations were obtained: F1 and BC ('backcross'). Fitness of the outcrossed offspring was compared with fitness of the offspring of the reference population for both generations and for three different between-population combinations. Four fitness components were measured throughout the rotifer life cycle: the diapausing egg-hatching proportion, clone viability (for the clones originating from diapausing eggs), initial net growth rate R for each viable clone, and the proportion of male-producing clones. Additionally, both the parental fertilisation proportion and a compound fitness measure, integrating the complete life cycle, were estimated. Results In the F1 generation, hybrid vigour was detected for the diapausing egg-hatching proportion, while R was lower in the outcrossed offspring than in the offspring of the reference population. Despite these contrasting results, hybrid vigour was globally observed for the compound measure of fitness. Moreover, there was evidence that this vigour could increase with the genetic differentiation of the outcrossed populations. In the BC generation, the hybrid vigour detected for the egg-hatching proportion in the F1 generation reverted to outbreeding

Assessment of Zooplankton Community Structure of the Bahir Dar ...

African Journals Online (AJOL)

In general, species richness, evenness, and diversity increased as average abundance increased in the littoral zones of the lake. The dominant zooplankton were Bosmina longirostris, Daphnia lumholtzi, Thermodiaptomus galebi, Thermocyclops ethiopiensis, Diaphanosoma sarsi, Keratella sp., Brachionus sp., Filinia sp.

USING ROTIFER POPULATION DEMOGRAPHIC PARAMETERS TO ASSESS IMPACTS OF THE DEGRADATION PRODUCTS FROM TRINITROTOLUENE PHYTOREMEDIATION

Science.gov (United States)

The objective of this study was to evaluate the aquatic chronic lethal and sublethal toxicity effects from the phytoremediation of water contaminated with 2,4,6-trinitrotoluene (2,4,6-TNT) by the wetland plant species Myriophyllum aquaticum (parrot feather). Rotifers (Brachionus...

Study on zooplankton distributions in Mahin Lagoon within ...

African Journals Online (AJOL)

Ciliophorans (such as Tintinnopsis, Codonellopsis spp) were distributed mostly within the stations close to the Atlantic Ocean with higher salinity while freshwater stations further upstream were prevailed mostly by rotifers (such as Ascomorpha, Brachionus, Keratella, Filinia spp.). Copepods (such as Acartia, Paracalanus, ...

Composición taxonómica del zooplancton del embalse de Betania, departamento del Huila, Colombia

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Yimy Herrera Martinez

1999-01-01

Full Text Available To determine the species composition of the zooplancton in the reservoir Betania (altitude; 560 m.a.s.l.; area: 7.4 km2; vol: 1971 x 106 m3; mean depht 28 m, at seven sites and several depths, bimonthly net samples (100 and 200 microns mesh size were taken during 1991.  Alltogether 24 species were found: Thermocyclops decipiens (Crustacea, Copepoda, Moina sp., Ceriodaphnia cornuta y Allona sp. (Crustacea, Cladocera; 19 species of rotífers, of which 7 belong to the genus Brachionus, as well as larvas of the dipter Chaoborus sp. For the first time Brachionus havanaensis, B. falcatus falcatus, b. quadridentatus, y Platyias cuadricornis  f. brevispinus  were found in Colombia.  The species composition was compared with the composition of other lakes and comparison shows that the Betania reservoir has a typical species composition for warms tropical lakes.

The zooplankton community of Lake Abo Zaabal, a newly-formed ...

African Journals Online (AJOL)

Cladocera were seldom recorded. Hexarthra, Brachionus and Rotaria were the dominant rotifer taxa. Several characteristics — including the community composition, the dominance of small ciliates and nauplii, the abundance of Cyanobacteria, and the absence of macrophytes — indicated that it is a severely eutrophic lake.

Responses in sediment bioassays used in the Netherlands: can observed toxicity be explained by routinely monitored priority pollutants?

NARCIS (Netherlands)

Lahr, J.; Maas-Diepeveen, J.L.; Stuijfzand, S.C.; Leonards, P.E.G.; Drueke, J.M.; Luecker, S.; Espeldoorn, A.

2003-01-01

In order to identify the cause of toxicity in sediments and suspended matter, a large number of samples with different degrees of contamination was taken at various locations in The Netherlands. Standard acute bioassays were carried out with the bacterium Vibrio fischeri, the rotifer Brachionus

Browse Title Index

African Journals Online (AJOL)

Items 51 - 100 of 175 ... Vol 12 (2003), Incidence of feeding, growth and survival of the toothed carp, Aphyosemion gardneri larvae reared on the freshwater rotifer, Brachionus calyciflorus, Abstract. FO Arimoro, PC Ofojekwu. Vol 10 (2001), Incidence of pathogenic bacteria in the Asejire Lake, western Nigeria, Abstract.

seasonal variation of biomass and secondary production of ...

African Journals Online (AJOL)

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(Thermocyclops consimilis, 71% in abundance) and the rotifer Brachionus calyciflorus (12%). T. consimilis was cultured in ... Kuriftu were low compared to other tropical lakes and related cyclopoids and rotifers, and some reasons for this observation are ... particles and bacteria appeared to contribute the major nutrition to ...

African Journal of Biotechnology - Vol 5, No 7 (2006)

African Journals Online (AJOL)

Culture of the freshwater rotifer, Brachionus calyciflorus, and its application in fish larviculture technology · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT ... Occurrence and growth potentials of hydrocarbon degrading bacteria on the phylloplane of some tropical plants · EMAIL FREE FULL TEXT EMAIL FREE FULL ...

FLUCTUACIÓN DE LOS ENSAMBLES PLANCTÓNICOS EN LA CIÉNAGA DE AYAPEL (CÓRDOBA-COLOMBIA DURANTE UN CICLO SEMANAL FLUCTUATION OF PLANKTON ASSEMBLAGES AT AYAPEL SWAMP IN CÓRDOBA (COLOMBIA DURING A WEEKLY CYCLE

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Juan Carlos Jaramillo-Londoño

2012-12-01

Full Text Available En esta investigación se evaluó la variación espacial y temporal de los ensamblajes fitoplanctónicos y zooplanctónicos, diariamente y durante un ciclo semanal, en seis estaciones de muestreo en la ciénaga de Ayapel (Córdoba, Colombia, tomando muestras integradas de la columna de agua. Ambos ensamblajes presentaron diferencias espaciales y una alta homogeneidad temporal. El fitoplancton estuvo dominado por cianobacterias principalmente Cylindropermopsis raciborskii y Planktolyngbya limnetica, y el zooplancton por rotíferos del género Brachionus.This research was intended to spatially and temporally evaluate phytoplankton and zooplankton assemblages on a daily basis during a weekly cycle, in six sampling stations at Ayapel swamp in Córdoba (Colombia, taking integrated samples of the water column. Both assemblages showed spatial differences and a high temporal homogeneity. Phytoplankton was dominated by cyanobacteria, specifically Cylindropermopsis raciborskii and Planktolyngbya limnetica; and zooplankton was dominated by Brachionus-genus rotifers..

Limnología e ictiofauna de la laguna José María (Córdoba, Argentina, con especial referencia al pejerrey (Odontesthes bonariensis -Valenciennes, 1835-

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M. Mancini

2016-09-01

Full Text Available La región sur de la provincia de Córdoba presenta numerosas lagunas cuyo origen y salinidad varían ampliamente. Muchos de estos ambientes son utilizados para la pesca recreativa del pejerrey (Odontesthes bonariensis. El objetivo del presente trabajo fue caracterizar la calidad del agua y determinar la diversidad del zooplancton y de la ictiofauna con especial referencia a O. bonariensis, de la laguna José María (34º50’17’’S, 63º37’23’’O. Este ambiente se ubica en la cuenca del río Quinto (Córdoba y está comunicado con numerosas lagunas. Se analizaron in situ (n=8, el pH, el oxígeno, la temperatura y transparencia del agua y se tomaron muestras de agua y zooplancton para su análisis en laboratorio. Para la captura de peces se utilizaron redes de enmalle, arrastre, trampa y espineles. La profundidad promedio fue de 1,99 m, con un máximo de 2,20 m. Los registros medios del pH, oxígeno disuelto, temperatura y transparencia fueron 8,51, 9,03 mg/L, 24,3 ºC y 44 cm respectivamente. Por su transparencia, la laguna fue caracterizada como “turbia”. El agua se clasificó como oligohalina (4,09 g/L, sulfatada-sódica y muy dura (484 ppm de CO3Ca. El zooplancton estuvo representado por 3 especies de crustáceos y 7 de rotíferos. Entre los primeros, Metacyclops mendocinus fue el que registró la mayor densidad (162,2 ind/L, mientras que entre los rotíferos fue Brachionus plicatilis con 482,7 ind/L. Se capturaron 12 especies de peces, pertenecientes a 5 órdenes y 9 familias (Shannon = 2,23 bits. El pejerrey fue la especie de mayor abundancia (50,8% y junto al sabalito Cyphocharax voga y la carpa Cyprinus carpio representaron el 85 % del total de biomasa de los peces capturados. Los parámetros poblacionales de O. bonariensis fueron: Peso= 0,0000047081*LEst3,178 (R2=0,99, n=116; longitud total= 5,854+LEst*1,168 (R2= 0,99, n= 117; LEst(t= 489,02 (1-e-0,225(t-0,46 y W(t= 1647,5 (1- e-0,225(t-0,463,177.

Effects of population outcrossing on rotifer fitness

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Serra Manuel

2010-10-01

Full Text Available Abstract Background Outcrossing between populations can exert either positive or negative effects on offspring fitness. Cyclically parthenogenetic rotifers, like other continental zooplankters, show high genetic differentiation despite their high potential for passive dispersal. Within this context, the effects of outcrossing may be relevant in modulating gene flow between populations through selection for or against interpopulation hybrids. Nevertheless, these effects remain practically unexplored in rotifers. Here, the consequences of outcrossing on the rotifer Brachionus plicatilis were investigated. Cross-mating experiments were performed between a reference population and three alternative populations that differed in their genetic distance with regard to the former. Two offspring generations were obtained: F1 and BC ('backcross'. Fitness of the outcrossed offspring was compared with fitness of the offspring of the reference population for both generations and for three different between-population combinations. Four fitness components were measured throughout the rotifer life cycle: the diapausing egg-hatching proportion, clone viability (for the clones originating from diapausing eggs, initial net growth rate R for each viable clone, and the proportion of male-producing clones. Additionally, both the parental fertilisation proportion and a compound fitness measure, integrating the complete life cycle, were estimated. Results In the F1 generation, hybrid vigour was detected for the diapausing egg-hatching proportion, while R was lower in the outcrossed offspring than in the offspring of the reference population. Despite these contrasting results, hybrid vigour was globally observed for the compound measure of fitness. Moreover, there was evidence that this vigour could increase with the genetic differentiation of the outcrossed populations. In the BC generation, the hybrid vigour detected for the egg-hatching proportion in the F1

Effect of three food types on the population growth of Brachionus calyciflorus and Brachionus patulus (Rotifera: Brachionidae

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S.S.S. Sarma

2001-03-01

Full Text Available We compared the population growth of B. calyciflorus and B. patulus using the green alga Chlorella vulgaris, baker’s yeast Saccharomyces cerevisiae or their mixture in equal proportions as food. Food was offered once every 24 h in two concentrations (low: 1x10(6 and high: 3x10(6 ind. ml-1 separately for each species. The experiments were terminated after 15 days. In general, at any food type or concentration, B. patulus reached a higher population density. A diet of Chlorella alone supported a higher population growth of both rotifer species than yeast alone. B. calyciflorus and B. patulus achieved highest population densities (103+8 ind. ml-1 and 296+20 ind. ml-1, respectively on a diet of Chlorella at 3x10(6 ind. ml-1. When cultured using the mixture of Chlorella and yeast, the maximal population densities of B. calyciflorus were lower than those grown on Chlorella. Under similar conditions, the maximal abundance values of B. patulus were comparable in both food types. Regardless of food type and density the rate of population increase per day (r for B. calyciflorus varied from 0.13+0.03 to 0.63+0.04. These values for B. patulus ranged from 0.19+0.01 to 0.37+0.01. The results indicated that even though Chlorella was a superior foof for the tested rotifers, yeast can be effectively used at low concentrations to supplement algal requirements in rotifer culture systems.Se comparó el crecimiento poblacional de dos especies planctónicas (B. calyciflorus y B. patulus desarrolladas con el alga verde Chlorella vulgaris, la levadura de cerveza Saccharomyces cerevisiae y la mezcla de ambas dietas en proporciones iguales. B. patulus alcanzó las mayores densidades con cualquier tipo de alimento utilizado en comparación con B. calyciflorus. La dieta a base de Chlorella vulgaris sola promovió el mayor crecimiento poblacional en relación con la dieta de levadura sola. B. calyciflorus y B. patulus alcanzaron las mayores densidades de 103+8 ind. ml-1 y 296+20 ind. ml-1, respectivamente, con la dieta de Chlorella en 3x10(6 células ml-1. En condiciones similares, los valores máximos de abundancia de B. patulus fueron semejantes para ambos tipos de alimento. La tasa de incremento poblacional por día (r para B. calyciflorus vario de 0.13+0.03 a 0.63+0.04, sin importar el tipo y densidad de alimento. Los resultados indican que la dieta a base de Chlorella fue mejor para los rotíferos considerados, y que la levadura puede usarse de manera efectiva a concentraciones bajas para complementar los requerimientos algales del sistema de cultivo de rotíferos.

シオミズツボワムシの栄養強化成績に対する一次培養の方法と個体群増殖フェーズの影響

OpenAIRE

小谷, 知也; 源河, 輝久; 伏見, 浩; 林, 雅弘; コタニ, トモナリ; ゲンカ, テルヒサ; フシミ, ヒロシ; ハヤシ, マサヒロ; Tomonari, Kotani; Teruhisa, Genka; Hiroshi, Fushimi; Masahiro, Hayashi

2007-01-01

植え継ぎ及び連続方式で培養したシオミズツボワムシBrachionus plicatilis(以下ワムシ)を栄養強化後の脂肪酸の取り込みにより質的に比較した。植え継ぎ培養は3日周期で植え継ぎを行い、初期収容密度を800個体/mLとした。粗放連続培養法を改変した方法で連続培養を実施し、培養を行う水槽(以下培養槽)と培養槽から流出した培養を収容する水槽(以下収穫槽)を使用した。培養密度が1,000個体/mLを維持するように設定した。植え継ぎ培養からはワムシ接種後1時間後、24時間後、48時間後のワムシを栄養強化に用いた。連続培養では培養槽及び収穫槽からワムシを収穫し二次培養(栄養強化)に用いた。栄養強化は、Nannochloropsis oculataを給餌して24時間培養する区と、市販栄養強化剤(以下栄養強化剤)を用いて8時間培養する区を設定した。栄養強化を行わない区も設定した。栄養強化後、脂質を抽出し、ガスクロマトグラフィーにより脂肪酸組成を分析した。栄養強化を行わなかった区では連続培養で生産したワムシの方が脂質含量が多くなった。N. oculataで栄養強化した区では、ARAおよ...

Species composition, abundance and distribution of zooplankton in a tropical eutrophic lake: Lake Catemaco, México

OpenAIRE

Roberto E. Torres-Orozco B.; Sandra A. Zanatta

1998-01-01

From April 1992 to May 1993, zooplankton samples were collected monthly by means of horizontal tows in nine sites of the lake. Prior to the towing, temperature of surface water, transparency (Secchi), pH and dissolved oxygen were evaluated. A total of 31 zooplankton forms, including 14 species of rotifers, three copepods, five cladocerans and one ostracod, as well as protozoans (mainly vorticellids and ciliates), were detected. Rotifers were the dominant organisms, mainly Brachionus havanaens...

Seasonal variations of rotifers from a high altitude urban shallow water body, La Cantera Oriente (Mexico City, Mexico)

Science.gov (United States)

Gutiérrez, Sergio González; Sarma, S. S. S.; Nandini, S.

2017-11-01

La Cantera Oriente is a shallow freshwater volcanic water body located at an altitude of 2 270 m above sea level in the Ecological Reserve of San Angel Pedregal of Mexico City (Mexico). In order to ensure the conservation of its biological heritage including zooplankton, the present work was undertaken to quantify the seasonal changes in the diversity and density of rotifers and the selected physico-chemical variables during 2013-2014. Qualitative analysis of the zooplankton samples yielded 68 rotifer species which represented 24 genera in 15 families. B rachionus calyciflorus Pallas, 1766, B. quadridentatus Hermann, 1783, Polyarthra vulgaris Carlin, 1943, Lecane closterocerca (Schmarda, 1859) and Keratella cochlearis (Gosse, 1851) were the most common species. Preston plots of species frequency-density revealed that as many as 30% of the rotifer taxa were dominant throughout the year. The species with high population densities were Brachionus quadridentatus, Lecane closterocerca, Keratella cochlearis, and Lepadella patella; their peak densities were 2 000, 1 000, 180 and 90 ind./L, all occurring in summer. Canonical correspondence analysis showed that Platyias quadricornis was related to the concentration of phosphates available in the environment and the conductivity, while B. quadridentatus was positively correlated with chlorophyll- a. The trophic status of the lake was eutrophic based on Chl- a content but oligotrophic with relation to the Brachionus: Trichocerca ratio.

Experimental evidence of the effect of nutrient enrichment on the zooplankton in a Brazilian coastal lagoon

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B. KOZLOWSKY-SUZUKI

Full Text Available Non-treated sewage disposal is one of the main impacts to which Imboassica Lagoon has been subjected. The aim of this study was to evaluate the effect of a potential increase in the artificial enrichment on the environmental conditions and zooplankton of this system. To this end, an experimental study was conducted in mesocosms where nutrients were added daily. Bacterial numbers, chlorophyll-a, and picoplanktonic cyanobacteria densities showed an increase with the availability of nutrients. Bacterio- and phytoplankton seemed to be regulated by the rotifers Brachionus rotundiformis and Hexarthra brandorffi.

Combined effect of concentrations of algal food (Chlorella vulgaris and salt (sodium chloride on the population growth of Brachionus calyciflorus and Brachionus patulus (Rotifera

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Víctor M. Peredo-Álvarez

2003-06-01

Full Text Available Salinity is an important variable influencing the density and diversity of rotifers. Studies on salt tolerance of rotifers have so far concentrated on euryhaline species while very little information is available on noneuryhaline taxa. In the present work, we have evaluated the combined effects of Chlorella vulgaris and sodium chloride on the population growth of two freshwater rotifers B. calyciflorus and B. patulus. A 24 hr acute tolerance test using NaCl revealed that B. calyciflorus was more resistant (LC50 = 3.75 ± 0.04 g l-1 than B. patulus (2.14 ± 0.09 g l-1 . The maximal population density (mean±standard error for B. calyciflorus in the control at 4.5 X10 6 cells ml-1 (algal level was 80 ±5 ind. ml-1 , which was nearly a fifth of the one for B. patulus (397 ± 7 ind. ml-1 under comparable conditions. Data on population growth revealed that regardless of salt concentration, the density of B. calyciflorus increased with increasing food levels, while for B. patulus, this trend was evident only in the controls. Regardless of salt concentration and algal food level, the day of maximal population density was lower (4 ± 0.5 days for B. calyciflorus than for B. patulus (11 ±1 day. The highest rates of population increase (r values for B. calyciflorus and B. patulus were 0.429 ± 0.012 and 0.367 ± 0.004, respectively, recorded at 4.5 X10(6 cells ml-1 of Chlorella in the controls. The protective role of algae in reducing the effect of salt stress was more evident in B. calyciflorus than B. patulus.La salinidad es una variable importante que tiene influencia sobre la densidad y la diversidad de los rotíferos. Los estudios de rotíferos sobre tolerancia a la sal que se tienen hasta ahora se han concentrado en especies eurihalinas, sin embargo, hay muy poca información sobre taxas no eurihalinos. En el presente trabajo, se evaluaron los efectos combinados de las concentraciones de Chlorella vulgaris y cloruro de sodio sobre el crecimiento poblacional de dos rotíferos de agua dulce, B. calyciflorus y B. patulus. Una prueba de toxicidad aguda de 24 h utilizando cloruro de sodio reveló que B. calyciflorus fue más resistente (CL50 = 3.75 ± 0.04 g l -1 que B. patulus (2.14 ± 0.09 g l-1 . La máxima densidad de población (media ± error estándar de B. calyciflorus en el lote control, utilizando una concentración 4.5 X10(6 células ml-1 de alga fue de 80 ± 5 ind. ml-1 , casi una quinta parte de B. patulus (397 ±7 ind. ml-1 sobre condiciones comparables. Datos sobre el crecimiento poblacional revelaron que cualquier concentración de sal carece de efecto, la densidad de B. calyciflorus se incrementa cuando aumentan los niveles de alimento. Sin embargo para B. patulus esta tendencia fue evidente únicamente en los controles. Independientemente de las concentraciones de sal y los niveles de alimento, el día de abundancia máxima fue menor para B. calyciflorus (4 ± 0.5 días que para B. patulus (11 ±1 días. Los valores de la máxima tasa de crecimiento poblacional (r fueron para B. calyciflorus y B. patulus de 0.429 ± 0.012 y 0.367 ± 0.004, respectivamente en lotes control con 4.5 X10(6 células ml-1 de Chlorella. El papel de protección de alga para reducir el efecto del estrés de la sal fue más evidente en B. calyciflorus que en B. patulus.

Determination of trace elements in freshwater rotifers and ciliates by total reflection X-ray fluorescence spectrometry

Science.gov (United States)

Woelfl, S.; Óvári, M.; Nimptsch, J.; Neu, T. R.; Mages, M.

2016-02-01

Element determination in plankton is important for the assessment of metal contamination of aquatic environments. Until recently, it has been difficult to determine elemental content in rotifers or ciliates derived from natural plankton samples because of the difficulty in handling and separation of these fragile organisms. The aim of this study was to evaluate methods for separation of rotifers and large ciliates from natural plankton samples (μg range dry weight) and subsequent analysis of their elemental content using total-reflection X-ray fluorescence spectrometry (TXRF). Plankton samples were collected from different aquatic environments (three lakes, one river) in Chile, Argentina and Hungary. From one to eighty specimens of five rotifer species (Brachionus calyciflorus, Brachionus falcatus, Asplanchna sieboldii, Asplanchna sp., Philodina sp.) and four to twelve specimens of one large ciliate (Stentor amethystinus) were prepared according to the dry method originally developed for microcrustaceans, and analysed by TRXF following in situ microdigestion. Our results demonstrated that it possible to process these small and fragile organisms (individual dry mass: 0.17-9.39 μg ind- 1) via careful washing and preparation procedures. We found species-dependent differences of the element mass fractions for some of the elements studied (Cr, Mn, Fe, Ni, Cu, Zn, As, Pb), especially for Cu, Fe and Mn. One large rotifer species (A. sieboldii) also showed a negative correlation between individual dry weight and the element content for Pb, Ni and Cr. We conclude that our application of the in situ microdigestion-TRXF method is suitable even for rotifers and ciliates, greatly expanding the possibilities for use of plankton in biomonitoring of metal contamination in aquatic environments.

The zooplankton biodiversity of some freshwater environments in Parnaíba basin (Piauí, Northeastern Brazil

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JDN. Paranhos

Full Text Available The plankton fauna of the state of Piauí, Northeastern Brazil, especially in the Parnaíba basin, is still poorly known; the results of most studies of the subject have not been published and can only be found in grey literature (unpublished scientific works, such as course completion work and consulting reports. Thus, this paper presents data from samples taken recently from different water bodies in Piauí and represents the second study to be published on the region's zooplankton since the pioneering work of Spandl (1926. A total of 38 species were recorded, including 23 new occurrences of rotifers, 10 of cladocerans and 2 of copepods for the state of Piauí. The greatest richness was observed for the rotifers, of which the genus Brachionus must be highlighted, especially at the Joana reservoir. Among the crustaceans, the greatest richness was observed at the Bezerra reservoir, where cladocerans of the genus Bosmina were prominent. The rotifers Brachionus havanaensis Rousselet, 1911 and Filinia longiseta (Ehrenberg, 1834; the cladocerans Diaphanosoma spinulosum Herbst, 1967 and Moina micrura Kurz, 1874; and the copepods Notodiaptomus cearensis Wright, 1936 and Thermocyclops decipiens Kiefer, 1927 occurred in all or in most environments in which the respective groups were studied. The results presented here expand the taxonomic list of zooplankton for the state of Piauí, including a total fauna of 30 species of rotifers, 15 of cladocerans and 3 of copepods. The zooplankton richness was considered low in the studied reservoirs compared to other freshwater ecosystems from Northeastern Brazil; however, the few studies developed in the Parnaíba basin suggest that the diversity for these organisms should be higher.

Dicty_cDB: Contig-U05044-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available pSkeMus1 Xenopus (Sil... 40 0.47 3 ( CB078367 ) hj66g06.g1 Hedyotis terminalis flower - Stage 2 (... 36 0.48...) 1092343402430 Global-Ocean-Sampling_GS-27-01-01-1... 44 0.013 2 ( CR389591 ) Gallus gallus finished cDNA, ...cigd039p01, 3' en... 48 9e-04 2 ( EJ556699 ) 1092959507186 Global-Ocean-Sampling_GS-29-01-01-1... 42 0.001 2... ( EJ554022 ) 1092959481122 Global-Ocean-Sampling_GS-29-01-01-1... 42 0.001 2 ( FM928382 ) Brachionus pli...s ML CMVsport jasme... 50 0.18 1 ( EK107136 ) 1092963062468 Global-Ocean-Sampli

Phototransformation of Amlodipine in Aqueous Solution: Toxicity of the Drug and Its Photoproduct on Aquatic Organisms

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Marina DellaGreca

2007-01-01

Full Text Available The phototransformation of amlodipine in water was investigated under various conditions. A quantum yield ΦS2.2×10−4 and a half-life time t1/2 0.419 days were calculated when the drug in water (10−4 M was exposed to sunlight. The only photoproduct found was its pyridine derivative. Formation of this product was explained on the basis of a radical cation intermediate. The acute and chronic toxicity of the drug and its photoproduct were evaluated on different organisms of the freshwater chain (Brachionus calyciflorus, Thamnocephalus platyurus, Daphnia magna, Ceriodaphnia dubia. The photoproduct exhibited a stronger toxic potential than the parent drug on the long time for C. dubia.

Zooplankton community structure in the presence of low levels of cyanotoxins: a case study in a high altitude tropical reservoir (Valle de Bravo, Mexico

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Michael A. Figueroa-Sanchez

2014-02-01

Full Text Available Valle de Bravo water reservoir in the State of Mexico is being intensively studied since it provides water to about 2,500,000 people living in Mexico City. Cyanobacterial blooms reduce the water quality in this reservoir and this poses health risks. We hypothesize that one of the reasons for these persistent blooms is the dominance of small sized zooplankton throughout the year. Zooplankton samples were collected monthly by filtering 50 L of water from the surface (10-20 cm using a 50 µm mesh and the samples were fixed in 4% formalin in the field. We measured temperature, pH, conductivity, Secchi disk transparency, dissolved oxygen, nitrates and phosphates. The microcystin levels were also quantified. The Secchi depth ranged from 0.86 to 9 m, nitrate levels were low (0.28 to 2.06 mg L-1, while phosphates were in the range of 1 to 14 mg L-1. The temperature varied from 14 to 25 °C. The zooplankton community was represented by 25 species of rotifers Keratella cochlearis had the highest density (840 ind L-1, followed by Polyarthra vulgaris (750 ind L-1. As compared to previous studies where the genus Brachionus was practically absent, we found four brachionid species. Among cladocerans, Bosmina longirostris was the dominant taxa reaching up to 100 ind L-1. Small sized zooplankton (<200 µm dominated throughout the year. The zooplankton biomass in the winter months (December to February was contributed by Daphnia laevis, copepodites and adult copepods. Unlike a decade ago when a dominance by cyanobacteria was recorded, in this study we found that the phytoplankton was dominated by diatoms and chlorophytes with an occasional presence of the cyanobacteria Anabaena spp. and Microcystis spp. The concentration of microcystins ranged from 0.5 to 0.7 µg L-1 and was within the parameters set by the WHO. Carlson’s Trophic State Index and Sladecek’s Brachionus/Trichocera ratio indicated that the reservoir was mesotrophic during the study period.

Fecundity, survival, and growth of the seahorse Hippocampus ingens (Pisces: Syngnathidae under semi-controlled conditions

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A.A Ortega-Salas

2006-12-01

Full Text Available Estudiamos la fecundidad, supervivencia, y crecimiento del caballito de mar, Hippocampus ingens en condiciones semi-controladas. Tres machos reproductores silvestres de 14.8, 24.5 y 32.0 g produjeron 1 598, 1 703 y 1 658 jóvenes. La densidad utilizada fue de 12 jóvenes por acuario de 60 l. Se agruparon en 1, 12 y 20 días de nacidos por acuario. La supervivencia fue de 78.5, 38.1 y 41.0 % en 35 días. Se les alimentó con una mezcla de rotíferos B. plicatilis y nauplios de Artemia para después transferirlos a estanques de 100 000 l a una densidad de 50/1 000 l, donde se les alimentó con Artemia adulta durante 60 días más. Crecieron de un promedio de 0.7, 1.5, y 2.7 a 4.5, 5.4 6.7 cm, respectivamente, en 95 días. La temperatura del agua marina utilizada varió de 17 a 23 ºC.We studied fecundity, survival, and growth of the seahorse Hippocampus ingens under semi-controlled conditions. Three wild brood stock mature males of 14.8, 24.5, and 32.0 g released 1 598, 1 703, and 1 658 juveniles. Juvenile stocking densities of 12 were settled in 60-l aquariums in groups of 1, 12, and 20 days old organisms. The rate of survival was 21.5, 61.9, and 59.0 %, respectively, in 35 days. Juveniles were fed a mix diet of rotifers B. plicatilis and Artemia nauplii, then they were transferred to a cement tank of 100 000 l at a density of 50/1 000 l and fed with live adult Artemia for 60 days more. They grew from an average of 0.7, 1.5, and 2.7 to 4.5, 5.4, and 6.7 cm, respectively, in 95 days. The seawater temperature varied from 17 to 23 ºC. Rev. Biol. Trop. 54 (4: 1099-1102. Epub 2006 Dec. 15.

Acute and chronic toxicity testing of bisphenol A with aquatic invertebrates and plants.

Science.gov (United States)

Mihaich, Ellen M; Friederich, Urs; Caspers, Norbert; Hall, A Tilghman; Klecka, Gary M; Dimond, Stephen S; Staples, Charles A; Ortego, Lisa S; Hentges, Steven G

2009-07-01

Bisphenol A (BPA, 4,4'-isopropylidine diphenol) is a commercially important chemical used primarily as an intermediate in the production of polycarbonate plastic and epoxy resins. Extensive effect data are currently available, including long-term studies with BPA on fish, amphibians, crustaceans, and mollusks. The aim of this study was to perform additional tests with a number of aquatic invertebrates and an aquatic plant. These studies include acute tests with the midge (Chironomus tentans) and the snail (Marisa cornuarietis), and chronic studies with rotifers (Brachionus calyciflorus), amphipods (Hyalella azteca), and plants (Lemna gibba). The effect data on different aquatic invertebrate and plant species presented in this paper correspond well with the effect and no-effect concentrations (NOECs) available from invertebrate studies in the published literature and are within the range found for other aquatic species tested with BPA.

Effects of food quality on life history of the rotifer Brachionus calyciflorus Pallas

NARCIS (Netherlands)

Jensen, T.C.; Verschoor, A.M.

2004-01-01

1. Herbivorous zooplankton face considerable temporal and spatial variation in food quality, to which they respond by adapting their life histories. Zooplankton may even take up mineral nutrients directly, and use these to counter the effects of algal nutrient limitation (mineral compensation). This

Effects on parathion on the ecology of a eutrophic aquatic ecosystem: limnocorral experiment

International Nuclear Information System (INIS)

Gasith, A.; Perry, A.S.; Mozel, Y.; Albright, J.L.

1983-01-01

Repetitive exposure of a eutrophic fish pond ecosystem, enclosed in limnocorrals, to 30 ppb parathion resulted in elimination of the potentially dominant zooplankton species, Moina micrura. Consequently, the populations of the rotifers Brachionus and Asplanchna markedly increased. Changes in the zooplankton composition and abundance were followed by increased fluctuations in phytoplankton biomass, phytoplankton photosynthesis, plankton respiration and community metabolism. Similar responses to parathion treatment were observed in previous studies under fish pond conditions. In the presence of fish the effect of parathion on the ecosystem was generally less pronounced and not uniform. The collapse of the zooplankton community and the rapid changes in limnological conditions in the control (untreated) limnocorrals severely limited the duration of the experiment. The results suggest that under eutrophic conditions, small enclosures may be useful for evaluation of the effect of toxicants on the ecosystem only in short term experiments with short lived chemicals. (author)

The Selective Use of Hypochlorite to Prevent Pond Crashes for Algae-Biofuel Production.

Science.gov (United States)

2015-09-21

Although algae-biofuels have many advantages including high areal productivity, algae can be preyed upon by amoebas, protozoans, ciliates, and rotifers, particularly in open pond systems. Thus, these higher organisms need to be controlled. In this study, Chlorella kessleri was used as the algal culture and Brachionus calyciflorus as the source of predation. The effect of sodium hypochlorite (bleach) was tested with the goal of totally inhibiting the rotifer while causing minor inhibition to the alga. The 24-hr LC50 for B. calyciflorus in spring water was 0.198 mg Cl/L while the 24-hr LC50 for C. kessleri was 0.321 mg Cl/L. However, chlorine dissipates rapidly as the algae serves as reductant. Results showed a chlorine dosage between 0.45 to 0.6 mg Cl/L and a dosing interval of two hours created the necessary chlorine concentrations to inhibit predation while letting the algae grow; thus giving algae farmers a tool to prevent pond crashes. Water Environ. Res., 87 (2015).

Integrated study of labelled contaminant or substrate-biological species interactions in a selected aquatic ecosystem. Part of a coordinated programme on isotopic-tracer aided research and monitoring on agricultural residue - biological interactions in aquatic ecosystems

International Nuclear Information System (INIS)

Perry, A.S.

1982-06-01

Repetitive exposure of a eutrophic fish pond ecosystem, enclosed in limnocorrals to 30 ppb parathion resulted in elimination of the potentially dominant zooplankton species, Moina micrura. Consequently, the populations of the rotifers Brachionus and Asplanchna markedly increased. Changes in the zooplankton composition and abundance were followed by increased fluctuations in phytoplankton biomass, phytoplankton photosynthesis, plankton respiration and community metabolism. Similar responses to parathion treatment were observed in previous studies under fish pond conditions. In the presence of fish the effect of parathion on the ecosystem was generally less pronounced and not uniform. The collapse of the zooplankton community and the rapid changes in limnological conditions in the control (untreated) limnocorrals severely limited the duration of the experiment. The results suggest that under eutrophic conditions, small enclosures may be useful for evaluation of the effect of toxicants on the ecosystem only in short term experiments with short lived chemicals. This document is out of INIS subject scope and is included because it is published by the IAEA

The effect of sex on the mean and variance of fitness in facultatively sexual rotifers.

Science.gov (United States)

Becks, L; Agrawal, A F

2011-03-01

The evolution of sex is a classic problem in evolutionary biology. While this topic has been the focus of much theoretical work, there is a serious dearth of empirical data. A simple yet fundamental question is how sex affects the mean and variance in fitness. Despite its importance to the theory, this type of data is available for only a handful of taxa. Here, we report two experiments in which we measure the effect of sex on the mean and variance in fitness in the monogonont rotifer, Brachionus calyciflorus. Compared to asexually derived offspring, we find that sexual offspring have lower mean fitness and less genetic variance in fitness. These results indicate that, at least in the laboratory, there are both short- and long-term disadvantages associated with sexual reproduction. We briefly review the other available data and highlight the need for future work. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

Diel vertical migration and distribution of zooplankton in a tropical Brazilian reservoirlian

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Ana M. A. da Silva

2009-08-01

amostradas em quatro profundidades (Sub-superfície, 50% Io, 1% Io e Fundo em uma estação de amostragem com cinco metros de profundidade, em intervalos de quatro horas, ao longo de 24 horas. Duas espécies de Cladocera (Moina minuta e Diaphanosoma spinulosum e uma espécie de Copepoda (Notodiaptomus cearensis apresentaram padrões relativamente semelhantes de migração noturna, permanecendo no fundo durante o dia e se deslocando próximo à superfície no fim da tarde e ao longo da noite. Brachionus falcatus e Hexarthra mira (Rotifera não apresentaram padrões migratórios e as suas distribuições verticais foram relativamente homogêneas. As variáveis ambientais e as distribuições das espécies correlacionaram-se fracamente, sugerindo que outros mecanismos podem ser responsáveis por induzir a migração vertical.

Fecundity, survival, and growth of the seahorse Hippocampus ingens (Pisces: Syngnathidae under semi-controlled conditions

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A.A Ortega-Salas

2006-12-01

Full Text Available Estudiamos la fecundidad, supervivencia, y crecimiento del caballito de mar, Hippocampus ingens en condiciones semi-controladas. Tres machos reproductores silvestres de 14.8, 24.5 y 32.0 g produjeron 1 598, 1 703 y 1 658 jóvenes. La densidad utilizada fue de 12 jóvenes por acuario de 60 l. Se agruparon en 1, 12 y 20 días de nacidos por acuario. La supervivencia fue de 78.5, 38.1 y 41.0 % en 35 días. Se les alimentó con una mezcla de rotíferos B. plicatilis y nauplios de Artemia para después transferirlos a estanques de 100 000 l a una densidad de 50/1 000 l, donde se les alimentó con Artemia adulta durante 60 días más. Crecieron de un promedio de 0.7, 1.5, y 2.7 a 4.5, 5.4 6.7 cm, respectivamente, en 95 días. La temperatura del agua marina utilizada varió de 17 a 23 ºC.

Species composition, abundance and distribution of zooplankton in a tropical eutrophic lake: Lake Catemaco, México

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Roberto E. Torres-Orozco B.

1998-06-01

Full Text Available From April 1992 to May 1993, zooplankton samples were collected monthly by means of horizontal tows in nine sites of the lake. Prior to the towing, temperature of surface water, transparency (Secchi, pH and dissolved oxygen were evaluated. A total of 31 zooplankton forms, including 14 species of rotifers, three copepods, five cladocerans and one ostracod, as well as protozoans (mainly vorticellids and ciliates, were detected. Rotifers were the dominant organisms, mainly Brachionus havanaensis (27.6 ind l-¹, B. angularis (6.9 ind l-¹, Keratella cochlearis (4.9 ind l-¹, Conochilus unicornis (10.8 ind l-¹ and C. dossuarius (3.1 ind l-¹. Within crustaceans, higher densities were shown by larvae (nauplii and copepodites of calanoid (16.8 ind l-¹ and cyclopoid (15.6 ind l-¹ copepods, as well as Arctodiaptomus dorsalis (2 ind l-¹, Mesocyclops edax (0.5 ind l-¹, and the cladocerans Bosmina longirostris (1.6 ind l-¹ and Diaphanosoma brachyurum (0.5 ind l-¹. Densities were low, probably because of a high predation pressure imposed by fishes. A gradual increase in total zooplankton density related with a progressive diminution of transparency was observed throughout the sampling period. Zooplankton densities in the stations located at the central part of the lake were higher when compared with those at a more peripheral position. Time variation in rotifer's relative abundance was directly related to temperature fluctuations. The low density and diversity values, the small size of the zooplankters, the presence of an important number of indicator species, and the calanoid copepods: other planktonic crustaceans low ratio, are all indicators of eutrophy. Evidences suggest that the eutrophication process of Lake Catemaco is still progressing rapidly.Entre abril de 1992 y mayo de 1993, se realizaron mensualmente recolectas subsuperficiales de zooplancton, con red, en nueve localidades del lago, en donde también se determinaron la temperatura

Sildenafil and tadalafil in simulated chlorination conditions: Ecotoxicity of drugs and their derivatives

Energy Technology Data Exchange (ETDEWEB)

Temussi, Fabio; DellaGreca, Marina; Pistillo, Paola; Previtera, Lucio; Zarrelli, Armando [UdR Napoli 4 INCA, Dipartimento di Scienze Chimiche, Complesso Universitario di Monte Sant' Angelo, Università Federico II, Via Cintia, I-80126 Napoli (Italy); Criscuolo, Emma; Lavorgna, Margherita; Russo, Chiara [Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, I-81100 Caserta (Italy); Isidori, Marina, E-mail: marina.isidori@unina2.it [Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, I-81100 Caserta (Italy)

2013-10-01

Chlorination experiments on two drugs (sildenafil and tadalafil) were performed mimicking the conditions of a typical wastewater treatment process. The main transformation products were isolated by chromatographic techniques (Thin Layer Chromatography (TLC), Column Chromatography (CC), High Performance Liquid Chromatography (HPLC)) and fully characterized employing Nuclear Magnetic Resonance (NMR) and Mass Spectrometry (MS) analyses. The environmental effects of the parent compounds and transformation products were evaluated using an overall toxicity approach that considered aquatic acute and chronic toxicity on Brachionus calyciflorus and Ceriodaphnia dubia as well as mutagenesis and genotoxicity on bacterial strains. The results revealed that both parent drugs did not show high acute and chronic toxicity for the organisms utilized in the bioassays while, chronic exposure to chlorine derivatives caused inhibition of growth population on rotifers and crustaceans. A mutagenic potential was found for all the compounds investigated. - Highlights: • Simulated disinfection process of pharmaceuticals was performed. • Toxicity and genotoxicity of sildenafil, tadalafil and their derivatives were evaluated. • Chlorine derivatives caused chronic toxicity on rotifers and crustaceans. • A mutagenic potential was found for all the compounds investigated.

Diversity and distribution of Brachionidae (Rotifera in Thailand, with a key to the species

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Sujeephon Athibai

2013-08-01

Full Text Available We investigated the diversity of brachionid rotifers in Thailand. Rotifers were collected from a wide range of habitat types (294 sites, 508 samples including canals, lakes, peat swamps, ponds, reservoirs, rice fields, rivers, swamps and temporary ponds from April 1998 to January 2004. Twenty-eight species including 11 infrasubspecific forms belonging to five genera were identified. The most frequently encountered species was Brachionus falcatus (50.7% of the sampling sites, followed by Keratella cochlearis (50%, B. angularis (49.7%, K. tropica (46.3% and B. forficula (45.9%. Less frequently encountered species were B. caudatus, B. durgae and B. urceolaris. These species were found in low abundances and only in a single site. Two sites in the Northeast – Nong Changpeuak and Bueng Srithat – recorded the greatest richness with 15 taxa, whereas no brachionid rotifers were found in 31 sites. On average, the species richness was five taxa per sampling site. A key to the genera and species of Thai brachionid rotifers is provided.

Loktak Lake, Manipur, northeast India: a Ramsar site with rich rotifer (Rotifera: Eurotatoria diversity and its meta-analysis

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Bhushan Kumar Sharma

2016-04-01

Full Text Available A total of 162 species (S of Rotifera belonging to 40 genera and 20 families examined from Loktak Lake, an important floodplain lake of northeast India (NEI that is one of the richest assemblages of the taxon known from the Indian sub-region. It merits biodiversity value as ~40.0% and ~62.0% of species recorded from India and NEI, respectively. One species is new to India, 23 species are new to Manipur and 14 species are new to Loktak basin. Biogeographically interesting elements included three Australasian, five Oriental, ten palaeotropical and one cosmo-subtropical species. Lecanidae > Lepadellidae > Brachionidae > Trichocercidae collectively comprised 65.4% of S; Lecane > Lepadella > Trichocerca are diverse genera; and paucity of Brachionus spp. is distinct. Loktak Rotifera indicated importance of cosmopolitan, the littoral-periphytonic and small-sized species, and ‘tropical character’. ANOVA recorded significant variations of the rotifer richness amongst three sampling sites of Loktak during June 2010–May 2012 survey. The richness followed osscillaring monthly variations and indicated lack of significant influence of any individual abioitic parameter at all three stations.

Combined toxicity effects of chlorine, ammonia, and temperature on marine plankton. Progress report, November 1976--31 January 1978

Energy Technology Data Exchange (ETDEWEB)

Goldman, J. C.

1978-02-01

Studies on the effects of chlorine, chloramines, and temperature on marine plankton have been carried out for three years. Species studied include marine phytoplankton, lobster larvae (Homarus americanus), oyster larvae (Crassostrea virginica), copepods (Acartia tonsa), rotifers (Brachionas plicatilis), grass shrimp (Palamonetes pugio) summer flounder larvae (Paralichthys dentatus), larval and juvenile killifish (Fundulus heteroclitus), juvenile scup (Stenotomus versicolor), and juvenile winter flounder (Pseudopleuronectes americanus). In addition extensive studies on chlorine chemistry in seawater have been carried out. The major conclusions are that entrainment effects on permanent plankton such as phytoplankton, copepods, and rotifers are temporary, that is those organisms surviving chlorination and temperature shocks are capable of renewed and unrestricted growth once returned to the receiving water. Because chlorine is only applied for short periods daily in most power plants, the total population of the above organisms actually exposed to chlorine is small and the effects may be hardly measurable in receiving waters. However, chlorination effects on larval species that spawn intermittently could be catastrophic. In addition, there are many unanswered questions regarding the fate of chlorine that is dissipated in marine waters. Are the losses real and, if so, do they pose a toxicity threat to marine biota.

Toxicity evaluation of the process effluent streams of a petrochemical industry.

Science.gov (United States)

Reis, J L R; Dezotti, M; Sant'Anna, G L

2007-02-01

The physico-chemical characteristics and the acute toxicity of several wastewater streams, generated in the industrial production of synthetic rubber, were determined. The acute toxicity was evaluated in bioassays using different organisms: Danio rerio (fish), Lactuca sativa (lettuce) and Brachionus calyciflorus (rotifer). The removal of toxicity attained in the industrial wastewater treatment plant was also determined upstream and downstream of the activated sludge process. The results obtained indicate that the critical streams in terms of acute toxicity are the effluents from the liquid polymer unit and the spent caustic butadiene washing stage. The biological treatment was able to partially remove the toxicity of the industrial wastewater. However, a residual toxicity level persisted in the biotreated wastewater. The results obtained with Lactuca sativa showed a high degree of reproducibility, using root length or germination index as evaluation parameters. The effect of volatile pollutants on the toxicity results obtained with lettuce seeds was assessed, using ethanol as a model compound. Modifications on the assay procedure were proposed. A strong correlation between the toxic responses of Lactuca sativa and Danio rerio was observed for most industrial effluent streams.

Differentiation between activity of digestive enzymes of .i.Brachionus calyciflorus./i. and extracellular enzymes of its epizooic bacteria

Czech Academy of Sciences Publication Activity Database

Štrojsová, Martina; Ahlrichs, W.H.

2009-01-01

Roč. 68, č. 2 (2009), s. 409-412 ISSN 1129-5767 Institutional research plan: CEZ:AV0Z60170517 Keywords : rotifers * phosphatase * beta-N-acetylhexosaminidase * enzyme localization Subject RIV: EG - Zoology Impact factor: 0.932, year: 2009

Captive propagation, reproductive biology, and early life history of the Diamond Darter (Crystallaria cincotta)

Science.gov (United States)

Ruble, Crystal L.; Rakes, Patrick L.; Shute, John R.; Welsh, Stuart A.

2014-01-01

Reproductive biology and early life history data are critical for the conservation and management of rare fishes. During 2008–2012 a captive propagation study was conducted on the Diamond Darter, Crystallaria cincotta, a rare species with a single extant population in the lower Elk River, West Virginia. Water temperatures during spawning ranged from 11.1–23.3 C. Females and males spawned with quick vibrations, burying eggs in fine sand in relatively swift clean depositional areas. Egg size was 1.8–1.9 mm, and embryos developed within 7 to 11 d. Diamond Darters were 6.7–7.2 mm total length (TL) at hatch. Larvae ranged from 9.0–11.0 mm TL following a 5–10 d period of yolk sac absorption. Larvae had relatively large mouth gapes and teeth and were provided brine shrimp Artemia sp., Ceriodaphnia dubia neonates, marine Brachionus rotifers, and powdered foods (50–400 µm) but did not appear to feed in captivity, except for one observation of larval cannibalization. Larvae survived for a maximum of 10 d. To increase larval survival and reduce the possibility of cannibalism, other alternative food sources are needed during captive propagation.

The Use of the Schizonticidal Agent Quinine Sulfate to Prevent Pond Crashes for Algal-Biofuel Production

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Chunyan Xu

2015-11-01

Full Text Available Algal biofuels are investigated as a promising alternative to petroleum fuel sources to satisfy transportation demand. Despite the high growth rate of algae, predation by rotifers, ciliates, golden algae, and other predators will cause an algae in open ponds to crash. In this study, Chlorella kessleri was used as a model alga and the freshwater rotifer, Brachionus calyciflorus, as a model predator. The goal of this study was to test the selective toxicity of the chemical, quinine sulfate (QS, on both the alga and the rotifer in order to fully inhibit the rotifer while minimizing its impact on algal growth. The QS LC50 for B. calyciflorus was 17 µM while C. kessleri growth was not inhibited at concentrations <25 µM. In co-culture, complete inhibition of rotifers was observed when the QS concentration was 7.7 µM, while algal growth was not affected. QS applications to produce 1 million gallons of biodiesel in one year are estimated to be $0.04/gallon or ~1% of Bioenergy Technologies Office’s (BETO projected cost of $5/gge (gallon gasoline equivalent. This provides algae farmers an important tool to manage grazing predators in algae mass cultures and avoid pond crashes.

Effect of water irrigation volume on Capsicum frutescens growth and plankton abundance in aquaponics system

Science.gov (United States)

Andriani, Y.; Dhahiyat, Y.; Zahidah; Subhan, U.; Iskandar; Zidni, I.; Mawardiani, T.

2018-03-01

This study aimed to understand Capsicum frutescens growth and plankton abundance in aquaponics culture. A Completely Randomized Design (CRD) with six treatments in triplicates comprising of treatment A (positive control using organic liquid fertilizer), B (negative control without fertilizer), C (drip irrigation aquaponics with a water debit of 100 ml/day/plant), D (drip irrigation aquaponics with a water debit of 150 ml/day/plant), E (drip irrigation with a water debit of 200 ml/day/plant), and F (drip irrigation aquaponics with a water debit of 250 ml/day/plant) was applied. The water used in treatments C, D, E, and F contained comet fish feces as fertilizer. C. frutescens growth and plankton abundance were observed. Analysis was conducted using analysis of variance for plant productivity and descriptive analysis for plankton abundance and water quality. The results of this study showed that the highest plant growth was seen in plants receiving F treatment with 50 ml/day drip irrigation. However, no significant difference was found when compared to the positive control with organic artificial fertilizer. Eleven types of phytoplankton and six types of zooplankton were found, with Stanieria sp. as the most abundant phytoplankton and Brachionus sp. and Epistylis sp. as the most abundant zooplanktons.

Loss of sexual reproduction and dwarfing in a small metazoan.

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Claus-Peter Stelzer

2010-09-01

Full Text Available Asexuality has major theoretical advantages over sexual reproduction, yet newly formed asexual lineages rarely endure. The success, or failure, of such lineages is affected by their mechanism of origin, because it determines their initial genetic makeup and variability. Most previously described mechanisms imply that asexual lineages are randomly frozen subsamples of a sexual population.We found that transitions to obligate parthenogenesis (OP in the rotifer Brachionus calyciflorus, a small freshwater invertebrate which normally reproduces by cyclical parthenogenesis, were controlled by a simple Mendelian inheritance. Pedigree analysis suggested that obligate parthenogens were homozygous for a recessive allele, which caused inability to respond to the chemical signals that normally induce sexual reproduction in this species. Alternative mechanisms, such as ploidy changes, could be ruled out on the basis of flow cytometric measurements and genetic marker analysis. Interestingly, obligate parthenogens were also dwarfs (approximately 50% smaller than cyclical parthenogens, indicating pleiotropy or linkage with genes that strongly affect body size. We found no adverse effects of OP on survival or fecundity.This mechanism of inheritance implies that genes causing OP may evolve within sexual populations and remain undetected in the heterozygous state long before they get frequent enough to actually cause a transition to asexual reproduction. In this process, genetic variation at other loci might become linked to OP genes, leading to non-random associations between asexuality and other phenotypic traits.

Environmental and endogenous control of sexuality in a rotifer life cycle: developmental and population biology.

Science.gov (United States)

Gilbert, John J

2003-01-01

Induction of mictic females, and hence initiation of sexuality, in the life cycle of some Brachionus requires an environmental stimulus associated with crowding. The inducing stimulus appears to be a taxonomically specific chemical released into the environment by the rotifers. Oocytes are induced to develop into mictic females before they are oviposited by their amictic mothers and begin cleavage divisions. Thus, the inducer affects the oocyte in the maternal body cavity either directly or indirectly by altering the physiology of its mother. The level of sexual reproduction expressed in populations of a Florida strain of B. calyciflorus is controlled by two types of endogenous factors and by the degree of crowding. First, some fraction of genetically identical oocytes in a clonal population fails to respond to even extreme crowding conditions, thus ensuring some potential for continued population growth by female parthenogenesis. Second, the propensity of amictic females to produce mictic daughters is extremely low when they hatch from fertilized resting eggs and then gradually increases to an asymptote after about 12 parthenogenetic generations. This multigenerational parental effect likely is due to a cytoplasmic factor in fertilized eggs that inhibits expression of the mictic-female phenotype and that is gradually diluted in successive parthenogenetic generations. The effect may increase a clone's genetic contribution to the resting-egg bank by increasing its population size through parthenogenetic generations before mictic females are induced.

The impact assessment of anticancer drug imatinib on the feeding behavior of rotifers with an integrated perspective: Exposure, post-exposure and re-exposure.

Science.gov (United States)

Yan, Zhengyu; Yan, Kun; He, Xingliang; Liu, Yanhua; Zhang, Jie; Lopez Torres, Oscar; Guo, Ruixin; Chen, Jianqiu

2017-10-01

The anticancer drugs are getting increasing attention as an emerging contaminant in the aquatic environments. In the present study, feeding behavior of the rotifer Brachionus calyciflorus under the impact of anticancer drug imatinib was evaluated. Traditional toxicological studies usually focus on dose-effect relationship at a given exposure time, while ignore the possible impact after the exposure. Thus, how the impact varied in the post-exposure and re-exposure was also considered in the present study. The feeding depression of the rotifers was attributed to the increased concentration of imatinib. Although the filtration and ingestion rate of the rotifers recovered to a certain extent after the exposure, the significant feeding inhibition still persisted even if the exposure was ended. In the re-exposure period, the feeding behavior was less depressed than those of the exposure period, which implied that rotifers might develop a tolerance to the same toxics. The activities of acetylcholine esterase (AchE) and the levels of reactive oxygen species (ROS) in rotifers were also detected. Imatinib inhibited the activities of AchE in the exposure and re-exposure while ROS levels increased significantly in the re-exposure period. Our present study provided an integrated assessment the potential environmental risks of imatinib at a new perspective. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rotifer assemblages (Rotifera: Eurotatoria of the floodplain lakes of Majuli River Island, the Brahmaputra river basin, northeast India

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Bhushan Kumar Sharma

2014-12-01

Full Text Available Our plankton and semi-plankton collections from twelve floodplain lakes (beels of Majuli River Island, Upper Assam reveal 124 rotifer species (32 genera and 17 families; these merit biodiversity value as ~52.0% and ~30.0% of species, ~68.0 and ~45.0% of  genera and ~74.0 and ~65.0% of the families of the Phylum known from northeast India (NEI and India, respectively. Two species are new to India with Trichocerca uncinata as new record to the Oriental region.  Eleven species are new to the study area and we provide an updated list (144 species for following meta-analyses of Majuli Rotifera. Biogeographically important elements include one Australasian, four Oriental, four Palaeotropical and one cosmo (sub tropical species while several species are of regional distribution interest. The rotifer fauna is predominantly tropical and Lecanidae > Lepadellidae collectively include ~53.0% species but it records paucity of Brachionus species. Individual beels record total richness of 60-100 (77 ± 12 species, monthly richness between 24 ± 7-34 ± 7 species and maximum up to 54 species/sample. The results are characterized by high community similarities (59.7-90.4% vide Sørensen’s index, more rotifer homogeneity amongst beels, lack of any pattern of temporal richness variations and much limited influence of abiotic parameters.

The Marine Fungi Rhodotorula sp. (Strain CNYC4007) as a Potential Feed Source for Fish Larvae Nutrition

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Barra, M.; Llanos-Rivera, A.; Cruzat, F.; Pino-Maureira, N.; González-Saldía, R. R.

2017-01-01

Fish oil is used in the production of feed for cultured fish owing to its high polyunsaturated fatty acid content (PUFA). The over-exploitation of fisheries and events like “El Niño” are reducing the fish oil supply. Some marine microorganisms are considered potentially as alternative fatty acid sources. This study assesses a strain of Rhodotorula sp. (strain CNYC4007; 27% docosahexaenoic acid (DHA) of total fatty acids), as feed for fish larvae. The total length and ribonucleic acid (RNA)/deoxyribonucleic acid (DNA) ratio of Danio rerio larvae was determined at first feeding at six and 12 days old (post-yolk absorption larvae). Larvae fed with microencapsulated Rhodotorula sp. CNYC4007 had a significantly higher RNA/DNA ratio than control group (C1). At six days post-yolk absorption group, the RNA/DNA ratio of larvae fed with Rhodotorula sp. bioencapsulated in Brachionus sp. was significantly higher than control group fed with a commercial diet high in DHA (C2-DHA). Finally, at 12 days post-yolk absorption, the RNA/DNA ratio was significantly higher in larvae fed with Rhodotorula sp. CNYC4007 and C2-DHA (both bioencapsulated in Artemia sp. nauplii) than in control group (C1). These results suggest that Rhodotorula sp. CNYC4007 can be an alternative source of DHA for feeding fish at larval stage, providing a sustainable source of fatty acids. PMID:29194350

Bioestadística como apoyo a la praxis pedagógica de la Zoología de invertebrados en la determinación de Rotíferos de hábitat planctónico en el ecosistema de la laguna del Parque Recreacional de la ciudad de Cúcuta, aplicando las claves dicotómicas para su clasificación.

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María Eugenia Muñoz-Peñaloza

2012-01-01

Full Text Available The study involved the identification and classification of phylum specimens rotifers from planktonic habitat in the recreational lagoon park ecosystem in Cucuta City. Was made a topographic uprising to the lagoon, was distributed in eight areas and physicochemical water analyses were performed. Rotifers were collected and identified in two ways, first, using representative schemes of the most common genera, according to Barnes (1995, Gardiner (1978, Hickman (1995, Arteaga, Herrera (2005, Strebler and Krauter (1987 Iafrancesco (1997 and second, the systematic identification through the application of the dichotomous key to genera, according to James G. Needham And Paul R. Needham (1982. To characterize the presence of rotifers according to zones, we used the frequency distribution, at the rates: Jaccard (presence or absence, Raup-Crick index (similarity in relation to the areas and Margalef index (for diversity. The lagoon water according to the physicochemical parameters and bioindication was classified as beta mesosapria, being secondary contact for recreational purposes. We found six families of rotifers: Brachionidae, Philodinidae, Notommatidae, Synchaetidae, Collotheidae, Lecanidae and ten genera Brachionus, Lepadella, Colurella, Philodina, Rotary, Cephalodella, Trichocerca, Polyartha, Collotheca and Lecane and through the application of biostatistics rotifers were distributed according to areas. The procedures and photographic records developed in the study are a support material, for pedagogical praxis in rotifer phylum topic in invertebrate zoology.

تأثیر غلظت‌های مختلف جلبک رشته‌ای Oscillatoria spp. بر فاکتورهای رشد و تولیدِمثل روتیفر آب شور Brachionus plicatilis

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احمد احمدی

2016-11-01

نتایج: در انتهای پنجمین روز از دورۀ پرورش بیشترین تراکم (33/6±66/453 فرد در میلی‌لیتر (میانگین± انحراف معیار در غلظت غذایی 106×5/4 سلول در میلی‌لیتر به دست آمد که به‌طور معنی‌داری (05/0p

The ghost of herbivory past: slow defence relaxation in the chlorophyte Scenedesmus obliquus

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Jacobus VIJVERBERG

2009-08-01

Full Text Available The freshwater chlorophyte Scenedesmus obliquus (Turpin Kützing produces colonies as an inducible defence against herbivores. We investigated the dynamics of Scenedesmus colony formation and disintegration in response to the density of the herbivorous rotifer Brachionus calyciflorus in large-scale mesocosms. Additional bioassays were performed to investigate Scenedesmus colony disintegration under different light regimes. In the mesocosm experiment, colony formation took place rapidly, but relaxation towards the initial size took relatively long (>10 d after cessation of herbivory. In the bioassays, in the absence of infochemicals, colonies disintegrated almost immediately in the dark (1-1.5 d, within 4 d under a photoperiod of 16:8 (L:D and between 8 and 12 days under full light. Colony disintegration times in the mesocosm experiment were substantially longer as compared to treatments with the same photoperiod (L:D 16:8 in the bioassays. So after a peak of herbivory, the 'ghost of herbivory past', i.e. the remaining infochemicals, may continue to induce colony formation, causing an additional lengthening of colony disintegration times and associated fitness costs (higher sedimentation loss rates. This indicates that costs of colony formation are not only important during the induction phase, but may be even more important during the relaxation phase. We compared these sedimentation costs to the costs of herbivory for differently sized Scenedesmus, and found a clear trade-off pattern for these costs.

The Marine Fungi Rhodotorula sp. (Strain CNYC4007 as a Potential Feed Source for Fish Larvae Nutrition

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M. Barra

2017-12-01

Full Text Available Fish oil is used in the production of feed for cultured fish owing to its high polyunsaturated fatty acid content (PUFA. The over-exploitation of fisheries and events like “El Niño” are reducing the fish oil supply. Some marine microorganisms are considered potentially as alternative fatty acid sources. This study assesses a strain of Rhodotorula sp. (strain CNYC4007; 27% docosahexaenoic acid (DHA of total fatty acids, as feed for fish larvae. The total length and ribonucleic acid (RNA/deoxyribonucleic acid (DNA ratio of Danio rerio larvae was determined at first feeding at six and 12 days old (post-yolk absorption larvae. Larvae fed with microencapsulated Rhodotorula sp. CNYC4007 had a significantly higher RNA/DNA ratio than control group (C1. At six days post-yolk absorption group, the RNA/DNA ratio of larvae fed with Rhodotorula sp. bioencapsulated in Brachionus sp. was significantly higher than control group fed with a commercial diet high in DHA (C2-DHA. Finally, at 12 days post-yolk absorption, the RNA/DNA ratio was significantly higher in larvae fed with Rhodotorula sp. CNYC4007 and C2-DHA (both bioencapsulated in Artemia sp. nauplii than in control group (C1. These results suggest that Rhodotorula sp. CNYC4007 can be an alternative source of DHA for feeding fish at larval stage, providing a sustainable source of fatty acids.

Impact of chromium and aluminium pollution on the diversity of zooplankton: a case study in the Chimaliapan wetland (Ramsar site) (Lerma basin, Mexico).

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García-García, Gerardo; Nandini, S; Sarma, S S S; Martínez-Jerónimo, Fernando; Jiménez-Contreras, Jorge

2012-01-01

Biological monitoring and the use of biotic indices are important in evaluating the health of aquatic systems. However, zooplankton are rarely included in biomonitoring protocols. We conducted a one-year study (March 2008-February 2009) at two sites from the Chimaliapan wetland, with concentrations of aluminium (Al) and chromium (Cr) above and within the permissible limits, respectively. Metals in the sediment and water were analyzed from three locations per site every two months. In addition to analyses of the abundance and diversity of rotifers, cladocerans and copepods, we sampled 11 physicochemical variables in the water and six from the sediments. The metal concentration in the polluted site (significantly above the permissible limits) ranged between 7266-8174 mg Kg(-1) of Al and 14.6-18.3 mg Kg(-1) of Cr. We found 92 species of rotifers, cladocerans and copepods. The Brillouin index for both sites ranged from 3.9-5.4, the Shannon-Wiener index from 4.2-5.5 while the Brachionus-Trichocerca ratio ranged between 1.0 and 1.7. The Wetland Zooplankton Index was significantly different among the sites; 2.63 at site 1 and 2.13 at site 2. The saprobic index was 3.2 for both sites. Data analyses using multifactorial techniques suggested that zooplankton can be used to evaluate the impact of the metals aforementioned, since these organisms are generally more sensitive than other groups and also have a high ecological relevance.

Effect of addition of Navicula sp. on plankton composition and postlarvae growth of Litopenaeus vannamei reared in culture tanks with zero water exchange

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Yllana Ferreira-Marinho

2014-07-01

Full Text Available The aim of this study was to evaluate the effect of the addition of Navicula sp. on plankton composition and postlarvae growth of Litopenaeus vannamei reared in culture tanks with zero water exchange systems. Four treatments were considered: zero water exchange (ZWE; ZWE with the addition of feed (ZWE-F; ZWE with the addition of Navicula sp. (ZWE-N and ZWE with the addition of feed and Navicula sp. (ZWE-FN, all in triplicate. Shrimp of 17.7 ± 0.02 mg were stocked at a density of 2500 shrimp m-3 and microalgae added on the 1st, 5th and 15th day at a density of 5x10(4 cell mL-1. The shrimp were fed a commercial feed composed by 42% crude protein four times a day except in the ZWE treatment. For data analysis we used Cochran, Shapiro-Wilk, ANOVA, Tukey and Student-t tests (P < 0.05. The most frequent genera were: Anabaena, Arcella, Asplanchma, Bosmina, Brachionus, Cylindrotheca, Daphnia, Fragilaria, Hemiaulus, Keratella, Orthoseira, Oscillatoria, Phymatodocis, Rhabdonema, Skeletonema, Sckizothrix and Ulothrix. Significant differences between treatments were observed for TAN, NO2-N, alkalinity, final weight, weight gain, final biomass, biomass gain, feed conversion ratio, specific growth rate and survival. The ZWE-FN treatment showed better production parameters, indicating the benefits of the addition of Navicula sp. as a natural food source for L. vannamei postlarvae in zero water exchange systems.

Higher rates of sex evolve in spatially heterogeneous environments.

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Becks, Lutz; Agrawal, Aneil F

2010-11-04

The evolution and maintenance of sexual reproduction has puzzled biologists for decades. Although this field is rich in hypotheses, experimental evidence is scarce. Some important experiments have demonstrated differences in evolutionary rates between sexual and asexual populations; other experiments have documented evolutionary changes in phenomena related to genetic mixing, such as recombination and selfing. However, direct experiments of the evolution of sex within populations are extremely rare (but see ref. 12). Here we use the rotifer, Brachionus calyciflorus, which is capable of both sexual and asexual reproduction, to test recent theory predicting that there is more opportunity for sex to evolve in spatially heterogeneous environments. Replicated experimental populations of rotifers were maintained in homogeneous environments, composed of either high- or low-quality food habitats, or in heterogeneous environments that consisted of a mix of the two habitats. For populations maintained in either type of homogeneous environment, the rate of sex evolves rapidly towards zero. In contrast, higher rates of sex evolve in populations experiencing spatially heterogeneous environments. The data indicate that the higher level of sex observed under heterogeneity is not due to sex being less costly or selection against sex being less efficient; rather sex is sufficiently advantageous in heterogeneous environments to overwhelm its inherent costs. Counter to some alternative theories for the evolution of sex, there is no evidence that genetic drift plays any part in the evolution of sex in these populations.

Seasonal variations of species composition and abundance of zooplankton in Ehoma Lake, a floodplain lake in Nigeria

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Okechukwu. I Okogwu

2010-03-01

Full Text Available Ehoma Lake is among the important breeding sites of the major fishes in the Mid-Cross River, Nigeria. The juveniles of these fishes are solely dependent on zooplankton, which has not been studied previously. I studied monthly the lake’s physico-chemical variables and zooplankton composition in three stations (littoral, sub-littoral and pelagic from March 2005 to August 2006. Sixty-seven zooplankton species (42 rotifers, 19 cladocerans and 6 copepods were identified. Daphnia obtusa Kurz, Keratella valga Ehrenberg, Keratella ticinensis Callerrio, Keratella hiemalis Carlin, Brachionus dimidiatus Bryce and Lecane candida Hauer and Murray are new records for Nigeria. The dominant zooplankters were Diaphanosoma excisum Kurz and Moina micrura Kurz. There was an inverse relationship between species richness and abundance. Richness was highest in the dry season while peak zooplankton abundance was recorded in the rainy season. Zooplankton abundance and species richness decreased progressively from the littoral to the pelagic station while the Shannon-Weaver diversity index varied from 0.68 to 1.28 without a clear seasonal trend. There is a succession pattern: rotifers that are dominant in the dry season are replaced by cladocerans in the rainy season. This succession was greatly influenced by seasonal flooding of the lake. As no previous information on the zooplankton of the lake is available, this study provides baseline data on the lake`s zooplankton. Rev. Biol. Trop. 58 (1: 171-182. Epub 2010 March 01.El lago Ehoma, situado en la mitad del río Cross, es uno de los lugares de reproducción de las principales especies de peces del río. Los juveniles de estos peces dependen exclusivamente del zooplancton, sin embargo poco se sabe sobre este recurso en el lago. En este estudio, las variables físico-químicas y del zooplancton del lago fueron estudiadas mensualmente en tres estaciones (litoral, sub-litoral y pelágica, de marzo de 2005 a agosto de

Microcrustáceos y Vibrio cholerae O1 viable no cultivable (VNC: resultados en la Cuenca del Río Salí, Tucumán, Argentina Microcrustaceans and viable but nonculturable (VNC Vibrio cholerae O1: results in the Salí River basin, Tucumán, Argentina

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Cecilia Locascio de Mitrovich

2010-01-01

Full Text Available Vibrio cholerae reside habitualmente en aguas marinas y continentales. Según las condiciones ambientales y los recursos le sean “favorables” o “desfavorables”, se generan estados viables cultivables (VC o viables no cultivables (VNC respectivamente y, bajo esta última forma sobrevive. Para abordar la problemática del cólera en la Cuenca del Río Salí (Tucumán, Argentina, se realizaron muestreos durante los años 2003-2005 donde se consideraron aspectos fisicos, químicos, biológicos y sanitarios. Para evaluar los probables reservorios del patógeno, se analizó el zooplancton del Río Salí (Canal Norte y Banda Río Salí y Río Lules. La mayor representatividad taxonómica la registraron los copépodos, especialmente Eucyclops neumani (Pesta, 1927, junto a Acanthocyclops robustus (Sars, 1863, Metacyclops sp., Paracyclops chiltoni y Notodiaptomus incompositus (Brian, 1925, además de algunos rotíferos y cladóceros como (Lecane sp., y (Brachionus sp., Moina sp. y Leydigia sp.. La frecuencia de ocurrencia fue baja y no superó el 25%. El Canal Norte fue ambiente más propicio por la riqueza específica, abundancia y constancia de la comunidad. Las variables fisicas y químicas asociadas al zooplancton coincidirían con los valores que por nuestros registros y los antecedentes, se conocen para el desarrollo del patógeno. En el período estival hubo coincidencia entre la presencia de la forma VNC de V. cholerae O1 (inmunofluorescencia con anticuerpos anti O1 y el desarrollo del zooplancton. Se observaron formas VNC sobre apéndices o estructuras de copépodos ciclopoideos y cladóceros quidóridos, reflejando probablemente afinidad con sustratos quitinosos.Vibrio cholerae habitually lives in marine and continental waters. According to "favourable" or "unfavourable" resources and environmental conditions, viable (VC or viable non-culturable (VNC states will be generated, surviving only the latter form. To address the problem of

Sequence stratigraphy and tectonosedimentary history of the Upper Jurassic of the Eastern Paris Basin (Lower and Middle Oxfordian, Northeastern France)

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Carpentier, Cédric; Lathuilière, Bernard; Ferry, Serge; Sausse, Judith

2007-04-01

In the present study, the difficulty which lies in the identification of sea-level fall discontinuities in deep depositional environments led the authors to use the transgressive surfaces (i.e. the most noticeable surfaces in the present case) to determine depositional cycles. Four (3rd order?) Lower and Middle Oxfordian cycles were identified (S1, S2, S3, and S4) in the Eastern Paris Basin. These four cycles can be organised into two lower frequency cycles (So I and So II) which comprise the S1, S2 and the S3, S4 cycles respectively. During the time intervals of the S1, S2, and S3 cycles, sedimentation occurred along a southward dipping carbonate-siliciclastic ramp, prograding from the northern Ardennes area. The S4 cycle shows the development of a reefal distally steepened ramp which subsequently evolved into a flat-topped platform as a result of the compensation infill of the available accommodation space by the carbonate production during a climatic warming, in this case reef growth. Isopach and facies maps suggest synsedimentary activities of hercynian faults coevals with the floodings of the So I and So II cycles. One of these events generated a diachronism of the maximum flooding (Plicatilis Zone) during the So II cycle between the northwestern and southeastern parts of the studied area. The depositional patterns found in the Eastern Paris Basin and the Swiss Jura show great similarities for the Early-Middle Oxfordian. Both regions were probably connected and recorded the same tectonosedimentary evolution. In contrast a tectonic control certainly generated differences between the sequence-stratigraphic framework of the Eastern Paris Basin and the eustatic chart.

The effect of live feeds bathed with the red seaweed Asparagopsis armata on the survival, growth and physiology status of Sparus aurata larvae.

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Castanho, S; Califano, G; Soares, F; Costa, R; Mata, L; Pousão-Ferreira, P; Ribeiro, L

2017-08-01

Larval rearing is affected by a wide range of microorganisms that thrive in larviculture systems. Some seaweed species have metabolites capable of reducing the bacterial load. However, no studies have yet tested whether including seaweed metabolites on larval rearing systems has any effects on the larvae development. This work assessed the development of Sparus aurata larvae fed preys treated with an Asparagopsis armata product. Live prey, Brachionus spp. and Artemia sp., were immersed in a solution containing 0.5% of a commercial extract of A. armata (Ysaline 100, YSA) for 30 min, before being fed to seabream larvae (n = 4 each). In the control, the live feed was immersed in clear water. Larval parameters such as growth, survival, digestive capacity (structural-histology and functional-enzymatic activity), stress level (cortisol content), non-specific immune response (lysozyme activity), anti-bacterial activity (disc-diffusion assay) and microbiota quantification (fish larvae gut and rearing water) were monitored. Fish larvae digestive capacity, stress level and non-specific immune response were not affected by the use of YSA. The number of Vibrionaceae was significantly reduced both in water and larval gut when using YSA. Growth was enhanced for YSA treatment, but higher mortality was also observed, especially until 10 days after hatching (DAH). The mortality peak observed at 8 DAH for both treatments, but higher for YSA, indicates larval higher susceptibility at this development stage, suggesting that lower concentrations of YSA should be used until 10 DAH. The application of YSA after 10 DAH onwards promotes a safer rearing environment.

Correspondence of zooplankton assemblage and water quality in wetlands of Cachar, Assam, India: Implications for environmental management

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Kar Sulata

2018-03-01

Full Text Available The zooplankton assemblage of selected wetlands of Assam, India was assessed to deduce the structural variation in the context of water quality parameters. A two year study between 2012 and 2014 comprising of 530 samples from the five wetlands revealed the presence of 46 taxa, 26 Rotifera, 15 Cladocera, 4 Copepoda and 1 Ostracoda, in varying density. The rotifers dominated in terms of abundance (48 ind. cm−3 followed by the cladocerans (28 ind. cm−3 and the copepods (19 ind. cm−3 and showed significant (p <0.05 correlations with turbidity, alkalinity, hardness and phosphate contents of the water samples. The diversity and the richness of the zooplankton showed an increasing trend with the water temperature. Among the different taxa, Brachionus sp. was most abundant followed by Mesocyclops sp. while Beauchampiella sp. was represented in the least numbers. Application of the cluster analysis allowed the segregation of the different zooplankton based on the similarities of abundance in the samples. The water quality parameters like temperature, alkalinity, turbidity, magnesium and calcium were observed to be significant contributors in shaping the zooplankton community composition of the wetlands, revealed through the correlations and canonical correspondence analysis. As an extension, the information can be used in monitoring the quality of the freshwater habitats of the concerned and similar geographical regions, using the zooplankton as the major constituents. The variations in the abundance of cladoceran, copepod and rotifer zooplanktons can be used to understand the mechanisms that sustain the food webs of the aquatic community of the freshwater bodies.

Filming of zooplankton: a case study of rotifer males and Daphnia magna

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Pierluigi Colangeli

2015-11-01

Full Text Available Filming live organisms can give new insights into the hidden life of plankton. Accessibly priced digital cameras are now available for a large range of users. Here, we demonstrate the technical setup and workflow of using a single-lens reflex (DSLR camera to film the behaviour of males of two rotifer species, Brachionus angularis Gosse (1851 and Keratella cochlearis Gosse (1851, and of the cladoceran Daphnia magna Straus (1820. Rotifers are cyclical parthenogens that produce males only under certain environmental conditions. Thus, knowledge on rotifer males is still limited because of their ephemeral nature and because they are often smaller than females. We filmed males of B. angularis and K. cochlearis with a DSLR camera connected to a compound microscope to better understand their morphology and behaviour in comparison to conspecific females. While written descriptions have their scientific value, seeing is complementary because everyone can verify what has been described. We made our videos publicly accessible through links connected to the paper. Our videos are, to our best knowledge, the first on males of B. angularis and K. cochlearis. Furthermore, we filmed the behavioural response of D. magna to ultraviolet (UV radiation with a macro lens attached to the DSLR camera. Approaches like this are valuable tools in environmental teaching. To see live organisms with one’s own eyes may contribute to raising public awareness about the value of water resources and their hidden communities. In summary, filming can be a valuable tool to ignite scientific discussion, but the videos need an open-access platform where they can be referenced in a topic-related order.

The evolution of sex is favoured during adaptation to new environments.

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Becks, Lutz; Agrawal, Aneil F

2012-01-01

Both theory and experiments have demonstrated that sex can facilitate adaptation, potentially yielding a group-level advantage to sex. However, it is unclear whether this process can help solve the more difficult problem of the maintenance of sex within populations. Using experimental populations of the facultatively sexual rotifer Brachionus calyciflorus, we show that rates of sex evolve to higher levels during adaptation but then decline as fitness plateaus. To assess the fitness consequences of genetic mixing, we directly compare the fitnesses of sexually and asexually derived genotypes that naturally occur in our experimental populations. Sexually derived genotypes are more fit than asexually derived genotypes when adaptive pressures are strong, but this pattern reverses as the pace of adaptation slows, matching the pattern of evolutionary change in the rate of sex. These fitness assays test the net effect of sex but cannot be used to disentangle whether selection on sex arises because highly sexual lineages become associated with different allele combinations or with different allele frequencies than less sexual lineages (i.e., "short-" or "long-term" effects, respectively). We infer which of these mechanisms provides an advantage to sex by performing additional manipulations to obtain fitness distributions of sexual and asexual progeny arrays from unbiased parents (rather than from naturally occurring, and thereby evolutionarily biased, parents). We find evidence that sex breaks down adaptive gene combinations, resulting in lower average fitness of sexual progeny (i.e., a short-term disadvantage to sex). As predicted by theory, the advantage to sex arises because sexually derived progeny are more variable in fitness, allowing for faster adaptation. This "long-term advantage" builds over multiple generations, eventually resulting in higher fitness of sexual types.

Application of a battery of biotests for the determination of leachate toxicity to bacteria and invertebrates from sewage sludge-amended soil.

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Malara, Anna; Oleszczuk, Patryk

2013-05-01

The objective of the study was to determine the leachates toxicity from sewage sludge-amended soils (sandy and loamy). Samples originated from a plot experiment realized over a period of 29 months. Two types of soil were fertilized with sewage sludges at the dose of 3 % (90 t/ha). Soil samples were taken after 0, 7, 17, and 29 months from the application of sewage sludges. Leachates were obtained according to the EN 12457-2 protocol. The following commercial tests were applied for the estimation of the toxicity: Microtox (Vibrio fischeri), Microbial assay for toxic risk assessment (ten bacteria and one yeast), Protoxkit F (Tetrahymena thermophila), Rotoxkit F (Brachionus calyciflorus), and Daphtoxkit F (Daphnia magna). The test organisms displayed varied toxicity with relation to the soils amended with sewage sludges. The toxicity of the leachates depended both on the soil type and on the kind of sewage sludge applied. Notable differences were also observed in the sensitivity of the test organisms to the presence of sewage sludge in the soil. The highest sensitivity was a characteristic of B. calyciflorus, while the lowest sensitivity to the presence of the sludges was revealed by the protozoa T. thermophila. Throughout the periods of the study, constant variations of toxicity were observed for most of the test organisms. The intensity as well as the range of those variations depended both on the kind of test organism and on the kind of sludge and soil type. In most cases, an increase of the toxicity of soils amended with the sewage sludges was observed after 29 months of the experiment.

EFECTOS DE LA FLUCTUACIÓN DEL NIVEL DEL AGUA SOBRE LA ESTRUCTURA DEL ENSAMBLAJE DE ROTÍFEROS EN EL LAGO LARGO (SISTEMA YAHUARCACA - LLANURA DE INUNDACIÓN DEL RÍO AMAZONAS - COLOMBIA

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Andrade Camilo

2011-12-01

Full Text Available Se realizó un reconocimiento taxonómico y estimación de la densidad en el ensamblaje de rotíferos en el lago Largo, del sistema de lagos Yahuarcaca, en la ribera colombiana del río Amazonas, a partir de muestreos en las fases hidrológicas de aguas bajas, ascenso y descenso. Se identificaron 68 especies, 28 de ellas son nuevos registros para ambientes colombianos. Se encontró aumento en la riqueza en las épocas de ascenso y descenso, siendo mayor en la zona litoral respecto de la limnética, y la tendencia a mayor similitud taxonómica entre ambas zonas en el periodo de aguas bajas, debido al mínimo desarrollo de macrófitas en esta fase y la consecuente menor heterogeneidad espacial. Se observó el predominio de rotíferos con trofi adaptados para moler y triturar partículas (maleado y maleorramado en las épocas de aguas bajas (Brachionus ahlstromi y descenso (Filina saltator y en la época de ascenso de Polyarthra vulgaris, con trofi adaptado para perforar y succionar fluidos de algas y otros organismos (virgado y apéndices que favorecen la rápida natación. En general, se establecieron posibles relaciones entre la riqueza y la densidad de rotíferos con cambios en características como el desarrollo de vegetación acuática en el litoral, profundidad del lago, nivel de conectividad con los otros lagos del sistema Yahuarcaca, influencia de aguas blancas del Amazonas y negras de origen local, potenciales recursos nutricionales y depredadores, y posible efecto de arrastre por la corriente.

Spatial variations in zooplankton diversity in waters contaminated with composite effluents

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Asitava CHATTERJEE

2007-08-01

Full Text Available Zooplankton species are cosmopolitan in their clean freshwater habitat and are also found in industrial and municipal wastewaters. The present study records for the first time the aspects of zooplankton diversity in relation to physico-chemical environment of five selected sites of the East Calcutta wetlands, a Ramsar site of Kolkata city, India, heavily contaminated by industrial and municipal wastewaters. The study revealed the occurrence of 22 species of zooplankton, among these 3 species of Cladocera, 2 species of Copepoda, 15 species of Rotifera, and 2 species of Ostracoda were recorded. The copepod Mesocyclops leuckarti was found in all the five sites, rotifers Asplanchna brightwelli, Brachionus angularis, B. calyciflorus and Cladocera Ceriodaphnia cornuta were found in four sites; Moina micrura and Diaphanosoma sarsi were found at three sites. Site wise variation in dominance, diversity, evenness and richness were calculated. Site 1, a fish-pond that stabilized composite wastewater, showed the maximum species richness having 17 species, while Site 2, SWF wastewater carrying canal, showed only 4 species. The calculated Jack 1 values of Sites 1 to 5 were 21.78, 3.77, 18.63, 12.5 and 16.95 respectively. Shannon-Wiener species diversity index (H/ values were almost similar for all the three relatively less polluted sites viz, Site 1 (1.959, Site 4 (2.010, Site 5 (2.047. However, at highly polluted sites viz., 2 and 3, H/ value of 1.336 and 0.984 respectively, were calculated. Simpson’s Dominance index (Dsimp value was highest at Site 3 (0.618 indicating maximum dominance, whereas at Site 5 dominance was lowest (0.1680 and diversity was highest. We discuss the role of zooplankton in the amelioration of wastewater.

Genome-wide identification of 31 cytochrome P450 (CYP) genes in the freshwater rotifer Brachionus calyciflorus and analysis of their benzo[alpha]pyrene-induced expression patterns

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Han, Jeonghoon; Kim, Duck-Hyun; Kim, Hui-Su; Kim, Hee-Jin; Declerck, S.A.J.; Hagiwara, Atsushi; Lee, Jae-Seong

2017-01-01

While marine invertebrate cytochrome P450 (CYP) genes and their roles in detoxification mechanisms have been studied, little information is available regarding freshwater rotifer CYPs and their functions. Here, we used genomic sequences and RNA-seq databases to identify 31 CYP genes in the

Efeitos de fertilização na biomassa e qualidade nutricional do zooplâncton utilizado para alimentação de alevinos na estação de hidrobiologia e piscicultura de Furnas, MG Fertilization effects on biomass and nutritional quality of zooplancton in feeding of fry in the Furnas (MG, Brazil hydrobiology and pisciculture station

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Raquel Magalhães Santeiro

2000-05-01

Full Text Available O estudo objetivou avaliar os efeitos da adição intensiva de dejetos orgânicos e de nutrientes na qualidade do zooplâncton obtido em tanques de plâncton, empregado na alimentação de alevinos de “trairão” (Hoplias lacerdae. Os teores de lipídeos totais do zooplâncton bem como sua abundância e biomassa foram acompanhados, através de duas coletas semanais, em dois tanques de produção de plâncton durante dois meses seguidos. Foram medidos ainda a temperatura, pH, oxigênio dissolvido, condutividade elétrica na coluna de água. As concentrações de clorofila-a, fósforo total, amônia e nitrogênio total (TKN foram acompanhadas semanalmente. Nos primeiros trinta dias, foi feita a adubação a cada cinco dias e, nos últimos trinta dias, não houve qualquer adubação em ambos os tanques. A interrupção da fertilização causou uma notável e rápida mudança na qualidade físico-química da água bem como na estrutura da comunidade zooplanctônica. Houve um decréscimo nos teores de condutividade, amônia, nitrogênio total, fósforo total e clorofila-a. Em contraste, houve um aumento nos níveis de oxigênio dissolvido e pH. Logo após a parada da fertilização, houve um pico na biomassa total do zooplâncton que perdurou por cerca de 20 dias, em ambos os tanques. Nesse período, o cladócero Moina reticulata e o rotífero Brachionus calyciflorus foram os mais abundantes. No entanto, ao final do período de estudos, os ciclopóides voltaram a ser os organismos dominantes, embora com predominância de formas imaturas. Os teores de lipídeos totais do zooplâncton permaneceram baixos durante todo o período de estudos (6-10%, sugerindo a má qualidade do seu alimento dentro dos tanques. O estudo demonstra que a fertilização é necessária para que seja obtido um zooplâncton com maiores valores nutricionais mas a baixa qualidade da água causada pela hipereutrofização e os baixos níveis de lipídeos encontrados no zoopl

The effect of pH on chronic aquatic nickel toxicity is dependent on the pH itself: Extending the chronic nickel bioavailability models.

Science.gov (United States)

Nys, Charlotte; Janssen, Colin R; Van Sprang, Patrick; De Schamphelaere, Karel A C

2016-05-01

The environmental quality standard for Ni in the European Commission's Water Framework Directive is bioavailability based. Although some of the available chronic Ni bioavailability models are validated only for pH ≤ 8.2, a considerable fraction of European surface waters has a pH > 8.2. Therefore, the authors investigated the effect of a change in pH from 8.2 to 8.7 on chronic Ni toxicity in 3 invertebrate (Daphnia magna, Lymnaea stagnalis, and Brachionus calyciflorus) and 2 plant species (Pseudokirchneriella subcapitata and Lemna minor). Nickel toxicity was almost always significantly higher at pH 8.7 than at pH 8.2. To test whether the existing chronic Ni bioavailability models developed for pH ≤ 8.2 can be used at higher pH levels, Ni toxicity at pH 8.7 was predicted based on Ni toxicity observed at pH 8.2. This resulted in a consistent underestimation of toxicity. The results suggest that the effect of pH on Ni(2+) toxicity is dependent on the pH itself: the slope of the pH effect is steeper above than below pH 8.2 for species for which a species-specific bioavailability model exists. Therefore, the existing chronic Ni bioavailability models were modified to allow predictions of chronic Ni toxicity to invertebrates and plants in the pH range of 8.2 to 8.7 by applying a pH slope (SpH ) dependent on the pH of the target water. These modified Ni bioavailability models resulted in more accurate predictions of Ni toxicity to all 5 species (within 2-fold error), without the bias observed using the bioavailability models developed for pH ≤ 8.2. The results of the present study can decrease the uncertainty in implementing the bioavailability-based environmental quality standard under the Water Framework Directive for high-pH regions in Europe. © 2015 SETAC.

Caracterización limnológica de la laguna de Cashibococha (UcayaliPerú durante el año 2001

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José Riofrío

2013-06-01

Full Text Available Durante el año 2001 se realizaron muestreos bimensuales en tres estaciones fijas en la laguna de Cashibococha (Ucayali, Perú. Cashibococha presenta aguas de color verdoso a café oscuro, con pH entre 6 a 6,8, Conductividad entre 10 y 30µS.cm −1 , Transparencia de 21 a 59 cm y Alcalinidad Total entre 14 y 22 mg CaCO3 / L . La temperatura superficial del agua osciló entre 24,4 y 37 ºC y el Oxígeno Disuelto entre 1,3 y 7,4 mg/ L. Los análisis bacteriológicos registraron recuentos de aerobios mesófilos entre 350 y 3600 UFC/ mL. Los coliformes totales oscilaron entre 3 y 43 NMP/ 100 mL. Se diferenciaron 47 especies pertenecientes a 20 familias de macrófitas acuáticas; el mayor número de especies se reportó durante la época de Transición − Creciente (octubre − noviembre, debido a la inundación del bosque. Fueron identificadas 52 especies de fitoplancton, la División Chlorophyta fue la mas dominante. La comunidad fitoplanctónica está dominada por las especies Actinastrum hantzschi, Spirogyra sp., Eudorina elegans, Pandorina morum y Closterium kuetzingui. Se diferenciaron 54 especies de Zooplancton. Los rotíferos fue el taxa dominante. La densidad de zooplancton está dominada por Brachionus patulus macracanthus y Polyarthra vulgaris. Fueron identificadas 66 especies de peces, pertenecientes a 55 géneros, 11 familias y 4 órdenes. El orden dominante en diversidad y abundancia fue el de Characiformes, Curimata vittata fue la especie dominante en la comunidad de peces en éstas áreas litorales. Los índices de diversidad fueron superiores a 3,0 bits. ind –1 , en todas las estaciones y lugares de muestreo. De igual manera los valores de equitabilidad fueron superiores a 0,8 en todas las estaciones y lugares de muestreo.

Non-genetic polymorphisms in rotifers: environmental and endogenous controls, development, and features for predictable or unpredictable environments.

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Gilbert, John J

2017-05-01

reversibility. Two cases of morphological variation also involve the simultaneous production of different morphs and likely are adaptations for an uncertain future: continuous spine-length variation due to maternal age in Brachionus calyciflorus, and production of discrete cruciform and campanulate females in Asplanchna spp. © 2016 Cambridge Philosophical Society.

Development of fingerlings of Piracanjuba (Brycon orbignyannus, Vallencienes (1849 (Teleostei: characidae in tanks fertilized with organic manures/ Desenvolvimento de juvenis de Piracanjuba (Brycon orbignyannus, Vallencienes (1849 (Teleostei: characidae em tanques experimentais fertilizados com adubação orgânica

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Carmino Hayashi

2005-06-01

Full Text Available The objective of this paper was to study the development of Piracanjuba (Brycon orbignyanus in tanks under differents organic fertilizers. The experiment, entirely randomized, was accomplished in 16 tanks of 1000 liters, fertilized with manures of bovine (BOV, pigs (SUI, chickens (FRG and others without fertilizer (SAO, using 15 fish/m3 with an initial average weight and length of 10,87+0,31 g e 9,78+0,07 cm. After 30 days, the experiment showed a uniform development of the fish and high survival rate in thestudied density. The treatments presented significant statistical differences (PO objetivo deste trabalho foi estudar o desenvolvimento de juvenis de Piracanjuba (Brycon orbignyanus, em tanques com adubações orgânicas. O experimento, inteiramente casualizado, foi realizado em 16 tanques de 1000 litros, adubados com estercos de bovinos (BOV, suínos (SUI, frangos de corte (FRG e outros sem adubação (SAO, utilizando 15 peixes/m3 com peso e comprimento médios iniciais de 10,87+0,31 g e 9,78+0,07 cm. Após 30 dias, o experimento mostrou um desenvolvimento uniforme dos peixes e alta taxa de sobrevivência na densidade estudada. Os tratamentos apresentaram diferenças estatisticamente significativas (p < 0,05 para ganho de peso e crescimento diário, com exceção dos tratamentos BOV e SUI quando comparados entre si. A temperatura e o oxigênio dissolvido foram os fatores abióticos que exerceram maior influência sobre a biota aquática, afetando o desenvolvimento dos peixes. Entre o fitoplâncton houve maior abundância de organismos nanoplanctônicos favorecendo o desenvolvimento do zooplâncton, destacando-se as clorófitas, com o gênero Scenedesmus, e as cianofíceas, com o gênero Microcystis, e entre o zooplâncton, a maior abundância foi de rotíferos dos gêneros Brachionus e Keratella, seguido por copépodas. O tratamento adubado com esterco de frangos possibilitou um maior desenvolvimento da comunidade planctônica, e melhores

Plankton and Macrobiota Composition and Diversity of Three Tropical Freshwaters Rivers in Ogun and Ondo States, Southwest Nigeria

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Taofikat Abosede ADESALU

2016-06-01

Full Text Available Three different rivers in Ogun and Ondo states were investigated for both micro and macro-biota of the water bodies. Several physical and chemical properties of these rivers were determined. The pH value of the studied water bodies was essentially neutral with salinity values between 0.02 - 4.0‰. Microalgae communities were represented by three divisions: Cyanophyta, Bacillariophyta and Chlorophyta at Oluwa and Ifara Rivers (Ondo state, while at Ibefun River (Ogun state, five divisions: Cyanophyta, Bacillariophyta, Chlorophyta, Euglenophyta and Pyrrhophyta were identified. Diatoms dominated these water bodies, with Navicula radiosa Kutz. at Ifara River, Fragilaria sp. in Oluwa River, while out of 90 algal taxa identified in Ibefun river, 64 were diatoms species belonging to 26 genera, with Melosira sp. and Synedra sp. recording the highest numbers of cell count. Dinoflagellates recorded only Peridinium sp. while Phacus orbicularis Hubner and Trachelomonas sp. dominated the euglenoids. For the zooplankton composition at Ibefun, rotifers (75.95% were represented by Brachionus sp., which recorded 62.03%, and Gastropus sp. with 13.92% of the total zooplankton, thus dominated the spectrum, while the copepod recorded 22.78% of the total organisms, with Copilia sp. and Euchirella sp. having 8.86% each. The macrobenthic invertebrates were represented by 3 taxa, belonging to 3 groups, with the dominant group Insecta accounted for 57% of the total individuals (7 individuals/m2, while Oligochaeta and Hirudinea accounted for 29% and 14% respectively of the total individuals at Oluwa and Ifara Rivers. At Ibefun River, the macrobenthic invertebrates were represented by 5 taxa, belonging to 3 groups, Bivalves, Oligochaeta and Insecta, with bivalves being the dominant group (51.7% of the total individuals, as 64 individuals/m2, while Oligochaeta and Insecta accounted for 26.6% and 21.9% respectively of the total individuals. The dominant taxon, Macoma cumana

Plancto e hidrobiologia sanitária de tanques tropicais com dáfnias e rotíferos

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Lejeune P. H. de Oliveira

1967-01-01

NH[4 subscripted]. b Species of the genus Chlamydomonas; it is even possible that all the species of theses genus inhabit strong-mesosaprobic to polysaprobic waters when in massive blooms. c Several species of Euglenaceae in fast growing number, at the same time of the protozoa Amoebidae, Vorticellidae and simultaneous with deposition of the decaying cells of the blue algae Anacystis cyanea (= Microcystis when the consumed oxygen by organic matter resulted in 40 mg. L. But, we found, among various Euglenacea the cosmopolite species (Euglena viridis, a well known polysaprobic indicatior of which presence occur in septic zone. d Analcystis cyanea (= M. aeruginosa as we observed was in blooms increasing to the order of billions of cells per litter, its maximum in the summer. Temperatures 73ºF to 82ºF but even 90ºF, the pH higher than 8. When these blue algae was joined to the rotifer Brachionus calyflorus the waters gets a milky appearance, but greenished one. In fact, that cosmopolite algae is used as a mesosaprobic indicator. Into the water of the ponds its predominance finished when the septic polysaprobic conditions began. e Ankistrodesmus falcatus was present in the 5th pond from 26the. April untill the 26th July, and when N.NH[4 subscripted] gets 1.28 mg. L. and when chlorinity stayed from 0.034 to 0.061 mg. L. It never was found at N.NH[4 subscripted] higher than 1 mg. L. The green algae A. falcatus, an indicatior of pollution, lives in moderate mesosaprobic waters. f As everyone knows, the rotifer eggs may be widely dispersed by wind. The rotifer Asplanchna brightwelli in our observation seemed like a green colored bag, overcharged by green cells and detritus, specially into its spacious stomach, which ends blindly (the intestine, cloaca, being absent. The stock of Asplanchna in the ponds, during the construction of the bridge "PONTE OSWALDO CRUZ" inhabits alkaline waters, pH 8,0 a 8,3, and when we observed we noted its dissolved oxygen from 3.5 to 4 mg. L

Complete genome sequence and description of Salinispira pacifica gen. nov., sp. nov., a novel spirochaete isolated form a hypersaline microbial mat.

Science.gov (United States)

Ben Hania, Wajdi; Joseph, Manon; Schumann, Peter; Bunk, Boyke; Fiebig, Anne; Spröer, Cathrin; Klenk, Hans-Peter; Fardeau, Marie-Laure; Spring, Stefan

2015-01-01

During a study of the anaerobic microbial community of a lithifying hypersaline microbial mat of Lake 21 on the Kiritimati atoll (Kiribati Republic, Central Pacific) strain L21-RPul-D2(T) was isolated. The closest phylogenetic neighbor was Spirochaeta africana Z-7692(T) that shared a 16S rRNA gene sequence identity value of 90% with the novel strain and thus was only distantly related. A comprehensive polyphasic study including determination of the complete genome sequence was initiated to characterize the novel isolate. Cells of strain L21-RPul-D2(T) had a size of 0.2 - 0.25 × 8-9 μm, were helical, motile, stained Gram-negative and produced an orange carotenoid-like pigment. Optimal conditions for growth were 35°C, a salinity of 50 g/l NaCl and a pH around 7.0. Preferred substrates for growth were carbohydrates and a few carboxylic acids. The novel strain had an obligate fermentative metabolism and produced ethanol, acetate, lactate, hydrogen and carbon dioxide during growth on glucose. Strain L21-RPul-D2(T) was aerotolerant, but oxygen did not stimulate growth. Major cellular fatty acids were C14:0, iso-C15:0, C16:0 and C18:0. The major polar lipids were an unidentified aminolipid, phosphatidylglycerol, an unidentified phospholipid and two unidentified glycolipids. Whole-cell hydrolysates contained L-ornithine as diagnostic diamino acid of the cell wall peptidoglycan. The complete genome sequence was determined and annotated. The genome comprised one circular chromosome with a size of 3.78 Mbp that contained 3450 protein-coding genes and 50 RNA genes, including 2 operons of ribosomal RNA genes. The DNA G + C content was determined from the genome sequence as 51.9 mol%. There were no predicted genes encoding cytochromes or enzymes responsible for the biosynthesis of respiratory lipoquinones. Based on significant differences to the uncultured type species of the genus Spirochaeta, S. plicatilis, as well as to any other phylogenetically related

The chronic toxicity of molybdate to freshwater organisms. I. Generating reliable effects data

Energy Technology Data Exchange (ETDEWEB)

De Schamphelaere, K.A.C., E-mail: karel.deschamphelaere@Ugent.be [Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University (Belgium); Stubblefield, W. [Oregon State University, Department of Environmental and Molecular Toxicology, 421 Weniger Hall, Corvallis, OR 97331 (United States); Rodriguez, P. [Centro de Investigacion Minera y Metalurgica (CIMM), Santiago (Chile); Vleminckx, K. [Department for Molecular Biomedical Research, Ghent University (Belgium); Janssen, C.R. [Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University (Belgium)

2010-10-15

The European Union regulation on Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH) (EC, 2006) requires the characterization of the chronic toxicity of many chemicals in the aquatic environment, including molybdate (MoO{sub 4}{sup 2-}). Our literature review on the ecotoxicity of molybdate revealed that a limited amount of reliable chronic no observed effect concentrations (NOECs) for the derivation of a predicted no-effect concentration (PNEC) existed. This paper presents the results of additional ecotoxicity experiments that were conducted in order to fulfill the requirements for the derivation of a PNEC by means of the scientifically most robust species sensitivity distribution (SSD) approach (also called the statistical extrapolation approach). Ten test species were chronically exposed to molybdate (added as sodium molybdate dihydrate, Na{sub 2}MoO{sub 4}.2H{sub 2}O) according to internationally accepted standard testing guidelines or equivalent. The 10% effective concentrations (EC10, expressed as measured dissolved molybdenum) for the most sensitive endpoint per species were 62.8-105.6 (mg Mo)/L for Daphnia magna (21 day-reproduction), 78.2 (mg Mo)/L for Ceriodaphnia dubia (7 day-reproduction), 61.2-366.2 (mg Mo)/L for the green alga Pseudokirchneriella subcapitata (72 h-growth rate), 193.6 (mg Mo)/L for the rotifer Brachionus calyciflorus (48 h-population growth rate), 121.4 (mg Mo)/L for the midge Chironomus riparius (14 day-growth), 211.3 (mg Mo)/L for the snail Lymnaea stagnalis (28 day-growth rate), 115.9 (mg Mo)/L for the frog Xenopus laevis (4 day-larval development), 241.5 (mg Mo)/L for the higher plant Lemna minor (7 day-growth rate), 39.3 (mg Mo)/L for the fathead minnow Pimephales promelas (34 day-dry weight/biomass), and 43.2 (mg Mo)/L for the rainbow trout Oncorhynchus mykiss (78 day-biomass). These effect concentrations are in line with the few reliable data currently available in the open literature. The data

The chronic toxicity of molybdate to freshwater organisms. I. Generating reliable effects data

International Nuclear Information System (INIS)

De Schamphelaere, K.A.C.; Stubblefield, W.; Rodriguez, P.; Vleminckx, K.; Janssen, C.R.

2010-01-01

The European Union regulation on Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH) (EC, 2006) requires the characterization of the chronic toxicity of many chemicals in the aquatic environment, including molybdate (MoO 4 2- ). Our literature review on the ecotoxicity of molybdate revealed that a limited amount of reliable chronic no observed effect concentrations (NOECs) for the derivation of a predicted no-effect concentration (PNEC) existed. This paper presents the results of additional ecotoxicity experiments that were conducted in order to fulfill the requirements for the derivation of a PNEC by means of the scientifically most robust species sensitivity distribution (SSD) approach (also called the statistical extrapolation approach). Ten test species were chronically exposed to molybdate (added as sodium molybdate dihydrate, Na 2 MoO 4 .2H 2 O) according to internationally accepted standard testing guidelines or equivalent. The 10% effective concentrations (EC10, expressed as measured dissolved molybdenum) for the most sensitive endpoint per species were 62.8-105.6 (mg Mo)/L for Daphnia magna (21 day-reproduction), 78.2 (mg Mo)/L for Ceriodaphnia dubia (7 day-reproduction), 61.2-366.2 (mg Mo)/L for the green alga Pseudokirchneriella subcapitata (72 h-growth rate), 193.6 (mg Mo)/L for the rotifer Brachionus calyciflorus (48 h-population growth rate), 121.4 (mg Mo)/L for the midge Chironomus riparius (14 day-growth), 211.3 (mg Mo)/L for the snail Lymnaea stagnalis (28 day-growth rate), 115.9 (mg Mo)/L for the frog Xenopus laevis (4 day-larval development), 241.5 (mg Mo)/L for the higher plant Lemna minor (7 day-growth rate), 39.3 (mg Mo)/L for the fathead minnow Pimephales promelas (34 day-dry weight/biomass), and 43.2 (mg Mo)/L for the rainbow trout Oncorhynchus mykiss (78 day-biomass). These effect concentrations are in line with the few reliable data currently available in the open literature. The data presented in this

Characterization of biocenosis in the storage-reservoirs of liquid radioactive wastes of 'Mayak' PA

Energy Technology Data Exchange (ETDEWEB)

Pryakhin, E.; Tryapitsina, G.; Andreyev, S.; Akleyev, A. [Urals Research Center for Radiation Medicine - URCRM (Russian Federation); Mokrov, Y.; Ivanov, I. [Mayak PA (Russian Federation)

2014-07-01

cycle. In reservoir R-3 there was no small pelophylic mollusks either, 90% of zooplankton community was represented by rotifers, in zoo-benthos community there was no small pelophylic mollusks, in species composition of ichthyofauna there was no carnivorous species of fish. In reservoir R-17 ichthyofauna was completely absent, species diversity of phytoplankton was significantly reduced, zooplankton was represented only by rotifers, and zoo-benthos was represented only by gnat larvae. In reservoir R-9 there was no ichthyofauna; phytoplankton was almost a mono-culture of cyanobacteria Geitlerinema amphibium, zooplankton was almost a mono-culture of rotifers Brachionus calyciflorus or Hexartra fennic in different years. In all of the above mentioned reservoirs, the development of bacterial plankton was at the levels characteristic of the standing water bodies of this geographical zone. Document available in abstract form only. (authors)

Review on the acute Daphnia magna toxicity test – Evaluation of the sensitivity and the precision of assays performed with organisms from laboratory cultures or hatched from dormant eggs

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Persoone G.

2009-08-01

daphnids from lab cultures. The obvious advantages of Daphnia microbiotests over tests with Daphnias stemming from lab cultures have led to the worldwide use of these culture/maintenance free and low cost small-scale assays in both research and toxicity monitoring. The Daphnia microbiotest is in current use in several countries for toxicity testing in a regulatory framework, and recent calculations indicate that about 10 000 acute D. magna assays are now performed annually with neonates hatched from dormant eggs. The use of dormant eggs to obtain test organisms independently of stock culturing has recently also been accepted in international standards for toxicity testing. ISO standard 20665 (2008 related to the determination of chronic toxicity with Ceriodaphnia dubia, and ISO standard 20666 (2008 for the determination of the chronic toxicity with Brachionus calyciflorus in 48 h, both indicate that the assays can be conducted with organisms hatched from dormant eggs. On the basis of the extensive scientific evidence provided in this review that is justifiably supported by the two ISO methods mentioned above, the authors therefore recommend that the use of Daphnias hatched from dormant eggs should also be incorporated in national and international standards, as an alternative to the use of Daphnias taken from laboratory cultures.

Review on the acute Daphnia magna toxicity test – Evaluation of the sensitivity and the precision of assays performed with organisms from laboratory cultures or hatched from dormant eggs

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G. Persoone

2009-08-01

dormant eggs.The use of dormant eggs to obtain test organisms independently of stock culturing has recently also been accepted in international standards for toxicity testing. ISO standard 20665 (2008 related to the determination of chronic toxicity with Ceriodaphnia dubia, and ISO standard 20666 (2008 for the determination of the chronic toxicity with Brachionus calyciflorus in 48 h, both indicate that the assays can be conducted with organisms hatched from dormant eggs.On the basis of the extensive scientific evidence provided in this review that is justifiably supported by the two ISO methods mentioned above, the authors therefore recommend that the use of Daphnias hatched from dormant eggs should also be incorporated in national and international standards, as an alternative to the use of Daphnias taken from laboratory cultures.