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Atsushi Hagiwara - One of the best experts on this subject based on the ideXlab platform.
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complete mitochondrial genome of the euryhaline monogonont rotifer Brachionus paranguensis rotifera brachionidae
Mitochondrial DNA Part B, 2020Co-Authors: Beomsoon Choi, Atsushi Hagiwara, Duckhyun Kim, Jinsol Lee, Hee Jin Kim, Jaeseong LeeAbstract:The two complete mitochondrial genomes were sequenced from the euryhaline monogonont rotifer Brachionus paranguensis. The mitochondrial genome sequences were 11,603 bp and 12,901 bp in size, and th...
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complete mitochondrial genome of the freshwater monogonont rotifer Brachionus rubens rotifera brachionidae
Mitochondrial DNA Part B, 2020Co-Authors: Beomsoon Choi, Atsushi Hagiwara, Jinsol Lee, Hee Jin Kim, Young Hwan Lee, Erick Ochieng Ogello, Jaeseong LeeAbstract:The two complete mitochondrial genomes were sequenced from the freshwater monogonont rotifer Brachionus rubens. The genome sequences were 12,041 bp and 13,793 bp in size, and the gene order and con...
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The use of non-Brachionus plicatilis species complex rotifer in larviculture
Hydrobiologia, 2019Co-Authors: Atsushi Hagiwara, Helen S. MarcialAbstract:Due to the expanding world aquaculture production, the demand for high quality and quantity of fish larvae has also increased. Up to date, the bottleneck in larviculture is the stable and ample production of appropriate live food such as rotifers and copepods. Among rotifers, Brachionus plicatilis species complex, which encompasses 15 species with varied sizes ranging from 100 to 400 µm, is commonly used in most hatcheries. The use of B. plicatilis species complex ( B. plicatilis , B. koreanus , and B. rotundiformis ) in larviculture is reported in several review papers. In this review, we first described rotifer species not classified under B. plicatilis species complex, some of which are already used in larviculture, while some have high potential for use based on their characteristics, life history, and distribution. Rotifers, Brachionus angularis , Brachionus calyciflorus, and Proales similis , are described in detail in comparison with B. plicatilis species complex. Furthermore, we discussed some characteristics of rotifers which can affect their predation.
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the genome of the freshwater monogonont rotifer Brachionus calyciflorus
Molecular Ecology Resources, 2018Co-Authors: Changbum Jeong, Ikyoung Choi, Steven Declerck, Spiros Papakostas, Hyemin Kang, Daesik Hwang, Atsushi Hagiwara, Heum Gi ParkAbstract:Monogononta is the most speciose class of rotifers, with more than 2,000 species. The monogonont genus Brachionus is widely distributed at a global scale, and a few of its species are commonly used as ecological and evolutionary models to address questions related to aquatic ecology, cryptic speciation, evolutionary ecology, the evolution of sex and ecotoxicology. With the importance of Brachionus species in many areas of research, it is remarkable that the genome has not been characterized. This study aims to address this lacuna by presenting, for the first time, the whole‐genome assembly of the freshwater species Brachionus calyciflorus. The total length of the assembled genome was 129.6 Mb, with 1,041 scaffolds. The N50 value was 786.6 kb, and the GC content was 24%. A total of 16,114 genes were annotated with repeat sequences, accounting for 21% of the assembled genome. This assembled genome may form a basis for future studies addressing key questions on the evolution of monogonont rotifers. It will also provide the necessary molecular resources to mechanistically investigate ecophysiological and ecotoxicological responses.
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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
Comparative Biochemistry and Physiology Part D: Genomics and Proteomics, 2018Co-Authors: Steven Declerck, Atsushi HagiwaraAbstract: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.
S. Nandini - One of the best experts on this subject based on the ideXlab platform.
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comparative population dynamics of six brachionid rotifers rotifera fed seston from a hypertrophic high altitude shallow waterbody from mexico
Hydrobiologia, 2019Co-Authors: S S S Sarma, S. NandiniAbstract:In hypertrophic waterbodies, seston may be an important food for planktonic rotifers. Therefore, we hypothesized that seston in the hypertrophic waterbody (Lake Xochimilco, State of Mexico) supports high diversity and density of rotifers. To test this, we conducted growth experiments using six rotifer species (Brachionus bidentatus, Brachionus budapestinensis, Brachionus calyciflorus, Brachionus caudatus, Brachionus havanaensis and Plationus patulus) cultured on three seston size fractions (< 3, 3–15 and < 15 µm) for 15 days. The three fractions of seston contained 3.15, 6.30, and 9.45 μg C ml−1, respectively. The physical and chemical variables of the waterbody were fairly stable during the study period. Brachionus budapestinensis, B. calyciflorus and B. caudatus showed negative growth rates when cultured on seston size of 3–15 or < 15 µm, while B. bidentatus had negative r on < 3 µm particle size. Brachionus havanaensis and P. patulus were well adapted to feed on different sizes of seston, while B. budapestinensis and B. caudatus had higher growth on < 3 µm particle size. These results explain the high diversity and density of brachionid rotifers in this waterbody where they coexist by partitioning the available seston.
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Predation by Acanthocyclops americanus (Copepoda: Cyclopoida) in the hypertrophic shallow waterbody, Lake Albufera (Spain): field and laboratory observations
Hydrobiologia, 2019Co-Authors: Maria Rosa Miracle, S. Nandini, Eduardo VicenteAbstract:We quantified the predation of Acanthocyclops americanus from the shallow Mediterranean lake Albufera, using gut contents from field collections and laboratory feeding tests. For functional response studies, we used Brachionus plicatilis (at 6 concentrations, 400–4000 ind. 40 ml^−1) and Diaphanosoma mongolianum (at 2–20 ind. 40 ml^−1). Copepod feeding rates were also estimated using different proportions of rotifer prey and lake seston (0–67.5% of seston + 40 individuals of B. plicatilis ). Prey selection studies were conducted using five zooplankton species: Brachionus angularis, Brachionus plicatilis, Keratella tropica, Daphnia magna and Diaphanosoma mongolianum . Gut contents of field-collected adult Acanthocyclops contained filamentous algae and cyanobacteria and 16 zooplankton species ( Keratella cochlearis , unspined and spined forms, K. tropica, Brachionus plicatilis, Brachionus calyciflorus, Brachionus angularis, Brachionus variabilis, Asplanchna girodi, Polyarthra vulgaris, Synchaeta pectinata, Lepadella rhomboides, unidentified bdelloids , Alona rectangula, Chydorus sphaericus, Bosmina longirostris, D. magna, Ceriodaphnia dubia and copepod nauplii). When fed B. plicatilis or D. mongolianum , female A . americanus had higher prey consumption rates than males. Increased proportion of lake seston caused reduced consumption of brachionid prey. Our data suggest that A. americanus is omnivorous in nature.
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effects of selected pharmaceuticals ibuprofen and amoxicillin on the demography of Brachionus calyciflorus and Brachionus havanaensis rotifera
The Egyptian Journal of Aquatic Research, 2016Co-Authors: Brenda Karen Gonzalezperez, S S S Sarma, S. NandiniAbstract:Abstract 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.
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functional responses and feeding rates of mesocyclops pehpeiensis hu copepoda fed different diets rotifers cladocerans alga and cyanobacteria
Journal of Natural History, 2013Co-Authors: S S S Sarma, Rocio Fernandez, S. Nandini, Jorge Jimenezcontreras, G GarciagarciaAbstract:The feeding rates and functional responses of the copepod Mesocyclops pehpeiensis (adult females) were quantified using rotifers (Brachionus rubens, Brachionus havanaensis and Plationus patulus), cladocerans (Moina macrocopa, Ceriodaphnia dubia and Alona glabra), the green alga Chlorella vulgaris and the cyanobacterium Anabaena sp. as food. Mesocyclops pehpeiensis showed preferences for B. havanaensis, B. rubens and M. macrocopa when offered mixed rotifer and cladoceran species. Functional response curves showed increased consumption with increasing density of B. rubens in the medium until about 160 ind. 40 ml−1 of prey, and thereafter reached an asymptote. In general, regardless of water temperature, prey consumption was higher in the absence of algae in the medium. Consumption was highest at 35°C and declined with decreasing temperatures. Ingestion rates of the alga and cyanobacterium showed maxima at 25°C. Our results also indicated that M. pehpeiensis is an omnivore, consuming phytoplankton and zoopla...
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effect of algal and animal diets on life history of the freshwater copepod eucyclops serrulatus fischer 1851
Aquatic Ecology, 2007Co-Authors: S. Nandini, S S S SarmaAbstract:We studied the survivorship and reproduction of the cyclopoid Eucyclops serrulatus using four diet types: algae Chlorella vulgaris and Scenedesmus acutus separately and each together with the rotifer Brachionus havanaensis. We used equal biomass (3.9 mg C l−1) of C. vulgaris and S. acutus while B. havanaensis was offered at a density of 0.5 ind. ml−1. Regardless of the food type, the average lifespan of female E.␣serrulatus varied from 30 to 50 days, and those of males from 22 to 27 days. When Chlorella was offered alone as food, the female lifespan was 40% lower than when fed together with B. havanaensis. The number of nauplii per female (gross reproductive rate, GRR) was higher on Scenedesmus alone than on Chlorella alone or Chlorella and Scenedesmus offered with Brachionus. Thus, GRR was not significantly influenced by the presence of rotifer in mixed diet. Net reproductive rate (R o) and the rate of population increase (r) were similar at all the four food types. This implies that the diet-related differences of GRR did not ultimately translate to the differences in R o or r, due to the survivorship patterns of the adult females.
S S S Sarma - One of the best experts on this subject based on the ideXlab platform.
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comparative population dynamics of six brachionid rotifers rotifera fed seston from a hypertrophic high altitude shallow waterbody from mexico
Hydrobiologia, 2019Co-Authors: S S S Sarma, S. NandiniAbstract:In hypertrophic waterbodies, seston may be an important food for planktonic rotifers. Therefore, we hypothesized that seston in the hypertrophic waterbody (Lake Xochimilco, State of Mexico) supports high diversity and density of rotifers. To test this, we conducted growth experiments using six rotifer species (Brachionus bidentatus, Brachionus budapestinensis, Brachionus calyciflorus, Brachionus caudatus, Brachionus havanaensis and Plationus patulus) cultured on three seston size fractions (< 3, 3–15 and < 15 µm) for 15 days. The three fractions of seston contained 3.15, 6.30, and 9.45 μg C ml−1, respectively. The physical and chemical variables of the waterbody were fairly stable during the study period. Brachionus budapestinensis, B. calyciflorus and B. caudatus showed negative growth rates when cultured on seston size of 3–15 or < 15 µm, while B. bidentatus had negative r on < 3 µm particle size. Brachionus havanaensis and P. patulus were well adapted to feed on different sizes of seston, while B. budapestinensis and B. caudatus had higher growth on < 3 µm particle size. These results explain the high diversity and density of brachionid rotifers in this waterbody where they coexist by partitioning the available seston.
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effects of selected pharmaceuticals ibuprofen and amoxicillin on the demography of Brachionus calyciflorus and Brachionus havanaensis rotifera
The Egyptian Journal of Aquatic Research, 2016Co-Authors: Brenda Karen Gonzalezperez, S S S Sarma, S. NandiniAbstract:Abstract 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.
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functional responses and feeding rates of mesocyclops pehpeiensis hu copepoda fed different diets rotifers cladocerans alga and cyanobacteria
Journal of Natural History, 2013Co-Authors: S S S Sarma, Rocio Fernandez, S. Nandini, Jorge Jimenezcontreras, G GarciagarciaAbstract:The feeding rates and functional responses of the copepod Mesocyclops pehpeiensis (adult females) were quantified using rotifers (Brachionus rubens, Brachionus havanaensis and Plationus patulus), cladocerans (Moina macrocopa, Ceriodaphnia dubia and Alona glabra), the green alga Chlorella vulgaris and the cyanobacterium Anabaena sp. as food. Mesocyclops pehpeiensis showed preferences for B. havanaensis, B. rubens and M. macrocopa when offered mixed rotifer and cladoceran species. Functional response curves showed increased consumption with increasing density of B. rubens in the medium until about 160 ind. 40 ml−1 of prey, and thereafter reached an asymptote. In general, regardless of water temperature, prey consumption was higher in the absence of algae in the medium. Consumption was highest at 35°C and declined with decreasing temperatures. Ingestion rates of the alga and cyanobacterium showed maxima at 25°C. Our results also indicated that M. pehpeiensis is an omnivore, consuming phytoplankton and zoopla...
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effect of mixed toxic diets microcystis and chlorella on the rotifers Brachionus calyciflorus and Brachionus havanaensis cultured alone and together
Limnologica, 2009Co-Authors: Alejandro Federico Alvamartinez, S S S Sarma, Rocio Fernandez, Suresh NandiniAbstract:Abstract Brachionus havanaensis is a common planktonic rotifer sometimes found together with Brachionus calyciflorus in Microcystis-infected waterbodies in Mexico. Here, we evaluate the impact of mixed diets (dry weight basis, 0%, 25%, 50%, 75% and 100% Microcystis or Chlorella) on the growth of and competition between B. calyciflorus and B. havanaensis. In general, a higher proportion of Microcystis aeruginosa in the diet resulted in decreased population growth rate of both rotifer species. Whether grown separately or together, B. havanaensis was always numerically more abundant than B. calyciflorus, regardless of the proportion of Microcystis in the diet. However, when both species were grown together, the impact of M. aeruginosa in the diet had a more adverse effect on B. calyciflorus than on B. havanaensis. When grown alone, both rotifer species showed better population growth on a diet of 75% Chlorella and 25% Microcystis than either 100% Chlorella or Microcystis.
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effect of algal and animal diets on life history of the freshwater copepod eucyclops serrulatus fischer 1851
Aquatic Ecology, 2007Co-Authors: S. Nandini, S S S SarmaAbstract:We studied the survivorship and reproduction of the cyclopoid Eucyclops serrulatus using four diet types: algae Chlorella vulgaris and Scenedesmus acutus separately and each together with the rotifer Brachionus havanaensis. We used equal biomass (3.9 mg C l−1) of C. vulgaris and S. acutus while B. havanaensis was offered at a density of 0.5 ind. ml−1. Regardless of the food type, the average lifespan of female E.␣serrulatus varied from 30 to 50 days, and those of males from 22 to 27 days. When Chlorella was offered alone as food, the female lifespan was 40% lower than when fed together with B. havanaensis. The number of nauplii per female (gross reproductive rate, GRR) was higher on Scenedesmus alone than on Chlorella alone or Chlorella and Scenedesmus offered with Brachionus. Thus, GRR was not significantly influenced by the presence of rotifer in mixed diet. Net reproductive rate (R o) and the rate of population increase (r) were similar at all the four food types. This implies that the diet-related differences of GRR did not ultimately translate to the differences in R o or r, due to the survivorship patterns of the adult females.
Thi Kim Hue Nguyen - One of the best experts on this subject based on the ideXlab platform.
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low doses of the quaternary ammonium salt cetyltrimethylammonium bromide can be used as a pesticide to control grazers in microalgal cultures
Algal Research-Biomass Biofuels and Bioproducts, 2019Co-Authors: Bert Deruyck, Thi Kim Hue Nguyen, Ramasamy Praveenkumar, Koenraad MuylaertAbstract:Contamination of large-scale microalgal cultures by grazers can cause huge losses in biomass productivity. Here we propose the use of a quaternary ammonium salt cetyltrimethylammonium bromide (CTAB) to eradicate three types of commonly occurring grazers in microalgal cultures: the rotifer Brachionus, the ciliate Sterkiella and the flagellate Paraphysomonas. Low, premicellar doses (≤3 μM) of CTAB rapidly eradicated (within 1–2 d) all three tested grazers from microalgal cultures without significant losses (p < 0.05) in microalgal productivity. However, doses exceeding 5 μM also negatively affected microalgal growth. The optimal dose of CTAB that resulted in complete eradication of the grazers with minimum impact on microalgal productivity was 3 μM for Brachionus, 2 μM for Sterkiella and 3 μM for Paraphysomonas. Thus, being a readily available chemical, CTAB has the potential to be used as a fast-acting, low-cost control agent against a range of frequently occurring grazer types in large-scale microalgal cultures.
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Low doses of the quaternary ammonium salt Cetyltrimethylammonium bromide can be used as a pesticide to control grazers in microalgal cultures
'Elsevier BV', 2019Co-Authors: Deruyck Bert, Thi Kim Hue Nguyen, Praveenkumar Ramasamy, Muylaert KoenraadAbstract:© 2019 Elsevier B.V. Contamination of large-scale microalgal cultures by grazers can cause huge losses in biomass productivity. Here we propose the use of a quaternary ammonium salt cetyltrimethylammonium bromide (CTAB) to eradicate three types of commonly occurring grazers in microalgal cultures: the rotifer Brachionus, the ciliate Sterkiella and the flagellate Paraphysomonas. Low, premicellar doses (≤3 μM) of CTAB rapidly eradicated (within 1–2 d) all three tested grazers from microalgal cultures without significant losses (p < 0.05) in microalgal productivity. However, doses exceeding 5 μM also negatively affected microalgal growth. The optimal dose of CTAB that resulted in complete eradication of the grazers with minimum impact on microalgal productivity was 3 μM for Brachionus, 2 μM for Sterkiella and 3 μM for Paraphysomonas. Thus, being a readily available chemical, CTAB has the potential to be used as a fast-acting, low-cost control agent against a range of frequently occurring grazer types in large-scale microalgal cultures.status: publishe
Guido Persoone - One of the best experts on this subject based on the ideXlab platform.
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ecotoxicological studies with the freshwater rotifer Brachionus calyciflorus i conceptual framework and applications
Hydrobiologia, 1993Co-Authors: Colin R. Janssen, Ferrando Rodrigo, Guido PersooneAbstract:The use of the freshwater rotifer Brachionus calyciflorus as a test organism for ecotoxicological studies was examined. Changes in the feeding-, swimming behavior- and demographic characteristics of the rotifers exposed to increasing concentrations of copper (Cu) were studied and the relationships between the different test parameters and their ecological relevance evaluated.
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ecotoxicological studies with the freshwater rotifer Brachionus calyciflorus resource competition between rotifers and daphnids under toxic stress
Science of The Total Environment, 1993Co-Authors: M D Ferrando, Colin R. Janssen, E Andreu, Guido PersooneAbstract:Abstract This study examined the ability of the freshwater rotifer Brachionus calyciflorus to coexist with the large cladoceran Daphnia magna, and the effect of sublethal concentrations of copper on the competition between both species. Preliminary laboratory experiments showed that large Daphnia (> 1.2 mm) can kill and rapidly exclude the rotifer B. calyciflorus in mixed-species cultures. Brachionus populations were suppressed by Daphnia both through exploitative competition for shared, limited food resources and through mechanical interference. At a food concentration of 1 X 105 cells/ml of Nannochloris oculata, competition caused high mortality rates and decreased fertility in the rotifer populations (1000 ind/1), even at low Daphnia densities (40 ind/1). Daphnia removed increasingly disproportionate shares of the daily algal food supply, leaving the rotifer populations to gradually starve to extinction. In other experiments the effect of sublethal copper concentrations (2.5, 5.0, 12.0 and 20 μg/1) on the competition between both species was analysed. Short experiments (5 days) were carried out to study the effect of this toxicant on the rotifer populations with and without Daphnia. Changes in the competitive relationships between both organisms under toxic stress and the possible ecological consequences of these observations will be discussed.