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At least 307 records · Page 17Linked to original sources
PubMed2001

Individual and population variation in invertebrates revealed by Inter-simple Sequence Repeats (ISSRs).

PCR-based molecular markers are well suited for questions requiring large scale surveys of plant and animal populations. Inter-simple Sequence Repeats or ISSRs are analyzed by a recently developed technique based on the amplification of the regions between inverse-oriented microsatellite loci with oligonucleotides anchored in microsatellites themselves. ISSRs have shown much promise for the study of the population biology of plants, but have not yet been explored for similar studies of animals. The value of ISSRs is demonstrated for the study of animal species with low levels of within-population variation. Sets of primers are identified which reveal variation in two aphid species, Acyrthosiphon pisum and Pemphigus obesinymphae, in the yellow fever mosquito Aedes aegypti, and in a rotifer in the genus Philodina.

Aedes↗
PubMed2004

Effects of advanced oxidation processes (AOPs) on the toxicity of a mixture of pharmaceuticals.

The possibility of applying main AOP techniques, namely ozonation, H2O2/UV photolysis and TiO2 photocatalysis to provide a significant reduction of toxicity of pharmaceutical mixtures has been evaluated. For the preparation of the mixture six pharmaceuticals were chosen among those found at highest concentrations in Sewage Treatment Plant effluents, namely carbamazepine, clofibric acid, diclofenac, sulfamethoxazole, ofloxacin and propranolol. The blue-green alga Synechococcus leopoliensis and the rotifer Brachyonus calyciflorus were utilised to assess the toxicity of the mixtures after AOP treatments. All the toxicity tests were performed using chronic standardized bioassays. The best results were obtained with ozonation. With this type of treatment a complete removal of mixture toxicity on S. leopolensis was obtained even after the shortest time of application (1 min). The ozonation treatment leads also to removal of all the pharmaceutical mixture toxicity on B. calyciflorus, by applying the oxidizing agent for at least for 2 minutes.

Animals↗
PubMed2004

[Interspecific interaction between Moina mongolica and Brachionus plicatilis].

In a laboratory experiment, Moina mongolica and Brachionus plicatilis were polycultured at four relatively inoculating densities, i.e., 0.06/0.30, 0.10/0.30, 0.30/0.30 and 0.60/0.30 (ind x ml(-1)/ind x ml(-1)), while M. mongolica monocultured at 0.06, 0.10, 0.30 and 0.60 ind x ml(-1) and B. plicatilis at 0.30 ind x ml(-1) were used as the control. Interspecific interference did exist between M. mongolica and B. plicatilis when these two species coexisted in a microcosm. In the polycultured microcosms, depressed population density of M. mongolica resulted from the coexistence of B. plicatilis, and M. mongolica maintained at extremely low density. In opposite, M. mongolica had negligibly negative influence on the population of B. plicatilis. Further experiment showed that the mortality of M. mongolica deprived of food for 120 h was 100%, while 90% of B. plicatilis survived after 144 h of food deprivation. The relatively strong capacity of B. plicatilis in tolerating starvation may be one of the important reasons for it wins the competition against M. mongolica.

Animals↗
PubMed2004

[Effect of temperature and food concentration on the population dynamics of three Brachionus calyciflorus strains].

Effects of temperature (20 degrees C, 25 degrees C, 30 degrees C) and food concentration (1.5, 3.0, 6.0, 9.0 x 10(6) cells x ml(-1)) on the population dynamics of Brachionus calyciflorus of Qingdao, Wuhu and Guangzhou strains were studied by means of individual culture. The result showed that the temperature was an important factor affecting generation time and intrinsic rate of population increase. With rising of temperature, the intrinsic rate of population increase increased, but generation time decreased. There were significant effects of food concentration on life expectancy and average lifespan. The effect of strain on net reproductive rate, generation time, life expectancy and average lifespan was also significant. Net reproductive rate, generation time, life expectancy, and average lifespan of Guangzhou strain was all the maximum, and that of Wuhu strain minimum among the three strains. The rotifers fed on the algae at the concentration of 3.0 x 10(6) cells x ml(-1) had the longest life expectancy and average lifespan, but those at 9.0 x 10(6) cells x ml(-1) had the shortest. Net reproductive rate, generation time, gross reproductive rate, life expectancy, and average lifespan of the three strains decreased linearly with the rise of temperature, except for the net reproductive rate of Guangzhou strain, while the intrinsic rate of population increase of all the three strains and gross reproductive rate of Guangzhou strain increased linearly with the rise of temperature. The relationships between all the life history parameters of Qingdao and Guangzhou strains and food concentration were all curvilinear, however, those between generation time, average lifespan, and life expectancy of Wuhu strain and food concentration could all be described by linear regression.

Animals↗
PubMedDate not supplied

Nitrogen and photosynthetic function of hermatypic corals. Oxygen exchange of Stylophora pistillata coral under artificial feeding.

The change of Stylophora pistillata coral photosynthetic function (oxygen exchange and biomass of symbionts) under starvation and food enrichment was studied to understand the role of heterotrophy in nitrogen supplements of zooxanthellae. The starvation caused the decrease of frequency of zooxanthellae cells division in 7-10 times. The number of degraded algae cells increased in same proportion and, as a result, the density of zooxanthellae in corals decreased about two times during one-two weeks. Under starvation corals kept their photosynthetic capacity at the level of corals in situ by means of enhancing the zooxanthellae gross photosynthesis. The respiration rate of coral had tendency to increase and the dry mass of polyp tissue to decrease. Under artificial feeding which was following starvation the zooxanthellae density increased in 1.5-2 times, and particular food caused more intensive accumulation of zooxanthellae comparing to dissolved inorganic ammonium. The feeding regime did not affect dry mass of polyp tissue and chlorophyll content as well as respiration and gross productivity of the corals. The conclusion about high effectiveness of particular feeding for supplying symbiotic algae with nitrogen was made and trophic status of zooxanthellae in hospite was determined as unlimited by nitrogen.

Animals↗
PubMed2005

[Effects of Branchionus calyciflorus culture media filtrate on Microcystis aeruginosa, Scenedesmus obliquus and Chlorella vulgaris colony formation and growth].

To examine the possible information transfer by chemicals between zooplankton and algae, this paper studied the effects of Brachionus calyciflorus culture media filtrate on the colony formation and growth of Microcystis aeruginosa, Scenedesmus obliquus and Chlorella vulgaris. The results showed that the test filtrate could significantly promote the colony formation and population growth of S. obliquus, while no significant effect was observed on M. aeruginosa and C. vulgaris. The induced colony formation of S. obliquus increased its resistance to grazing, and thus, reduced the risk of its being grazed, which could be viewed as a kind of inducing defense. The accelerated growth of C. vulgaris and the toxin production of M. aeruginosa could also be interpreted as a defense mechanism against grazing. It maybe concluded that M. aeruginosa, S. obliquus and C. vulgaris could adopt different ecological strategies to resist the potential grazing by rotifer B. calyciflorus, and thus, to keep their population on a certain scale.

Animals↗
PubMed2005

[Effects of glyphosate on life histroy characteristics of freshwater rotifer Brachionus calyciflorus].

The life table study on the life history characteristics of freshwater rotifer Brachionus calyciflorus under effects of different concentrations glyphosate showed that glyphosate had significant effects on the embryonic developmental time, duration of juvenile and reproductive periods, average lifespan, net reproductive rate, and intrinsic population increasing rate of the rotifer. The embryonic developmental time was significantly lengthened when exposed to 3 and 8 mg x L(-1) glyphosate, the juvenile period began to be lengthened significantly when exposed to 3 mg x L(-1) glyphosate, while the net reproductive rate and intrinsic population increasing rate decreased significantly when the rotifer was exposed to 8.00 and 10.50 mg x L(-1) glyphosate, respectively. Among all the parameters, intrinsic population increasing rate was the most sensitive parameter which could be used in monitoring the effects of glyphosate on the life history characteristics of B. calyciflorus.

Animals↗
PubMedDate not supplied

[Evolution of rotifer population dynamics in a heterogeneous habitat: mathematical modeling].

We present the results of mathematical modeling of a rotifer species inhabiting two coupled habitats with different environmental conditions. We use the modified Consensus model and show that the exchange between the habitats can lead to chaotization of originally regular plankton dynamics and synchronization of plankton biomass oscillations. As a result, the invasion of a chaotic regime takes place.

Animals↗
PubMed2005

[Advances in research effects of temperature fluctuation on aquatic fauna].

This paper reviewed the researches on the effects of diurnal temperature fluctuation on aquatic fauna, including the test species involved, design of thermal regimes, growth responses of aquatic fauna to various fluctuated temperature, and growth-promotion mechanisms of temperature fluctuation. The problems existed in related researches and the application perspectives in the future were also highlighted.

Animals↗
PubMed2005

[A comparative study on feeding intensity of two rotifer Brachionus calyciflorus strains].

The study on the feeding intensity and its relationships with food concentration, food quality and cultural duration of Guangzhou and Wuhu Brachionus calyciflorus strains showed that the filtration and ingestion rates of the rotifers decreased with their increasing cultural duration. Within 20 hours, there was a curvilinear relationship between the filtration rate of both the two strains and food concentration, but a linear relationship between the ingestion rate and food concentration. The filtration rate of Guangzhou and Wuhu strains was 0.0029 +/- 0.0001 ml x ind. (-1) x h(-1) and 0.0039 +/- 0.0008 ml ind. (-1) x h(-1), respectively, when fed on Chlorella pyrenoidosa, which were higher than fed on the other two types of food. The ingestion rate of Guangzhou strain fed on Chlorella pyrenoidosa (0.3992 x 10(4) +/- 0.00850 x 10(4) cell ind. (-1) x h(-1)) was higher than that fed on Scenedesmus obliquus (0.1670 x 10(4) +/- 0.0370 x 10(4) cell x ind.(-1) x h(-1)), but each of them was similar with that on mixed algae. The ingestion rate of Wuhu strain was not significantly affected by food type. The filtration and ingestion rates between the two strains differed with food concentration, food type and culture duration.

Animals↗
PubMed2006

[Storage and diurnal change of organic carbon pools in rotifer-culturing pond ecosystem].

This paper studied the storage and diurnal change of various organic carbon pools in two rotifer (Brachinus plicatilis) -culturing ponds with different models in Panjin Photosynthesis Fisheries Limited Company, Dawa County, Liaoning Province from May to June 2001. The results indicated that the mean storage of particulate organic carbon (POC) and dissolved organic carbon (DOC) in static water pond was 5.69 +/- 2.90 mg x L(-1) and 24.56 +/- 2.12 mg x L(-1), and that in current water pond was 9.61 +/- 3.17 mg x L(-1) and 24. 3 +/- 2.91 mg x L(-1), respectively. The ratio of total organic carbon (TOC), DOC and POC in current and static water ponds was 1:0.75: 0. 25 and 1:0.82:0.18, respectively. The pond with a high POC concentration was also with a high DOC content. The diurnal change of POC and DOC in current water pond was bigger than that in static water pond, i. e., the POC concentration in current water pond increased in daytime (from 5:00 to 17:00), while that in static water pond was more stable. The POC concentration in the two ponds was decreased from 15:00 to 23:00 but increased from 23:00 to next 5:00, and its peak time was 17:00 for current water pond and 5:00 for static water pond. The DOC/POC ratio in current water pond was increased gradually in daytime (from 5:00 to 17:00), while that in static water pond was decreased. The DOC/POC ratio in the two ponds was increased at night, and tended to dicline from 23:00 to next 5:00.

Animals↗
PubMed2006

[Morphological characteristics of resting eggs produced by different Brachionus calyciflorus].

In this paper, the Qingdao and Wuhu strains of Brachionus calyciflorus were cultured at 20 degrees C, 25 degrees C and 30 degrees C, and fed with 1.0 x 10(6) and 5.0 x 10(6) cells x ml(-1) of Scenedesmus obliquus. The morphological study of their produced resting eggs showed that at the two food concentrations, the resting eggs produced at 20 degrees C were the largest in length, width and volume, while those produced at 25 degrees C and 30 degrees C were the smallest. The effects of strain on the morphological characteristics of resting eggs also depended on food concentration. When the food concentration was 1.0 x 10(6) cells x ml(-1), the length, width and volume of the resting eggs produced by Wuhu strain and Qingdao strain were 156.00 microm, 99.95 microm and 12 269.11 microm3, and 145. 13 microm, 91.97 microm and 10 498. 19 microm3, respectively, while when the food concentration was 5.0 x 10(6) cells x ml(-1), the corresponding values were 155. 68 microm, 100.85 microm and 12 348.59 microm, and 156.63 microm, 98.04 microm and 12 054. 20 microm3, respectively. For test strains, only Wuhu strain showed a marked curvilinear correlation in the length, width and volume of its resting eggs with temperature. At the same temperature, the volumes of the resting eggs produced by both Qingdao and Wuhu strains were increased with increasing food concentration, with the exception that the resting eggs produced by Wuhu strain at 30 degrees C decreased with increasing food concentration.

Animals↗
PubMed2006

A study of the microbial quality and organoleptic properties of ophthalmic preparations obtained from traditional medical practitioners in South Western Nigeria.

Twenty eight samples of traditional ophthalmic preparations were obtained from various traditional medical practitioners in the South Western states of Nigeria over a one-year period. They were examined for sterility, clarity, presence of particulate contamination and pH. All of them were found to be contaminated with bacteria to the order of 2.00 x 10(6) to 1.60 x 10(11) colony forming units/ml, with Pseudomonas species and other potential pathogens such as Staphylococcus aureus, Yersinia enterocolita, Micrococcus varians and others being isolated from these preparations. A rotifer Rotaria rotatoria, at the adult stage, was also isolated from one sample, this being an indication of gross faecal contamination. All the samples were also found to contain significant particulate contamination and pH values encountered varied over the range of 2.5-9.2. None of the samples was found to comply with official specifications and all of them may therefore be regarded as being potentially dangerous to the users.

Animals↗