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.2.2. Rather, we detect divergent selection among our two lineages in genes related to metabolism (lipid metabolism, metabolism of xenobiotics). Specific reactions of different clones of the same rotifer species to environmental conditions have been discussed and reported by other authors. Phylum: Rotifera Class: Monogononta Scientific Name: Brachionus Asexually budded medusae were collected from colonies and reared for three generations obtained by asexual budding of medusae. parameters. Body length is 180 - 570 µm, body width is 124 - 300 µm, posterolateral spines 0-115 µm, anterolateral dorsal spines 15 … competition; or (3) siblings distributions may be influenced by physical factors other than salinity. Salinities experienced by hydroid colonies had only minor effects on initial size, time to maturity, medusa budding, sexual production of planulae by medusae, and survival. This genus is recognized as a suitable organism for testing environmental and evolutionary hypotheses. All rights reserved. ) These two algal species were in size positioned symmetrically in the bell shaped curve around the optimal prey size for the rotifers. (marine type) as control. The small teeth on these two lobes move back and forth very quickly, and create a vortex. Brachionus plicatilis is between 0.2 and 0.6 mm long and belongs to the wheel animals (Rotifera). This vortex is both used for moving around, as for catching food: unicellular microalgae. Likewise, at 35 ppm the highest values of growth rate (K: 1.66) and yield (r: 129) correspond, followed by 25 ppm. B.plicatilis s. s. attained a higher population growth rate at low–medium salinities (5–20ppt) than at high salinities (25–40ppt). sized and transferred to new food daily. Self-cultivated food for the ARTIS-sea horses. Genetic divergence is impacted by many factors, including phylogenetic history, gene flow, genetic drift, and divergent selection. We describe species-diagnostic allozyme loci that can be used for rapid identification of these species. 3. The size of the genome of haploid '1C' genome sizes in the Complex species Brachionus plicatilis range from at least 0.056 to 0.416 pg. Rotifers are microscopic organisms that are recognized as animals despite their size, which typically ranges from 200-500 micrometers in length in most species (Baqai et al., 2000). Rotifers are the famous asexual. life history of B. plicatilis, the results cannot always be directly applied to larger cultures. The rotifer lost 0.22 day−1 when starved. … The processes that might be involved in the long periods of overlapping seasonal distributions of species which are potentially competitors are discussed. Three different mechanisms potentially account for the partial co-occurrence of sibling species: (1) siblings have differing salinity tolerances that partially overlap; (2) siblings physiological tolerances may be, 1. However, the limitations of this study may be alleviated when the data that different Brachionus clones always exhibited similar morphological, reproductive or physiological alterations in response to experimental selections are considered, A detailed study of the life history of the rotifer Brachionus plicatilis was done at 20 °C, 20 ppt salinity, and 90 mg Cl-1 food concentration. One group was associated with B. plicatilis-like strains, and the other group was associated with B. rotundiformis and B. ibericus. rotundiformis 6TOS) by measuring population growth rate (μ, day−1) and egg development time in response to salinity (5–60‰) and salinity fluctuations (≤ Δ40‰). The coexistence of five cryptic species of the rotifer species complex Brachionus plicatilis was investigated in four coastal Mediterranean ponds. Ingestion of Schizothrix was shown not to be required for enhancement of rotifer reproduction. By contrast, the competitor almost always decreased the density of B. calyciflorus. We tested with laboratory experiments the response of the pampean strain of B. plicatilis for two of its main stressors (conductivity and temperature). The similarity of the biodiversity and abundance of the micro-zooplankton was > 80% among two out of eight mass cultivation sites (C and D), while the remaining cultivation sites exhibited their own unique microzooplankton biodiversity characteristics. © 2008-2021 ResearchGate GmbH. Body length could be related to carbon by C(ngC)=1.06×10−4L(μm)2.74. Rotifers fed Isochrysis averaged 21 offspring per female, a 6.7 day reproductive period, a lifespan of 10.5 days and a mean length of 234 µm. nov. , is formally described and presented as a representative of the L4 clade. ID; 1824), var. Rotifer. females (73 ± 7 ind/mL), population density (354 ± 3 ind/mL) and specific growth rate (0.75 ± 0.01 / day) were obtained for the rotifers fed with freshwater Chlorella. Iranian Journal of Science and Technology. Due to the unique metabolic compounds and biochemical composition of A. platensis, this species is a strong candidate to utilize in many biotechnological applications such as human food supplements, pharmaceuticals, animal feed additives, omega- 3 fatty acids, essential amino acids, biofertilizer, and pigments [ 4, 14, 21, 23, 24 ]. NOELIA S. FERRANDO, MARÍA C. CLAPS, HERNÁN H. BENÍTEZ, NÉSTOR A. GABELLONE, Influence of temperature and conductivity on the life-history characteristics of a pampean strain of Brachionus plicatilis, Anais da Academia Brasileira de Ciências, 10.1590/0001-3765201820170455, 90, 2, (1431-1444), (2018). Rotifers were grown individually in culture plate wells (150 µl culture volume) and fed Isochrysis galbana Tahiti, Tetraselmis sp., Nannochloris atomus, or a 1:1 mixture (weight) of two of the algae. Brachionus calyciflorus also seems to be a cryptic species complex. Dunaliella salina with an ESD=7.7μm was considered to be the best food for B.plicatilis s. s. while Synechococcus appeared to be an inadequate food algae. in activated sludge from different WWTPS, as in this case. The rotifers were grown at temperature of 31 ± 1 ° C, pH 8.33 and were fed with a single dose of Saccharomyces cerevisiae (1 x 106 cells/ml). Enhancement of rotifer reproductive rate was not observed on a mixed diet of Chlorella and Dunaliella compared with a unialgal diet of Chlorella. A modern discussion of diversity in B. plicatilis began when two strains with differing morphological and ecological characteristics were recognised as the L (large) and S (small) types (Oogami, 1976). However, the highest number of rotifers in reproductive stage was observed at 25 ppm (96% of rotifers with eggs and a reproductive index value of 0.964). Maximum production was 81 080 rotifers/1 day −1.The size and growth rate of four different strains of B. The phytoplankton suspension was adjusted at the concentration which had been decided previously as the desirable cell concentration for population growth of the rotifers. It has a broad distribution in salt lakes around the world and has become a model system for studies in ecology and evolution. A total of 19 different parameters were compared. According to Yin, ... Salinity changes to higher and lower values resulted in a reduced percentage of mobile rotifers (Brachionus plicatilis), but only a small fraction of rotifers became immobilized after transferring to higher salinity [40]. and Thalassiosira fluviatilis (T.f.) Natural populations of planktonic rotifers are affected by salinity and food density, among other stressors. (LPU-2), Chaetoceros sp. The maintenance food concentration was 1.02 ppm (R.b. Brachionus plicatilis is a euryhaline (tolerate a wide range of salinity) rotifer in the Family Brachionidae, and is possibly the only commercially important rotifer, being raised in the aquaculture industry as food for fish larvae. Brachionus plicatilis occurs in seas and oceans throughout the world, and has an important ecological role. The phenotypic traits of B. plicatilis included morphological phenotypic traits and behavioral phenotypic traits. the Spanish species, the tropical SS strains and the clusters previously described, remained unknown. Mixis in Brachionus plicatilis has been shown to be induced density dependent on the chemical signal. and Nitzschia clostelium as deficient. 12 150 ml−1). Moreover, competition among congeneric species limits the abundance of certain rotifers in ecosystems without spatial heterogeneity and environmental fluctuations. Here, we have used RNA-seq to explore expressed genetic diversity in B. calyciflorus s.s. in two mitochondrial DNA lineages with different phylogenetic histories and differences in thermotolerance. The increased production of planulae by medusae in low salinity indicated that they were transitioning to a benthic polyp life form more resistant to environmental stress. Biomass was inversely related to salinity for both species, and was significantly affected by competition in B. plicatilis. Brachionus plicatilis has been demonstrated to be a large cryptic species complex consisting of several different species. ABSTRACT. Fig. Egg development time was largely invariant with salinity except for B. plicatilis IOM and where rotifers were transferred from 30 to 60‰. Unialgal and mixed diets of the green alga Chlorella and the blue-green alga Schizothriz were compared. The lowest salinity level proved to be unfavourable for the population growth of B. plicatilis, but at higher salinity levels the growth was similar to that of controls (without competition), even in the presence of the competitor and at either food concentration. Brachionus plicatilis is between 0.2 and 0.6 mm long and belongs to the wheel animals (Rotifera). Rotifers fed Isochrysis averaged 21 offspring per female, a 6.7 day reproductive period, a lifespan of 10.5 days and a mean length of 234 µm. temperature. The euryhaline rotifers (Brachionus plicatilis species [sp.] Although many investigations have been carried out in the past, the relationships among Redundancy analysis (RDA) showed that there was a positive relationship between harmful species of Brachionus plicatilis and salinity, while the other two harmful species of Heterolobosean amoeba and Frontonia sp. The specific growth rate vs. food availability followed Monod kinetics with a maximum specific growth rate (Gmax)=0.49 day−1 and a Km=2.25 ppm (R.b. (LPU-1)/Chaetoceros sp. 3.4. This rotifer is one of the most useful foods for the intensive culture of marine larval fish and crustaceans (Lubzens et al. Undoubtedly, wide tolerances in B. plicatilis are adaptations to ephemeral and seasonally variable habitats. Characteristics of the rotifer Brachionus plicatilis that make it an attractive candidate as a tool in numerous re- search fields. We do not find adaptive divergence in established candidate genes for thermal adaptation. 2000;Sampaio and Bianchini 2002), and reproduction (e.g., Rippingale and Kelly 1995;Purcell et al. (LPU-3), Chaetoceros sp. Acute reduction in osmolarity of the medium resulted in a reduction in oxygen consumption and activity.4.4. 100 Venetia Kostopoulou et al. Spirulina (Arthrospira) platensis is the most commonly produced microalgae for commercial applications, such as nutraceuticals and feed. 2018), growth (e.g., Bøhle 1972;Pechenik et al. Comparison of expressed genes allows us to assess the impact of stressors on both expression and sequence divergence among disparate populations within a single species. On the day of the experiment, they were placed in a battery of four experimental groups (without acclimatization): control group (35 ppm), Treatment 1 (25 ppm), Treatment 2 (10 ppm) and Treatment 3 (7 ppm), N = 30 rot / ml. had a positive relationship with oxidation-reduction potential (ORP). An integrated approach using DNA taxonomy through COI and ITS1 markers, morphology, and ecology was used to confirm the identity of the new species. The production of neonates at. SUMMARY The body fluid osmolarity of individual rotifers was measured at 12 external concentrations ranging from 32 to 957 m-osmol/1. in the production of rotifer (Brachionus plicatilis) revealed that a 0.6 g L 1 FL significantly increased the rotifer population females carrying eggs, confirming that FL can be used efficiently for B. plicatilis production. We evaluated the effects of eight conductivity values from 1 to 17 mS.cm-1 and two temperatures … 2001). As China is the number one producer of Spirulina in the world, comprehensive information on the biodiversity and identity of microzooplanktons in Spirulina farms is essential for the long-term commercial viability of these farms. Cryptic species complex Brachionus plicatilis has long been divided into forms L- and S-type. Coexistence of cryptic rotifer species: Ecological and genetic characterisation of Brachionus plicat... Euryhaline Brachionus Strains (Rotifera) from Tropical Habitats: Morphology and Allozyme Patterns. After Isochrysis, the foods giving the highest growth, survival, and reproduction in decreasing order were Isochrysis + Nannochloris, Nannochloris, Isochrysis + Tetraselmis, Tetraselmis + Nannochloris, and Tetraselmis. In addition to coding sequence divergence, variation in gene expression may relate to variable heat tolerance, and can impose ecological barriers within species. (LPU-2), and Chaetoceros sp. After Isochrysis, the foods giving the highest growth, survival, and reproduction in decreasing order were Isochrysis + Nannochloris, Nannochloris, Isochrysis + Tetraselmis, Tetraselmis + Nannochloris, and Tetraselmis. ... 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. This, combined with its sensitivity to aquatic toxins, makes Brachionus plicatilis a highly suitable toxicological research subject in seawater. Rotifers were grown individually in culture plate wells (150 µl culture volume) and fed Isochrysis galbana Tahiti, Tetraselmis sp., Nannochloris atomus, or a 1:1 mixture (weight) of two of the algae. There were no alterations in somatic growth and swimming activity in B. calyciflorus when they were exposed to Asplanchna kairomones; however, we observed predator-induced –reduction of food intake in Brachionus. used in aquaculture as live food for larval fish, increasing temperature. Instead, we illustrate using a simple model that subtle differences in physiological tolerances may have important impacts on interactions between sibling species, which may in turn influence distributions. The match between temporal and spatial distribution and limnological conditions suggested ecological specialisation in some cases, although we found striking examples of extensive seasonal overlap. Furthermore, we identified the major grazers that appear to directly affect the productivity of Spirulina cultures. Rapid changes in salinity reduced growth rates, but net mortality occurred only in one treatment (100% mortality on transfer from 10 to 40‰). equivalent spherical diameter (ESD) of food algae, salinity and ESD×salinity had significant effects on the life history Transaction A, Science. This proves that the reaction to the type of food may differ in individuals of the same species originating from different environments, i.e. An own strain of Brachionus plicatilis from the Pacific Marine Park stock was used, which is located in the city of Puntarenas (9,97° N 84,82°W), Costa Rica at an altitude of 0 meters above the sea level. A few weeks ago, the ARTIS-Micropia laboratory started an experiment to breed Brachionus for the Aquarium. We indicate that several siblings are similarly euryhaline and tolerate salinity fluctuations. (LPU-3) for the cultivation of the rotifer Brachionus plicatilis was tested. Here, salinity’s impact on reproduction and survival of the hydrozoan Eleutheria dichotoma was investigated using laboratory-cultured individuals originating from Banyuls-sur-Mer (southern France) collected several decades ago. 5. Many studies using freshwater animals as models failed to find evidences as predicted from PSRs. It was further shown that the enhancing factor is a heat labile substance. We isolated Brachionus plicatilis and Brachionus calyciflorus from Salado River basin waterbodies and studied the demographic characteristics and competition between them at three salinity levels (0.75, 1.75 and 2.75 g L –1 NaCl) and at two food concentrations (0.1 × 10 6 and 0.5 × 10 6 cells mL –1 Chlorella vulgaris). rate, generation time and lifespan. Exposure of prey to predation risk usually leads to increased metabolism and decreased nutrient deposition as physiological stress responses (PSRs) of prey to their predators. Furthermore, although grazing sub-optimally, the rotifer grazed with an equal efficiency (60%) on two different algae Rhodomonas baltica (R.b.) Nevertheless, no studies have been carried out on specific salinity preferences of the L group species. Changes in the hydrogen-ion concentration had no detectable effect on either activity or metabolism.3.3. Indeed, different forms of osmoregulation can compromise many aspects of an organism's life-sustaining processes, including immune defense (e.g., Birrer et al. A rotifer surrounded by other marine microorganisms. High salinity (45) delayed asexual maturity, prevented sexual maturity in medusae, and led to lower survival and asexual reproduction rates. NOELIA S. FERRANDO, MARÍA C. CLAPS, HERNÁN H. BENÍTEZ, NÉSTOR A. GABELLONE, Influence of temperature and conductivity on the life-history characteristics of a pampean strain of Brachionus plicatilis, Anais da Academia Brasileira de Ciências, 10.1590/0001-3765201820170455, 90, 2, (1431-1444), (2018). The rotifer strains were differentially affected by salinity of medium, and Zbl and Ba strains had their maximum growth rates and population densities at 5 and 25 g/L, respectively. It appears that B. plicatilis is unable to tolerate the low concentrations that are frequently associated with acid water environ- ments and this is responsible for the restriction of this species to alkaline and brackish waters. Observations were made every 2–8 hr and rotifers were sized and transferred to new food daily. but also between geographical strains (Lubze. Treatments were established using a monoalgal and dialgal diet: Schizochytrium sp. Just like all other Rotifera, Brachionus has radar-like structures on its head. These results show that B. calyciflorus is more adversely affected than B. plicatilis by competition and high salinity, and explain why both species can coexist in eutrophic saline lowland rivers and pampean shallow lakes. The effects of isolated strains on the population growth and nutritional content (proteins, lipids, carbohydrates, and fatty acid composition) of B. plicatilis were evaluated. In this study, allozyme Distilled water was used to reduce salinity. Many studies have been conducted trying to explore the diversity within the complex, leading to the recognition of three major morphotypes: large (L), small-medium (SM), and small (SS). Does inducible defense mitigate physiological stress responses of prey to predation risk? A review of temperature and salinity effects on rotifer population dynamics is presented together with original data of these effects for three clones of Brachionus plicatilis.There is a clear relationship between temperature and the intrinsic rate of increase, r: an increase of temperature — within the natural environmental range — produces an exponential increase of … They were cultured in a medium with a saline concentration of 35 ppm and kept until the beginning of the experiment. The equivalent spherical diameter (ESD). commonly broad, but relatively small differences in tolerances differentiate distributions via interactions e.g. Lorica is smooth and transparent; appears as one piece. In the ARTIS Aquarium they are also used to feed the sea horses. Cluster analysis based on genetic distance allowed the 74 strains to Together with other wheel animals, Brachionus plicatilis forms a large part of the zooplankton, and is considered a staple food for larger organisms. It is believed by zoologists that the last sex of the Bdelloidea, a member of one group of animals, was about 80 million years ago.Members of Brachionus plicatilis It is not very sexually hungry, but it is mostly parthenogenetic. Given common broad salinity tolerances, it is unlikely that the differential distributions of sibling species are a direct result of physiological constraints. Here we present the description of a new species and the phylogenetic relationship within the genus Brachionus as revealed by morphometric … In this study, the natural Eight species of phytoplankton were evaluated in terms of nutritional effect on population growth of the rotifers as follows. Altitude and seasonal polymorphism of Auvergne, Central The size variation in rotifers of different populations geographic or temporally separated can be of genetic origin (Serra & Miracle, 1987; Walsh & Zhang, 1992). A temperature of 30 °C and a food concentration of 10 7 cells/ml of the alga Chlorella vulgaris were identified as the most suitable conditions for culture of this rotifer. From these daily counts, intrinsic rate of population growth and net reproduction rate were calculated as the indices for evaluating the nutritional effect of phytoplankton on population growth of the rotifers. The results show that the native microalgae of a North Pacific area mixed are an excellent source of nutrients for the growth and enhancement of the nutritional value of the rotifers, which can be used in the future to feed the larvae of marine fish more nutritionally and economically. The characteristics of various types are as follows: typical type - Posterior spines about one half or three quaters of body length, not so divergent. Responses differed significantly between siblings, although the broad trends were similar. This might be explained by the accumulation of damage with each generation, and/or by internal rhythms. Rotifers were grown individually in culture plate wells (150 µl culture volume) and fed Isochrysis ... Senescence can also be indirectly accelerated by shifting resource allocation from tissue maintenance and repairs to the metabolic costs of osmoregulation (Kozłowski 1992;Cichoń 1997). Rotifers are an important component of aquatic ecosystems, and genetic variation is essential to their ongoing adaptive diversification and local adaptation. They were cultured separately in many test tubes, each containing two individuals and were observed daily to obtain the survival rate and the fecundity, while food phytoplankton suspension was renewed daily. (LPU-3). 2). The carbon yield (specific growth rate vs. specific ingestion rate) was 0.29. Among twenty-three species that include 2 flagellates, 2 amoebae, 15 ciliates, and 4 rotifers, Brachionus plicatilis, Frontonia sp. The maximum number of ovigerous, Join ResearchGate to discover and stay up-to-date with the latest research from leading experts in, Access scientific knowledge from anywhere. En, ... Brachionus plicatilis is a filter feeding rotifer and often feeds on algae, and it has been considered as a cosmopolitan and euryoecious species [30]. Results generated using the 2 techniques, using data on laboratory cohorts of Daphnia pulex, were almost identical, as were results for a hypothetical D. pulex population whose sampling distribution was approximately normal. Budding rates decreased across the generations; however, planula production rates decreased in medium salinity but increased in low salinity. Results obtained from the classic Brachionus-Asplanchna model indicated that inducible defenses did not alleviate PSRs in B. calyciflorus, which were manifested as increased respiration and enhanced body molar ratios of carbon (C) to nitrogen (N) and C to phosphorus (P). the life history parameters. The rotifers were fed with five algal types (freshwater and marine Chlorella vulgaris, Nannochloropsis occulata, Isochrysis galbana and Scenedesmus obliquus) at three different salinities (5, 15 and 25 g/L) and their reproductive and growth parameters were assessed. 1.1. with equivalent spherical diameters of 6.5 μm and 12.9 μm, respectively, when they were offered one algae at a time. At this temperature, larvae become adults after 0.5 to 1.5 days and then females start to lay eggs Two Iranian strains of Brachionus rotifers were cultured under different food and salinity regimes. Sibling species were identified by analysis of the mitochondrial COI gene, and salinity responses were compared by regression analysis. Error bars that are not apparent are smaller than the symbols, Branch tree of Brachionus plicatilis s. s., B. rotundiformis and B. plicatilis Yamamoto's type based on biometric characters obtained using the between-groups linkage cluster method and squared Euclidean distance interval measurement. The small teeth on these two lobes move back and forth very quickly, and create a vortex. A detailed study of the life history of the rotifer Brachionus plicatilis was done at 20 °C, 20 ppt salinity, and 90 mg Cl-1 food concentration. One possible reason is that energetic costs during development of inducible defenses may lower the quantity of resources, which can be allocated to production of costly PSRs. Currently six species have been described and classified under these types and another nine taxa have been identified but not formally described.

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