Objective:To investigate the effect of rotifer internalization into snail tissue on the development of schistosomes.Methods:Susceptible laboratory-bred Biomphalaria alexandrina(B.alexandrina)snails were exposed to lab...Objective:To investigate the effect of rotifer internalization into snail tissue on the development of schistosomes.Methods:Susceptible laboratory-bred Biomphalaria alexandrina(B.alexandrina)snails were exposed to lab-maintained rotifers;Philodinaspp.,two weeks before and after being infected with Schistosoma mansoni(S.mansoni)miracidia.The consequent histopathological impact on snail tissues and cercarial biology were investigated before and after emergence from snails.Results:Contamination of B.alexandrinasnails with philodina,two weeks before miracidial exposure,was found to hinder the preliminary development of S.mansonicercariae inside the snail tissues.Furthermore,when snails were contaminated with rotifers two weeks post miracidial exposure;growth of already established cercariae was found to be retarded.The consequent influence of internalized rotifers within the snail tissue was clearly reflected on cercarial em ergence,activity and infectivity along the four weeks duration of shedding.In the present study,comparison of snail histopathological findings and altered cercarial biology observed between the experimental and control groups indicated that the rotifers may have affected the levels of snail's energy reservoirs,which eventually was found to have had an adverse impacton reproduction,growth and survival of the parasite within the snail host,coupled with its performance outside the snail.Conclusions:In future biological control strategies of schistosomiasis,ritifers should be considered as a parasitic scourge of humanity.展开更多
Planktonic rotifers were examined from April to October 2007 in two ponds created by sand extraction: Hubertus III (infrequently used for recreation)—pond I and Stawiki (commonly used for recreation)—pond II. The po...Planktonic rotifers were examined from April to October 2007 in two ponds created by sand extraction: Hubertus III (infrequently used for recreation)—pond I and Stawiki (commonly used for recreation)—pond II. The ponds are located within the protected Landscape Complex “Szopienice-Borki” in Silesian Upland (SW Poland). A total number of 58 taxa of rotifers were noted. The number of rotifer species and their densities were smaller in pond I than in pond II. In pond I, Polyarthra species were the most abundant, accounting for 48% of total rotifer density, whereas in pond II, Keratella cochlearis reached the highest density (accounting for 36% of total density). Analysis of variance (ANOVA) revealed a significant difference between communities of rotifers in species diversity (F = 5.88, p = 0.02) and species richness (F = 5.57, p = 0.03). The research proved that the pond commonly used for recreation (pond II) is characterized by a higher trophic state. Results of this study indicate that the methods and range of use of water bodies by humans have an important influence on the species richness and diversity of communities of planktonic rotifers.展开更多
STUDIES on the nutrition requirement of larval fish have made some progress abroad, but therehave been no reports on such studies in China. It was determined recently that n-3 HUFA (es-pecially 22: 6(n-3) (DHA) and 20...STUDIES on the nutrition requirement of larval fish have made some progress abroad, but therehave been no reports on such studies in China. It was determined recently that n-3 HUFA (es-pecially 22: 6(n-3) (DHA) and 20:5 (n-3) (EPA)) is essential for larval seafish growth. Thehigh content of DHA in seafish eggs and the low content of DHA in rotifers show that rotifersas live food cannot satisfy the n-3 HUFA requirement of larval seafish. Some scientists ob-展开更多
This study aims to establish a simple and efficient method for the mass culture of bdelloid rotifers,which is the basis for the application of bdelloid rotifers as biological manipulators to improve wastewater biologi...This study aims to establish a simple and efficient method for the mass culture of bdelloid rotifers,which is the basis for the application of bdelloid rotifers as biological manipulators to improve wastewater biological treatment performance.A common bdelloid rotifer,Habrotrocha sp.,in a wastewater biological treatment system was selected as the culture target.Rotifers fed on flour could reproduce faster than those fed traditional food such as Chlorella vulgaris or mixed bacteria.As a rotifer food,flour has the advantages of simple preparation,effortless preservation,and low cost compared to live Chlorella vulgaris or mixed bacteria,so it is more suitable for the mass culture of rotifers.The optimal rotifer culture conditions using flour as food were also studied.According to the experimental results,the recommended rotifer culture conditions arc a flour particle size of 1 a flour concentration of 6×10^(6) cell/mL,a temperature of 28℃,a pH level of 6.5 and salinity of 100-500 mg/L.In addition,the sludge volume index in the sequencing batch reactor(SBR)with the addition of cultured rotifers was 59.9 mL/g at the end of operation and decreased by 18.2%compared to SBR without rotifer,which indicates that the cultured rotifers still retained the ftinction of helping to improve sludge settling.This function may be related to the rotifer's role in inhibiting bacteria from producing loosely bound extracellular polymeric substances in the SBR.展开更多
The long-term data(1996-2021)on the summer abundances of the dominant zooplankton species(copepod Arctodiaptomus salinus(Daday,1885),rotifers Brachionus plicatilis(Müller,1786)and Hexarthra sp.)in saline Lake Shi...The long-term data(1996-2021)on the summer abundances of the dominant zooplankton species(copepod Arctodiaptomus salinus(Daday,1885),rotifers Brachionus plicatilis(Müller,1786)and Hexarthra sp.)in saline Lake Shira were used to analyze the response of zooplankton to air temperature and a change in the circulation regime of the lake:breakdown and reestablishment of meromixis.All groups of zooplankton responded to prolonged summer elevated temperatures by increasing their abundance.During the breakdown of the stable stratification of Lake Shira(2015-2016),zooplankton abundance increased on average by a factor of two and amounted to 9×10^(5)inds./m^(2)in the water column for copepods.That increase coincided with similar responses of other components of the lake’s mixolimnion ecosystem,whose biomasses increased approximately two-fold during that period.After the reestablishment of the meromixis,the abundance of zooplankton decreased to previous values.Thus,the abundance of zooplankton is largely determined by weather(the effect of temperature)and ecological factors(mixing regime).展开更多
While the fauna of Australian salt lakes is now well-known, seasonal phenological patterns of invertebrates are not. Two studies on saline lakes in southern Australia suggest the lakes fill in early winter and remain ...While the fauna of Australian salt lakes is now well-known, seasonal phenological patterns of invertebrates are not. Two studies on saline lakes in southern Australia suggest the lakes fill in early winter and remain at salinities characteristic for each lake during winter-spring before elevating and drying in summer. The fauna is dominated by crustaceans with few insects and all component species are present most of the time and randomly fluctuating in numbers. Lakes in the southern inland(mainly Lake Eyre) fill in summer, change little in salinity until near drying, and are dominated by crustaceans but have some insects. By contrast temporary salinas in the central inland fill episodically mainly in summer and then their salinity increases steadily as they dry without further rain. Their fauna is also dominated by crustaceans, but with a significant insect component and composition varies though the hydrological cycle. This study reports on an unusual winter fill in two central Paroo lakes and two pools, in which the crustacean fauna is similar to that in summer but insects are delayed till late spring and are not as common as in summer fills. It seems therefore that while insects are more restricted by medium and high salinities than crustaceans, they are also more restricted by cooler temperatures than crustaceans.展开更多
Trophi is only found in rotifers. The trophi has been used as a tool to identify species as well as an instrument for reconstructing the phylogeny of the organism, morphometric analysis, etc. Twelve species of rotifer...Trophi is only found in rotifers. The trophi has been used as a tool to identify species as well as an instrument for reconstructing the phylogeny of the organism, morphometric analysis, etc. Twelve species of rotifers of the genus Brachionus Pallas, 1766 were collected from different regions of the state of Aguascalientes, Mexico. An ultra-structure analysis was performed to examine the structural composition of the trophi of each species using scanning electron microscopy (SEM). The SEM observations show significant differences in the structural composition of each species, with the most considerable differences found in the trophi of B. budapestinensis.展开更多
The Mouanko mangrove is subjected to major anthropogenic activities such as agriculture, fishing and deforestation, hence information on Cladocerans and Rotifers amongst other aquatic organisms in order to monitor and...The Mouanko mangrove is subjected to major anthropogenic activities such as agriculture, fishing and deforestation, hence information on Cladocerans and Rotifers amongst other aquatic organisms in order to monitor and manage this ecosystem is vital. The aim of this work is to study the physicochemical parameters of the environment that influence the diversity and spatiotemporal distribution of Cladocerans and Rotifers in the mangrove waters of Mouanko. This study was carried out from November 2019 to October 2020 at 8 sampling stations. Both biological and physico-chemical sampling and analyses were done following standard recommendations. The results of the phyico-chemical analyses revealed that the waters of the Mouanko mangroves were slightly basic (7.64 ± 0.71 UC), moderately oxygenated (69.56% ± 14.29%) with low levels of nutrients [ NO <sup>-</sup>2</sub> (0. 06 ± 0.05 mg/L), NH<sup>+</sup>4</sub> (0.39 ± 0.3 mg/L) and PO<sup>3-</sup>4</sub> (up to 0.12 mg/L)] and high values of electrical conductivity (up to 6531.04 μS/cm), salinity (up to 3.71‰). 15 species of Cladocerans and 30 species of Rotifers were identified accounting for a total abundance of 612 ind/L. The species richness was higher in freshwater influenced zones (40 taxa) compared to marinewater influenced zones (17 taxa). Among these species, the Cladocera, Penilia avirostris was the most abundant in marinewater influenced zones (84 ind/L) while the Rotifer, Keratella tecta was the most abundant in freshwater influenced zones (64 ind/L). Shannon-Weaver’s diversity and Pielou’s equitability indices indicated that freshwater influenced zones host a diverse community with a tendency towards equi-partition of species while marinewater influenced zones revealed the opposite. The low levels of organic pollution indicator variables recorded and the high diversity of the freshwater influenced zones population studied attested to the low level of anthropization in this environment. High salinity and electrical conductivity values influence the distribution of these organisms.展开更多
To explore the size-dependent responses of zooplankton to submerged macrophyte restoration, we collected macrophyte, zooplankton and water quality samples seasonally from a subtropical shallow lake from 2010 to 2012. ...To explore the size-dependent responses of zooplankton to submerged macrophyte restoration, we collected macrophyte, zooplankton and water quality samples seasonally from a subtropical shallow lake from 2010 to 2012. Special attention was given to changes in rotifers and crustaceans(cladocerans and copepods). The rotifers were grouped into three size classes(<200 μm, 200 μm–400 μm, >400 μm) to explore their size-related responses to macrophyte restoration. The results showed that during the restoration, the annual mean biomass and macrophyte coverage increased significantly from 0 to 637 g/m^2 and 0 to 27%, respectively. In response, the density and biomass of crustaceans and the crustacean-to-rotifer ratio increased significantly, while the rotifer density decreased significantly. Moreover, rotifers showed significant sizedependent responses to macrophyte restoration. Specially, rotifers <400 μm were significantly suppressed, while those ≥400 μm were significantly encouraged. Overall, the population of large-sized zooplankton tended to boom, while that of small rotifers was inhibited during macrophyte restoration. Redundancy analysis(RDA) revealed positive correlations between macrophytes and crustaceans, rotifers and COD or Chl-a, but negative correlations between macrophytes and COD or Chl-a, and between crustaceans and Chl-a. Moreover, the results indicate that increased predation on phytoplankton by large-sized zooplankton might be an important mechanism for macrophyte restoration during development of aquatic ecosystems, and that this mechanism played a very important role in promoting the formation of a clear-water state in subtropical shallow lakes.展开更多
The composition and distribution of benthic, periphytic and planktonic rotifers in different habitatsin Krottensee were investigated. Sixty-five rotifer taxa were identified, their relative abundance estimated. Classi...The composition and distribution of benthic, periphytic and planktonic rotifers in different habitatsin Krottensee were investigated. Sixty-five rotifer taxa were identified, their relative abundance estimated. Classification of the data set by cluster analysis allowed the recognition of distinct habitat groupe con-fined to acid bog ponds, macrophytes, sediments, and open water. Five groups of rotifer taxa were identifiedon the basis of their habitat preferences and the occurrence of the taxa. Highest diversities were found onmacrophytes and in acid bog ponds.展开更多
Maternal eff ects are one of the most interesting topics in evolutionary ecology as they can aff ect the rate of evolution and population dynamics by phenotypic manipulation of off spring related to fi tness. At prese...Maternal eff ects are one of the most interesting topics in evolutionary ecology as they can aff ect the rate of evolution and population dynamics by phenotypic manipulation of off spring related to fi tness. At present, studies examining the interaction between maternal environment eff ects and maternal age (birth order) eff ects are scarce. We designed an experiment to reveal whether environmentally induced maternal manipulation works equally on off spring across birth orders in rotifer Brachionus calycifl orus. In the experiment, newborn amictic mothers (F0) were cultured parallelly in low (LD) and high (HD) population density. Off spring (F1) of young (YF0) and old (OF0) mothers in both LD and HD groups were cultured under a crowded condition and the mixis ratios of both F1 and F2 were examined. Results show that F1 from HD-YF0 had a signifi cantly higher mixis ratio and those amictic ones produced daughters (F2 ) with higher mixis ratio in response to crowding than those from HD-OF0. In contrast, no such diff erences among F1 siblings were found in the LD-F0 group. Therefore, the eff ect of maternal age on the sexual propensity of the off spring can be aff ected independently by the maternal population density.展开更多
Of more than 90 rotifer taxa found in Denghu Lake and its nearby ponds in Wuhan, Hubei,the following were new to science: Brachionus angularis pyriformis, B. a. donghuensis, B. (Schizocerca) brevispina, Anuraeopsis fi...Of more than 90 rotifer taxa found in Denghu Lake and its nearby ponds in Wuhan, Hubei,the following were new to science: Brachionus angularis pyriformis, B. a. donghuensis, B. (Schizocerca) brevispina, Anuraeopsis fissa donghuensis, A. f. pseudonavicula, Mytilina ventralis Wuhanensis and Trichocerca similis strumosa.展开更多
A new freshwater rotifer Cephalodella changdensis sp.nov.discovered in two locations in Changde,Hunan,China,is described morphologically.The new species is characterized by body shape moderately elongate,double eyespo...A new freshwater rotifer Cephalodella changdensis sp.nov.discovered in two locations in Changde,Hunan,China,is described morphologically.The new species is characterized by body shape moderately elongate,double eyespots frontally,toes conical and almost straight,about one fourth of total length,trophi type B(classification after Wulfert,1937),rami asymmetrical with a pair of long alulae,fulcrum inverted T-shaped(ventral/dorsal view)with dorsally directed distal projection(lateral view),and manubria asymmetrical,left one slightly longer and stronger,with J-shaped or crutch-shaped posterior ends.展开更多
[Objective]This paper was to research the water purification mechanism of Ipomoea aquatica and its correlation with algae and rotifer. [Methods]Taking I. aquatica as the test material,Chlorella vulgaris,Scenedesmus ob...[Objective]This paper was to research the water purification mechanism of Ipomoea aquatica and its correlation with algae and rotifer. [Methods]Taking I. aquatica as the test material,Chlorella vulgaris,Scenedesmus obliquus,Microcystis aeroginosa and rotifer Adineta vaga with different densities were added to the hydroponics nutrients solutions of I. aquatica by the hydroponic ecological simulation method. The growth characteristics of I. aquatica,changes of microbial populations and the consumption status of nutrients in the nutritional solution were determined. And the interactions between the plant and the microbial populations were researched. [Results]When I. aquatica seedlings grew to a certain stage,growth of principal root stopped; while the lateral roots emerged greatly; and the nutrition absorption efficiency enhanced. As the inoculation concentration of C. vulgaris increased,root length of I. aquatica increased relatively great due to the competition for nutrients. The competition and allelopathy of M. aeroginosa and S. obliquus restricted the development of root system of I. aquatica. The grazing pressure of Chlorella vulgaris had little effects on M. aeroginosa,but restricted the rapid growth of S. obliquus. [Conclusions]This research provided data support for the application of fish-shrimp-vegetable aquaculture system.展开更多
Coral trout Plectropomus leopardus is a high-economical value of marine fish commodity.So,the larviculture for this species should be performed in hatchery scale for their sustainability.One of the important thing in ...Coral trout Plectropomus leopardus is a high-economical value of marine fish commodity.So,the larviculture for this species should be performed in hatchery scale for their sustainability.One of the important thing in larval stage is hormonal mechanisms.Thyroid hormone is known plays an important role in the metamorphosis of marine fish larvae.The source of that hormone is assumed derived from zooplankton as their live feeds.The live feeds commonly used for marine fish larvae in hatchery are zooplankton copepods and rotifers.The purpose of this research to determine the influence of feeding copepods and rotifers on thyroid hormone profile activity,consisted of triiodothyronine(T3)and thyroxine(T4),related to the metamorphoses of coral trout larvae.The research was conducted using three feeding schemes:copepods(A),copepods-rotifers(B),and rotifers(C).It was done for 50 Days After Hatching(DAH).The results showed that larvae from treatment(A)and(B)achieved the highest level of T3 and T4 earlier at 30 DAH,which indicated that both of those larvae have entered the metamorphosis stage earlier.On the other hand,larvae from treatment(C)achieved it and entered the metamorphosis stage later at 40 DAH.In addition,iodine levels in the copepods were significantly higher than those of in rotifers(P<0.05).Based on this research,live feeds copepods and rotifers have effect on thyroid hormone activity.Copepods have better potential in accelerating the metamorphosis achievement of coral trout larvae with the fact that they have higher iodine content.展开更多
Copepods are the main natural food of many marine fish larvae.However,enriched rotifers are the most commonly used live prey in larval rearing.Impacts on the feeding behavior,growth,survival,and fatty acid(FA)composit...Copepods are the main natural food of many marine fish larvae.However,enriched rotifers are the most commonly used live prey in larval rearing.Impacts on the feeding behavior,growth,survival,and fatty acid(FA)composition of winter flounder larvae fed with copepods and rotifers were determined and compared to the FA composition of the two live prey.Nauplii of Eurytemora spp.and Acartia sp.,two of the main species of copepods present in the St.Lawrence estuary,showed no significant differences in their essential fatty acid profiles,suggesting similar nutritional quality.Thus,only Eurytemora herdmani was compared to enriched rotifers in this study.Copepod nauplii were characterized by higher levels of essential fatty acids,particularly docosahexaenoic acid(DHA)and eicosapentaenoic acid(EPA).The selective incorporation of essential fatty acids from diets in larval tissues(polar lipids)indicated that nauplii might better fulfill larval nutritional requirements for DHA than rotifers.Furthermore,larval behavior was modified according to the diet:larvae fed with nauplii spent more time swimming with no changes in the occurrence of hunting events.展开更多
We investigated rotifer community structure in the Backshore Wetland of the Expo Garden in Shanghai from September 2009 to August 2010.We identified 116 rotifer species,determined the dominant species and their relati...We investigated rotifer community structure in the Backshore Wetland of the Expo Garden in Shanghai from September 2009 to August 2010.We identified 116 rotifer species,determined the dominant species and their relationships with environmental factors,and community diversity indices.Polyarthra trigla was the most common species over the four seasons and proportionally most dominant in spring and autumn,whereas Cephalodella exigua and Keratella cochlearis were the most dominant species in winter and summer,respectively.There was seasonal variability in species numbers,with the highest numbers in summer,followed by autumn and winter.The mean annual density was 815±1346 ind./L and the biomass was 0.3649±0.4940 mg/L.There were significant differences between months:the highest density(2723±2926 ind./L)and biomass(0.7938±0.8197 mg/L)occurred in June,while the lowest density(238±271 ind./L)and biomass(0.0476±0.0429 mg/L)occurred in May.Canonical correspondence analysis(CCA)indicated that temperature,pH,nitrite nitrogen(NO2-N),and total phosphorus(TP)were the most important abiotic factors affecting rotifer distribution.Our research showed that the adaptability of the rotifers to temperature was the important factor.展开更多
The ecological impacts of urbanization and eutrophication on zooplankton communities in urban waterbodies have recently gained wide interest.Study findings vary across species and urban waterbodies.How the development...The ecological impacts of urbanization and eutrophication on zooplankton communities in urban waterbodies have recently gained wide interest.Study findings vary across species and urban waterbodies.How the development of such changes affects the variation of biotic assemblages has only been explored to a limited extent in tropical urban lakes.Spatial and temporal variations of zooplankton community structure in 11 urban waterbodies in the Klang Valley,Malaysia were investigated along trophic and urbanization gradients.Zooplankton and water quality samples were collected three times,between May and November 2017,from two different locations in each lake.All three main zooplankton groups(rotifera,copepoda,and cladocera)were recorded from the study areas throughout the sampling period.The zooplankton community structure,particularly with regard to rotifers and cladocerans,varied between lakes and seasons.Zooplankton diversity does not vary with lake size or distance from the city center but does vary with shoreline development index and urbanization impacts.The zooplankton populations were dominated by rotifers,mainly Brachionus angularis at all study sites during the study period followed by copepods and cladocerans.The total density of zooplankton was significantly highest(p<0.05)in the hypereutrophic lakes and during the dry season.Zooplankton diversity and rotifer species richness were negatively correlated with total phosphorus(TP).Diversity increased with urbanization and shoreline development,with rotifers as a potential bioindicator of trophic state in urban tropical lakes,due to their close relationship with TP.展开更多
Objective:To identify the presence of joint muscular and cholinergic systems in two freshwater rotifer species,Brachionus calyciflorus and Lecane quadridentata.Methods:The muscle actin fibers were stained with phalloi...Objective:To identify the presence of joint muscular and cholinergic systems in two freshwater rotifer species,Brachionus calyciflorus and Lecane quadridentata.Methods:The muscle actin fibers were stained with phalloidin-linked fluorescent dye,and acetylcholine was detected with Amplex Red Acetylcholine/Acetylcholinesterase Assay Kit,and then confocal scanning laser microscopy was used.Results:The musculature of Brachionus calyciflorus showed a pattern similar to other species of the same genus,while that of Lecane quadridentata was different from other rotifer genera described previously.The cholinergic system was determined by co-localization of both muscles and acetylcholine labels in the whole rotifer,suggesting the presence of neuromuscular junctions.Conclusions:The distribution pattern of muscular and acetylcholine systems showed considerable differences between the two species that might be related to different adaptations to particular ecological niches.The confirmation of a cholinergic system in rotifers contributes to the development of potential neuro-pharmacological and toxicological studies using rotifers as model organism.展开更多
基金Supported by Alexandria University Research Fund,Egupt(Gran 9522-2010)
文摘Objective:To investigate the effect of rotifer internalization into snail tissue on the development of schistosomes.Methods:Susceptible laboratory-bred Biomphalaria alexandrina(B.alexandrina)snails were exposed to lab-maintained rotifers;Philodinaspp.,two weeks before and after being infected with Schistosoma mansoni(S.mansoni)miracidia.The consequent histopathological impact on snail tissues and cercarial biology were investigated before and after emergence from snails.Results:Contamination of B.alexandrinasnails with philodina,two weeks before miracidial exposure,was found to hinder the preliminary development of S.mansonicercariae inside the snail tissues.Furthermore,when snails were contaminated with rotifers two weeks post miracidial exposure;growth of already established cercariae was found to be retarded.The consequent influence of internalized rotifers within the snail tissue was clearly reflected on cercarial em ergence,activity and infectivity along the four weeks duration of shedding.In the present study,comparison of snail histopathological findings and altered cercarial biology observed between the experimental and control groups indicated that the rotifers may have affected the levels of snail's energy reservoirs,which eventually was found to have had an adverse impacton reproduction,growth and survival of the parasite within the snail host,coupled with its performance outside the snail.Conclusions:In future biological control strategies of schistosomiasis,ritifers should be considered as a parasitic scourge of humanity.
文摘Planktonic rotifers were examined from April to October 2007 in two ponds created by sand extraction: Hubertus III (infrequently used for recreation)—pond I and Stawiki (commonly used for recreation)—pond II. The ponds are located within the protected Landscape Complex “Szopienice-Borki” in Silesian Upland (SW Poland). A total number of 58 taxa of rotifers were noted. The number of rotifer species and their densities were smaller in pond I than in pond II. In pond I, Polyarthra species were the most abundant, accounting for 48% of total rotifer density, whereas in pond II, Keratella cochlearis reached the highest density (accounting for 36% of total density). Analysis of variance (ANOVA) revealed a significant difference between communities of rotifers in species diversity (F = 5.88, p = 0.02) and species richness (F = 5.57, p = 0.03). The research proved that the pond commonly used for recreation (pond II) is characterized by a higher trophic state. Results of this study indicate that the methods and range of use of water bodies by humans have an important influence on the species richness and diversity of communities of planktonic rotifers.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39470562).
文摘STUDIES on the nutrition requirement of larval fish have made some progress abroad, but therehave been no reports on such studies in China. It was determined recently that n-3 HUFA (es-pecially 22: 6(n-3) (DHA) and 20:5 (n-3) (EPA)) is essential for larval seafish growth. Thehigh content of DHA in seafish eggs and the low content of DHA in rotifers show that rotifersas live food cannot satisfy the n-3 HUFA requirement of larval seafish. Some scientists ob-
基金This research was financially supported by the National Natural Science Foundation of China(Grant No.21777092).
文摘This study aims to establish a simple and efficient method for the mass culture of bdelloid rotifers,which is the basis for the application of bdelloid rotifers as biological manipulators to improve wastewater biological treatment performance.A common bdelloid rotifer,Habrotrocha sp.,in a wastewater biological treatment system was selected as the culture target.Rotifers fed on flour could reproduce faster than those fed traditional food such as Chlorella vulgaris or mixed bacteria.As a rotifer food,flour has the advantages of simple preparation,effortless preservation,and low cost compared to live Chlorella vulgaris or mixed bacteria,so it is more suitable for the mass culture of rotifers.The optimal rotifer culture conditions using flour as food were also studied.According to the experimental results,the recommended rotifer culture conditions arc a flour particle size of 1 a flour concentration of 6×10^(6) cell/mL,a temperature of 28℃,a pH level of 6.5 and salinity of 100-500 mg/L.In addition,the sludge volume index in the sequencing batch reactor(SBR)with the addition of cultured rotifers was 59.9 mL/g at the end of operation and decreased by 18.2%compared to SBR without rotifer,which indicates that the cultured rotifers still retained the ftinction of helping to improve sludge settling.This function may be related to the rotifer's role in inhibiting bacteria from producing loosely bound extracellular polymeric substances in the SBR.
基金Supported by the RFBR and Krasnoyarsk Krai Government and the Krasnoyarsk Regional Fund of Science(No.19-44-240002)supported by the State Assignment of the Ministry of Science and Higher Education of the RF(No.0287-2021-0019).
文摘The long-term data(1996-2021)on the summer abundances of the dominant zooplankton species(copepod Arctodiaptomus salinus(Daday,1885),rotifers Brachionus plicatilis(Müller,1786)and Hexarthra sp.)in saline Lake Shira were used to analyze the response of zooplankton to air temperature and a change in the circulation regime of the lake:breakdown and reestablishment of meromixis.All groups of zooplankton responded to prolonged summer elevated temperatures by increasing their abundance.During the breakdown of the stable stratification of Lake Shira(2015-2016),zooplankton abundance increased on average by a factor of two and amounted to 9×10^(5)inds./m^(2)in the water column for copepods.That increase coincided with similar responses of other components of the lake’s mixolimnion ecosystem,whose biomasses increased approximately two-fold during that period.After the reestablishment of the meromixis,the abundance of zooplankton decreased to previous values.Thus,the abundance of zooplankton is largely determined by weather(the effect of temperature)and ecological factors(mixing regime).
文摘While the fauna of Australian salt lakes is now well-known, seasonal phenological patterns of invertebrates are not. Two studies on saline lakes in southern Australia suggest the lakes fill in early winter and remain at salinities characteristic for each lake during winter-spring before elevating and drying in summer. The fauna is dominated by crustaceans with few insects and all component species are present most of the time and randomly fluctuating in numbers. Lakes in the southern inland(mainly Lake Eyre) fill in summer, change little in salinity until near drying, and are dominated by crustaceans but have some insects. By contrast temporary salinas in the central inland fill episodically mainly in summer and then their salinity increases steadily as they dry without further rain. Their fauna is also dominated by crustaceans, but with a significant insect component and composition varies though the hydrological cycle. This study reports on an unusual winter fill in two central Paroo lakes and two pools, in which the crustacean fauna is similar to that in summer but insects are delayed till late spring and are not as common as in summer fills. It seems therefore that while insects are more restricted by medium and high salinities than crustaceans, they are also more restricted by cooler temperatures than crustaceans.
文摘Trophi is only found in rotifers. The trophi has been used as a tool to identify species as well as an instrument for reconstructing the phylogeny of the organism, morphometric analysis, etc. Twelve species of rotifers of the genus Brachionus Pallas, 1766 were collected from different regions of the state of Aguascalientes, Mexico. An ultra-structure analysis was performed to examine the structural composition of the trophi of each species using scanning electron microscopy (SEM). The SEM observations show significant differences in the structural composition of each species, with the most considerable differences found in the trophi of B. budapestinensis.
文摘The Mouanko mangrove is subjected to major anthropogenic activities such as agriculture, fishing and deforestation, hence information on Cladocerans and Rotifers amongst other aquatic organisms in order to monitor and manage this ecosystem is vital. The aim of this work is to study the physicochemical parameters of the environment that influence the diversity and spatiotemporal distribution of Cladocerans and Rotifers in the mangrove waters of Mouanko. This study was carried out from November 2019 to October 2020 at 8 sampling stations. Both biological and physico-chemical sampling and analyses were done following standard recommendations. The results of the phyico-chemical analyses revealed that the waters of the Mouanko mangroves were slightly basic (7.64 ± 0.71 UC), moderately oxygenated (69.56% ± 14.29%) with low levels of nutrients [ NO <sup>-</sup>2</sub> (0. 06 ± 0.05 mg/L), NH<sup>+</sup>4</sub> (0.39 ± 0.3 mg/L) and PO<sup>3-</sup>4</sub> (up to 0.12 mg/L)] and high values of electrical conductivity (up to 6531.04 μS/cm), salinity (up to 3.71‰). 15 species of Cladocerans and 30 species of Rotifers were identified accounting for a total abundance of 612 ind/L. The species richness was higher in freshwater influenced zones (40 taxa) compared to marinewater influenced zones (17 taxa). Among these species, the Cladocera, Penilia avirostris was the most abundant in marinewater influenced zones (84 ind/L) while the Rotifer, Keratella tecta was the most abundant in freshwater influenced zones (64 ind/L). Shannon-Weaver’s diversity and Pielou’s equitability indices indicated that freshwater influenced zones host a diverse community with a tendency towards equi-partition of species while marinewater influenced zones revealed the opposite. The low levels of organic pollution indicator variables recorded and the high diversity of the freshwater influenced zones population studied attested to the low level of anthropization in this environment. High salinity and electrical conductivity values influence the distribution of these organisms.
基金Supported by the Major Science and Technology Program for Water Pollution Control and Treatment of China 12th Five-Year Plan(No.2012ZX07101007-005)the National Natural Science Foundation of China(Nos.51178452,51208498,51308530)
文摘To explore the size-dependent responses of zooplankton to submerged macrophyte restoration, we collected macrophyte, zooplankton and water quality samples seasonally from a subtropical shallow lake from 2010 to 2012. Special attention was given to changes in rotifers and crustaceans(cladocerans and copepods). The rotifers were grouped into three size classes(<200 μm, 200 μm–400 μm, >400 μm) to explore their size-related responses to macrophyte restoration. The results showed that during the restoration, the annual mean biomass and macrophyte coverage increased significantly from 0 to 637 g/m^2 and 0 to 27%, respectively. In response, the density and biomass of crustaceans and the crustacean-to-rotifer ratio increased significantly, while the rotifer density decreased significantly. Moreover, rotifers showed significant sizedependent responses to macrophyte restoration. Specially, rotifers <400 μm were significantly suppressed, while those ≥400 μm were significantly encouraged. Overall, the population of large-sized zooplankton tended to boom, while that of small rotifers was inhibited during macrophyte restoration. Redundancy analysis(RDA) revealed positive correlations between macrophytes and crustaceans, rotifers and COD or Chl-a, but negative correlations between macrophytes and COD or Chl-a, and between crustaceans and Chl-a. Moreover, the results indicate that increased predation on phytoplankton by large-sized zooplankton might be an important mechanism for macrophyte restoration during development of aquatic ecosystems, and that this mechanism played a very important role in promoting the formation of a clear-water state in subtropical shallow lakes.
文摘The composition and distribution of benthic, periphytic and planktonic rotifers in different habitatsin Krottensee were investigated. Sixty-five rotifer taxa were identified, their relative abundance estimated. Classification of the data set by cluster analysis allowed the recognition of distinct habitat groupe con-fined to acid bog ponds, macrophytes, sediments, and open water. Five groups of rotifer taxa were identifiedon the basis of their habitat preferences and the occurrence of the taxa. Highest diversities were found onmacrophytes and in acid bog ponds.
基金Supported by the National Natural Science Foundation of China(Nos.31470445,30970349)
文摘Maternal eff ects are one of the most interesting topics in evolutionary ecology as they can aff ect the rate of evolution and population dynamics by phenotypic manipulation of off spring related to fi tness. At present, studies examining the interaction between maternal environment eff ects and maternal age (birth order) eff ects are scarce. We designed an experiment to reveal whether environmentally induced maternal manipulation works equally on off spring across birth orders in rotifer Brachionus calycifl orus. In the experiment, newborn amictic mothers (F0) were cultured parallelly in low (LD) and high (HD) population density. Off spring (F1) of young (YF0) and old (OF0) mothers in both LD and HD groups were cultured under a crowded condition and the mixis ratios of both F1 and F2 were examined. Results show that F1 from HD-YF0 had a signifi cantly higher mixis ratio and those amictic ones produced daughters (F2 ) with higher mixis ratio in response to crowding than those from HD-OF0. In contrast, no such diff erences among F1 siblings were found in the LD-F0 group. Therefore, the eff ect of maternal age on the sexual propensity of the off spring can be aff ected independently by the maternal population density.
文摘Of more than 90 rotifer taxa found in Denghu Lake and its nearby ponds in Wuhan, Hubei,the following were new to science: Brachionus angularis pyriformis, B. a. donghuensis, B. (Schizocerca) brevispina, Anuraeopsis fissa donghuensis, A. f. pseudonavicula, Mytilina ventralis Wuhanensis and Trichocerca similis strumosa.
基金Supported by the National Natural Science Foundation of China(Nos.31601840,41673080)。
文摘A new freshwater rotifer Cephalodella changdensis sp.nov.discovered in two locations in Changde,Hunan,China,is described morphologically.The new species is characterized by body shape moderately elongate,double eyespots frontally,toes conical and almost straight,about one fourth of total length,trophi type B(classification after Wulfert,1937),rami asymmetrical with a pair of long alulae,fulcrum inverted T-shaped(ventral/dorsal view)with dorsally directed distal projection(lateral view),and manubria asymmetrical,left one slightly longer and stronger,with J-shaped or crutch-shaped posterior ends.
基金Supported by the Fund of Tianjin Key Laboratory of Animal and Plant Resistance in Tianjin Normal University(No.52XS1209)Transformation and Extension Program of Agricultural Science and Technology Achievements in Tianjin City(No.201001040)Doctoral Fund of Tianjin Normal University(No.52LX30)
文摘[Objective]This paper was to research the water purification mechanism of Ipomoea aquatica and its correlation with algae and rotifer. [Methods]Taking I. aquatica as the test material,Chlorella vulgaris,Scenedesmus obliquus,Microcystis aeroginosa and rotifer Adineta vaga with different densities were added to the hydroponics nutrients solutions of I. aquatica by the hydroponic ecological simulation method. The growth characteristics of I. aquatica,changes of microbial populations and the consumption status of nutrients in the nutritional solution were determined. And the interactions between the plant and the microbial populations were researched. [Results]When I. aquatica seedlings grew to a certain stage,growth of principal root stopped; while the lateral roots emerged greatly; and the nutrition absorption efficiency enhanced. As the inoculation concentration of C. vulgaris increased,root length of I. aquatica increased relatively great due to the competition for nutrients. The competition and allelopathy of M. aeroginosa and S. obliquus restricted the development of root system of I. aquatica. The grazing pressure of Chlorella vulgaris had little effects on M. aeroginosa,but restricted the rapid growth of S. obliquus. [Conclusions]This research provided data support for the application of fish-shrimp-vegetable aquaculture system.
文摘Coral trout Plectropomus leopardus is a high-economical value of marine fish commodity.So,the larviculture for this species should be performed in hatchery scale for their sustainability.One of the important thing in larval stage is hormonal mechanisms.Thyroid hormone is known plays an important role in the metamorphosis of marine fish larvae.The source of that hormone is assumed derived from zooplankton as their live feeds.The live feeds commonly used for marine fish larvae in hatchery are zooplankton copepods and rotifers.The purpose of this research to determine the influence of feeding copepods and rotifers on thyroid hormone profile activity,consisted of triiodothyronine(T3)and thyroxine(T4),related to the metamorphoses of coral trout larvae.The research was conducted using three feeding schemes:copepods(A),copepods-rotifers(B),and rotifers(C).It was done for 50 Days After Hatching(DAH).The results showed that larvae from treatment(A)and(B)achieved the highest level of T3 and T4 earlier at 30 DAH,which indicated that both of those larvae have entered the metamorphosis stage earlier.On the other hand,larvae from treatment(C)achieved it and entered the metamorphosis stage later at 40 DAH.In addition,iodine levels in the copepods were significantly higher than those of in rotifers(P<0.05).Based on this research,live feeds copepods and rotifers have effect on thyroid hormone activity.Copepods have better potential in accelerating the metamorphosis achievement of coral trout larvae with the fact that they have higher iodine content.
基金This work was supported by the FQRNT(Fonds Quebecois pour la Recherche,Nature et Technologiesproject 2016-PR-190063)by Ressources Aquatiques Quebec(RAQ).
文摘Copepods are the main natural food of many marine fish larvae.However,enriched rotifers are the most commonly used live prey in larval rearing.Impacts on the feeding behavior,growth,survival,and fatty acid(FA)composition of winter flounder larvae fed with copepods and rotifers were determined and compared to the FA composition of the two live prey.Nauplii of Eurytemora spp.and Acartia sp.,two of the main species of copepods present in the St.Lawrence estuary,showed no significant differences in their essential fatty acid profiles,suggesting similar nutritional quality.Thus,only Eurytemora herdmani was compared to enriched rotifers in this study.Copepod nauplii were characterized by higher levels of essential fatty acids,particularly docosahexaenoic acid(DHA)and eicosapentaenoic acid(EPA).The selective incorporation of essential fatty acids from diets in larval tissues(polar lipids)indicated that nauplii might better fulfill larval nutritional requirements for DHA than rotifers.Furthermore,larval behavior was modified according to the diet:larvae fed with nauplii spent more time swimming with no changes in the occurrence of hunting events.
基金Project of Shanghai Municipal Committee of Fisheries Animal Genetics and Breeding Center of Shanghai Collaborative Innovation Center(ZF1206)National Science and Technology Commission of Scientific and Technological Research of Expo special(2005ba908b23)Shanghai Science and Technology Commission Expo special(05dz05823)。
文摘We investigated rotifer community structure in the Backshore Wetland of the Expo Garden in Shanghai from September 2009 to August 2010.We identified 116 rotifer species,determined the dominant species and their relationships with environmental factors,and community diversity indices.Polyarthra trigla was the most common species over the four seasons and proportionally most dominant in spring and autumn,whereas Cephalodella exigua and Keratella cochlearis were the most dominant species in winter and summer,respectively.There was seasonal variability in species numbers,with the highest numbers in summer,followed by autumn and winter.The mean annual density was 815±1346 ind./L and the biomass was 0.3649±0.4940 mg/L.There were significant differences between months:the highest density(2723±2926 ind./L)and biomass(0.7938±0.8197 mg/L)occurred in June,while the lowest density(238±271 ind./L)and biomass(0.0476±0.0429 mg/L)occurred in May.Canonical correspondence analysis(CCA)indicated that temperature,pH,nitrite nitrogen(NO2-N),and total phosphorus(TP)were the most important abiotic factors affecting rotifer distribution.Our research showed that the adaptability of the rotifers to temperature was the important factor.
基金by the Ministry of Water,Land and Natural Resources Malaysia(Vote Number:P23170000190001).
文摘The ecological impacts of urbanization and eutrophication on zooplankton communities in urban waterbodies have recently gained wide interest.Study findings vary across species and urban waterbodies.How the development of such changes affects the variation of biotic assemblages has only been explored to a limited extent in tropical urban lakes.Spatial and temporal variations of zooplankton community structure in 11 urban waterbodies in the Klang Valley,Malaysia were investigated along trophic and urbanization gradients.Zooplankton and water quality samples were collected three times,between May and November 2017,from two different locations in each lake.All three main zooplankton groups(rotifera,copepoda,and cladocera)were recorded from the study areas throughout the sampling period.The zooplankton community structure,particularly with regard to rotifers and cladocerans,varied between lakes and seasons.Zooplankton diversity does not vary with lake size or distance from the city center but does vary with shoreline development index and urbanization impacts.The zooplankton populations were dominated by rotifers,mainly Brachionus angularis at all study sites during the study period followed by copepods and cladocerans.The total density of zooplankton was significantly highest(p<0.05)in the hypereutrophic lakes and during the dry season.Zooplankton diversity and rotifer species richness were negatively correlated with total phosphorus(TP).Diversity increased with urbanization and shoreline development,with rotifers as a potential bioindicator of trophic state in urban tropical lakes,due to their close relationship with TP.
基金Supported by Consejo Nacional de Ciencia y Tecnología(Conacyt)through the scholarship(Grant No.136453)Sistema Nacional de Investigadores(Grant No.49351).
文摘Objective:To identify the presence of joint muscular and cholinergic systems in two freshwater rotifer species,Brachionus calyciflorus and Lecane quadridentata.Methods:The muscle actin fibers were stained with phalloidin-linked fluorescent dye,and acetylcholine was detected with Amplex Red Acetylcholine/Acetylcholinesterase Assay Kit,and then confocal scanning laser microscopy was used.Results:The musculature of Brachionus calyciflorus showed a pattern similar to other species of the same genus,while that of Lecane quadridentata was different from other rotifer genera described previously.The cholinergic system was determined by co-localization of both muscles and acetylcholine labels in the whole rotifer,suggesting the presence of neuromuscular junctions.Conclusions:The distribution pattern of muscular and acetylcholine systems showed considerable differences between the two species that might be related to different adaptations to particular ecological niches.The confirmation of a cholinergic system in rotifers contributes to the development of potential neuro-pharmacological and toxicological studies using rotifers as model organism.
