Some rotifers are symbiotic with, or parasitic on, other organisms. Members of the genera Seison and Paraseison live on the legs and gills of Nebalia , a genus of marine leptostracan crustaceans, feeding on their host's eggs and detritus. Members of genus Embata are known to live in the gills of amphipods and decapods. Some rotifers are endoparasitic sometimes epizoic , mainly on invertebrates including crustaceans, brachiopods, algae, protists, bacteria, bryozoans, other rotifers, sponges, fungi, mosses, snail eggs, annelids, oligochaetes, and slugs.
As mainly planktonic animals, rotifers are an important food source for many animals, including some that are economically important to humans. They are also studied by scientists around the world. As a broadly cosmopolitan phylum, rotifers in general are not considered endangered or threatened in any way.
It is the second largest ocean in the world after the Pacific Ocean. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
In otherwords, Europe and Asia and northern Africa. Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans below m are sometimes referred to as the abyssal zone.
Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria. Bogs have a flora dominated by sedges, heaths, and sphagnum. Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate.
Vegetation is dominated by stands of dense, spiny shrubs with tough hard or waxy evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.
More specifically refers to a group of organisms in which members act as specialized subunits a continuous, modular society - as in clonal organisms. Found on all continents except maybe Antarctica and in all biogeographic provinces; or in all the major oceans Atlantic, Indian, and Pacific. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry.
This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots. At about the time a female gives birth e.
Embryos produced at this mating develop only as far as a hollow ball of cells the blastocyst and then become quiescent, entering a state of suspended animation or embryonic diapause.
The hormonal signal prolactin which blocks further development of the blastocyst is produced in response to the sucking stimulus from the young in the pouch. When sucking decreases as the young begins to eat other food and to leave the pouch, or if the young is lost from the pouch, the quiescent blastocyst resumes development, the embryo is born, and the cycle begins again.
Macdonald Used mainly by aquatic invertebrates, especially plankton, but also by baleen whales. An aquatic habitat. Iteroparous animals must, by definition, survive over multiple seasons or periodic condition changes. This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
An aquatic biome consisting of the open ocean, far from land, does not include sea bottom benthic zone. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
Coral reefs are found in warm, shallow oceans with low nutrient availability. They form the basis for rich communities of other invertebrates, plants, fish, and protists. The polyps live only on the reef surface. Because they depend on symbiotic photosynthetic algae, zooxanthellae, they cannot live where light does not penetrate. Referring to something living or located adjacent to a waterbody usually, but not always, a river or stream.
Coniferous or boreal forest, located in a band across northern North America, Europe, and Asia. This terrestrial biome also occurs at high elevations. Long, cold winters and short, wet summers. Few species of trees are present; these are primarily conifers that grow in dense stands with little undergrowth.
Some deciduous trees also may be present. A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia. A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest.
See also Tropical savanna and grassland biome. Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
A terrestrial biome with low, shrubby or mat-like vegetation found at extremely high latitudes or elevations, near the limit of plant growth. Soils usually subject to permafrost. Plant diversity is typically low and the growing season is short. Encyclopedia of Life.
Environmental Leverage Inc. Environmental Leverage. Ahlrichs, W. Brusca, R. Invertebrates 2nd Edition. Sunderland, MA: Sinauer Associates. Garcia-Varela, M. Phylogenetic relationships among Syndermata inferred from nuclear and mitochondrial gene sequences. Molecular Phylogenetics and Evolution , Glime, J.
Bryophyte Ecology: Volume 2, Bryological Interaction. Harmer, S. The Cambridge Natural History. Hyman, L. Kristensen, R. An introduction to Loricifera , Cycliophora , and Micrognathozoa. Integrative and Comparative Biology , Marini, F.
Currently, one can find in the scientific literature reports of almost every class of chemical compound used or produced by man, investigating their toxicological properties. These papers are relatively abundant in several websites specialized in gathering such kind of information, which is available to everyone who has access to the published material. For scientist, collecting this material is a daily activity that guarantees their studies to follow the right direction by not working in exactly the same topic and manner, which would represent the duplicity of information but at higher cost because of multiple double efforts and resources investment.
Nonetheless, it must be pointed out that differences in susceptibility to toxicants can be found among clones or strains, which is very interesting to assess by multiclonal analyses [ 22 , ]. However, when it is not possible to access multiple clones or strains, previous reports published material from databases become more relevant as a source of comparison to improve the comprehension of the observed results.
It provides a user-friendly interface and allows discrimination among taxonomic and chemical groups, aquatic or terrestrial environment, tests results or conditions, and type year of publication.
Although it does not give access to the cited references, it returns a list of publications to be consulted elsewhere. In the ECOTOX results table, the data shown are species name, exposure type, chemical, media type, end points, bioconcentration factor, effects, and statistics, among others Figure 4. A complete list of all abbreviations used in the ECOTOX database can be directly downloaded for the same host website. Query terms were Brachionus and chromium, selected from the options displayed in the database [].
Nowadays, toxicity assays with rotifers include very diverse toxicants, and a relatively high number of test have been assessed the effect of inorganic metals and metalloids and very versatile organic compounds like pesticides, solvents, colorants, detergents, and emergent toxicants, in which health and care products and pharmaceuticals form part of it Table 4.
Some of these toxicants are effective at concentrations as low as some nanograms per liter, altering rotifers population dynamics by different mechanisms like endocrine disruption. The available data about toxicity to rotifers show that organic compounds, as a complex group, is the most studied The last one comprised those commonly named heavy metals [ ].
Other groups might not be as numerous as the former ones, but this should not be misinterpreted as a lack of interest from the environmental toxicologists, but a challenge and a continuous research to find out how these chemicals are affecting the aquatic ecosystems and their inhabitants like rotifers species.
Comparison of toxicity tests between chemical groups conducted with different rotifers species. Several rotifer species have been used to evaluate the effect and toxic mechanisms of the chemical groups aforementioned, where B. However, there are other species that present advantages over brachionids, such as the littoral genus Lecane that might be used to assess the effect of sediment-associated toxicants, or the predator genus Asplanchna , used to evaluate toxicants biomagnification among rotifers and other aquatic invertebrates [ ].
Therefore, rotifers represent a group of organisms that have not been completely studied and require more attention from toxicologists. Number of ecotoxicological studies through by different rotifer species. Cyst production is an outstanding characteristic that has enabled the development of several toxicity protocols using rotifers that have been used worldwide [ ]. Rotifers are not directly represented in the legislation of several countries as the cladocerans Daphnia magna and Ceriodaphnia dubia do.
However, toxicity tests with rotifers have been published by official societies [ 43 , 84 , ] Perhaps the most notorious participation of rotifer toxicity tests is when EPA asked BP plc the former name of the company was British petroleum to use the acute toxicity test with the euryhaline rotifer B. The marine water rotifer toxicity test TK22 was used to analyze thousands of sites in the Gulf of Mexico; toxicity was analyzed for both oil and the oil dispersant used [ 36 ].
The convention started working in One of their goals was the development of directives for the analysis of toxicity both in marine and freshwater environments. In the Port of Aveiro, Portugal, standardized acute toxicity test using the marine rotifer, B.
Isidori et al. Differences were observed in the sensitivity of the test organisms to the presence of sewage sludge in the soil. The highest sensitivity was a characteristic of B. The Resource Management Act of New Zealand [ ] requires local authorities and industry to apply for consent to discharge effluent to water or land.
Therefore, the requirement for whole effluent toxicity testing is now being included in these Resource Consents. The Ministry for the Environment MfE has encouraged research which evaluates technology used to monitor environmental parameters e. Sarma et al. Acute h lethal effect measurements generated with L. The municipal drinking water wells of Aguascalientes have also been assessed using acute toxicity tests with L.
An ecotoxicological study of the most important river in the State of Aguascalientes has also been performed [ 93 ]. Six rivers and a shallow lake located in rural and urban areas were sampled during 4 weeks.
River microzooplankton abundance and rotifer species assemblages were found to be good indicators of land use. Brachionus spp. Many Asian countries have used rotifer toxicity tests for diverse monitoring and scientific purposes. Microcosm studies with rotifers have been used in India to evaluate tannery effluent [ ]. Different rotifer species from all around the globe have been used to test the toxicity of a huge number of chemicals, both from freshwater FW and marine water MW ecosystems see Rico-Martinez et al.
Such species were initially collected from their natural habitats, a specific biogeographical zone, for their further acclimation to laboratory conditions and use as model organisms in toxicity evaluation protocols. Nowadays, the rotifer species used as model organisms, due to their representativeness and wide natural distribution, include those of the genus Brachionus sp.
Moreover, organisms within the genus Lecane sp. Despite all efforts to understand rotifers biology and their susceptibility to contaminants, there is still a need to conduct new studies with rotifers belonging to different habitats biogeographical zones , climates, and niches.
For such studies, researchers should take into consideration topics like clonal cultures obtaining, rotifers identification and classification through morphological and genetic cytochrome oxidase rDNA, COI characters, and the production of sexual eggs to preserve them in a resting eggs bank. Such eggs could be also a source for developing toxicity assessments kits, like those of Microbiotests Inc.
For example, Brachionus sp. In addition, the rotifers B. Thus, genetic and phylogeographic studies should be performed to assess how this species are distributed around the world. In aquatic toxicology, currently there are methods that help elucidating the toxicity mechanisms for different sorts of chemicals. Therefore, they can be listed as follows:. Standardized protocols for evaluation of acute, chronic, and sublethal toxicity.
These methods are carried out by exposing neonates or resting eggs, for 24 to 48 h or more depending exposure concentrations, periods, and end points to measure. Acute and chronic toxic ratios are still in use despite all new technologies, as they are finally a reference point for further analysis. Mortality or immobility are the common responses observed in acute toxicity tests, but in chronic assays, population parameters are followed during the exposure period, such as the intrinsic rate of population increase r obtained from the life table analysis.
Another possibility is assessing the hatching percentage, which represent the stability and health of cysts produced during stressful conditions, including abiotic factors like desiccation or the presence of contaminants. Their findings demonstrated that there was no significant difference between exposed and nonexposed organisms. In addition, the population parameter r of rotifers hatching from VZ-promoted cysts was 1.
It has been shown that multigenerational studies should be conducted as these could reproduce what happens in natural conditions when parthenogenetic females are exposed to toxicants and in their offspring is in certain way altered even before hatching [ ], a phenomenon called the maternal effect, which could be for good while providing more energetic resources to deal with the stressful conditions in the medium, or negative through inheriting mutations that could bring deleterious effects in consecutive generations.
In vivo enzyme activity assessment esterases and phospholipase A2 : This method has the potential to assess the adverse effects of contaminants for rotifers. In the rotifer E. This study concluded that both enzymes are very sensitive to toxicants-induced alterations [ 96 , 97 ]. Stress granules SGs : Eukaryotes share diverse mechanisms of adaptation and responses to the stress.
In this matter, it has been shown in different insects, trypanosomids, yeast, mammal cells, and rotifers, in which they can sequester some proteins and mRNA into granules that protect cellular mRNA. Thus, SGs appear to be useful as biomarkers in rotifers [ ]. Therefore, BCF are very valuable tools to study exposure to a certain kind of compounds. Moreover, these assessments could help to trace toxicants in discharges to aquatic ecosystems, by monitoring both in laboratory and in natural conditions exposed animals [ , ].
Elemental composition using X-ray analysis on rotifers cuticles. This is an easy method that qualitatively determines different elements of interest, principally inorganic metals [ 48 ].
Morphological analysis: These are changes induced by toxic exposure; although it could be controversial, it can be carried out by comparing morphological characters through image analysis. Because of rotifers phenotypic plasticity, the comparisons should be carefully performed to avoid misinterpretation of the results.
However, is has been demonstrated, in B. However, the percentage of deformities is low, only 0. Nevertheless, this is still significantly different to the control groups. Hence, morphometric analysis in rotifers could be a helpful tool to identify unrevealed targets of toxicants, and it might contribute to create a database for such effects and for several rotifers species to further comparisons among them, besides the likely identification process through image analysis [ 48 ].
Aging in rotifers: because there is a great diversity in aging rates among species, geographical populations, and mutants within species, Smith and Snell [ ] designed an experiment to follow rotifers longevity through 84 generations about 1 year. Their results show that optimal growing conditions e. Rotifers are considered good models to investigate the effect not only of toxicant on their life span but also other factors such as caloric restriction and the effect of vitamins.
Thus, this represents a new field to incorporate studies with rotifers [ , ]. Hormones: Alvarado-Flores et al. Then it will be possible to assess their participation in mechanisms of detoxification and likely be used as toxicity models. Additionally, the studies performed by Hason et al. Heat shock proteins HSPs : The genes for these proteins synthesis are found from bacteria to higher eukaryotes and are related to functions like refolding denatured proteins due to stress that includes heat shock, reason for which they are called HSPs.
Smith et al. Metallothionein Mt : These are low-molecular weight and cysteine-rich proteins present in eukaryotes. They provide potent metal binding and some other functions are being discovered. Their presence in rotifers has been demonstrated as a consequence of chromium exposure [ ]. P-glycoprotein 8P-gp Pg-p : This protein could be considered as the first line of defense against some chemicals, including pharmaceuticals and endocrine disruptors. This protein has been found and characterized in the rotifer B.
Specimens of this rotifer were exposed to several pharmaceuticals that retarded growth and promoted the overexpression of Pg-p [ ]. Epigenetics: Germ cells can be specified early in embryogenesis by maternal determinants inherited in the cytoplasm of the oocyte or they can be selected later in the embryonic development from undifferentiated precursors by a localized inductive signal that is called epigenesis [ ].
Epigenetic processes were found in the ovary of B. As the first description of its kind, it opens the possibilities to explore and perform embryo development within the phylum. Cell-penetrating peptides CPPs : Liu et al. This method provides a tool not only for genetic material but also for nanoparticles and proteins, which in the future could facilitate studying the effect of chemicals within rotifer cells. Innate immunity in rotifers: In invertebrates, the nomenclature, annotation, and reports of cytokines could be controversial.
Nonetheless, there is a continuous and increasing knowledge about cytokine-mediated immune regulation, although adaptive immune responses are likely absent in invertebrates, including rotifers. In this field, Jeong et al. The in silico analysis showed that these genes could be involved in innate immunity in primitive rotifers. Thereafter, LITAF genes have potential sensitivities to immune stimulator-triggered oxidative stress. In conclusion, rotifers as models for ecotoxicological tests present several advantages, including a relative short life cycle that allows multigenerational studies and epigenetic research to unveil functions and processes in mictic and amictic rotifers, the simplicity of their body structure that ease the permeability of dyes for in vivo examination to quantify toxicant concentrations e.
Nowadays, there are several protocols that describe the use of rotifers as indicators of water quality and safety as even thousands of probes can be performed in very short periods. Furthermore, every year, new technologies are becoming available to explore in deep detail the effect, the mechanisms, and the targets of toxicants. Hence, rotifer studies cannot be the exception, opening new possibilities to explore and describe more accurately the interaction of toxicants with the aquatic biota.
Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution 3. Help us write another book on this subject and reach those readers. Login to your personal dashboard for more detailed statistics on your publications.
Edited by Marcelo L. We are IntechOpen, the world's leading publisher of Open Access books. Built by scientists, for scientists. Our readership spans scientists, professors, researchers, librarians, and students, as well as business professionals. Downloaded: Abstract An important objective of aquatic ecotoxicology is to determine the effects of toxic compounds in organisms that play a central role in aquatic communities where rotifers have a large impact on several important ecological processes.
Keywords aquatic toxicology ecotoxicology metal toxicity acute toxicity endocrine disruption. Introduction The analytical equipment can identify and quantify a chemical substance but not its toxicity in the organisms or the environment, which can be evaluated only in life organisms [ 1 ]. Phylum Rotifera Rotifers are aquatic or semiaquatic microscopic invertebrates with nearly species; they are unsegmented, pseudocoelomate, and bilaterally symmetric [ 4 , 9 , 10 ].
Ecological relevance Rotifers are cosmopolitans. Culture Rotifers can be obtained directly from a natural aquatic system or from laboratory cultures. Reproduction The life cycles of rotifers are shorter than many other animals [ 14 ].
Cysts Once the eggs are produced, they fall into the bottom and are deposited in the sediments [ 18 ]. Rotifers as sentinels or bioindicators Aquatic invertebrates are attractive model organisms in aquatic toxicology due to their short generation time compared with fishes besides their small size require small test volumes [ 14 , 24 ].
Table 1. Table 2. Toxicity range for some pesticides and organic compounds to rotifers used in bioassays. Table 3. Toxicity range for different metals to rotifers used in bioassays. Table 4. Relation of toxicants and rotifers species used in ecotoxicological studies. Oceania The Resource Management Act of New Zealand [ ] requires local authorities and industry to apply for consent to discharge effluent to water or land. Latin America and the Caribbean Sarma et al.
Asia Many Asian countries have used rotifer toxicity tests for diverse monitoring and scientific purposes. More Print chapter. How to cite and reference Link to this chapter Copy to clipboard. Available from:. Over 21, IntechOpen readers like this topic Help us write another book on this subject and reach those readers Suggest a book topic Books open for submissions.
More statistics for editors and authors Login to your personal dashboard for more detailed statistics on your publications. Access personal reporting. More About Us. Daphnia magna [ 62 - 65 ]. Ceriodaphnia dubia [ 62 , 64 , 66 , [ 72 ]. Thamnocephalus platyurus [ 73 - 76 ]. Eurytemora affinis [ 77 - 80 ].
Eucyclops serrulatus [ 31 , 81 - 83 ]. Brachionus calyciflorus [ 43 , 84 ]. Lecane quadridentata [ 91 - 93 ]. Euchlanis dilatata [ 96 , 97 ]. Asplanchna brightwelli [ 98 - ]. Hydra attenuata [ 45 ].
Elliptio complanata [ 58 ]. Lampsilis siliquoidea [ 58 ]. Corbicula fluminea [ - ]. Freshwater sediments. Hyallela azteca [ , ]. Lumbriculus variegatus [ - ]. Stylodrilus heringianus [ , ]. Philodina roseola [ ]. The evolutionary relationship of rotifers and acanthocephalans. Gilbert , J. The Polyarthra escape response: Defense against interference from Daphnia. Kairomone-induced morphological defenses in rotifers.
Tollrian and C. Harvell eds. Princeton University Press, Princeton. Asexual diapause induced by food limitation in the rotifer Synchaeta pectinata. Ecology , 79 Allozyme electrophoresis: Its application to rotifers. Carvalho, and D. Phylogeography and regional endisms of a passively dispersing zooplankter: Mitochondrial DNA variation in rotifer resting egg banks. London B , Herzig , A. The analysis of planktonic rotifer populations: A plea for long—term investigations. Hutchinson , G.
A treatise on limnology, Vol. Joanidopoulos , K. Specific behavioural responses triggered by identified mechanosensory receptor cells in the apical field of the giant rotifer Asplanchna sieboldi.
Bio , King , C. Genetics of reproduction, variation, and adaptation in rotifers. Beih , 8 A re-examination of the Lansing Effect. Seasonal variation as a determinant of population structure in rotifers reproducing by cyclical parthenogenesis. Kleinow , W. Stereopictures of internal structures and trophi of rotifers. Kotikova , E. Localization and neuroanatomy of catecholaminergic neurons in some rotifer species.
Catecholaminergic neurons in the brain of rotifers. Kristensen , R. Micrognathozoa: A new class with complicated jaws like those of Rotifera and Gnathostomulida.
Morph , 1 Leech , D. Is tolerance to UV radiation in zooplankton related to body size, taxon, or lake transparency? Appl , 10 Lorenzen , S. Phylogenetic aspects of pseudocoelomate evolution. Conway Morris, J. George, and H. Platt eds. Volume Clarendon Press, Oxford. Lubzens , E. Tandler, and G. Rotifers as food in aquaculture. Zmora, and Y. Biotechnology and aquaculture of rotifers. Rotifers as indicators of lake types in Estonia. Mark Welch , D. Evidence from a protein-coding gene that acanthocephalans are rotifers.
Bio , 17 Early contributions of molecular phylogenetics to understanding the evolution of Rotifera. Measurements of the genome size of the monogonont rotifer Brachionus plicatilis and of the bdelloid rotifers Philodina roseola and Habrotrocha constricta. Evidence for the evolution of bdelloid rotifers without sexual reproduction or genetic exchange. Science , A survey of introns in three genes of rotifers. Mark Welch , J. Karyotypes of bdelloid rotifers from three families.
Marneffe , Y. Comblin, and J. McNair , J. Boraas, and D. Size-structure dynamics of the rotifer chemostat: A simple physiologically structure model. Melone , G. Ricci, H. Segers, and R. Phylogenetic relationships of the phylum Rotifera with emphasis on the families of Bdelloidea.
Miner , R. A drama of the microscope. Nielsen , C. Animal evolution, 2nd ed. Oxford University Press, Oxford. Nogrady , T. Wallace, and T. Dumont ed. Perez-Legaspi , I. Acute toxicity tests on three species of the genus Lecane Rotifera: Monogononta. Pourriot , R. Revue d'Ecologie et de Biologie du Sol , 16 Ricci , C. Are lemnisci and proboscis present in the Bdelloidea? Dormancy patterns in rotifers.
Dwarf males in monogonont rotifers. Eco , 32 Caprioli, and A. Microgravity and hypergravity effect on survival and reproduction of microinvertebrates. Gravitational Physiol , 5 Cross-mating tests re-discovered: A tool to assess species boundaries in rotifers. Rieger , R. Sister-group relationship of Gnathostomulida and Rotifera-Acanthocephala. Rublee , P. Rotifers in arctic North America with particular references to their role in microplankton community structure and response to ecosystem perturbations in Alaskan Arctic LTER lakes.
Segers , H. The nomenclature of the Rotifera: Annotated checklist of valid family- and genus-group names. Serra , M. Optimal rates of bisexual reproduction in cyclical parthenogens with density-dependent growth. Biol , 12 Why are male rotifers dwarf? TREE , 13 Ecological genetics of Brachionus sympatric species. Rotifers as indicators of water quality. Funch, E.
Willerslev, A. Hansen, and J. On the phylogeny of the Metazoa in the light of Cycliophora and Micrognathozoa. Anz , Snell , T. Chemical ecology of rotifers. Rotifers in ecotoxicology: A review. Starkweather , P. Pandian and F. Vernberg eds. Near-coronal fluid flow patterns and food cell manipulation in the rotifer Brachionus calyciflorus.
Wallace , R. Ecology of sessile rotifers. Hydrobiologia , 73 Coloniality in the phylum Rotifera. Knobil and J. Neil eds. Academic Press, San Diego. Rundle, A. Robertson, and J. Schmid-Araya eds. Backhuys Publishers, Leiden. Phylum Rotifera. Thorpe and A. Covich eds. Walz , N.
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