| Daphnia |
Daphnia magna with eggs | | Scientific classification | | | | Species | -
- D. ambigua
- D. arenata
- D. catawba
- D. cheraphila
- D. latispina
- D. melanica
- D. middendorffiana
- D. minnehaha
- D. neo-obtusa
- D. obtusa
- D. oregonensis
- D. parvula
- D. pileata
- D. prolata
- D. pulex
- D. pulicaria
- D. retrocurva
- D. tanakai
- D. tenebrosa
- D. villosa
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- D. curvirostris
- D. dentifera
- D. dubia
- D. galeata
- D. hyalina
- D. laevis
- D. longiremis
- D. mendotae
- D. thorata
- D. umbra
-
- D. brooksi
- D. ephemeralis
- D. exilis
- D. lumholtzi
- D. magna
- D. salina
- D. similis
| Daphnia are small, mostly planktonic, crustaceans, between 0.2 and 5 mm in length. Daphnia are members of the order Cladocera, and are one of the several small aquatic crustaceans commonly called water fleas because of their saltatory swimming style (although fleas are insects and thus only very distantly related). They live in various aquatic environments ranging from acidic swamps to freshwater lakes, ponds, streams and rivers. Image File history File linksMetadata Daphnia_magna01. ...
Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. ...
For other uses, see Animal (disambiguation). ...
Subphyla and Classes Subphylum Trilobitomorpha Trilobita - trilobites (extinct) Subphylum Chelicerata Arachnida - spiders,scorpions, etc. ...
For the Dutch band, see Crustacean (band). ...
Subclasses and Orders Subclass Sarsostraca Order Anostraca (fairy shrimp) Subclass Phyllopoda Order Notostraca (tadpole shrimp) Superorder Diplostraca Order Cladocera (water fleas) Order Conchostraca (clam shrimps) Suborder Laevicaudata Suborder Spinicaudata Suborder Cyclestherida Branchiopoda is a group of primitive and primarily fresh water crustaceans, mostly resembling shrimp. ...
Families Suborder Anomopoda Daphniidae Moinidae Bosminidae Macrothricidae Chydoridae Suborder Ctenopoda Sididae Holopedidae Suborder Onychopoda Polyphemidae Cercopagidae Podonidae Suborder Haplopoda Leptodoridae Daphnia are members of the order Cladocera. ...
Otto Friedrich Müller Otto Friedrich Müller (March 11, 1730 - December 26, 1784) was a Danish naturalist. ...
The hierarchy of scientific classification. ...
Binomial name Daphnia galeata Subspecies Daphnia galeata is a small species of planktonic crustacean. ...
Photomontage of plankton organisms Plankton are any drifting organism that inhabits the water column of oceans, seas, and bodies of fresh water. ...
For the Dutch band, see Crustacean (band). ...
A millimetre (American spelling: millimeter, symbol mm) is an SI unit of length that is equal to one thousandth of a metre. ...
In scientific classification used in biology, the order (Latin: ordo, plural ordines) is a rank between class and family (termed a taxon at that rank). ...
Families Suborder Anomopoda Daphniidae Moinidae Bosminidae Macrothricidae Chydoridae Suborder Ctenopoda Sididae Holopedidae Suborder Onychopoda Polyphemidae Cercopagidae Podonidae Suborder Haplopoda Leptodoridae Daphnia are members of the order Cladocera. ...
Water flea is a generic term for a number of small aquatic crustacea characterised by their jumping or jerky mode of swimming. ...
Saltation is usually used as a biology term to describe a sudden change in the appearance of a species. ...
For other uses, see Flea (disambiguation). ...
Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Subclass Pterygota Infraclass Paleoptera (Probably paraphyletic) Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera (webspinners) Zoraptera (angel insects) Dermaptera (earwigs) Orthoptera (grasshoppers, etc) Phasmatodea (stick insects) Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Psocoptera...
For other uses, see Acid (disambiguation). ...
This article does not cite any references or sources. ...
For the village on the Isle of Wight, see Freshwater, Isle of Wight. ...
Biology
The division of the body into segments is nearly invisible. The head is fused, and is generally bent down towards the body with a visible notch separating the two. In most species the rest of the body is covered by a carapace, with a ventral gap in which the five or six pairs of legs lie. The most prominent features are the compound eyes, the second antennae, and a pair of abdominal setae. In many species, the carapace is translucent or nearly so and as a result they make excellent subjects for the microscope as one can observe the beating heart. Vertebrates have a segmented vertebral column and brain. ...
The term carapace refers to a dorsal section of an exoskeleton or shell, in a number of animal groups. ...
Compound eye of a dragonfly Compound eye of Antarctic krill as imaged by an electron microscope A compound eye is a visual organ found in certain arthropods such as insects and crustaceans. ...
Insects display a wide variety of antennal shapes. ...
Look up seta in Wiktionary, the free dictionary. ...
Robert Hookes microscope (1665) - an engineered device used to study living systems. ...
Even under relatively low power, it is possible to observe the feeding mechanism working, watch immature young moving in the brood-pouch, observe the eye being moved by the ciliary muscles and even watch blood corpuscles being pumped round the circulatory system by the simple heart. The heart is at the top of the back, just behind the head. and their average heart rate is approximately 180bpm under normal conditions. Daphnia, like many animals, are prone to alcohol intoxication, and make excellent subjects for studying the effects of the depressant on the nervous system – due to the translucent exoskeleton, and the visibly altered heart rate. They are tolerant of being observed live under a cover slip and appear to suffer no harm when returned to open water. This experiment can also be done using caffeine, nicotine or adrenaline and observing an increase in heart rate. The ciliary muscle is a smooth muscle that affects zonular fibers in the eye (fibers that suspend the lens in position during accommodation), enabling changes in lens shape for light focusing. ...
Corpuscle is J.J. Thomsons term for a subatomic particle similar to the electron. ...
For transport in plants, see Vascular tissue. ...
Ethanol, also known as ethyl alcohol, drinking alcohol or grain alcohol, is a flammable, colorless, slightly toxic chemical compound, and is best known as the alcohol found in alcoholic beverages. ...
The nervous system of an animal coordinates the activity of the muscles, monitors the organs, constructs and also stops input from the senses, and initiates actions. ...
Heart rate is a term used to describe the frequency of the cardiac cycle. ...
Caffeine is a xanthine alkaloid compound that acts as a stimulant in humans. ...
Nicotine is an alkaloid found in the nightshade family of plants (Solanaceae), predominantly in tobacco, and in lower quantities in tomato, potato, eggplant (aubergine), and green pepper. ...
“Adrenaline†redirects here. ...
A few Daphnia prey on tiny crustaceans and rotifers, but most are filter feeders, ingesting mainly unicellular algae and various sorts of organic detritus including protists and bacteria. Daphnia can be kept easily on a diet of yeast. Beating of the legs produces a constant current through the carapace which brings such material into the digestive tract. The trapped food particles are formed into a food bolus which then moves down the digestive tract until voided through the anus located on the ventral surface of the terminal appendage. The first and second pair of legs are used in the organisms' filter feeding ensuring large unabsorbable particles are kept out while the other sets of legs create the stream of water rushing into the organism. Swimming, on the other hand, is powered mainly by the second set of antennae which are larger in size than the first set. The action of this second set of antennae is responsible for the jumping motion. For the Dutch band, see Crustacean (band). ...
Classes Monogononta Digononta The rotifers make up a phylum of microscopic and near-microscopic pseudocoelomate animals. ...
Filter feeders (also known as suspension feeders) are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized structure, such as the baleen of baleen whales. ...
A seaweed (Laurencia) up close: the branches are multicellular and only about 1 mm thick. ...
Typical phyla Chromalveolata Chromista Heterokontophyta Haptophyta Cryptophyta (cryptomonads) Alveolata Dinoflagellata Apicomplexa Ciliophora (ciliates) Cabozoa Excavata Euglenozoa Percolozoa Metamonada Rhizaria Radiolaria Foraminifera Cercozoa Archaeplastida (in part) Rhodophyta (red algae) Glaucophyta (basal archaeplastids) Amoebozoa Choanozoa Many others; classification varies Protists (IPA: (RP); (GenAm)), Greek protiston -a meaning the (most) first of all...
Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ...
Reproduction
 Resting egg pouch (ephippium) and the juvenile Daphnid that just hatched from it. Daphnia reproduce parthenogenetically usually in the spring until the end of the summer. One or more juvenile animals are nurtured in the brood pouch inside the carapace.The newly hatched Daphnia must moult several times before they are fully grown into an adult usually after about two weeks. The young are small copies of the adult; there are no true nymphal or instar stages. The fully mature females are able to produce a new brood of young about every ten days under ideal conditions. The reproduction process continues while the environmental conditions continue to support their growth. When winter approaches or in drought conditions or at times of other harsh environmental conditions, production of new female generations cease and parthenogenic males are produced. However, even in harsh environmental conditions males may make up considerably less than half the population, in some species they are unknown entirely. Males are much smaller in size than the female and they typically possess a specialised abdominal appendage which is used in mating to grasp a female from behind and prise open her carapace and insert a [[spermatheca and thus fertilise the eggs. These fertilised eggs are termed winter eggs and are provided with extra shell layer called ephippium. The extra layer preserves and protects the egg inside from harsh environmental conditions until the more favourable times, such as spring, when the reproductive cycle is able to take place once again. Image File history File links Metadata Size of this preview: 732 × 599 pixelsFull resolution (800 × 655 pixel, file size: 54 KB, MIME type: image/jpeg) Resting egg pouch (ephippium) and the juvenile Daphnid that just hatched from it. ...
Image File history File links Metadata Size of this preview: 732 × 599 pixelsFull resolution (800 × 655 pixel, file size: 54 KB, MIME type: image/jpeg) Resting egg pouch (ephippium) and the juvenile Daphnid that just hatched from it. ...
It has been suggested that this article or section be merged into Asexual reproduction. ...
Praying mantis nymphs, approximately 4mm long, clustered on a leaf In biology, a nymph is the immature form of some insect species, which undergoes incomplete metamorphosis (Hemimetabolism) before reaching its adult stage; unlike a larva, a nymphs overall form already resembles that of an adult. ...
An instar is a developmental stage of arthropods, such as insects, between each molt. ...
An appendage is, in general, an external body part that projects from the body, or a natural prolongation or projection from a part of any organism. ...
The term carapace refers to a dorsal section of an exoskeleton or shell, in a number of animal groups. ...
In addition to the production of eggs capable of overwintering, this switch to sexual reproduction has also been proposed to allow greater offspring variation (through genetic recombination) which may be useful in varied or unpredictable conditions, this idea is often proposed under the name of the lottery model.
Lifespan The lifespan of a Daphnia does not exceed one year and is largely temperature dependent. For example, individual organisms can live up to 108 days at 3°C while some organisms live for only 29 days at 28°C. A clear exception to this trend is during the winter time in which harsh conditions limit the population in which females have been recorded to live for over six months. These females generally grow at slower rate but in the end are larger than ones under normal conditions. Celsius is, or relates to, the Celsius temperature scale (previously known as the centigrade scale). ...
Uses Daphnia provide an important source of food for many larger aquatic organisms including various fish species (e.g. lake trout) and the immature stages of many insects including the Odonata: dragonflies and damselflies. They are also prey for hydras. Image File history File links Size of this preview: 365 × 599 pixelsFull resolution (666 × 1093 pixel, file size: 403 KB, MIME type: image/png) File historyClick on a date/time to view the file as it appeared at that time. ...
Image File history File links Size of this preview: 365 × 599 pixelsFull resolution (666 × 1093 pixel, file size: 403 KB, MIME type: image/png) File historyClick on a date/time to view the file as it appeared at that time. ...
Binomial name Salvelinus namaycush (Walbaum, 1792) Lake trout (Salvelinus namaycush) is a freshwater char living mainly in lakes in northern North America. ...
Suborders Epiprocta (dragonflies), including infraorder Anisoptera (true dragonflies) Zygoptera (damselflies) Reference: ITIS 101593 as of 2002-07-26 Odonata is an order of insects, encompassing dragonflies (Anisoptera) and damselflies (Zygoptera). ...
This article is about the insect. ...
Families Amphipterygidae Calopterygidae - Demoiselles Chlorocyphidae - Jewels Coenagrionidae - Pond Damselflies Dicteriadidae - Barelegs Euphaeidae - Gossamerwings Hemiphlebidae - Reedlings Isosticidae - Narrow-wings Lestidae - Spreadwings Lestoididae Megapodagrionidae - Flatwings Perilestidae - Shortwings Platycnemidae - Brook Damselflies Platystictidae - Forest Damselflies Polythoridae - Bannerwings Protoneuridae - Pinflies Pseudostigmatidae - Forest Giants Synlestidae - Sylphs The Damselfly (Suborder Zygoptera) is an insect in the Order...
Species Hydra americana Hydra attenuata (or Hydra vulgaris) Hydra canadensis Hydra carnea Hydra cauliculata Hydra circumcincta Hydra hymanae Hydra littoralis Hydra magnipapillata Hydra minima Hydra oligactis Hydra oregona Hydra pseudoligactis Hydra rutgerensis Hydra utahensis Hydra viridis Hydra viridissima Hydra is a genus of simple, fresh-water animals possessing radial symmetry. ...
They are easy to culture in the laboratory, and D.magna has been a model species for developing the Dynamic energy budget theory. They are frequently used to test the effects of toxicants on reproduction and survival. Dynamic Energy Budget (DEB) theory aims to identify simple quantitative rules for the organization of metabolism of individual organisms that can be understood from basic first principles, The word Dynamic refers to the life cycle perspective of the theory, where the budget changes dynamically over time. ...
A toxicant is a chemical compound that has an effect on organisms. ...
Daphnia are sold by aquatic retailers in both live and freeze-dried form as food for aquarium fish. Their tiny size renders them edible in live form even for fish as small as the neon tetra Binomial name Paracheirodon innesi (Myers, 1936) The neon tetra (Paracheirodon innesi) is a freshwater fish of the characin family (family Characidae) of order Characiformes. ...
Daphnia may also be used to clear unwanted algae from fish tanks, provided they are not eaten by the fish.
Many species of Daphnia are used in aquatic toxicology. As experimental animals they have many advantages being simple to produce in large numbers and exhibiting consistent responses to toxins. Toxicology (from the Greek words toxicos and logos [1]) is the study of the adverse effects of chemicals on living organisms [2]. It is the study of symptoms, mechanisms, treatments and detection of poisoning, especially the poisoning of people. ...
Daphnia is considered an indicator species or sentinel species which is an indicator of ecosystem health. Indicator species are unique environmental indicators as they offer a signal of the biological condition in a watershed or ecosystem, and are a warning system that pollution has entered the food web. ...
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