Ephippia

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Resting egg pouch (ephippium) and the juvenile daphnid that just hatched from it Daphnid GLERL 1.jpg
Resting egg pouch (ephippium) and the juvenile daphnid that just hatched from it
Female Daphnia longispina carrying a resting egg (ephippium). The two dark, oval spots on the ephippium mark the places where the two resting eggs are located. The female was collected in a rock pool in south-western Finland. The animal is about 2 mm long. Female Daphnia longispina carrying a resting egg ("ephippium").JPG
Female Daphnia longispina carrying a resting egg (ephippium). The two dark, oval spots on the ephippium mark the places where the two resting eggs are located. The female was collected in a rock pool in south-western Finland. The animal is about 2 mm long.
Schematic representation of cyclic parthenogenesis in the cladoceran Daphnia (water flea). The sexual cycle results in the production of the sexual eggs, the resting stages enclosed by the ephippium. DaphniaMagna LifeCycle DVizoso.svg
Schematic representation of cyclic parthenogenesis in the cladoceran Daphnia (water flea). The sexual cycle results in the production of the sexual eggs, the resting stages enclosed by the ephippium.

Ephippia (singular: ephippium) are winter or dry-season eggs of the various species of small crustacean in the order Cladocera (within the Branchiopoda); they are provided with an extra shell layer, [1] which preserves and protects the resting stages inside from harsh environmental conditions until the more favorable times, such as spring, when the reproductive cycle is able to take place once again. Ephippia are part of the back of a mother carrying them until they are fully developed. After molting, the ephippium stays in the water, or in the soil of dried puddles, small ponds, and vernal pools. The resting stages are often called eggs, but are in fact embryos with arrested development. Ephippia can rest for many years before the embryo resumes development upon an appropriate hatching stimulus. [1] [2]

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<span class="mw-page-title-main">Branchiopoda</span> Class of crustaceans

Branchiopoda is a class of crustaceans. It comprises fairy shrimp, clam shrimp, Diplostraca, Notostraca, the Devonian Lepidocaris and possibly the Cambrian Rehbachiella. They are mostly small, freshwater animals that feed on plankton and detritus.

<span class="mw-page-title-main">Outline of biology</span>

Biology – The natural science that studies life. Areas of focus include structure, function, growth, origin, evolution, distribution, and taxonomy.

<i>Daphnia</i> Genus of crustaceans

Daphnia is a genus of small planktonic crustaceans, 0.2–6.0 mm (0.01–0.24 in) in length. Daphnia are members of the order Anomopoda, and are one of the several small aquatic crustaceans commonly called water fleas because their saltatory swimming style resembles the movements of fleas. Daphnia spp. live in various aquatic environments ranging from acidic swamps to freshwater lakes and ponds.

<span class="mw-page-title-main">Viviparity</span> Development of the embryo inside the mother

In animals, viviparity is development of the embryo inside the body of the mother, with the maternal circulation providing for the metabolic needs of the embryo's development, until the mother gives birth to a fully or partially developed juvenile that is at least metabolically independent. This is opposed to oviparity, where the embryos develop independently outside the mother in eggs until they are developed enough to break out as hatchlings; and ovoviviparity, where the embryos are developed in eggs that remain carried inside the mother's body until the hatchlings emerge from the mother as juveniles, similar to a live birth.

<span class="mw-page-title-main">Onychopoda</span> Suborder of small freshwater animals

Onychopoda are a specialised order of branchiopod crustaceans, belonging to the superorder Cladocera.

<i>Bythotrephes longimanus</i> Spiny water flea

Bythotrephes longimanus, or the spiny water flea, is a planktonic crustacean less than 15 millimetres (0.6 in) long. It is native to fresh waters of Northern Europe and Asia, but has been accidentally introduced and widely distributed in the Great Lakes area of North America since the 1980s. Bythotrephes is typified by a long abdominal spine with several barbs which protect it from predators.

<span class="mw-page-title-main">Diplostraca</span> Order of small freshwater animals

The Diplostraca or Cladocera, commonly known as water fleas, is a superorder of small, mostly freshwater crustaceans, most of which feed on microscopic chunks of organic matter, though some forms are predatory.

<i>Moina</i> Genus of small freshwater animals

Moina is a genus of crustaceans within the family Moinidae. The genus was first described by W. Baird in 1850. They are referred to as water fleas, but are related to the much larger Daphnia magna and the larger Daphnia pulex. This genus demonstrates the ability to survive in waters containing low oxygen levels, high salinity, and other impurities, including salt pans, and commonly eutrophication. An example of such an extreme habitat is the highly saline Makgadikgadi Pans of Botswana, which supports prolific numbers of Moina belli.

Threshold host density (NT), in the context of wildlife disease ecology, refers to the concentration of a population of a particular organism as it relates to disease. Specifically, the threshold host density (NT) of a species refers to the minimum concentration of individuals necessary to sustain a given disease within a population.

<i>Daphnia pulex</i> Species of small freshwater animal

Daphnia pulex is the most common species of water flea. It has a cosmopolitan distribution: the species is found throughout the Americas, Europe, and Australia. It is a model species, and was the first crustacean to have its genome sequenced.

<i>Daphnia magna</i> Species of small freshwater animal

Daphnia magna is a small planktonic crustacean that belongs to the subclass Phyllopoda.

<i>Leptodora</i> Genus of small freshwater animals

Leptodora is a genus containing two species of large, nearly transparent predatory water fleas. They grow up to 21 mm (0.83 in) long, with two large antennae used for swimming and a single compound eye. The legs are used to catch copepods that it comes into contact with by chance. Leptodora kindtii is found in temperate lakes across the Northern Hemisphere and is probably the only water flea species ever described in a newspaper; L. richardi is only known from eastern Russia. For most of the year, Leptodora reproduces parthenogenetically, with males only appearing late in the season, to produce winter eggs which hatch the following spring. Leptodora is the only genus in its family, the Leptodoridae, and suborder, Haplopoda.

Daphnia lumholtzi is a species of small, invasive water fleas that originates in the tropical and subtropical lakes of Africa, Asia, and Australia. As an invasive species, Daphnia lumholtzi disrupts aquatic habitats by spreading throughout the warmer waters of lakes and reservoirs.

Pasteuria is a genus of mycelial and endospore-forming, nonmotile gram-positive bacteria that are obligate parasites of some nematodes and crustaceans. The genus of Pasteuria was previously classified within the family Alicyclobacillaceae, but has since been moved to the family Pasteuriaceae.

<i>Daphnia longispina</i> Species of small freshwater animal

Daphnia longispina is a planktonic crustacean of the family Daphniidae, a cladoceran freshwater water flea. It is native to Eurasia. D. longispina is similar in size and sometimes confused with the often sympatric D. pulex, but much smaller than D. magna. D. longispina is found in a wide range of standing freshwater bodies from small, ephemeral rock-pools to large lakes.

<i>Ordospora colligata</i> Intracellular parasite

Ordospora colligata is an intracellular parasite belonging to the Microsporidia. It is an obligatory gut parasite with the crustacean Daphnia magna as its only host. So far it has been reported from Europe and Asia.

<span class="mw-page-title-main">Pasteuria ramosa</span> Species of bacterium

Pasteuria ramosa is a gram-positive, endospore-forming bacterium in the Bacillus/Clostridia clade within Bacillota. It is an obligate pathogen of cladoceran crustaceans from the genus Daphnia. Daphnia is a genus of small planktonic crustaceans including D. magna, P. ramosa's most popular host target. Other hosts include D. pulex, D. longispina, D. dentifera, and Moina rectirostris. An established and widely used coevolutionary model of host-pathogen interactions exists with P. ramosa and D. magna.

<i>Hamiltosporidium</i> Genus of fungi

Hamiltosporidium is a genus of Microsporidia, which are intracellular and unicellular parasites. The genus, proposed by Haag et al. in 2010, contains two species; Hamiltosporidium tvaerminnensis, and Hamiltosporidium magnivora. Both species infect only the crustacean Daphnia magna (Waterflea).

<i>Daphnia pulicaria</i> Species of small freshwater animal

Daphnia pulicaria is a species of freshwater crustaceans found within the genus of Daphnia, which are often called "water fleas," and they are commonly used as model organisms for scientific research. Like other species of Daphnia, they reproduce via cyclic parthenogenesis. D. pulicaria are filter-feeders with a diet primarily consisting of algae, including Ankistrodesmus falcatus, and they can be found in deep lakes located in temperate climates. Furthermore, D. pulicaria are ecologically important herbivorous zooplankton, which help control algal populations and are a source of food for some fish. D. pulicaria are closely related to Daphnia pulex, and numerous studies have investigated the nature and strength of this relationship because these species can produce Daphnia pulex-pulicaria hybrids. In recent years, D. pulicaria along with other Daphnia species have been negatively affected by invasive predators, such as Bythotrephes longimanus.

<span class="mw-page-title-main">Dieter Ebert</span>

Dieter Ebert is professor for Zoology and Evolutionary Biology at the Zoological Institute at the University of Basel in Basel, Switzerland. He is an evolutionary ecologist and geneticist, known for his research on host–pathogen interaction and coevolution, mainly using the model system Daphnia and its parasites.

References

  1. 1 2 N.N.Smirnov (2014). The physiology of the Cladocera. Amsterdam: Academic Press.
  2. Dieter Ebert (2005). "Introduction to Daphnia biology". Ecology, Epidemiology, and Evolution of Parasitism in Daphnia. Bethesda, MD: National Center for Biotechnology Information. ISBN   978-1-932811-06-3.

Further reading