''Cloeon dipterum'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

mayfly Mayflies (also known as shadflies or fishflies in Canada and the upper Midwestern United States, as Canadian soldiers in the American Great Lakes region, and as up-winged flies in the United Kingdom) are aquatic insects belonging to the ord ...

with a

Holarctic The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical region ...

distribution. It is the most common mayfly in ponds in the British Isles and the only

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...

mayfly in Europe. Males differ from females in having turbinate eyes.

Description

In common with other members of the genera ''

Cloeon ''Cloeon'' is a cosmopolitan genus of mayflies of the family Baetidae. Species * '' Cloeon degrangei'' * ''Cloeon dipterum ''Cloeon dipterum'' is a species of mayfly with a Holarctic distribution. It is the most common mayfly in ponds in the ...

'' and '' Procloeon'', ''C. dipterum'' has a single pair of wings. This is also reflected in the

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''dipterum'', which is from the Latin ', meaning two, and the Greek ', meaning

wing A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is expres ...

, and in his original description,

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

stated ' ("smaller wings hardly present"). The

compound eye A compound eye is a visual organ found in arthropods such as insects and crustaceans. It may consist of thousands of ommatidia, which are tiny independent photoreception units that consist of a cornea, lens, and photoreceptor cells which disti ...

s of ''C. dipterum'' show a striking

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

, whereby females have lateral

apposition eye Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and con ...

s, while the males' eyes have an additional dorsal "

turban A turban (from Persian دولبند‌, ''dulband''; via Middle French ''turbant'') is a type of headwear based on cloth winding. Featuring many variations, it is worn as customary headwear by people of various cultures. Communities with promine ...

-shaped" parts that function as superposition eyes. These extra eyes are thought to enable the males to locate isolated females in the mating swarm.

Ecology and life cycle

''Cloeon dipterum'' is unusual among mayflies in being

, and is the only ovoviviparous mayfly species known in Europe. Females lay eggs 10–14 days after mating, and the eggs hatch as soon as they hit the water. The

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

e can survive for months in

anoxic The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia and hypoxia are used in various contexts: * Anoxic waters, sea water, fresh water or groundwater that are depleted of diss ...

conditions, an

adaptation In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the po ...

which is necessary to survive the winter in ponds which freeze over and therefore contain little

dissolved oxygen Oxygen saturation (symbol SO2) is a relative measure of the concentration of oxygen that is dissolved or carried in a given medium as a proportion of the maximal concentration that can be dissolved in that medium at the given temperature. It ca ...

. In captivity, adult females have been kept alive for up to three weeks.

Distribution and taxonomy

''Cloeon dipterum'' was first described by

in the 2nd edition of his '' Fauna Suecica''. Since then, ''Cloeon dipterum'' has been the recipient of unusually many

taxonomic synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnae ...

s. Alongside new combinations of Linnaeus' original name in different genera (''

Ephemera Ephemera are transitory creations which are not meant to be retained or preserved. Its etymological origins extends to Ancient Greece, with the common definition of the word being: "the minor transient documents of everyday life". Ambiguous in ...

'', ''Chloeon'', ''Cloe'' and '' Cloeopsis''), true synonyms include three introduced by

Otto Friedrich Müller Otto Friedrich Müller, also known as Otto Friedrich Mueller (2 November 1730 – 26 December 1784) was a Danish naturalist and scientific illustrator. Biography Müller was born in Copenhagen. He was educated for the church, became tutor to a yo ...

in 1776 (''E. annulatum'', ''E. rufulum'' and ''E. dimidiatum''), one by

William Elford Leach William Elford Leach Royal Society, FRS (2 February 1791 – 25 August 1836) was an English zoologist and marine biologist. Life and work Elford Leach was born at Hoe Gate, Plymouth, the son of an attorney. At the age of twelve he began a me ...

in 1815 (''C. pallidum''), two by John Curtis in 1834 (''C. marmoratum'' and ''C. obscurum''), three by

James Francis Stephens James Francis Stephens (16 September 1792 – 22 December 1852) was an English entomologist and naturalist. He is known for his 12 volume ''Illustrations of British Entomology'' (1846) and the ''Manual of British Beetles'' (1839). Early li ...

in 1835 (''C. cognatum'', ''C. consobrinum'' and ''C. virgo''), and one each by

Jules Pierre Rambur Jules Pierre Rambur (21 July 1801 – 10 August 1870) was a French entomologist. Rambur was born in Chinon. He studied the insect fauna of Corsica and Andalusia. He was the author of ''Histoire naturelle des insectes'' (1842) amongst other works ...

in 1842 (''C. affinis''), Costa in 1882 (''C. apicalis''), Bengtsson in 1940 (''C. inscriptum'') and Jacob in 1969 (''C. szegedi''). ''Cloeon dipterum'' is widespread across Europe and Asia. In the British Isles, ''C. dipterum'' is the commonest mayfly in

pond A pond is an area filled with water, either natural or artificial, that is smaller than a lake. Defining them to be less than in area, less than deep, and with less than 30% emergent vegetation helps in distinguishing their ecology from th ...

s, with around 40% of all ponds containing ''C. dipterum'', rising to 70% in the south. In 1953, a single female ''Cloeon dipterum'' was discovered in

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...

, having not been previously recorded in North America, and was found near

Lucas Lucas or LUCAS may refer to: People * Lucas (surname) * Lucas (given name) Arts and entertainment * Luca Family Singers, also known as "lucas ligner en torsk" * ''Lucas'' (album) (2007), an album by Skeletons and the Kings of All Cities * ''L ...

Ohio Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...

in 1960. The species is now known to have a wide distribution in North America. Individuals of ''C. dipterum'' from

Madeira ) , anthem = ( en, "Anthem of the Autonomous Region of Madeira") , song_type = Regional anthem , image_map=EU-Portugal_with_Madeira_circled.svg , map_alt=Location of Madeira , map_caption=Location of Madeira , subdivision_type=Sovereign st ...

are now placed in a different species, '' Cloeon peregrinator''.

References

{{Taxonbar, from=Q691414 Mayflies Insects described in 1761 Taxa named by Carl Linnaeus Insects of Asia Insects of Europe Insects of North America

Description

Ecology and life cycle

Distribution and taxonomy

See also

References