''Enallagma cyathigerum'' (common blue damselfly or common bluet) is a species found mainly between

latitude In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...

s 40°N and 72°N; It is widely distributed in the

Palearctic The Palearctic or Palaearctic is a biogeographic realm of the Earth, the largest of eight. Confined almost entirely to the Eastern Hemisphere, it stretches across Europe and Asia, north of the foothills of the Himalayas, and North Africa. Th ...

, common in all European countries (including

Portugal Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it share ...

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

Great Britain Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European ...

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

Finland Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...

, etc.) and in Asia in

Turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...

Iran Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

, and

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...

. The species reaches a length of with wings long.

Damselflies Damselflies are flying insects of the suborder Zygoptera in the order Odonata. They are similar to dragonflies (which constitute the other odonatan suborder, Epiprocta) but are usually smaller and have slimmer bodies. Most species fold the win ...

are an important link between the health of the

aquatic ecosystem An aquatic ecosystem is an ecosystem found in and around a body of water, in contrast to land-based terrestrial ecosystems. Aquatic ecosystems contain communities of organisms—aquatic life—that are dependent on each other and on their environ ...

and its response to

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

. The closely related

Nearctic The Nearctic realm is one of the eight biogeographic realms constituting the Earth's land surface. The Nearctic realm covers most of North America, including Greenland, Central Florida, and the highlands of Mexico. The parts of North America ...

species '' Enallagma annexum'' (northern bluet) was at one time considered to be synonymous with it.

Habitat

These damselflies inhabit

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

bodies whose conditions range, they have been seen in acidic

fens A fen is a type of wetland. Fen, Fenn, Fens, Fenns, may also refer to: People * Fen (name), a Chinese given name and surname * Fen Cresswell (1915–1966), New Zealand cricketer * Fen McDonald (1891–1915), Australian rules footballer * Ke ...

as well as

eutrophic Eutrophication is a general term describing a process in which nutrients accumulate in a body of water, resulting in an increased growth of organisms that may deplete the oxygen in the water; ie. the process of too many plants growing on the s ...

pond A pond is a small, still, land-based body of water formed by pooling inside a depression (geology), depression, either naturally or artificiality, artificially. A pond is smaller than a lake and there are no official criteria distinguishing ...

s. They have been considered one of the more sensitive insects in an aquatic setting. They are important within the

trophic level The trophic level of an organism is the position it occupies in a food web. Within a food web, a food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the ...

s as they are an intermediate

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

. They consume smaller

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e and they are preyed on by fish and larvae bigger than them. The larvae prefer a habitat that has a more complex structure in the ground composition as well as the plants. The larval stages spend most of their time within the plants, climbing and feeding. Although they do prefer a more complex habitat, they can also be found in habitats with simpler vegetation. They are efficient in both complexities equally, but the complex vegetation also serves as protection from fish. These larvae are able to live in a dense population in shallow areas of water without showing signs of competition between the larvae. The damselfly larvae require a plant structure that can withstand the backward movement that occurs when the labium protracts to catch food.

Identification

The males of this species are a caerulean blue colour with black markings, while the females have a larger variation in their colouring. Within females there are a few different morphs in which they can take, andromorph and heteromorph. Andromorphic females resemble the caerulean blue males, but they have more black patterning on their bodies. The heteromorphic females are more of a brown or green brown colour and do not resemble the males at all. The reasoning behind the different morphs is to attempt to limit the amount of attention the female receives when she is near the water for reproduction. The common blue damselfly can be easily mistaken for the azure damselfly ('' Coenagrion puella''), but on the back and the

thorax The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main di ...

, the common blue damselfly has more blue than black; for the azure damselfly it is the other way around. The second segment of the thorax has a distinctive spot with a line below connecting to the third segment. Another difference can be observed when inspecting the side of the thorax. The common blue damselfly has only one small black stripe there, while all other blue damselflies have two.

Lifecycles

The lifecycle of this species begins in freshwater, they spend most of their time as larvae. The larval stage depends on the temperature, light, and the resource level. Once the temperatures drop the larvae can go into a state called

diapause In animal dormancy, diapause is the delay in development in response to regular and recurring periods of adverse environmental conditions.Tauber, M.J., Tauber, C.A., Masaki, S. (1986) ''Seasonal Adaptations of Insects''. Oxford University Press It ...

instead of dying. The damselflies that endure diapause effect the body size for the next season. Since these damselflies are flexible, they have two different lifecycles depending on latitude

univoltine Voltinism is a term used in biology to indicate the number of broods or generations of an organism in a year. The term is most often applied to insects, and is particularly in use in sericulture, where silkworm varieties vary in their voltinism. ...

or semivoltine. The more north these damselflies are found, the more likely they are to be semivoltine. By being able to shift the lifecycle due to the conditions this allows for twice the amount of development time, so larger adults are typically found in more northern areas. Once the larvae emerge as adults between May and August they have a brief time to feed before they are to find a mate and reproduce the next generation of larvae. Once emerged, there is an estimated

sex ratio A sex ratio is the ratio of males to females in a population. As explained by Fisher's principle, for evolutionary reasons this is typically about 1:1 in species which reproduce sexually. However, many species deviate from an even sex ratio, ei ...

of 1:1 within the colony, allows for mating within the colony to be less of a competition. During mating, the male clasps the female by her neck while she bends her body around to his reproductive organs – this is called a mating wheel. The pair flies together over the water and eggs are laid within a suitable plant, just below the surface. The eggs hatch and the larvae, called nymphs, live in the water and feed on small aquatic animals. Nymphs climb out of the water up a suitable stem to molt into damselflies.

Behaviour

All ''Coenagrionid'' larvae have a broad range in diet, so they can live in many different habitats. The larvae are able to eat relatively large prey items, but the prey are typically less mobile and therefore easier to catch. The males in the colony show a higher mobility level compared to other species. There has also been pairings with ''

Ischnura elegans The blue-tailed damselfly or common bluetail (''Ischnura elegans'') is a damselfly, belonging to the family Coenagrionidae. Subspecies and varieties Subspecies and varieties include: *''Ischnura elegans ebneri'' Schmidt, 1938 *''Ischnura eleg ...

'' and '' Coenagrion puella'' which are similar to '' Enallagma'', although this occurs when there is same species mates are unable to be located. This damselfly requires a close look for a beginner to distinguish them from an azure damselfly. Typically, they fly low through the reeds and often fly well out over the water, unlike azure damselflies. They are also a brighter blue.

Mitogenome

The

mitogenome Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the DNA contained in ...

was

sequenced In genetics and biochemistry, sequencing means to determine the primary structure (sometimes incorrectly called the primary sequence) of an unbranched biopolymer. Sequencing results in a symbolic linear depiction known as a sequence which succi ...

for this species. The circular DNA sequence is 16,661

base pair A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...

s long. Within the order ''

Odonata Odonata is an order of predatory flying insects that includes the dragonflies and damselflies (as well as the '' Epiophlebia'' damsel-dragonflies). The two major groups are distinguished with dragonflies (Anisoptera) usually being bulkier with ...

'' it is one of the largest mitogenomes to be sequenced thus far. The composition of the sequence is 74.2%

adenine Adenine (, ) (nucleoside#List of nucleosides and corresponding nucleobases, symbol A or Ade) is a purine nucleotide base that is found in DNA, RNA, and Adenosine triphosphate, ATP. Usually a white crystalline subtance. The shape of adenine is ...

and

thymine Thymine () (symbol T or Thy) is one of the four nucleotide bases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenine, guanine, and cytosine. Thymine is also known as 5-methyluracil, a pyrimidine ...

and 25.8%

cytosine Cytosine () (symbol C or Cyt) is one of the four nucleotide bases found in DNA and RNA, along with adenine, guanine, and thymine ( uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attac ...

and

guanine Guanine () (symbol G or Gua) is one of the four main nucleotide bases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine ( uracil in RNA). In DNA, guanine is paired with cytosine. The guanine nucleoside ...

. This knowledge assists with the placement within a

phylogenetic tree A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA. In ...

Human impacts

Pesticide Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...

s have a large impact on this species due to its sensitivity. These pesticides are introduced to the water by runoff and by being added directly. Being exposed to pesticides made these organisms less likely to be successful in

metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth transformation or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and different ...

with the effects being worse the longer the organism is exposed. The exposure to the larvae has effects on the adult life stage in regard to their fitness Behaviour is lessened by the introduction of pesticides.

Gallery

File:Enallagma cyathigerum 5(loz).jpg, Distinctive marking at base of abdomen of male segment S2 File:Common blue damselfly (Enallagma cyathigerum) male dark variant.jpg, Adult male, dark variant of S2 File:Common blue damselfly (Enallagma cyathigerum) male.jpg, Adult male File:Common blue damselfly (Enallagma cyathigerum) heterochrome female 2.jpg, Heterochrome female File:Common blue damselfly (Enallagma cyathigerum) heterochrome female (green variety).jpg, Heterochrome female (green variety) File:Common blue damselflies (Enallagma cyathigerum) (heterochrome female) in tandem.jpg, In tandem
(heterochrome female) File:Common blue damselflies (Enallagma cyathigerum) (homochrome female) in tandem.jpg, In tandem
(homochrome female) File:Common blue damselflies (Enallagma cyathigerum) mating Burren.jpg, Mating File:Enallagma cyathigerum - 2013-08-22.webm, Oviposition on ''

Marsilea quadrifolia ''Marsilea quadrifolia'' is a herbaceous plant found naturally in central and southern Europe, Caucasia, western Siberia, Afghanistan, south-west India, China, Japan, and Vietnam, though it is considered a weed in some parts of the United States, ...

'' File:Common bluet.webm, thumbtime=0, Common blue damselfly, genus Enallagma, family

Coenagrionidae Coenagrionidae is a family of damselflies, also known as pond damselflies, in the order Odonata and the suborder Zygoptera. The Zygoptera are the damselflies, which although less known than the dragonflies, are no less common. More than 1,300 spec ...

References

External links

*
Bugguide.net page on ''Enallagma'' damselflies

Youtube video of ''E. cyathigerum''
{{Taxonbar, from=Q608908 Coenagrionidae Damselflies of Europe Insects described in 1840 Odonata of Asia Odonata of North America Taxa named by Toussaint de Charpentier Articles containing video clips