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Emperor dragonfly

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Emperor dragonfly
Male
Tenerife, Spain
Female
Oxfordshire, England
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Odonata
Infraorder: Anisoptera
Family: Aeshnidae
Genus: Anax
Species:
A. imperator
Binomial name
Anax imperator
Leach, 1815
Synonyms[1]

The emperor dragonfly[2] or blue emperor[1] (Anax imperator) is a large species of hawker dragonfly of the family Aeshnidae. It is the largest dragonfly in most of Europe, including the United Kingdom,[2] although exceeded in some areas by other species.

Nomenclature

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The generic name Anax is from the ancient Greek ἄναξ, "lord";[3] the specific epithet imperator is the Latin for "emperor", from imperare, to command.[4]

Distribution

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This dragonfly has a wide distribution through Afroeurasia; it is found throughout Africa and through most of Europe, the Arabian Peninsula, and south-western and central Asia.[1] Since the 1990s, its range has expanded in Europe, both northwards and to higher altitudes. For example, the first Scandinavian record was in 1994 in Denmark; in 2002 it was first recorded in Sweden and in 2004 first in Scotland; today it is regular in all three countries.[1][2][5] The species' northward expansion has been tied to global warming, and it is among the first odonata to do so.[1][5]

Identification

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The emperor dragonfly is a large and bulky species. It is 73–82 mm (2.9–3.2 in) long, with average being 78 mm (3.1 in) and males growing larger than females.[2][6] The average wingspan is 104 mm (4.1 in).[6] When they first emerge, both sexes appear pale green with brown markings. The legs are brown with a yellow like base. Wings are born black but grow yellow-brown when they grow. Males have a bright sky blue or turquoise abdomen marked with a diagnostic black dorsal stripe.[7] However, their blue colour may be faded during cold weather spells. The thorax and head of a male is apple green and their prominent eyes are blue. Females have similar markings but they are mainly a duller green.[7] As the females age, their wings become browner. Less immediately visible features for both sexes are the yellow costa and brown spots on the wings.[8] Emperor dragonflies can also be recognised by their flight patterns: they often fly with their abdomen hanging slightly downwards.[2][8]

One of the largest species in Europe, the emperor dragonfly is exceeded by magnificent emperor, which occurs only marginally in the east Mediterranean[9] and in length by females of the golden-ringed dragonfly, a species with an unusually long ovipositor.[10] Thus, in most of Europe the emperor is the largest dragonfly species present.

Behaviour

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They frequently fly high up into the sky in search of prey, which includes butterflies, other odonata and tadpoles. If their hunt is successful, they eat their smaller prey while flying. The dragonflies breed in a variety of aquatic habitats from large ponds to dikes and slow-moving rivers, but require a plentiful supply of vegetation in the water.[5][11] They do sometimes breed in brackish water.[8] The females lay the eggs into plants such as pondweed, and always lay alone. The aquatic larvae are very aggressive and are likely to influence the native species composition of freshwater ecosystems they arrive in.[5] The larvae are also very large–around 46 millimetres (1.8 in).[12] The adult male is highly territorial, and difficult to approach.[7]

Conservation

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Emperor dragonflies are assessed as a least-concern species by the IUCN. The species has widespread and has a stable population.[1]

Mitochrondrial genome

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The mitogenome of the emperor dragonfly is the longest of all known dragonfly sequences. It has 16,087 base pairs.[5] For comparison, the human mitogenome has 16,569 bp[13] and the closely related dragonfly Anax parthenope has 15,366.[14]

References

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  1. ^ a b c d e f g Mitra, A. (2016). "Anax imperator". IUCN Red List of Threatened Species. 2016: e.T59812A72311295. doi:10.2305/IUCN.UK.2016-3.RLTS.T59812A72311295.en. Retrieved 19 November 2021.
  2. ^ a b c d e "Emperor". British Dragonfly Society. Retrieved 25 August 2010.
  3. ^ Beekes, Robert (2010) [2009]. "S.v. ἄναξ". Etymological Dictionary of Greek. Vol. 1. With the assistance of Lucien van Beek. Leiden, Boston: Brill. pp. 98–99. ISBN 978-900417-418-4.
  4. ^ "imperator (n.)". Online Etymology Dictionary. Retrieved 27 August 2021.
  5. ^ a b c d e Herzog, Rebecca; Osigus, Hans−Jürgen; Feindt, Wiebke; Schierwater, Bernd; Hadrys, Heike (29 October 2016). "The complete mitochondrial genome of the emperor dragonfly Anax imperator LEACH, 1815 (Odonata: Aeshnidae) via NGS sequencing". Mitochondrial DNA Part B. 1 (1): 783–786. doi:10.1080/23802359.2016.1186523. PMC 7799497. PMID 33473626. S2CID 89088747.
  6. ^ a b "Anax imperator (Leach, 1815)". Insects of Britain and Ireland: dragonflies and damselflies (Odonata). Retrieved 25 November 2023.
  7. ^ a b c "Emperor dragonfly videos, photos and facts — Anax imperator". ARKive. Archived from the original on 2015-04-09. Retrieved 2013-08-08.
  8. ^ a b c Smallshire, Dave; Swash, Andy (2020-07-14). Europe's Dragonflies: A field guide to the damselflies and dragonflies. Princeton University Press. ISBN 978-0-691-20497-0.
  9. ^ "Anax immaculifrons Rambur, 1842 – Magnificent Emperor". Dragonflies and Damselflies – in and around Europe. Retrieved 25 November 2023.
  10. ^ "Golden-ringed Dragonfly". British Dragonfly Society. Retrieved 25 November 2023.
  11. ^ "Emperor Dragonfly". Lincolnshire Species. Archived from the original on 25 Oct 2003.
  12. ^ Minot, Marceau; Le Gall, Mickael; Huste, Aurelie (2019-09-10). "Biometry of the large dragonfly Anax imperator (Odonata: Aeshnidae): A study of traits from larval development to adults". European Journal of Entomology. 116: 269–280. doi:10.14411/eje.2019.031.
  13. ^ García-Olivares, Víctor; Muñoz-Barrera, Adrián; Lorenzo-Salazar, José M.; Zaragoza-Trello, Carlos; Rubio-Rodríguez, Luis A.; Díaz-de Usera, Ana; Jáspez, David; Iñigo-Campos, Antonio; González-Montelongo, Rafaela; Flores, Carlos (2021-10-15). "A benchmarking of human mitochondrial DNA haplogroup classifiers from whole-genome and whole-exome sequence data". Scientific Reports. 11 (1): 20510. Bibcode:2021NatSR..1120510G. doi:10.1038/s41598-021-99895-5. ISSN 2045-2322. PMC 8519921. PMID 34654896.
  14. ^ Wang, Ying; Du, Yimin; Song, Xiang; Huang, Aijun (2021-01-02). "Complete mitochondrial genome sequence of Anax parthenope (Odonata: Anisoptera: Aeshnidae) and phylogenetic analysis". Mitochondrial DNA Part B. 6 (1): 122–123. doi:10.1080/23802359.2020.1848479. ISSN 2380-2359. PMC 7808743. PMID 33490598.
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