Baikal Azure Maiden
| Baikal Azure Maiden | ||||||||||||
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| Scientific name | ||||||||||||
| Coenagrion glaciale | ||||||||||||
| ( Selys , 1872) |
The Baikal Azurjungfer ( Coenagrion glaciale ) is a Kleinlibellenart from the family of Coenagrionidae (Coenagrionidae) used as refrigeration stenotopic preferably cold type clear and nutrient-poor water standing waters. The main distribution area is in eastern Siberia , two isolated occurrences south and west of the Urals , and thus already in the European part of Russia, were only recently discovered far west of the previously known area.
features
The Baikal Azurjungfer shows the characteristics typical for Azurjungfer , but with a body length of approx. 25 to 28 millimeters it is significantly smaller compared to the other representatives of the genus, even smaller than the Nordic Azurjungfer ( Coenagrion johanssoni ) living in the same habitat . The post-eyepiece spots are more elongated horizontally than other azure maids and are slightly jagged at the rear edge.
In male adults , the pattern of the abdomen is unmistakable, the majority of abdominal segments three to seven are blackened, the second segment shows a large black U-shaped drawing on the otherwise blue background. The male paraprocts are twice or almost twice as long as the variable cerci , in which the lower ones protrude well beyond the upper ones.
The upper side of the abdomen of the females is mostly black, so that only in the eighth segment, which shows a characteristic constriction of the drawing on the body-facing side of the abdominal segment, the intense deep blue basic color on the thorax and abdomen appears. The posterior edge of the prothorax of female adults shows a gentle but distinctive middle lobe in a dorsal view, which is even more pronounced in a lateral view and , when viewed from the side, makes the prothorax resemble a dog's head.
There is a risk of confusion with the similarly drawn moon azure maiden ( Coenagrion lunulatum ).
distribution
The main distribution area of C. glaciale is in eastern Siberia, from southern Yakutia to the Sea of Okhotsk , and south to northeast China. The exact extent of the occurrence is extremely hypothetical due to the lack of data.
The known occurrences are concentrated in a wide belt in southeast Russia from Lake Baikal and the upper Angara , along the Amur and its western tributaries to the regions of Khabarovsk and Primorye . Here C. glaciale reaches the border with North Korea , where an occurrence is therefore likely, but not confirmed. There are finds from the area southeast of Harbin for Manchuria , but the further distribution in China is practically unknown.
The western limit of distribution runs in a northerly direction along the upper Angara to Bratsk . Further north the course is unknown, the next documented occurrences are in the southwest of Yakutia, near the mouth of the Chayanda in the Njuja and in the basin of the lower Lena . The distribution area reaches its northernmost extent at Zhigansk and then runs southeast to the north of the Sea of Okhotsk. In this section too, there is only incomplete knowledge of the distribution, only a few findings from the basins of the Indigirka and the Moma are known.
The actual range of the Baikal Azure Damselfly is likely to be larger than what is known based on known data, especially at the northwestern limit of range. Two likely isolated occurrences were only discovered in 2009 in two separate studies far west of the previously known area. The first is located in the foothills of the Southern Urals near Chelyabinsk , the second in the Pinega region , west of the Urals and thus already in the European part of Russia and approx. 3200 km from the previously known distribution area and 1350 km from the occurrence in the Southern Urals. The distribution area of C. glaciale is thus more disjoint than previously assumed.
Way of life
The Baikal azure virgin is a species of coldest enotopic , which prefers cold, clear and nutrient-poor water and therefore only occurs in bodies of water that have been frozen over for a long time or are fed by a cold tributary. Standing water is preferred, but C. glaciale seems to be more tolerant in the choice of habitats than the Siberian Azure damsel ( Coenagrion hylas ) and also accepts acidic waters. The Baikal Azurjungfer, which lives mainly in the vegetation, prefers in particular sedge beds of various densities with admixtures of other plant species, which leave enough space for the activities of the species and at the same time offer protection from the wind. An important location factor seems to be the occurrence of wind-limiting forest or bush vegetation, which protects this small and sensitive species in developing waters. This is particularly important because of the adults' early flight time, which is associated with frequent and cool winds.
Systematics
Coenagrion glaciale is placed within the slender dragonflies in the genus of the azure maiden ( Coenagrion ), which was created in 1890 by William Forsell Kirby . The genus, numbering forty species, is mainly found in Europe and Asia, three species are represented in North America. Coenagrion glaciale was first described by Edmond de Selys-Longchamps in 1872 . The specific epithet glaciale is derived from the Latin word glacialis for 'icy' and describes the cold stenotopic species that only occurs in bodies of water that have frozen over for a long time.
swell
Individual evidence
- ↑ a b c d e Rafał Bernard, Bogusław Daraż: Relict occurrence of East Palaearctic dragonflies in northern European Russia, with first records of Coenagrion glaciale in Europe (Odonata: Coenagrionidae). International Journal of Odonatology, Volume 13, Issue 1, 2010, doi : 10.1080 / 13887890.2010.9748359
- ↑ Asmus Schröter: Coenagrion glaciale and Somatochlora graeseri ante portas. Dragonfly news, GdO newsletter, no. 29, February 2013. ISSN 1437-5621
- ^ Duden online: glacial [1] , accessed on April 24, 2013.