Green hippopotamus
| Green hippopotamus | ||||||||||||
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Green mermaid ( Ophiogomphus cecilia ), male |
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| Scientific name | ||||||||||||
| Ophiogomphus cecilia | ||||||||||||
| ( Fourcroy , 1785) |
The green mermaid ( Ophiogomphus cecilia , syn .: Ophiogomphus serpentinus ) is a type of dragonfly from the family of the river damsel ( Gomphidae ), which belongs to the large dragonflies ( Anisoptera ). The name Green Keiljungfer can often be found for the species in German-language literature . However, this name is not unambiguous, since the species of the genus Gomphus are also referred to as "wedge maids" .
features
The green mermaid is a strongly built dragonfly with a wingspan of 6.5 to 7.5 cm and a body length of about 5 cm. Due to the lime green color of the breast, the species in both sexes can hardly be confused with other river maidens, even if their abdomen, as in the other species of the genus, has a typical, yellow-black mark, which is an excellent camouflage color.
distribution
The main distribution area of the species is in Eastern Europe and reaches Kazakhstan in the east . In the west, the closed area ends around the Rhine . The distribution limit runs in the north through southern Scandinavia , in the south through the Balkan Peninsula and northern Greece to the Caucasus . Individual stray deposits can still be found in the Po plain, on the Loire and in southern France. All information on the occurrence of the Green Snaketail on the Iberian Peninsula are false and based on identification errors of pliers dragonfly larvae. The altitude distribution is mostly limited to lower altitudes below 500 meters. However, a few stray individuals have already been detected in the Alps up to 1300 m.
habitat
The green hippopotamus primarily inhabits flowing waters of the lowlands and the plains, from brooks from 50 cm wide to rivers and canals up to larger rivers. A smaller, shaded stream with a sandy bottom and clean water in forest areas is usually given as the ideal habitat type, but the ecological range of this species is much larger: it can colonize most rivers up to slow-flowing streams, and even in groundwater-influenced still waters larvae can develop. The larvae live in different, even coarser sediments, but avoid muddy areas.
Way of life
Flight time
The green hippopotamus is a dragonfly species of midsummer, its emergence period begins around the end of May and lasts into August. The flight time ends in October.
behavior
After hatching, the young adults leave the water and during a three-week maturation period spread out several kilometers from the developing water in the surrounding area, in warmer regions also often in the high areas of the surrounding mountainous region. They can only be found again in the water as sexually mature, adult animals. Usually you can only observe the males there, who like to sit next to each other from trees or stones to look for females at a distance of a few meters in smaller rivers, or who patrol slowly over the water in larger rivers. The females only come to the water to mate and lay their eggs and are therefore rarely seen.
Mating and laying eggs
The pairing begins immediately without a tandem flight with the pairing bike and takes about five to ten minutes. Then the females fly alone to the water, where they sit down and squeeze a pea-sized egg lump with their abdomen lifted, which they then gradually wipe off on the surface of the water with rocking movements.
Larval life
The nocturnal larvae often live in coarse sediments such as sand and coarse sand, where they quietly ambush their prey as hunters from high ground. As “substrate opportunists”, you can also work in coarse gravel or - in flow-calmed areas - even on larger stones such as B. those live on groynes, where they then actively catch prey. The development cycle of the larvae comprises more than ten stages and is three or four years, with a three-year development probably being the rule.
Endangerment and legal position
Due to its close ties to near-natural rivers that are only slightly contaminated with pollutants, the green mermaid disappeared from large parts of Central Europe after 1950. In addition to discharges of pollutants and nutrients, the main risk factors are hydraulic engineering measures such as straightening, bank reinforcement and excavation of sediment to improve navigability. In Germany, the species is no longer listed as endangered according to the current version of the Red List (previously it was considered "critically endangered"). In the last few years, at least in Germany, there have been signs of a recovery and re-expansion, presumably mainly due to an improvement in water quality.
According to the Red List of Austria, the endangerment situation of the green hippopotamus in four federal states is rated differently with category 1 ("critically endangered"), category 2 ("endangered") and category 4 ("potential endangerment or threat") . Switzerland lists this dragonfly species as "Endangered". The world population is classified by the International Union for Conservation of Nature IUCN in the 2009 edition of the Red List of Threatened Species as Least Concern.
The green mermaid is a type of the Habitats Directive , Annexes II (protected areas are to be designated) and IV (to be strictly protected). In Germany it is strictly protected under the Federal Nature Conservation Act.
swell
Individual evidence
- ↑ J. Ott, K.-J. Conze, A. Günther, M. Lohr, R. Mauersberger, H.-J. Rohland, F. Suhling: Red list and total species list of dragonflies in Germany with analysis of responsibility, third version, as of the beginning of 2012 (Odonata) . In: Libellula. Supplement Volume 14, 2015, pp. 395-422.
- ↑ z. E.g. J. Müller, R. Steglich: Red list of dragonflies (Odonata) in Saxony-Anhalt. In: Reports of the State Office for the Environment of Saxony-Anhalt. Volume 39, 2004, pp. 212-216. (lau.sachsen-anhalt.de ; pdf)
- ↑ WISIA.de
literature
- F. Suhling, O. Müller: The river maids of Europe - Gomphidae. (= The New Brehm Library. 628). Westarp, Magdeburg and Spektrum, Heidelberg 1996, ISBN 3-89432-459-7 .
- O. Müller: Ecological studies on gomphids (Odonata: Anisoptera) with special consideration of their larval stages. Cuvillier, Göttingen 1995, ISBN 3-89588-179-1 .
- K. Sternberg, B. Höppner, A. Heitz, S. Heitz: Ophiogomphus cecilia (Fourcoy, 1785). In: Klaus Sternberg, Rainer Buchwald (Hrsg.): Die Libellen Baden-Württemberg. Volume 2: Dragonflies (Anisoptera). Ulmer, Stuttgart 2000, ISBN 3-8001-3514-0 , pp. 358-373.
- O. Müller: Rock fillings from groynes as a larval habitat for Ophiogomphus cecilia (Odonata: Gomphidae). In: Libellula. Volume 23, 2004, pp. 45-51.
Web links
- Ophiogomphus cecilia onthe IUCN Red List of Threatened Species 2009.2. Posted by: Malikova, E., 2007. Retrieved December 27, 2009.