Ametropus fragilis
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| Scientific name | ||||||||||
| Ametropus fragilis | ||||||||||
| Albarda , 1878 |
Ametropus fragilis is a mayfly -Art. It is the only representative of its genus in Europe.
features
The adults of the species are similar to other mayflies and show few distinctive features. Identifying features are: short anterior tibia , features in the wing veins in the forewing. The animals have (small) hind wings and only two tail threads ( terminal filum is missing). The eyes are also undivided in the male. The wings are crystal clear without drawing.
The larvae are of the swimming type with a vertical head and a series of laterally protruding gill leaves on the abdomen, which makes them resemble larvae of the common Baetis genus when viewed superficially . Like many mayfly larvae, they are pale in color with dark markings. On the abdominal segments 8 and 9, small thorn-like projections sit on the rear corners.
Ecology and way of life
Ametropus fragilis is a type of large rivers ( Potamalart ) and is completely absent in streams. It occurs preferentially in the plain. The larvae colonize the sandy bottom of the water, preferably where the sand is somewhat secured by dead wood (submerged branches and tree trunks). The larvae are usually partially buried in the sand so that only the head and front body are visible. They feed on algae and other fine particulate organic material which they graze on the substrate surface. The larvae are nocturnal. The species takes a year to develop. Larvae grow rapidly in summer, complete their development in winter and hatch in late spring or early summer (peak: May). The subimaginal stage lives about 24 hours, the imago about two to three days.
distribution
The species is distributed holarctic and occurs in North America, Northern Asia and Europe. The North American and Siberian populations were described as separate species ( Ametropus albrighti , Ametropus eatoni ). In Europe today the species is very rare and only a little more common in the east. Larger populations are e.g. B. from the Warta and Pilica in Poland and from the Tisza (Tisza) in Hungary (where she survived the cyanide accident of January 30, 2000) known. In Germany the species was first discovered in 1999 in the Lausitzer Neisse , d. H. discovered immediately on the Polish border; this occurrence is the only known one in Germany to this day. Accordingly, the species is considered critically endangered in Germany ( Red List Category 1). In Austria it was first found in 2002 in the Lafnitz . Originally the species was probably widespread in the lowlands. The first description was made by Albarda using material from the Dutch Lower Rhine , where it is now extinct. The reason for the decline is presumably the combination of water pollution and the expansion and bank reinforcement of almost all major European rivers.
literature
- Torsten Berger, Udo Rothe: Ametropus fragilis Albarda, 1878 (Insecta, Ephemeroptera). New for Germany with notes on distribution, biology and status of the species. In: Lauterbornia. 37, 1999, pp. 199-211 ( PDF on ZOBODAT ).
- T. Jazdzewska: Notes on the biology and ecology of the mayfly Ametropus eatoni Brodskij (Ephemeroptera). In: Polskije Pismo Entomologiczne 43, 1973, pp. 469-477.
- Udo Jacob: Contribution to Potamalen Ephemeroptera species 1: Ametropus fragilis Albarda, 1878. In: Lauterbornia. 58, 2006, pp. 17-21.
- Tibor Kovacs, Ernst Bauernfeind, András Ambrus, Walter Reisinger: New records of mayflies from Austria. In: Linz Biological Contributions. Volume 34, Issue 2, Linz 2002, pp. 1035-1042 ( PDF on ZOBODAT ).
- AWM Mol: Een overzicht van de Nederlands adhere (Ephemeroptera). 2: Overige families. In: Entomological Reports 45, 1985, pp. 128-135.
- Klaus Wendling, Arne Haybach: Notes on some mayflies (Insecta: Ephemeroptera) from the Theiss in Hungary after the cyanide accident in Baja Mare (Romania) in 2000. In: Lauterbornia. 46, 2003, pp. 77-81 ( PDF on ZOBODAT ).