Euscorpius alpha

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Euscorpius alpha
Euscorpius alpha

Euscorpius alpha

Systematics
Sub-stem : Jawbearers (Chelicerata)
Class : Arachnids (arachnida)
Order : Scorpions (Scorpionides)
Family : Euscorpiidae
Genre : Euscorpius
Type : Euscorpius alpha
Scientific name
Euscorpius alpha
Caporiacco , 1950

Euscorpius alpha is a scorpion species from the family of euscorpiidae . The relatively small distribution area of ​​the very small species with a length of less than 30 mm is limited to the southern Alps .

features

With a length of less than 30 mm, E. alpha is one of the smallest species in the genus Euscorpius . Swiss males from populations of different origins had mean lengths between 19.9 and 23.3 mm, the slightly larger females reached an average of 21.0 to 26.4 mm. The animals are almost monochrome black, only the belly and the telson are a little lighter.

E. alpha differs from the other species of the genus in the lack of keels in the segments of the mesosoma and mostly 6, rarely 7 trichobothria on the underside of the pedipalpe hand (Chela manus). The morphological differences between E. alpha and the very closely related species Euscorpius germanus are very small, E. germanus normally has 5 trichobothria on the underside of the pedipalp hand.

distribution and habitat

The relatively small distribution area is limited to the southern Alps in Switzerland and Italy. In Switzerland the species occurs only in the extreme south in the cantons of Graubünden , Ticino and Valais , in Italy mainly west of the Adige in the regions of Piedmont , Lombardy and Trentino-South Tyrol .

In Switzerland, E. alpha lives in roughly equal parts near-natural and strongly anthropogenically influenced habitats. The former are mainly chestnut forests and beech and other deciduous forests, more rarely other forest types such as larch forests and pre-forests as well as stone rubble and scree meadows. The anthropogenic habitats are mainly split stone walls inside and outside of settlements. The species occurs in Switzerland and Italy up to altitudes of 1800 to 1900 m.

Systematics

E. alpha is placed together with four other species of the genus Euscorpius in the subgenus Alpiscorpius . E. alpha was only recognized as a species in its own right on the basis of genetic studies in 2000; the taxon was previously considered a subspecies of E. germanus .

Way of life

E. alpha , like all species of the genus Euscorpius, should eat arthropods of all kinds in the right size. Very little is known about nutrition in the wild; in Switzerland, field crickets , woodlice and caterpillars have been identified as prey .

Females with young animals have only been observed outdoors in August and September, and mating apparently only takes place during this period. According to this, the animals probably only have young once a year, with the gestation period lasting 11–11.5 months. E. alpha is like all scorpions viviparous ( viviparous ), the hatchlings break immediately after birth their Embryonalhaut and climb on the back of the mother. The number of young animals is only known from pregnant wild-caught animals whose young were born in the laboratory; here the number of young animals per female was between 1 and 18, the mean for different populations between 10 and 16 young animals. As is usual with scorpions, the young scorpions leave their mother after the first molt, with E. alpha this occurs after 5 to 7 days.

According to captivity observations, males need 4–5 moults, females 5–6 moults before sexual maturity. According to Braunwalder, the animals in the wild should then have an age of at least 1.5 (males) or at least 2 years (females). Both sexes usually have a life expectancy of 3 to 4 years. Information on natural enemies or parasites is not available from the field.

Danger

The hazard situation is assessed differently in different areas. In Italy the species is considered not endangered, in Switzerland as endangered. For Switzerland, Braunwalder sees the main risk factors in the rapid overgrowth of open, semi-arid sites, in erosion and landslides, in agricultural intensification and in the destruction of the preferred dry stone walls by new construction and reconstruction of buildings, roads, retaining walls, etc.

swell

Individual evidence

  1. ^ ME Braunwalder: Scorpiones (Arachnida). Fauna Helvetica 13, Neuchâtel 2005, ISBN 2-88414-025-5 : p. 38
  2. ^ ME Braunwalder: Scorpiones (Arachnida). Fauna Helvetica 13, Neuchâtel 2005, ISBN 2-88414-025-5 : pp. 24 and 28
  3. ^ ME Braunwalder: Scorpiones (Arachnida). Fauna Helvetica 13, Neuchâtel 2005, ISBN 2-88414-025-5 : pp. 38–39
  4. ^ ME Braunwalder: Scorpiones (Arachnida). Fauna Helvetica 13, Neuchâtel 2005, ISBN 2-88414-025-5 : p. 120, p. 126–144
  5. ^ ME Braunwalder: Scorpiones (Arachnida). Fauna Helvetica 13, Neuchâtel 2005, ISBN 2-88414-025-5 : p. 128
  6. ^ V. Fet: Scorpions of Europe. Acta Zool. Bulg. 62 (1), 2010: pp. 3-12
  7. ↑ B. Gantenbein, V. Fet, M. Bauer & A. Scholl: Nuclear and mitochondrial markers reveal the existence of two parapatric scorpion species in the Alps: Euscorpius germanus (CL Koch, 1837) and E. alpha Caporiacco, 1950, stat . nov. (Euscorpiidae). Revue Suisse de Zoologie 107 (4): pp. 843–869
  8. ^ ME Braunwalder: Scorpiones (Arachnida). Fauna Helvetica 13, Neuchâtel 2005, ISBN 2-88414-025-5 : pp. 66–68
  9. ^ ME Braunwalder: Scorpiones (Arachnida). Fauna Helvetica 13, Neuchâtel 2005, ISBN 2-88414-025-5 : pp. 70, 79 and 84
  10. ^ ME Braunwalder: Scorpiones (Arachnida). Fauna Helvetica 13, Neuchâtel 2005, ISBN 2-88414-025-5 : pp. 84–85 and 93–94
  11. ^ ME Braunwalder: Scorpiones (Arachnida). Fauna Helvetica 13, Neuchâtel 2005, ISBN 2-88414-025-5 : p. 68
  12. ^ ME Braunwalder: Scorpiones (Arachnida). Fauna Helvetica 13, Neuchâtel 2005, ISBN 2-88414-025-5 : pp. 191–193

literature

  • ME Braunwalder: Scorpiones (Arachnida). Fauna Helvetica 13, Neuchâtel 2005, ISBN 2-88414-025-5
  • B. Gantenbein, M. Bauer, V. Fet & A. Scholl: Nuclear and mitochondrial markers reveal the existence of two parapatric scorpion species in the Alps: Euscorpius germanus (CL Koch, 1837) and E. alpha Caporiacco, 1950, stat. nov. (Euscorpiidae). Revue suisse de Zoologie, 107 (4): pp. 843–869