Tarantulas

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Tarantulas
Prickly panther spider (A. aculeata), female

Prickly panther spider ( A. aculeata ), female

Systematics
Sub-stem : Jawbearers (Chelicerata)
Class : Arachnids (arachnida)
Order : Spiders (Araneae)
Subordination : Real spiders (Araneomorphae)
Family : Wolf spiders (Lycosidae)
Genre : Tarantulas
Scientific name
Alopecosa
Simon , 1885

The pseudo-tarantulas ( Alopecosa ), also known as aardwolves or panther spiders , are a genus from the family of the wolf spiders (Lycosidae) within the order of the web spiders that is almost worldwide . With 162 recognized species including subspecies , they are numerically the second largest genus of the family after the barrel wolves ( Pardosa ).

In English, the pseudo-tarantulas are referred to as fox spiders (translated: "fox spiders ") based on the scientific name (see section " Systematics ") .

features

Male of the thick-footed panther spider ( A. cuneata ) with conspicuously thickened tibiae of the first pair of legs

The pseudo-tarantulas have a body length of less than ten to about 20 millimeters, depending on the species, and thus belong to the medium-sized to large wolf spiders, whose physique also corresponds to the species of this genus. The pseudo-tarantulas are comparatively strong and stocky. The prosoma (front body) only gradually falls off compared to that of the common wolves ( Pardosa ), so that in the pseudo-tarantulas this body section is significantly wider than the eye area that is also located there. The species of the genus mostly have brown or grayish colors. The ventral side of the species show either a black or a pale basic color.

The carapace (back shield of the prosoma) of the pseudo-tarantulas is provided with a light median band that appears wider than the eye area. The edges of the carapace are also brightly colored. The radial stripes on the carapace are also typical of the pseudo-tarantulas, but in some species they can also be indistinct or blurred.

The legs of the pseudo-tarantulas are stocky and the tibia (greaves) of the first pair of legs are additionally thickened like a club in the males of some species, such as the thick-footed panther spider ( A. cuneata ).

The opisthosoma (abdomen) is provided with a conspicuous heart mark in all species of the genus, which is shaped and pronounced differently depending on the species. There are two basic shapes for the skewer. In addition, further drawing elements, such as pairs of points or angular spots in individual species of the pseudo-tarantula, can be present on the opisthosoma.

Structure of the sexual organs

The bulbi (male genital organs) in all pseudo-tarantulas each have a tegular apophysis ( chitinized process) which is different depending on the species .

The epigyne (female sex organ) each have a spermathec (seed pocket) and a sclerotized area (consisting of structural proteins ), the structure of which also varies with the different species.

Genera with similar species

Females of Erdwolfsspinne ( Trochosa terricola )
Male of the great sun wolf ( Xerolycosa nemoralis )

Apart from confusion of similar species within the same genus, some with other genera of wolf spiders are also possible. For example, there are similarities with species of the genera of the night wolves ( Trochosa ) and the sun wolves ( Xerolycosa ), whose species also have median bands on the carapace. In the case of the night wolves, however, these are not provided with white hairs and also have black borders.

This is also the case with the somewhat smaller sun wolves. In addition, in contrast to the more compactly built pseudo-tarantulas, these spiders have significantly longer and narrower legs, the tarsi of which each have four groups (two longer and two shorter) of trichobothria (whiskers).

The pseudo-tarantulas also differ from the pirate spiders ( Pirata ), which also belong to this family, by the drawing of the carapace. In contrast to them, pirate spiders have a pair of dark bands in the fovea (a visible indentation on the back of the prosoma) that run in a U or V shape.

Occurrence

Female Scheintarantel in US -State Oklahoma

The pseudo-tarantulas are found on all continents with the exception of Antarctica . The main distribution of the genus is in Asia with the exception of Southeast Asia , where only comparatively few species, including the Alopecosa balinensis endemic to Bali, occur. In Europe the genus is represented with 51 species.

Only a few species such as the prickly panther spider ( A. aculeata ) occur in North America . Alopecosa hirtipes also inhabits Canada and Alopecosa koponeni as the only species of the genus even exclusively inhabits this country. The pseudo-tarantulas are also represented with comparatively few species in South America . Examples would be the species Alopecosa andesiana that occurs in Ecuador, the species Alopecosa fulvastra that is widespread in Venezuela , or the species Alopecosa restricta that lives in Argentina .

Very few species of the pseudo-tarantula exist in Africa . These include Alopecosa atis in North Africa and Alopecosa kalahariana in Botswana . Alopecosa leonhardii occurs in Australia .

Species in German-speaking countries

The dark panther spider ( A. pulverluenta ) is one of the species of pseudo-tarantula that is widespread in Germany

In Germany , Austria and Switzerland there are 16 species of the pseudo-tarantula, with Alopecosa albofasciata only inhabiting the southern part of Switzerland. The species of the genus that are represented in German-speaking countries are the following:

Habitats

Many pseudo-tarantulas inhabit open and dry areas, such as this poor grassland in the Steinberg-Dürrenfeld nature reserve ( Swabian Alb )

The habitats can be very different depending on the species, but many species prefer open and dry areas, such as heaths , lawns and sand areas or also clearings and edges . Some species also inhabit ruderal areas .

The adaptability also varies between the different species, for example some, such as the dark panther spider ( A. pulverulenta ) , inhabit a variety of habitats, while others, such as the sandy dune tarantula ( Alopecosa fabrilis ), are only found in very specific habitats .

Threat and protection

The striped pseudo-tarantula ( A. striatipes ) is one of the endangered species of pseudo-tarantulas

Due to the fact that some species are tied to certain habitats (see section " Habitats "), they are exposed to a not insignificant risk of endangerment, which can sometimes be explained by the decline in these habitats.

Widespread and / or less sensitive species, including the bearded tarantula ( A. accentuata ) or the dark panther spider ( A. pulverulenta ), both of which are classified as "not endangered " in Germany's Red List of Endangered Species, Animals, Plants and Fungi less exposed to the potential danger of decline than the mountain tarantula ( A. inquiliana ), which is included in the warning list ("v").

Other species, such as the dune tarantula ( A. fabrilis ) listed in the Red List of Threatened Species of Animals, Plants and Fungi in Germany in Category 3 ("endangered" ) or the steppe tarantula ( A. schmidti ) listed in the same category , are much more affected by declines. The same applies in particular to the Striped Tarantula ( A. striatipes ) and Sulzer's Tarantula ( A. sulzeri ) listed in Category 2 ("Endangered" ). The pine tarantula ( A. pinetorum ) is also considered extremely rare, but is not included in any category of the Red List of Endangered Species of Animals, Plants and Fungi in Germany and may already be lost or extinct in Germany.

Way of life

Female of the dune tarantula ( A. fabrilis ) at the mouth of its living tube

The pseudo-tarantulas are primarily nocturnal wolf spiders. The females dig for themselves living tubes lined with webs , which serve as a place of residence for the spiders. These living tubes are left at night.

Some pseudo-tarantulas have the ability to move on the surface of the water thanks to their thick hair pads, which give them hydrophobic properties.

Hunting behavior and catch of prey

Male tarantula swimming on the water surface with prey

The hunting behavior of like almost all spiders predators living Scheintaranteln corresponds to the majority of wolf spiders, which also these types without a spider web hunting for the purpose of prey capture, but free-running.

As with wolf spiders, prey animals are perceived with their well-developed eyes. If one of these comes within range of the spider, it overwhelms the prey in a surprise jump, in which it uses the chelicerae (jaw claws) to give the prey a poisonous bite and thus disable it. The prey is then consumed.

Life cycle

The life cycle of the pseudo-tarantulas is divided into several stages and mostly depends on the season.

Phenology

The species of the pseudo-tarantula, which are predominantly found in the temperate climatic zones, have a different phenology (time of activity) depending on the species and sex . However, all species are mainly active in the warm season.

Courtship and mating

Video of a roaming male of the mountain tarantula ( A. inquiliana )

Sexually mature males of the pseudo-tarantulas seek out the living tubes of species-specific females and often do so during the day. If this was detected with the help of the species-specific pheromones (messenger substances) secreted by the female , it begins with a courtship dance that is usual for wolf spiders , in which the male includes all extremities including the pedipalps (transformed extremities in the head area) and the opisthosoma. Movements of the whole body are also not uncommon with the mock tarantulas' courtship behavior.

During mating, the male mounts the female from above as usual and alternately introduces his bulbi (male genital organs) into the epigyne (female genital organ) of his partner.

The young animals lay eggs and grow up

Female tarantula with an egg cocoon

Some time after mating, the female creates an egg cocoon , which, like all wolf spiders, is attached to the spinnerets and transported by the latter. Most of the time, however, the female stays with the egg cocoon in the living tube and occasionally holds it up to the sun during the day to warm it up.

The hatching young animals after a further period of time also climb onto the mother's opisthosoma in the manner of the wolf spiders and allow themselves to be carried there for a while before they become independent and scatter. After some time, like the adult spiders, the juveniles build up living tubes and behave and hunt just like them. In the temperate climate zones, both young and adult spiders overwinter in the living tube. The young animals then reach sexual maturity after wintering in the following year.

Systematics

The genus of the pseudo-tarantulas was first described by Eugène Simon in 1885 and today, with 162 recognized species including subspecies, is the second largest genus within the family of wolf spiders (Lycosidae) after the common wolves ( Pardosa ). The type species of the genus is the dune tarantula ( A. fabrilis ).

Before they were first described, the Mediterranean species of pseudo-tarantulas, like other similarly large wolf spiders found there, including those of the genera Hogna and Lycosa, were grouped together in the now dissolved genus Tarentula .

The scientific name Alopecosa comes from the Greek language and means fox . The generic name itself is a metonym and means something like "hunting like a fox".

Individual evidence

  1. ↑ a b c Alopecosa (Simon, 1885) in the WSC World Spider Catalog , accessed May 23, 2020.
  2. ↑ a b c d e f Alopecosa (Simon, 1885) from The Spiders of Europe and Greenland, accessed on May 23, 2020.
  3. ^ A b Heiko Bellmann: Cosmos Atlas Arachnids of Europe . 3rd ed., 2006. Kosmos, Stuttgart., P. 150, ISBN 978-3-440-10746-1 .
  4. ↑ a b c d e f Alopecosa (Simon, 1885) at the Wiki der Arachnologische Gesellschaft e. V., accessed on May 23, 2020.
  5. ↑ a b c Michael John Roberts: The Spiders of Great Britain and Ireland , Volume 2, Brill Archive, 1985, pp. 132-133, ISBN 9789004076587 .
  6. ↑ L. Bee, G. Oxford, H. Smith: Britain's Spiders: A Field Guide , Princeton University Press, 2017, p. 221, ISBN 9780691165295 .
  7. ↑ P. Just, V. Opatová, P. Dolejš: Does reproductive behavior reflect phylogenetic relationships? An example from Central European Alopecosa wolf spiders (Araneae: Lycosidae) , Zoological Journal of the Linnean Society, Volume 185, Issue 4, 2019, pp. 1039-1056.

literature

  • Heiko Bellmann: Cosmos Atlas Arachnids of Europe . 3rd edition, 2006. Kosmos, Stuttgart. ISBN 978-3-440-10746-1
  • Heiko Bellmann: The cosmos spider guide. Over 400 species in Europe. Kosmos Naturführer, Kosmos (Franckh-Kosmos), 2nd edition, 2016, ISBN 978-3-440-14895-2 .
  • Michael John Roberts: The Spiders of Great Britain and Ireland , Volume 2, Brill Archive, 1985, ISBN 9789004076587 .
  • L. Bee, G. Oxford, H. Smith: Britain's Spiders: A Field Guide , Princeton University Press, 2017, ISBN 9780691165295 .
  • P. Just, V. Opatova, P. Dolejš: Does reproductive behavior reflect phylogenetic relationships? An example from Central European Alopecosa wolf spiders (Araneae: Lycosidae) , Zoological Journal of the Linnean Society, Volume 185, Issue 4, 2019.

Web links

Commons : apparent tarantulas  - collection of images, videos and audio files