Tarantulas
Tarantulas | ||||||||||||
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Mygalomorphae | ||||||||||||
Pocock , 1892 |
Tarantulas (Mygalomorphae) are a suborder of arachnids from the order of the web spiders . An older name is Orthognatha (parallel jaw ). The tarantulas comprise 20 families with 351 genera and a total of 3037 species . (As of December 2018)
features
The animals are often relatively large and live mainly in warm climates. The mouthparts ( chelicerae ) work almost parallel to each other (orthognath), not like forceps against each other (labidognath). The eyes are usually close together on a flat hill on the back armor ( carapace ). The hips of the pedipalps (pair of legs of the spiders converted into antennae) are very similar to the hips of the legs , except for the Atypidae . They usually have two pairs of fan trachea and four, more rarely three pairs of ostia and two pairs of coxal glands .
The chelicerae of the tarantula are directed forward (orthognath), here using the example of a red chile tarantula ( Grammostola rosea ).
Real spiders like the wet nurse's thorn finger ( Cheiracanthium punctorium ), however, have inwardly directed chelicerae (labidognath).
Tarantulas usually have two pairs, less often one or three pairs of spinnerets . The anterior and middle pair of spinnerets are always missing, there is neither a cribellum nor a calamistrum .
The inputs of the semen stores (spermathek or receptacula seminis ) go directly from the vagina, the females lack an adjustable cover ( epigyne ) that blocks the internal genital organs and thus also the possibility of closing or closing the fertilization ducts leading to the external uterus for the semen To separate mating and fertilization of the eggs from one another in time, as is the case with the females of entelegynous spiders. The pedipalps of the tarantula-like are also more simply built , as well as the bulbs at the end, which have been converted into a secondary sex organ in the males , and which in this subordination are mostly pear-shaped and heavily armored.
Both sexes of the tarantulas usually reach a much higher age than is known from the real spiders, whereby the females always outlast the males significantly ( Brachypelma smithi females in captivity around up to 25 years, females of some atypus species at least up to 10 years). The highest documented age of a spider was 43 years for a female of the species Gaius villosus (Idiopidae). This is also seen as an archaic feature of these spiders.
At least similarly large species are also found among the following families or genera of real spiders (Araneomorphae):
External system
Spiders (Araneae) |
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Internal system
The relationships within the tarantulas are shown in the following cladogram according to Raven , 1985. Not included in the cladogram are the families Euctenizidae (7 genera, 76 species), an earlier subfamily of the Cyrtaucheniidae , and the Halonoproctidae (6 genera, 84 species), their genera previously belonged to the Ctenizidae . Numbers of genera and species according to the World Spider Catalog . (As of December 2018)
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literature
- Coddington, JA and HW Levi. 1991. Systematics and evolution of spiders (Araneae). Annual Review of Ecology and Systematics 22: 565-592.
- Miller, JA and FA Coyle. 1996. Cladistic analysis of the Atypoides plus Antrodiaetus lineage of mygalomorph spiders (Araneae, Antrodiaetidae). Journal of Arachnology 24: 201-213.
- Hans Ekkehard Gruner (Eds.), M. Moritz, W. Dunger; 1993; Textbook of special zoology, Volume I: Invertebrates, Part 4: Arthropoda (without insects)
Individual evidence
- ↑ a b Currently valid spider genera and species in the World Spider Catalog, Version 19.5. Natural history museum of the civic community of Bern. Retrieved December 24, 2018.
- ↑ Leanda Denise Mason, Grant Wardell-Johnson, Barbara York Main: The longest-lived spider: mygalomorphs dig deep, and persevere . In: CSIRO Publishing (Ed.): Pacific Conservation Biology . CSIRO Publishing, Perth, Australia. April 19, 2018, doi : 10.1071 / PC18015 .
- ↑ Marcus Schmitt: Where the wild things live: Tarantula relationship (Atypus affinis, Araneae) in Ruthertal between Werden and Kettwig (Essen) . , Electronic articles from the Biological Station Westliches Ruhrgebiet 12 (2008): 1-9; P. 3. (PDF; 680 KB)
- ^ Raven, Robert J. (1985): The spider infraorder Mygalomorphae (Araneae). Cladistics and systematics. Bull. Amer. Mus. Nat. Hist. 182, pp. 1-180.