Racata Millidge, 1995
publication ID |
https://doi.org/ 10.5281/zenodo.2619518 |
DOI |
https://doi.org/10.5281/zenodo.3706023 |
persistent identifier |
https://treatment.plazi.org/id/0C41EA60-516D-835E-FC4D-372835F1FD6A |
treatment provided by |
Carolina |
scientific name |
Racata Millidge, 1995 |
status |
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Racata Millidge, 1995 View in CoL
Type species: Racata grata Millidge, 1995 View in CoL , by original designation and monotypy.
Diagnosis: Members of the genus Racata can be easily recognised by the “micronetine”-like chaetotaxy, by the highly developed convector and by the presence of a panicle-shaped median membrane in the palpal organ. Females are distinguished by a distinct epigynal cavity, which is often surrounded by sclerotized swellings, and by mostly helical copulatory ducts. The genus contains medium-sized spiders with a total length of 1.45-1.75, which are characterized by the following combination of somatic and genitalic characters:
1) Carapace unmodified in both sexes, eyes somewhat enlarged, cephalic pits (= sulci) absent.
2) Chaetotaxy formula: TiI: 2-1-1-0; II: 2-0-1-0, III- IV: 2-0-0-0; MtI-IV without spines; MtIV without trichobothrium; TmI 0.20-0.30.
3) Palpal tibia simple, unmodified.
4) Distal part of cymbium narrowed.
5) Convector highly developed and sclerotized.
6) Median membrane panicle-shaped.
7) Epigyne with distinct cavity, usually surrounded by sclerotized swellings.
8) Copulatory ducts mostly wide, helical.
Species included: Racata brevis sp. nov., R. sumatera sp. nov. ( Indonesia: Sumatra), R. grata Millidge, 1995 ( Indonesia: Krakatoa, Java and Belitung) and R. laxa sp. nov. ( Indonesia: Sumatra; Thailand: Ko Chang).
Taxonomic remarks: The genus Racata was established from a male and placed into the subfamily Dubiaraneinae ( Millidge, 1995) on the basis of the structure of its embolic division. Due to the same reason Millidge (1995) also placed the following Southeast Asian genera into the Dubiaraneinae : Kenocymbium Millidge & Russell-Smith, 1992 , Ketambea Millidge & Russell-Smith, 1992 , Prosoponoides Millidge & Russell-Smith, 1992 and Thainetes Millidge, 1995 . The subfamily Dubiaraneinae is defined by only a single character of the vulva, i.e.: “… the seminal [= copulatory] duct of the epigynum running along the margins of a lamina, as in the Mynogleninae ; in the majority of the species, the lamina is coiled into a short, almost planar helix, the axis of which is more or less perpendicular to the plane of the epigynum…” ( Millidge, 1993). However, as pointed out by Millidge & Russell-Smith (1992), the epigyne in all above mentioned genera (including Racata ) is of the linyphiine type and is quite different from that of Dubiaranea Mello-Leitão, 1943 , the type genus of the Dubiaraneinae . At present it is premature to discuss the position of these genera in the system of subfamilies in the Linyphiidae until the subfamily Dubiaraneinae is clearly diagnosed. In the meantime I provisionally consider the genus Racata as belonging to the Erigoninae . The small size and erigoninelike general appearance, and the structure of the genitalia, which are similar to that of some Southeast Asian erigonines, i.e., Asiagone Tanasevitch, 2014a , Houshenzinus Tanasevitch, 2006 , Laogone Tanasevitch, 2014a , Nasoona Locket, 1982 , Oedothorax Bertkau in Förster & Bertkau, 1883 , etc., support the preliminarily inclusion of Racata in the Erigoninae . The only problem I see here is in the chaetotaxy formula, which is absolutely not characteristic for the subfamily, but rather for the Micronetinae or Linyphiinae .
The genus is closely related to Aperturina Tanasevitch, 2014b , known from Thailand and West Malaysia ( Tanasevitch, 2014b).
Distribution: So far known only from Indonesia and Thailand.
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