Sabacon Explained

Sabacon is a genus of the monotypic harvestman family Sabaconidae,[1] [2] with 59 species (as of 2023).[3]

Description

Species of the genus Sabacon have usually thickened pedipalps with stiff, fine hairs, which is unique among harvestmen. Although the small eye tubercle is usually not ornamented, there is a spine on one Nepalese species. Males have long, thin legs, females are stouter.[4]

While the Asian and North American species are easy to differentiate from one another by male genital traits. The various European species are very similar to each other, and can be closely related to Sabacon cavicolens from the eastern United States. Another American species Sabacon mitchelli, which, like the larger S. cavicolens also occurs in the eastern United States, notably lacks cheliceral glands in the male. Species from the western United States seem closely related to Asian forms. Sabacon astoriensis, initially collected from dried seaweed and debris in beach dunes from Oregon, is morphologically similar to the Asian species Sabacon dentipalpis and Sabacon makinoi.[4]

Range

Sabacon species exhibits a wide, yet highly disjunct, distribution. Species can be found throughout North America, Europe, and Asia,[3] [5] though individual species usually have very restricted distributions.[6] [7] [8]

The genus Sabacon is widespread in the temperate northern hemisphere, even extending into the subarctic, with the most southern records from caves in the southeastern United States and high elevations in Nepal. The center of diversification seems to be in Asia, where many species were described from Japan, Korea and Nepal. Some species occur in Europe.[4] [8]

Ecology

Almost all Sabacon species prefer moist, cool microhabitats, and many species live in caves, but none are modified for cave life. Outside of caves they are often found in forests or shaded ravines.[4]

Etymology

The name of the type genus is supposedly derived from "Sabacon", an Egyptian ruler.[9] Consequentially, genus name is treated as masculine, although before its derivation was clarified some authors or online sources mistakenly treated it as neuter, e.g. 's Biology Catalog.[10]

Fossil record

There is one extinct species †Sabacon claviger, known from Eocene Baltic amber. Another named species †Sabacon bachofeni also from Baltic amber was later revised as its junior synonym.[11] Staręga (2002: p. 602)[11] indicates that for all such the Baltic Amber material, "The Eocene locality fits into the present range of the genus Sabacon"

Relationships

Sabaconidae belongs to the superfamily Ischyropsalidoidea. The family Sabaconidae originally consisted of just the genus Sabacon, though Taracus was later added to the family. Hesperonemastoma was later transferred in to further expand this family after molecular studies confirmed it was closely related to Taracus. However, a new family, Taracidae, was then erected for Hesperonemastoma and Taracus, leaving Sabaconidae restored once again with just a single genus (i.e. monogeneric).[12] Currently, Sabaconidae is thought to be more closely related to Taracidae than Ischyropsalididae. The internal relationships of Sabaconidae are poorly understood.[13]

Taxonomy

See main article: List of Dyspnoi species.

Sabacon contains the following species, per World Catalog of Opiliones.[3] Of the 59 described species (as of 2023), two are further subdivided into subspecies.

Notes and References

  1. Book: Simon. E.. 1879. Les Arachnides de France. Tome 7. Contenant les ordres des Chernetes, Scorpiones et Opiliones. Librairie Encyclopédique de Roret. Paris. 7. 1–332, pl. 17–24.
  2. Dresco. E.. 1970. Recherches sur la variabilité et la phylogénie chez les opilions du genre Ischyropsalis C. L. Koch (Fam. Ischyropsalidae), avec création de la famille nouvelle des Sabaconidae. Bulletin du Muséum national d'histoire naturelle. 2. 14. 5. 1200–1213. en.
  3. Web site: Sabacon. 2023-12-08. Kury, A. et al. (2023). WCO-Lite: World Catalogue of Opiliones.
  4. Shear. W.A.. 1975. The opilionid genera Sabacon and Tomicomerus in America (Opiliones, Troguloidea, Ischyropsalidae). The Journal of Arachnology. 3. 1. 5–29. en.
  5. Web site: Sabacon. iNaturalist. 2023-12-08. en.
  6. Martens. J.. 1972. Opiliones aus dem Nepal-Himalaya. I. Das Genus Sabacon Simon (Arachnida: Ischyropsalididae). Senckenbergiana Biologica. 53. 3/4. 307–323. de.
  7. Martens. J.. 1983. Europäische Arten der Gattung Sabacon Simon 1879 (Arachnida: Opiliones: Sabaconidae). Senckenbergiana Biologica. 63. 3/4. 265–296. de.
  8. Book: Martens. J.. 2015. Sabacon Simon, 1879 in the Palaearctic: A survey of new and known species from France, Nepal, India, China, Russia and Japan (Arachnida: Opiliones: Sabaconidae). Hartmann. M.. Weipert. J.. Biodiversity and Natural Heritage of the Himalaya V.. Naturkundemuseum Erfurt. Germany. 167–210.
  9. Gruber. E.. 2003. Origin and gender of the name Sabacon Simon, 1879 (Opiliones, Palpatores, Ischyropsalidoidea). Newsletter of the British Arachnological Society. 96. 6. en.
  10. Web site: Sabaconidae. Joel Hallan's Biology Catalog. https://web.archive.org/web/20141013064730/https://insects.tamu.edu/research/collection/hallan/Acari/Family/Sabaconidae.txt . en. 2014-12-13. 2014-10-13 .
  11. Staręga. W.. 2002. Baltic amber harvestmen (Opiliones) from Polish collections. Annales Zoologici. 52. 601–604, 4 ff. en.
  12. Schönhofer. A.XL.. 2013. A taxonomic catalogue of the Dyspnoi Hansen and Sørensen, 1904 (Arachnida: Opiliones). Zootaxa. 3679. 1. 1–68. 10.11646/zootaxa.3679.1.1 . 26146693 . 1175-5326. en. free.
  13. Schönhofer. A.L.. McCormack. L.. Tsurusaki. N.. Martens. J.. Hedin. M.. 2013. Molecular phylogeny of the harvestmen genus Sabacon (Arachnida: Opiliones: Dyspnoi) reveals multiple Eocene-Oligocene intercontinental dispersal events in the Holarctic. Molecular Phylogenetics and Evolution. 66. 1. 303–315. 10.1016/j.ympev.2012.10.001. 23085535 . en.