Sorensenellinae Explained

Sorensenellinae is a subfamily of harvestmen in the family Triaenonychidae created by Ray Forster. It includes genera from New Zealand and South Africa, but later phylogenetic studies do not support the inclusion of the South African taxa. Egg guarding is reported in both New Zealand genera and appears to be an example of paternal care.[1] [2]

Taxonomy

Sorensenellinae is a subfamily of harvestmen in the family Triaenonychidae and was erected by Ray Forster in his 1954 monograph on New Zealand Laniatores. The subfamily includes four genera: Sorensenella Pocock, 1903 and Karamea Forster, 1954 from New Zealand, and Roeweria Lawrence, 1931[3] (now Lawrencella Strand, 1932) and Speleomontia Lawrence, 1931 from South Africa. Forster's spelling was Soerensenellinae, which he derived from Soerensenella, which was an incorrect spelling of the original name of Sorensenella.[4]

Key features

Forster described members of this subfamily as having the third and fourth tarsal claws with strong lateral processes equal to, or larger than the median prong. Forster also noted the laying of eggs in a single group that is subsequently guarded by the female until they hatch.

Paternal care

While Forster reported that egg guarding by females is a feature of the Sorensenellinae, Glauco Machado observed that a photograph on p56 of Ray and Lyn Forster's book Spiders of New Zealand and their Worldwide Kin[5] clearly showed a male specimen of Karamea guarding eggs, even though the caption states it is female. Based on Forster's statement of egg guarding behaviour across Sorensenellinae, Machado reasoned that paternal rather than maternal care was likely to be the rule in this subfamily.[6]

Phylogenetics

Molecular studies using Sanger[7] and ultra conserved element[8] sequencing show Sorensenella forms a clade with its nearest relative Karamea, and these genera are estimated to have diverged from one another during the Cretaceous. While these studies affirm the close relationship between Soerensenella and Karamea, they do not support Forster's inclusion of Roeweria (now Lawrencella) and Speleomontia from South Africa in Sorensenellinae.

Notes and References

  1. Forster, R.R. (1954) The New Zealand harvestmen (sub-order Laniatores). Canterbury Museum Bulletin, 2, 1–329
  2. Web site: Sorensenellinae Forster, 1954 COL . 2024-03-20 . www.catalogueoflife.org.
  3. Lawrence . Reginald Francis . 1931-01-01 . The harvest-spiders (Opiliones) of South Africa . Annals of the South African Museum . English . 29 . 341–508.
  4. Pocock . Reginald Innes . 1903-01-01 . On some new harvest-spiders of the order Opiliones from the southern continents . Proceedings of the Zoological Society of London . 1902 . 392–413.
  5. Book: Forster, Raymond Robert . Spiders of New Zealand and their Worldwide Kin . Forster . Lyndsay McLaren . 1999-01-01 . Otago University Press, Otago Museum.
  6. Machado . Glauco . 2007-04-01 . MATERNAL OR PATERNAL EGG GUARDING? REVISITING PARENTAL CARE IN TRIAENONYCHID HARVESTMEN (OPILIONES) . Journal of Arachnology . 35 . 1 . 202–204 . 10.1636/SH06-14.1.
  7. Baker . Caitlin M. . Sheridan . Kate . Derkarabetian . Shahan . González . Abel Pérez . Giribet . Gonzalo . 2020-08-14 . Molecular phylogeny and biogeography of the temperate Gondwanan family Triaenonychidae (Opiliones: Laniatores) reveals pre-Gondwanan regionalisation, common vicariance, and rare dispersal . Invertebrate Systematics . 34(6) . 637–660 . 10.1071/IS19069.
  8. Derkarabetian . Shahan . Baker . Caitlin M. . Hedin . Marshal . Prieto . Carlos E. . Giribet . Gonzalo . 2021-01-01 . Phylogenomic re-evaluation of Triaenonychoidea (Opiliones : Laniatores), and systematics of Triaenonychidae, including new families, genera and species . Invertebrate Systematics . 10.1071/IS20047.