Short-legged daddy longlegs: An integrative and comprehensive approach to unravel the evolution of the enigmatic spiders of the daddy longlegs subfamily Ninetinae (Araneae: Pholcidae)

• Applicants: Dr. Bernhard A. Huber; Professor Peter Michalik, Ph.D.
• Subject Area: Systematics and Morphology (Zoology) ; Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: from 2018 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 406691167

• Final Report Year: 2024

Final Report Abstract

The aim of this project was an integrative analysis of Ninetinae, the most poorly known subfamily of daddy long-legs spiders (Pholcidae). In particular, we aimed to: (1) collect these tiny and cryptic spiders across much of their geographic range; (2) analyze the phylogeny of Ninetinae and their position among Pholcidae by adding a large sample of Ninetinae taxa to the available molecular datasets and by improving these datasets using UCE data rather than only Sanger sequences; (3) study a range of biogeographical questions related to sampling biases, environmental niche evolution, and distribution modelling; and (4) analyze the morphology and biology of selected Ninetinae taxa in detail, with an emphasis on ultrastructure, internal anatomy (using TEM), sperm morphology, and sexual biology. These aims have mostly been achieved, and several manuscripts are either published, in press, or submitted. So far, we achieved the following main results: (1) we collected Ninetinae at nine expeditions to nine countries, resulting in ~3320 adult specimens, more than all previous collections worldwide taken together; (2) we generated a UCE dataset with a strong representation of Ninetinae, and combined these data with previously published and new Sanger sequences into the most comprehensive phylogeny in arachnology (>1000 species; 96% of all known pholcid genera); (3) we documented strong sampling biases, a phylogenetically conserved environmental niche for the subfamily, and used distribution modelling to predict occurrences of Ninetinae in several poorly sampled regions; (4) we analyzed in detail the ultrastructure of numerous species, added to two of the largest arachnological datasets on sperm ultrastructure and karyology, generated first data about internal anatomy, and studied for the first time the sexual biology of a Ninetinae spider. So far, a total of 14 publications resulted directly from this project, all submitted to peer-reviewed and rated journals. However, the COVID-19 pandemic was a serious challenge for the project, delaying collecting expeditions, lab work, and eventually the preparation of publications. Therefore, several planned publications are still in preparation.

Publications

• Evolutionary morphology of sperm in pholcid spiders (Pholcidae, Synspermiata). BMC Zoology, 7(1).
  Dederichs, Tim M.; Huber, Bernhard A. & Michalik, Peter
  
• Metagonia spiders of Galápagos: blind cave-dwellers and their epigean relatives (Araneae, Pholcidae). Invertebrate Systematics, 36(7), 647-678.
  Huber, Bernhard A.; Meng, Guanliang; Acurio, Andrea E.; Astrin, Jonas J.; Inclán, Diego J.; Izquierdo, Matias & Valdez-Mondragón, Alejandro
  
• Copulatory behaviour and genital mechanics suggest sperm allocation by a non-intromittent sclerite in a pholcid spider. Royal Society Open Science, 10(5).
  Izquierdo, M. A.; Dederichs, T. M.; Cargnelutti, F. & Michalik, P.
  
• High and dry: integrative taxonomy of the Andean spider genus Nerudia (Araneae: Pholcidae). Zoological Journal of the Linnean Society, 198(2), 534-591.
  Huber, Bernhard A.; Meng, Guanliang; Král, Jiří; Ávila, Herrera Ivalú M.; Izquierdo, Matias A. & Carvalho, Leonardo S.
  
• Humpback spiders from Ecuador: relationships, prosoma ‘inflation’ and genital asymmetry (Araneae: Pholcidae: Mecolaesthus). Invertebrate Systematics, 37(2), 117-151.
  Huber, Bernhard A.; Meng, Guanliang; Dupérré, Nadine; Herrera, Mauricio; Inclán, Diego J. & Wipfler, Benjamin
  
• Revision of the South American Ninetinae genus Guaranita (Araneae, Pholcidae). European Journal of Taxonomy, 900.
  Huber, Bernhard A.; Meng, Guanliang; Král, Jiří; Ávila, Herrera Ivalú M. & Izquierdo, Matías A.
  
• Short-legged daddy-long-leg spiders in North America: the genera Pholcophora and Tolteca (Araneae, Pholcidae). European Journal of Taxonomy, 880.
  Huber, Bernhard A.; Meng, Guanliang; Valdez-Mondragón, Alejandro; Král, Jiří; Ávila, Herrera Ivalú M. & Carvalho, Leonardo S.
  
• Castaways: the Leeward Antilles endemic spider genus Papiamenta (Araneae: Pholcidae). Invertebrate Systematics, 38(2).
  Huber, Bernhard A.; Meng, Guanliang; Dederichs, Tim M.; Michalik, Peter; Forman, Martin & Král, Jiří
  
• Diamonds in the rough: Ibotyporanga (Araneae, Pholcidae) spiders in semi-arid Neotropical environments. European Journal of Taxonomy, 963, 1-169.
  Huber, Bernhard A.; Meng, Guanliang; Král, Jiří; Ávila, Herrera Ivalú M. & Carvalho, Leonardo S.
  
• Thriving in dry conditions: on the Neotropical spider genus Galapa (Araneae: Pholcidae). Zootaxa, 5419(3), 301-347.
  HUBER, BERNHARD A.; MENG, GUANLIANG; GARCÍA, JIMMY CABRA & CARVALHO, LEONARDO S.