Tarsus and pretarsus: a storytelling on the evolution and function of the last segments of the spider's legs

• Grant number: 14/23369-2
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): March 01, 2015
• Effective date (End): July 31, 2017
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Cooperation agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal researcher: Antonio Domingos Brescovit
• Grantee: Facundo Martin Labarque
• Home Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Associated research grant: 11/50689-0 - Systematic of the neotropical haplogynae spiders (Arachnida, Araneae), AP.TEM

Abstract

The classical Haplogynae spiders include 18 families: Filistatidae, Caponiidae, Segestriidae, Dysderidae, Orsolobidae, Oonopidae, Ochyroceratidae, Telemidae, Leptonetidae, Tetrablemmidae, Pholcidae, Diguetidae, Plectreuridae, Sicariidae, Scytodidae, Drymusidae, Periegopidae and Trogloraptoridae. In females with haplogyne condition the gonopore serves as both a copulatory duct and a fertilization duct, being directly connected to the spermathecae, and usually lack complex external sclerotized structures (epigynum). This group emerges as monophyletic in most of the phylogenetic analyses, but the internal relationships among the families are still uncertain. To address these problems, we plan to study the comparative morphology, anatomy and function of the distal segments of the spiders' legs across the phylogeny of spiders with emphasis on Haplogynae. The tip of the spider's tarsus has two ventral condyles, one at each side, where the pretarsus articulates. The pretarsus is a plate-like structure that bears two lateral claws flexible articulated to it upper part and, usually, a protruding median claw. The distal tip of the legs also presents further "divisions" as the onychium, pretarsal scapulae, pretarsal slits and pseudosegments. These characters' system have never been characterized none studied in a spider's phylogenetic perspective. We will explore the diversity of configurations, set landmarks, and discuss homology, convergences and syndromes of the apical leg's segments using several microscopies techniques (light microscopy, scanning electron microscopy, X-ray microtomography and transmission electron microscopy), and adding this information to previously reported morphological phylogenies of Haplogynae spiders. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MICHALIK, PETER; KALLAL, ROBERT; DEDERICHS, TIM M.; LABARQUE, FACUNDO M.; HORMIGA, GUSTAVO; GIRIBET, GONZALO; RAMIREZ, MARTIN J. Phylogenomics and genital morphology of cave raptor spiders (Araneae, Trogloraptoridae) reveal an independent origin of a flow-through female genital system. JOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, v. 57, n. 4 AUG 2019. Web of Science Citations: 1.

LABARQUE, FACUNDO M.; PEREZ-GONZALEZ, ABEL; GRISWOLD, CHARLES E. Molecular phylogeny and revision of the false violin spiders (Araneae: Drymusidae) of Africa. ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, v. 183, n. 2, p. 390-430, JUN 2018. Web of Science Citations: 2.

LABARQUE, FACUNDO M.; WOLFF, JONAS O.; MICHALIK, PETER; GRISWOLD, CHARLES E.; RAMIREZ, MARTIN J. The evolution and function of spider feet (Araneae: Arachnida): multiple acquisitions of distal articulations. ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, v. 181, n. 2, p. 308-341, OCT 2017. Web of Science Citations: 4.