The evolution and function of spider feet (Araneae: Arachnida): multiple acquisitions of distal articulations

Autor(es)

Labarque, Facundo M. ^{[1, 2]} ; Wolff, Jonas O. ^{[3, 4]} ; Michalik, Peter ^[5] ; Griswold, Charles E. ^{[2, 6, 7, 8]} ; Ramirez, Martin J. ^[9]

Afiliação do(s) autor(es)

^[1] Inst Butantan, Lab Especial Colecoes Zool, Av Vital Brasil 1500, BR-05503900 Sao Paulo, SP - Brazil

^[2] Calif Acad Sci, 55 Mus Concourse Dr, San Francisco, CA 94118 - USA

^[3] Macquarie Univ, Dept Biol Sci, Sydney, NSW 2109 - Australia

^[4] Univ Kiel, Zool Inst, Funct Morphol & Biomech, D-24118 Kiel - Germany

^[5] Ernst Moritz Arndt Univ Greifswald, Zool Inst & Museum, Loitzer Str 26, D-17489 Greifswald - Germany

^[6] San Francisco State Univ, Biol Dept, 1600 Holloway Ave, San Francisco, CA 94132 - USA

^[7] Univ Calif Berkeley, Environm Sci Policy & Management, 101 Sproul Hall, Berkeley, CA 94704 - USA

^[8] George Washington Univ, Biol Dept, 2121 1 St NW, Washington, DC 20052 - USA

^[9] Consejo Nacl Invest Cient & Tecn, Museo Argentino Ciencias Nat Bernardino Rivadavia, Av Angel Gallardo 470, Buenos Aires, DF - Argentina

• Tipo de documento: Artigo Científico
• Fonte: ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY; v. 181, n. 2, p. 308-341, OCT 2017.
• Citações Web of Science: 4

Resumo

The tip of the legs concentrates the interactions that a spider has with the substrate where it lives. We review the morphology and evolution of spider feet, discussing the functional anatomy of their articulations and proposing a coherent terminology. All spiders consistently have two tendons to operate their feet and show a stereotyped sequence of levation of the pretarsus and its claws prior to detachment from the substrate. A pair of slit sensilla, the foot slits, provide a reliable landmark across most spiders. The evolutionary reconstruction of morphological variants using a composite tree of spiders indicates that similar morphologies arose independently, with multiple acquisitions of one to four distal articulations. A distal articulation appeared repeatedly at the foot slits, the podotarsite, and at least three independent origins of highly articulated feet correspond with cuticular structures to retain the flexor tendons in the proper ventral position. Our results indicate that while in some spiders the adhesive setae were added to articulate feet, in other taxa the sequence was opposite. We conclude that a limited repertoire of feet articulations appeared and reversed many times in spider evolution, and combine in many ways to produce a highly diverse functional unit. (AU)

• Processo FAPESP: 14/23369-2 - Tarso e pretarso: uma narrativa sobre a evolução e função dos últimos segmentos das pernas das aranhas
• Beneficiário: Facundo Martin Labarque
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado