On the function of the spoon-shaped pedipalps of harvestmen in the family Cosmetidae (Opiliones, Laniatores)

Autor(es)

Pagoti, Guilherme Ferreira ^{[1, 2]} ; Portela, Erika ^[3] ; Campanha, Jessica Silva ^[2] ; Dias, Jessica Morais ^{[1, 2]} ; Willemart, Rodrigo Hirata ^{[1, 2, 4]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biociencias, Programa Posgrad Zool, Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Lab Ecol Sensorial & Comportamento Artropodes, Escola Artes Ciencias & Humanidades, Sao Paulo, SP - Brazil

^[3] Inst Ciencias Biol, Dept Biol, Manaus, Amazonas - Brazil

^[4] Univ Fed Sao Paulo, Programa Posgrad Ecol & Evolucao, Campus Diadema, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Natural History; v. 53, n. 33-34, p. 2087-2098, SEP 10 2019.
• Citações Web of Science: 0

Resumo

Pedipalps in laniatorid harvestmen are usually cylindrical and raptorial, but species in Cosmetidae are exceptional in that adults, but not immature, have pedipalps flattened as a spoon. These have never been addressed with a functional approach. We have investigated possible roles of the pedipalps in Cosmetidae in exploration, social interactions and defence. Concerning exploration, we would expect the individuals to tap the substrate with the pedipalps, as species in the suborders Eupnoi and Dyspnoi do, but this was not observed. In social interactions, pedipalps could be used for holding females during mating or to fight other males but we could not relate the spoon-shape with any of the behaviours observed. For defence, we hypothesised that the pedipalp of adults would act as a barrier preventing the potentially noxious secretion from contacting the mouth when the individual performs `leg-dabbing'. This is typical in adult cosmetids but not in other laniatorids. Because immature cosmetids have cylindrical pedipalps, we predicted that they would not perform `leg-dabbing'. However, immature also performed leg-dabbing and the secretion did contact the mouth. We also found no evidence of pedipalps being used for digging, drinking or self-grooming. Although we have made progress, the question remains open. (AU)

• Processo FAPESP: 10/00915-0 - Comunicação química em opiliões (Arachnida, Opiliones): morfologia, comportamento e química
• Beneficiário: Rodrigo Hirata Willemart
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores