Putative thermo-/hygroreceptive tarsal sensilla on the sensory legs of an armored harvestman (Arachnida, Opiliones)

Autor(es)

Gainett, Guilherme ^{[1, 2]} ; Michalik, Peter ^[3] ; Mueller, Carsten H. G. ^[3] ; Giribet, Gonzalo ^{[4, 5]} ; Talarico, Giovanni ^[6] ; Willemart, Rodrigo H. ^{[7, 1, 2]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Escola Artes Ciencias & Humanidades, Lab Ecol Sensorial & Comportamento Artropodes, Rua Arlindo Beittio 100, BR-03828000 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Inst Biociencias, Programa Posgrad Zool, Rua Maaot 321, Travessa 14, BR-05508090 Sao Paulo, SP - Brazil

^[3] Ernst Moritz Arndt Univ Greifswald, Dept Gen & Systemat Zool, Museum & Inst Zool, Loitzer Str 26, D-17487 Greifswald - Germany

^[4] Harvard Univ, Museum Comparat Zool, 26 Oxford St, Cambridge, MA 02138 - USA

^[5] Harvard Univ, Dept Organism & Evolutionary Biol, 26 Oxford St, Cambridge, MA 02138 - USA

^[6] Univ Med Greifswald, Inst Legal Med, Dept Forens Toxicol, Kuhstr 30, D-17489 Greifswald - Germany

^[7] Univ Fed Sao Paulo, Programa Posgrad Ecol & Evolucao, Campus Diadema, Rua Prof Artur Riedel 275, BR-09972270 Diadema, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ZOOLOGISCHER ANZEIGER; v. 270, p. 81-97, 2017.
• Citações Web of Science: 2

Resumo

Most harvestman species are dependent on high humidity levels and amenable temperatures for homeostasis. While they are known to actively choose environments with these conditions, no thermo/hygroreceptor has yet been identified in harvestmen. Using electron microscopy, we investigated the ultrastructure of two types of hair sensilla of the armored harvestman Heteromitobates discolor (Laniatores, Gonyleptidae): namely the sensillum basiconicum and the hooded sensillum. Both structures occur in small numbers (sensilla basiconica: 28 units; hooded sensilla: 4 units) and are distributed on the distal parts of the legs. On the distalmost tarsomeres I and II, the receptor cells of paired sensilla basiconica and single hooded sensillum occupy a large volume of the inner tissue, and appear tightly associated. The sensillum basiconicum is innervated by 3-4 dendrites and has a longitudinal slit giving the impression of a shaft with two flaps, resembling a beak. The slit probably allows for evaporation of sensillum lymph. The hooded sensillum is innervated by two bundles of three dendrites each, has two pore-like structures on its tip and displays an unusual reticulate cuticle of the shaft. Details of shaft cuticle, the evidence of evaporation of sensillum lymph, and specific innervation patterns support our hypothesis that sensilla basiconica are thermo- and/or hygroreceptors. Even though the definite function of hooded sensilla remains unclear, its putative receptor modalities are assessed by means of specific ultrastructures. Finally, we discuss with regard to functional ultrastructures as to whether the evaporation system of sensilla basiconica fits mechanisms of hygroreception as known from current literature. (C) 2017 Elsevier GmbH. All rights reserved. (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
• Processo FAPESP: 13/23189-1 - Morfologia interna das potenciais cerdas olfativas no opilião Heteromitobates discolor (Arachnida: Opiliones: Laniatores)
• Beneficiário: Guilherme Gainett Cardoso Martins de Carvalho Florez
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 14/07671-0 - Ultraestrutura das sensilla chaetica no opilião Heteromitobates discolor (Arachnida: Opiliones: Laniatores)
• Beneficiário: Guilherme Gainett Cardoso Martins de Carvalho Florez
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Mestrado