Egg Production Constrains Chemical Defenses in a Neotropical Arachnid

Autor(es)

Nazareth, Tais M. ^[1] ; Machado, Glauco ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Programa Posgrad Ecol, Dept Ecol, Inst Biociencias, BR-05508900 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, LAGE, Dept Ecol, Inst Biociencias, BR-05508900 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLoS One; v. 10, n. 9 SEP 2 2015.
• Citações Web of Science: 6

Resumo

Female investment in large eggs increases the demand for fatty acids, which are allocated for yolk production. Since the biosynthetic pathway leading to fatty acids uses the same precursors used in the formation of polyketides, allocation trade-offs are expected to emerge. Therefore, egg production should constrain the investment in chemical defenses based on polyketides, such as benzoquinones. We tested this hypothesis using the harvestman Acutiosoma longipes, which produces large eggs and releases benzoquinones as chemical defense. We predicted that the amount of secretion released by ovigerous females (OFs) would be smaller than that of non-ovigerous females (NOF). We also conducted a series of bioassays in the field and in the laboratory to test whether egg production renders OFs more vulnerable to predation. OFs produce less secretion than NOFs, which is congruent with the hypothesis that egg production constrains the investment in chemical defenses. Results of the bioassays show that the secretion released by OFs is less effective in deterring potential predators (ants and spiders) than the secretion released by NOFs. In conclusion, females allocate resources to chemical defenses in a way that preserves a primary biological function related to reproduction. However, the trade-off between egg and secretion production makes OFs vulnerable to predators. We suggest that egg production is a critical moment in the life of harvestman females, representing perhaps the highest cost of reproduction in the group. (AU)

• Processo FAPESP: 12/50229-1 - Macro-ecologia da seleção sexual: influencia do clima sobre caracteres sexualmente selecionados em uma ampla escala geográfica
• Beneficiário: Glauco Machado
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 02/00381-0 - Investimento parental e evolução do comportamento sub-social em opiliões da família Gonyleptidae (Arachnida: Opiliones)
• Beneficiário: Glauco Machado
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 99/05446-8 - Biodiversidade de Arachnida e Myriapoda do estado de São Paulo
• Beneficiário: Antonio Domingos Brescovit
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Temático
• Processo FAPESP: 11/50800-8 - Defesa quimica em opilioes da familia gonyleptidae.
• Beneficiário: Taís Maria de Nazareth Gonçalves
• Modalidade de apoio: Bolsas no Brasil - Doutorado