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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Egg Production Constrains Chemical Defenses in a Neotropical Arachnid

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Nazareth, Tais M. [1] ; Machado, Glauco [2]
Total Authors: 2
[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
Total Affiliations: 2
Document type: Journal article
Source: PLoS One; v. 10, n. 9 SEP 2 2015.
Web of Science Citations: 6

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)

FAPESP's process: 99/05446-8 - Biodiversity of Arachnida and Myriapoda of the State of São Paulo
Grantee:Antonio Domingos Brescovit
Support type: BIOTA-FAPESP Program - Thematic Grants
FAPESP's process: 12/50229-1 - Macroecology of sexual selection: large-scale influence of climate on sexually selected traits
Grantee:Glauco Machado
Support type: Regular Research Grants