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| Author(s): |
Bruna de Oliveira Cassettari
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2016-02-18 |
| Examining board members: |
Fernando Ribeiro Gomes;
Cinthia Aguirre Brasileiro;
Pedro Augusto Carlos Magno Fernandes;
Patricia Izar Mauro
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| Advisor: | Fernando Ribeiro Gomes |
| Abstract | |
In most anuran species, vocal behavior is usually related to plasmatic levels of gonadal and interrenal steroid hormones. These hormones could mediate the relationship between signal intensity and immunocompetence, since they are involved in the development of sexual traits, courtship behavior and energetic mobilization during reproductive activity and also exert immunomodulatory effects. The aim of this study was to explore relations among vocal behavior, immunity and plasmatic levels of testosterone and corticosterone in males of a toad species from Brazilian semi-arid, Rhinella granulosa, during reproductive activity and after hormonal manipulation. Precipitation was the main environmental determinant to increase circulating levels of testosterone and corticosterone in R. granulosa males, stimulating vocal behavior. Physiological relations indicate that high circulating testosterone levels in the days right after rain may promote the initiation of vocal behavior, while corticosterone may modulate vocal effort. In general, exacerbation of vocal behavior in R. granulosa has negative effects on immunocompetence, however, some individuals with higher plasmatic levels of corticosterone can present both high vocal effort and good immunocompetence. Corroborating this interpretation, acute increase in glucocorticoid plasmatic levels after hormonal manipulation was accompanied by raised immune function. Despite the emphasis on androgens influence on sexual selected male traits, our results corroborate greater influence of corticosterone in the mediation of expression of courtship behavior and immunocompetence in R. granulosa (AU) | |
| FAPESP's process: | 13/10360-4 - Relationship between calling behavior, immunity and plasmatic levels of corticosterone and testosterone in bufonids from Caatinga |
| Grantee: | Bruna de Oliveira Cassettari |
| Support Opportunities: | Scholarships in Brazil - Master |