Poison frog chemical defense: does alkaloid diversity increase as individuals grow older?

• Grant number: 13/23715-5
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: February 14, 2014
• End date: August 13, 2014
• Field of knowledge: Biological Sciences - Zoology
• Principal Investigator: Taran Grant
• Grantee: Adriana Moriguchi Jeckel
• Supervisor: Ralph A. Saporito
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: John Carroll University (JCU), United States
• Associated to the scholarship: 13/14061-1 - Evaluation of the relation between age and diversity of defensive alkaloids in Melanophryniscus simplex (Anura: Bufonidae), BP.MS

Abstract

Many organisms use chemical defenses to reduce predation risk. Several lineages of anurans independently evolved the ability to secrete alkaloid-containing defensive chemicals from granular glands in the skin. Variability in alkaloid diversity has been found within almost all alkaloid-containing species and many causes have been suggested to explain the high diversity, including geography, season, gender and biomodification. In this project, our main goal is to test the Age Hypothesis, which predicts that the diversity of alkaloids (abundance, richness and composition) increases monotonically with individual frog age. To test this hypothesis directly, it is necessary to determine both the age and the alkaloid diversity of each individual. Melanophryniscus is a bufonid genus that is known to sequester alkaloids from dietary sources. For the present study, 50 individuals of Melanophryniscus moreirae will be collected at national park of Itatiaia; the long bones (phalanx, humerus and femur) will be used for sketochronology procedure and their skin will be analyzed with GC-MS for alkaloid quantification and identification. Thus, our secondary goals are to construct an ontogenetic series of bone growth in M. moreirae for age determination and to characterize the diversity of alkaloids present in the skin of all the individuals of M. moreirae collected. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

JECKEL, ADRIANA M.; SAPORITO, RALPH A.; GRANT, TARAN. The relationship between poison frog chemical defenses and age, body size, and sex. Frontiers in Zoology, v. 12, OCT 1 2015. (13/23715-5, 12/10000-5, 13/14061-1, 14/15730-7)

JECKEL, ADRIANA M.; GRANT, TARAN; SAPORITO, RALPH A.. Sequestered and Synthesized Chemical Defenses in the Poison Frog Melanophryniscus moreirae. Journal of Chemical Ecology, v. 41, n. 5, p. 505-512, MAY 2015. (13/23715-5, 12/10000-5, 13/14061-1, 14/15730-7)