Alkaloid defenses of co-mimics in a putative Müllerian mimetic radiation.
BACKGROUND
Polytypism in aposematic species is unlikely according to theory, but commonly seen in nature. Ranitomeya imitator is a poison frog species exhibiting polytypic mimicry of three congeneric model species (R. fantastica, R. summersi, and two morphs of R. variabilis) across four allopatric populations (a "mimetic radiation"). In order to investigate chemical defenses in this system, a key prediction of Müllerian mimicry, we analyzed the alkaloids of both models and mimics from four allopatric populations.


RESULTS
In this study we demonstrate distinct differences in alkaloid profiles between co-mimetic species within allopatric populations. We further demonstrate that R. imitator has a greater number of distinct alkaloid types than the model species and more total alkaloids in all but one population.


CONCLUSIONS
Given that R. imitator is the more abundant species in these populations, R. imitator is likely driving the majority of predator-learned avoidance in these complexes. The success of Ranitomeya imitator as a putative advergent mimic may be a direct result of differences in alkaloid sequestration. Furthermore, we propose that automimicry within co-mimetic species is an important avenue of research.
Department of Biology, East Carolina University, 1000 E, Fifth St, Greenville, NC 27858, USA. stuckerta10@students.ecu.edu.
Adam M M
AM
Stuckert
Ralph A
RA
Saporito
Pablo J
PJ
Venegas
Kyle
K
Summers
D000470:Alkaloids / Q000032:analysis*; D000818:Animals; D001001:Anura / Q000235:genetics / Q000502:physiology*; D005075:Biological Evolution; D020387:Food Chain
D000470:Alkaloids