Results
As expected, most individuals of P. vaillanti and P.
bicolor remained within 5 cm of the water column the majority of the
time (Figure 2). Interestingly, the smaller individuals of P.
bicolor were more evenly distributed along the water column, yet we
were unable to obtain data from medium or small larvae of the former
species. Both Phyllomedusa species were significantly more
conspicuous against the water background, compared C. tomopterna(Figure 3). In turn, P. vaillanti was more conspicuous thanP. bicolor , particularly concerning the frontal metallic patch
(Figure 3). Conspicuousness was higher in larger larvae of the most
conspicuous species, P. vaillanti (linear regression: F=24.69,
p=<0.001, R2=0.13, N=193) but this
relationship was absent in the other two species (Figure 3).
Dragonfly naiads preyed upon 73% of the tested frog larvae, and we
detected no significant differences in the vulnerability of the three
species of tadpoles (X2=0.102, df= 2, p= 0.94 (Figure
4-A) Nevertheless, seven out of the 13 naiads (54%) that preyed uponP. vaillanti died within 4 h, whereas none of them died after
consuming P. bicolor or C. tomopterna larvae (Figure 4-B).
We also found evidence of larvae toxicity for the tested vertebrate. The
tadpole skins of P. bicolor and P. vaillanti significantly
affected mice behavior: and eliciting spasms, lethargy, and decreased
movement throughout the arena. In contrast, the mice injected with skin
extracts of C. tomopterna were indistinguishable in behavior from
the mice injected with saline solution (Figure 5). Regarding body size,
we found no evidence supporting a relationship between larval size and
palatability (F = 0.60, p = 0.54, N = 38), or larval size and toxicity
(F = 1.86, p = 0.11, N = 76) in any of the frog species we studied.
At the species level, some relationship between toxicity and
conspicuousness was apparent: the non-toxic species (C.
tomopterna ) was the less conspicuous as well. And the twoPhyllomedusa species differed in conspicuousness but were
comparable in toxicity at least for our study system (Figure 5). At the
individual level, however, only the tadpoles of P. vaillantishowed a positive relationship between toxicity and the conspicuous of
the front patch (Figure 6).