Abstract:
A new species of the genus
Atelopus,
Atelopus fronterizo sp. nov. , from eastern Panama is described herein based on molecular, morphological, and bioacoustic evidence. The new species can be distinguished from its congeners occurring in the region by a combination of the following characters: (1) phalangeal reduction in thumb; (2) SVL (females only) (35.1–50.1;
n=13), HW/SVL (0.23–0.34;
n=59), EYND/HW (0.27–0.39;
n=60), TIBL/SVL (0.41–0.56;
n=58), and HAL/SVL (0.22–0.28;
n=49); (3) dorsal color pattern with green or yellow background and extensive dark olive blotches forming transversal bands or mottling; (4) advertisement call duration 176–235 ms with 19–34 pulses, average pulse rate 131.69 pulses/s, and dominant frequency 2 422.50–2 606.50 Hz. The new species is nested within the Central American clade of
Atelopus. The minimum Kimura‐2‐parameter (K2P) genetic divergence between
Atelopus fronterizo sp. nov. and its most phylogenetically similar congeners (
A.
certus and
A.
glyphus) is >2.6% for 16S and >4.9% for
COI (
Table 1). The phylogenetic relationship is strongly supported by ultrafast bootstrap values for the maximum-likelihood trees of both genetic markers (16S, 96;
COI, 100,
Figure 1A). Bayesian analysis of the concatenated sequences resulted in a tree with similar topology and high posterior probability support (0.99; Supplementary Figure S1). In addition, haplotype networks inferred from
COI and 16S (Supplementary Figure S2) showed a well-separated clade containing the new species (two for
COI, four for 16S). The number of mutational steps between haplotypes for the new species samples is very low (1–4 in 16S; one in
COI), and the minimum number of mutational steps from the nearest species is nine for 16S (distance to
A.
certus) and 28 for
COI (distance to
A.
glyphus).