Deep Divergences Among Inconspicuously Colored Clades ofEpipedobatesPoison Frogs

Abstract

Poison frogs (Dendrobatidae) are famous for their aposematic species, having a combination of diverse color patterns and defensive skin toxins, yet most species in this family are inconspicuous (cryptic) and considered non-aposematic.Epipedobatesis among the youngest genus-level clades of Dendrobatidae that includes both aposematic and cryptic species. Using mitochondrial and nuclear markers, we demonstrate deep genetic divergences among cryptic species ofEpipedobatesbut relatively shallow genetic divergences among conspicuous species. Our phylogenetic analysis includes broad geographic sampling of the cryptic lineages typically identified asE. boulengeriandE. espinosai, which reveals two putative new species, one in west-central Colombia (E.sp. 1) and the other in north-central Ecuador (E.aff.espinosai). We conclude thatE. darwinwallaceiis a junior subjective synonym ofE. espinosai. We also clarify the geographic distributions of crypticEpipedobatesspecies including the widespreadE. boulengeri. We provide a qualitative assessment of the phenotypic diversity in each nominal species, with a focus on the color and pattern of cryptic species. We conclude thatEpipedobatescontains eight known valid species, six of which are cryptic. A relaxed molecular clock analysis suggests that the most recent common ancestor ofEpipedobatesis ~11.1 million years old, which nearly doubles previous estimates. Last, genetic information points to a center of species diversity in the Chocó at the southwestern border of Colombia with Ecuador.

Honoring the Afro-Colombian musical culture with the naming ofEpipedobates [to be revealed]sp. nov. (Anura: Dendrobatidae), a frog from the Pacific rainforests

“…Epipedobates sensu is a taxon of neotropical poison frogs (Anura: Dendrobatidae) with nine putative species (Grant et al (2006, 2017) and López-Hervas et al (2023): Epipedobates aff. espinosai (see López-Hervas et al 2023) , E. anthonyi (Noble 1921), E. boulengeri (Barbour 1909), E. sp. 1 (see López-Hervas et al 2023) , E. espinosai (Funkhouser 1956), E. machalilla (Coloma 1995), E. maculatus (Peters 1873) , E. narinensis Mueses-Cisneros et al 2008, and E. tricolor (Boulenger 1899).…”

“…espinosai (see López-Hervas et al 2023) , E. anthonyi (Noble 1921), E. boulengeri (Barbour 1909), E. sp. 1 (see López-Hervas et al 2023) , E. espinosai (Funkhouser 1956), E. machalilla (Coloma 1995), E. maculatus (Peters 1873) , E. narinensis Mueses-Cisneros et al 2008, and E. tricolor (Boulenger 1899). Frogs of the genus Epipedobates inhabit dry and humid tropical forests from 0 to 1800 m across the Pacific lowlands and foothills of the western side of the Andes of Colombia, Ecuador, and northern Peru (Grant et al, 2006, 2017).…”

“…1, distributed in northwestern Ecuador and up into the southern end of the Andean foothills of Colombia; and E. aff. espinosai , distributed in central-western Ecuador (López-Hervas et al, 2023). In prior assessments of phenotypic diversity of this species, Lötters et al (2003) found differences in temporal characteristics of the advertisement call between specimens referred to as E. boulengeri from Colombia (Anchicayá, Valle del Cauca, corresponding to E. sp.…”

“…We also reviewed and summarized species-level phenotypic variation as described in López-Hervas et al (2023) to provide a species-level assessment of color pattern variation that can be used to distinguish species.…”

“…All images were taken by RDT except for A and C, which were taken by JCR. Photos are not to scale.Molecular and phylogenetic analysesWe estimated a phylogeny using existing data(López-Hervas et al 2023) and 10 new sequences from five E. [to be revealed] from the type locality. The resulting phylogeny contains strong support…”