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Multiple Quaternary glacial refugia in the Iberian Peninsula, commonly known as "refugia within refugia", allowed diverging populations to come into contact and admix, potentially boosting substantial mito-nuclear discordances. In this study, we employ a comprehensive set of mitochondrial and nuclear markers to shed light onto the drivers of geographical differentiation in Iberian high mountain populations of the midwife toads Alytes obstetricans and A. almogavarii from the Pyrenees, Picos de Europa and Guadarrama Mountains. In the three analysed mountain regions, we detected evidence of extensive mito-nuclear discordances and/or admixture between taxa. Clustering analyses identified three major divergent lineages in the Pyrenees (corresponding to the eastern, central and central-western Pyrenees), which possibly recurrently expanded and admixed during the succession of glacial-interglacial periods that characterised the Late Pleistocene, and that currently follow a ring-shaped diversification pattern. On the other hand, populations from the Picos de Europa mountains (NW Iberian Peninsula) showed a mitochondrial affinity to central-western Pyrenean populations and a nuclear affinity to populations from the central Iberian Peninsula, suggesting a likely admixed origin for Picos de Europa populations. Finally, populations from the Guadarrama Mountain Range (central Iberian Peninsula) were depleted of genetic diversity, possibly as a consequence of a recent epidemic of chytridiomycosis. This work highlights the complex evolutionary history that shaped the current genetic composition of high mountain populations, and underscores the importance of using a multilocus approach to better infer the dynamics of population divergence., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Lucati et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Recent reviews on sexual dichromatism in frogs included Mannophryne trinitatis as the only example they could find of dynamic dichromatism (males turn black when calling) within the family Aromobatidae and found no example of ontogenetic dichromatism in this group. We demonstrate ontogenetic dichromatism in M. trinitatis by rearing post-metamorphic froglets to near maturity: the throats of all individuals started as grey coloured; at around seven weeks, the throat became pale yellow in some, and more strongly yellow as development proceeded; the throats of adults are grey in males and variably bright yellow in females, backed by a dark collar. We demonstrated the degree of throat colour variability by analysing a large sample of females. The red: green (R:G) ratio ranged from ~1.1 to 1.4, reflecting variation from yellow to yellow/orange, and there was also variation in the tone and width of the dark collar, and in the extent to which the yellow colouration occurred posterior to the collar. Female M. trinitatis are known to be territorial in behaviour. We show a positive relationship between throat colour (R:G ratio) and escape performance, as a proxy for quality. Our field observations on Tobago's M. olmonae showed variability in female throat colour and confirmed that males in this species also turn black when calling. Our literature review of the 20 Mannophryne species so far named showed that all females have yellow throats with dark collars, and that male colour change to black when calling has been reported in eight species; in the remaining 12 species, descriptions of males calling are usually lacking so far. We predict that both dynamic and ontogenetic sexual dichromatism are universal in this genus and provide discussion of the ecological role of dichromatism in this genus of predominantly diurnal, non-toxic frogs, with strong paternal care of offspring., Competing Interests: The authors have declared that no competing interests exist.

In this study, we report, through molecular identification, the first African records of a digenean trematode parasite of the genus Euryhelmis. We recovered metacercariae encysted in an anuran, the endemic Moroccan painted frog (Discoglossus scovazzi), and a vulnerable caudate, the North African fire salamander (Salamandra algira), from four localities in North Africa (Morocco). Our records go back to the past century and have been confirmed in successive fieldwork seasons thereafter. Metacercarial stages of these parasites require amphibians as the last intermediate host, but the exact identity of the primary hosts and predators of the infected animals in Africa remain unknown. Our searches with basic local alignment search tool (BLAST) from Genbank revealed that hosts were infected by parasites of Euryhelmis costaricensis, which showed almost the same genetic identity (with only one substitution) to previous reports from Costa Rica and Japan, suggesting a recent introduction in Morocco. We proceed to discuss the likely role of introduced mustelids as the potential definitive hosts of trematode adults. Under this assumption, we conclude that the infestation of Discoglossus scovazzi and Salamandra algira might pose a risk to these threatened species.

The presence of Hyalinobatrachium orientale in Tobago and in northeastern Venezuela is puzzling as this species is unknown from the island of Trinidad, an island often hypothesized to be a stepping-stone for the mainland fauna to colonize Tobago. A period of extended isolation on Tobago could result in the Hyalinobatrachium population becoming distinct from the mainland H. orientale. Here, we use 12S and 16S rDNA gene fragments from nine H. orientale specimens from Tobago and the mainland to assess their relationship and taxonomy, as well as the tempo and mode of speciation. The results suggest H. orientale from Venezuela and Tobago are monophyletic and the two populations diverged about 3 million years ago. This estimate corresponds with the drier climate and lower sea levels of the Pliocene glaciation periods. We hypothesize that lower sea levels resulted in land-bridge formations connecting the mainland and Tobago, with a corridor of habitat allowing H. orientale to colonize Tobago to the west of Trinidad.