Low phylogeographic structure of Rhinella arunco (Anura: Bufonidae), an endemic amphibian from the Chilean Mediterranean hotspot

Abstract

Background: The Mediterranean zone of central Chile (30°to 38°S) is one of the 25 diversity hotspots in the world. However, there are few phylogeographic studies which identify the factors that have influenced population diversification in the fauna of this area. In this study, we investigated the phylogeographic structure of Rhinella arunco, an anuran endemic to Mediterranean Chile, using 160 individuals from 23 localities representative of its entire distribution (32°to 38°S). Results: The haplotype network revealed four haplogroups, three of which overlap geographically and only one of which has an exclusive geographic distribution. An analysis of molecular variance indicated that neither watershed limits nor the main rivers in the current distribution of this species have been important geographic barriers against the dispersion of individuals. Finally, the Geneland analysis showed three population units, one of which concurs with one of the haplogroups found in the haplotype network. Together, these analyses indicated a low level of phylogeographic structure for this species. On the other hand, the highest levels of intrapopulational genetic variation were concentrated in the central part of the distribution (33°to 34°S), which may indicate an effect of Pleistocene glaciations on the genetic diversity of the populations in the extreme south of its range.

Patterns of Genetic Variability in Island Populations of the Cane Toad (Rhinella marina) from the Mouth of the Amazon

“…There is a general assumption that most amphibians have low dispersion capacity due to their physiological constraints [ 34 ], and rivers appear to be one of most prominent barriers to gene flow [ 35 ]. However, accumulation of empirical data suggests that the barrier effect of rivers in amphibians could not be generalized [ 36 – 41 ]. Although data from introduced R .…”

Phylogeography of the arid-adapted Malagasy bullfrog, Laliostoma labrosum, influenced by past connectivity and habitat stability

“…Although low differentiation at this scale is rare in amphibians, it is present in some terrestrial species and has been attributed to frequent movement of individuals among breeding sites, severe population bottlenecks or recent expansion from glacial refugia (e.g. Burns et al, 2007;Makowsky et al, 2009;Vásquez et al, 2013;. Several hypotheses could explain the low level of mtDNA differentiation in L. labrosum: (i) range expansion after a species-wide bottleneck, (ii) selection or (iii) high levels of gene flow among populations.…”

Genetic variation of the Chilean endemic long-haired mouseAbrothrix longipilis(Rodentia, Supramyomorpha, Cricetidae) in a geographical and environmental context

“…Phylogeographic studies of other animal and plant species from Central Chile are available in the literature, revealing different genetic patterns and proposing distinct mechanisms to explain them. In some cases involving reptile and amphibian species, a combination of climatic and topographic effects have been invoked to explain population dynamics in Central Chile (e.g., Méndez et al, 2004;Victoriano et al, 2008;Vásquez et al, 2013). For Aborthrix longipilis, the Maipo River seems to be a barrier that either originated (primary barrier) or at least maintains (secondary barrier) the divergence between the southern lineage and the northern+central lineage (Fig.…”