Multiple refugia and glacial expansions in the Tucumane–Bolivian Yungas: The phylogeography and potential distribution modeling ofCalomys fecundus(Thomas, 1926) (Rodentia: Cricetidae)

Abstract

The Yungas, a subtropical mountain rainforest of South America, has been little studied in relation to the evolutionary history of the large‐bodied species of the genus Calomys. Particularly, two species have been synonymized: C. boliviae and C. fecundus; the first is only known from its type locality in the northern Bolivian Yungas, whereas the second is known along the Tucumane–Bolivian Yungas shared by Bolivia and Argentina. In this study, we combined a phylogeographic approach with ecological niche modeling, with samples covering most of the geographic range of C. fecundus. One mitochondrial and two nuclear genes were used for population genetic analyses. Current and paleoclimatic models were obtained. Nuclear genes resulted uninformative by retention of ancestral polymorphism with other species of Calomys. The mitochondrial marker revealed a complex network showing signals of several population expansions. Three genetic clusters in a latitudinal sense were detected, which are coincident with the three stable climatic zones estimated by current and paleoclimatic models. We determined a pattern of expansion during glacial cycles and ancestral refugia during interglacial cycles. None of the potential distribution models predicted the presence of C. fecundus in the type locality of C. boliviae. Therefore, we recommend making integrative taxonomic studies in the Bolivian Yungas, to determine whether or not C. fecundus and C. boliviae correspond to the same species.

Molecular systematics and biogeographic insights of the Calomys callosus complex (Rodentia, Cricetidae)

“…At chromosome level, specimens of C. fecundus from Famaillá in Tucumán Province present a 2 n = 54 (FN = 66; Hurtado de Catalfo & Wainberg, 1974), being the same 2 n reported for animals from Tarija and Chuquisaca in southern Bolivia (Salazar‐Bravo et al, 2002). These data agree with phylogeographic results presented by Pinotti et al (2020) and ours, where genetic continuity is found throughout the distribution range of the species. In relation to health issues, C. fecundus is a reservoir of the Laguna Negra orthohantavirus that causes the hantavirus pulmonary syndrome (Pini et al, 2012) and is also a reservoir of a Latino‐like mammarenavirus (apparently non‐pathogenic; Calderón et al, 2010).…”

“…However, these two entities should be considered different species, because in addition to Thomas original diagnostic traits, Olds (1988) noted that adult females of C. boliviae had five pairs of mammae, while those of C. fecundus had seven pairs. From a different point of view, Pinotti et al (2020), using ecological niche modelling, showed that none of the potential distribution models predicted the presence of C. fecundus in the type locality of C. boliviae . Therefore, the authors proposed that C. fecundus would be restricted to the Tucumane–Bolivian Yungas and C. boliviae to the northern Bolivian Yungas.…”

“…Since, C. boliviae is only known from its type locality and lacks genetic studies, it is not even known whether it is part of the C. callosus complex. On the other hand, C. fecundus has been collected in Argentina in the provinces of Jujuy, Salta, Tucumán and Santiago del Estero and in Bolivia in the departments of Tarija and Chuquisaca (Pinotti et al, 2020; Salazar‐Bravo, 2015; Salazar‐Bravo et al, 2002). At chromosome level, specimens of C. fecundus from Famaillá in Tucumán Province present a 2 n = 54 (FN = 66; Hurtado de Catalfo & Wainberg, 1974), being the same 2 n reported for animals from Tarija and Chuquisaca in southern Bolivia (Salazar‐Bravo et al, 2002).…”

“…Regarding the distribution of large‐bodied Calomys in the Tucumane–Bolivian Yungas ecoregion of southern Bolivia and north‐western Argentina, Pinotti et al (2020) genetically analysed 97 specimens from 24 localities and all corresponded to C. fecundus . This evidence contrast with data reported by Martínez et al (2016) who highlight the occurrence of C. venustus and C. callosus s.s. for this forested region, probably a misidentification due to the strong morphological resemblance among these species.…”

Modeling potential risk areas of orthohantavirus transmission in northwestern Argentina using ecological niche approach

“…For the former, Salazar Bravo et al (2001) based on molecular analysis of mitochondrial genes, suggested that the name C. fecundus should be applied to the Yungas populations of NWA and Bolivia, but then, without further evidence, he listed C. fecundus as a junior synonymous of C. boliviae in a recent checklist of South American Mammals [22]. Furthermore, Pinotti et al, (2020) based on molecular and potential distribution approaches suggest that the Bolivian Montane Dry Forest could have acted as a barrier for the differentiation between C. boliviae and C. fecundus. Thus, we included in our searches keywords O. f. occidentalis (the name applied by some authors for the western clade of O. avescens) and C. fecundus (the name applied to southern populations of C. boliviae).…”