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Integrative phylogeography of Calotriton newts (Amphibia, Salamandridae), with special remarks on the conservation of the endangered Montseny brook newt (Calotriton arnoldi).

Valbuena-Ureña E, Amat F, Carranza S - PLoS ONE (2013)

Bottom Line: SDM results suggest that tough environmental conditions on mountains tops during glacial periods, together with subsequent warmer periods could have prevented the contact between the two species.Within the critically endangered C. arnoldi, a high genetic structure is revealed despite its extremely small distribution range compared to C. asper.The genetic and morphological results are highly important for the ongoing conservation program of C. arnoldi and strongly justify the management of this species into at least two independent evolutionary significant units (eastern and western sectors) to guarantee the long-term population viability.

View Article: PubMed Central - PubMed

Affiliation: Unitat de Zoologia (Facultat de Biociències), Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Catalonia, Spain. emiliojavier.valbuena@uab.cat

ABSTRACT
The genus Calotriton includes two species of newts highly adapted to live in cold and fast-flowing mountain springs. The Pyrenean brook newt (Calotriton asper), restricted to the Pyrenean region, and the Montseny brook newt (Calotriton arnoldi), endemic to the Montseny massif and one of the most endangered amphibian species in Europe. In the present manuscript, we use an integrative approach including species distribution modeling (SDM), molecular analyses of mitochondrial and nuclear DNA sequence data and morphology to unravel the historical processes that have contributed to shaping the biogeography and genetic structure of the genus Calotriton, with special emphasis on the conservation of C. arnoldi. The results of the molecular analyses confirm that, despite having originated recently, being ecologically similar and geographically very close, there is no signal of hybridization between C. asper and C. arnoldi. SDM results suggest that tough environmental conditions on mountains tops during glacial periods, together with subsequent warmer periods could have prevented the contact between the two species. Within the critically endangered C. arnoldi, a high genetic structure is revealed despite its extremely small distribution range compared to C. asper. Haplotype networks, AMOVA and SAMOVA analyses suggest that two distinct groups of populations can be clearly differentiated with absence of gene flow. This is in concordance with morphological differentiation and correlates with its geographical distribution, as the two groups are situated on the eastern and western sides of a river valley that acts as a barrier. The genetic and morphological results are highly important for the ongoing conservation program of C. arnoldi and strongly justify the management of this species into at least two independent evolutionary significant units (eastern and western sectors) to guarantee the long-term population viability.

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The study area in the NE Iberian Peninsula showing the distribution of the genus Calotriton.Circles indicate populations of C. asper included in the molecular analyses; triangles correspond to additional populations included in the species distribution modeling (SDM). All localities of C. arnoldi are included in the molecular analyses. Locality codes correspond to names on Table 1. Localities of C. arnoldi represented do not correspond to the exact geographic locations intentionally due to conservation reasons.
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pone-0062542-g001: The study area in the NE Iberian Peninsula showing the distribution of the genus Calotriton.Circles indicate populations of C. asper included in the molecular analyses; triangles correspond to additional populations included in the species distribution modeling (SDM). All localities of C. arnoldi are included in the molecular analyses. Locality codes correspond to names on Table 1. Localities of C. arnoldi represented do not correspond to the exact geographic locations intentionally due to conservation reasons.

Mentions: The genus Calotriton Gray, 1858, includes only two species adapted to live in cold and fast-flowing waters: the Pyrenean brook newt (Calotriton asper) and the Montseny brook newt (Calotriton arnoldi). According to Carranza & Amat [20] the two species split during the Pleistocene, approximately 1.1–2 Mya. Although they have been evolving independently, their actual distribution ranges are only separated by 25 km in a straight line. The Pyrenean brook newt is the most widely distributed of the two species, occupying more than 20000 km2 across the Pyrenean mountain chain (NE Iberian Peninsula) with some populations extending northwards and southwards, reaching the Prepyrenees [22] (see Figure 1). In contrast, the endemic Montseny brook newt has a very restricted distribution range, occupying a small area of 20 km2 restricted to a few brooks in the Montseny massif [23], [24], [25], [26] (see Figure 1). Currently, a total of 7 populations of C. arnoldi have been found, fragmented into two main population groups on both sides of the Tordera river valley separated by inhospitable habitat. The eastern and western sectors comprise three and four populations, respectively, with a total estimation of 1000–1500 mature individuals [27]. Owing to its restricted and fragmented distribution and its low population density, C. arnoldi is catalogued as Critically Endangered in the International Union for Conservation of Nature (UICN) Red List of Threatened Species. Currently, the conservation planning is in the process of development by the Catalan Government in order to ensure the survival of this species.


Integrative phylogeography of Calotriton newts (Amphibia, Salamandridae), with special remarks on the conservation of the endangered Montseny brook newt (Calotriton arnoldi).

Valbuena-Ureña E, Amat F, Carranza S - PLoS ONE (2013)

The study area in the NE Iberian Peninsula showing the distribution of the genus Calotriton.Circles indicate populations of C. asper included in the molecular analyses; triangles correspond to additional populations included in the species distribution modeling (SDM). All localities of C. arnoldi are included in the molecular analyses. Locality codes correspond to names on Table 1. Localities of C. arnoldi represented do not correspond to the exact geographic locations intentionally due to conservation reasons.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3672179&req=5

pone-0062542-g001: The study area in the NE Iberian Peninsula showing the distribution of the genus Calotriton.Circles indicate populations of C. asper included in the molecular analyses; triangles correspond to additional populations included in the species distribution modeling (SDM). All localities of C. arnoldi are included in the molecular analyses. Locality codes correspond to names on Table 1. Localities of C. arnoldi represented do not correspond to the exact geographic locations intentionally due to conservation reasons.
Mentions: The genus Calotriton Gray, 1858, includes only two species adapted to live in cold and fast-flowing waters: the Pyrenean brook newt (Calotriton asper) and the Montseny brook newt (Calotriton arnoldi). According to Carranza & Amat [20] the two species split during the Pleistocene, approximately 1.1–2 Mya. Although they have been evolving independently, their actual distribution ranges are only separated by 25 km in a straight line. The Pyrenean brook newt is the most widely distributed of the two species, occupying more than 20000 km2 across the Pyrenean mountain chain (NE Iberian Peninsula) with some populations extending northwards and southwards, reaching the Prepyrenees [22] (see Figure 1). In contrast, the endemic Montseny brook newt has a very restricted distribution range, occupying a small area of 20 km2 restricted to a few brooks in the Montseny massif [23], [24], [25], [26] (see Figure 1). Currently, a total of 7 populations of C. arnoldi have been found, fragmented into two main population groups on both sides of the Tordera river valley separated by inhospitable habitat. The eastern and western sectors comprise three and four populations, respectively, with a total estimation of 1000–1500 mature individuals [27]. Owing to its restricted and fragmented distribution and its low population density, C. arnoldi is catalogued as Critically Endangered in the International Union for Conservation of Nature (UICN) Red List of Threatened Species. Currently, the conservation planning is in the process of development by the Catalan Government in order to ensure the survival of this species.

Bottom Line: SDM results suggest that tough environmental conditions on mountains tops during glacial periods, together with subsequent warmer periods could have prevented the contact between the two species.Within the critically endangered C. arnoldi, a high genetic structure is revealed despite its extremely small distribution range compared to C. asper.The genetic and morphological results are highly important for the ongoing conservation program of C. arnoldi and strongly justify the management of this species into at least two independent evolutionary significant units (eastern and western sectors) to guarantee the long-term population viability.

View Article: PubMed Central - PubMed

Affiliation: Unitat de Zoologia (Facultat de Biociències), Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Catalonia, Spain. emiliojavier.valbuena@uab.cat

ABSTRACT
The genus Calotriton includes two species of newts highly adapted to live in cold and fast-flowing mountain springs. The Pyrenean brook newt (Calotriton asper), restricted to the Pyrenean region, and the Montseny brook newt (Calotriton arnoldi), endemic to the Montseny massif and one of the most endangered amphibian species in Europe. In the present manuscript, we use an integrative approach including species distribution modeling (SDM), molecular analyses of mitochondrial and nuclear DNA sequence data and morphology to unravel the historical processes that have contributed to shaping the biogeography and genetic structure of the genus Calotriton, with special emphasis on the conservation of C. arnoldi. The results of the molecular analyses confirm that, despite having originated recently, being ecologically similar and geographically very close, there is no signal of hybridization between C. asper and C. arnoldi. SDM results suggest that tough environmental conditions on mountains tops during glacial periods, together with subsequent warmer periods could have prevented the contact between the two species. Within the critically endangered C. arnoldi, a high genetic structure is revealed despite its extremely small distribution range compared to C. asper. Haplotype networks, AMOVA and SAMOVA analyses suggest that two distinct groups of populations can be clearly differentiated with absence of gene flow. This is in concordance with morphological differentiation and correlates with its geographical distribution, as the two groups are situated on the eastern and western sides of a river valley that acts as a barrier. The genetic and morphological results are highly important for the ongoing conservation program of C. arnoldi and strongly justify the management of this species into at least two independent evolutionary significant units (eastern and western sectors) to guarantee the long-term population viability.

Show MeSH
Related in: MedlinePlus