Tuesday, March 14, 2017

[Herpetology • 2017] Pelodytes atlanticus & P. hespericus • Integration of Molecular, Bioacoustical and Morphological Data Reveals Two New Cryptic Species of Pelodytes (Anura, Pelodytidae) from the Iberian Peninsula


Pelodytes hespericus  
Díaz-Rodríguez, Gehara, Márquez, Vences, Gonçalves, Sequeira,Martínez-Solano & Tejedo, 2017 


Abstract

Parsley frogs (Pelodytes) comprise the only genus in the family Pelodytidae, an ancient anuran lineage that split from their closest relatives over 140 million years ago. Pelodytes is a Palearctic group restricted to Western Eurasia including three extant species: the eastern species P. caucasicus, endemic to the Caucasus area, and two closely related species inhabiting Western Europe: the Iberian endemic P. ibericus and the more widespread P. punctatus. Previous studies based on mitochondrial and nuclear DNA markers have revealed the existence of two additional lineages of Parsley frogs in the Iberian Peninsula, which have been flagged as candidate species. Here, we integrate novel molecular, morphological and bioacoustical data to assess the differentiation of the four western Parsley frog lineages. Species trees and Bayesian population assignment analyses based on nuclear markers confirm previous studies and concordantly delineate four parapatric lineages with narrow hybrid zones. Mitochondrial divergence is low (< 2% pairwise distances in the 16S rRNA gene), in line with previously reported low mitochondrial substitution rates in non-neobatrachian frogs. Based on concordance between mitochondrial and nuclear markers, we conclude that four species of Parsley frogs occur in Western Europe: Pelodytes punctatus, distributed from northern Italy to northeastern Spain; Pelodytes ibericus, inhabiting southern Spain and southern Portugal; Pelodytes atlanticus sp. nov., from the Portuguese Atlantic coast; and Pelodytes hespericus sp. nov., occurring in central and eastern Spain. However, bioacoustical and morphological differentiation of these species is low, with no obvious and qualitative diagnostic characters allowing full species discrimination. Differences in the relative size of metacarpal tubercles exist but this character is variable. Pelodytes ibericus and Pelodytes atlanticus are smaller than the other two species, and Pibericus has shorter limbs and various distinctive osteological characters. Bioacoustically, the pattern by which two different note types are combined in advertisement calls separates P. hespericus from the remaining species. Despite these differences, we emphasize that the taxonomic status of all four western Parsley frogs requires additional investigation, especially the patterns of genetic admixture across contact zones. While a status of separate species best conforms to the currently available data, alternative hypotheses are also discussed.

Keywords: Amphibia, Pelodytidae, cryptic species, species delimitation, population assignment, Pelodytes punctatus, Pelodytes ibericus, Pelodytes atlanticus sp. nov., Pelodytes hespericus sp. nov.


Taxonomy

 Pelodytes punctatus (Daudin, 1802) 
Common Parsley frog

Pelodytes ibericus Sánchez-Herráiz, Barbadillo, Machordom, and Sanchiz, 2000 
Iberian Parsley Frog

Pelodytes atlanticus sp. nov.

Etymology. The specific epithet atlanticus is a genitive adjective derived from the name of Titan Atlas who, according to the ancient greek mythology, lived beyond the strait of Gibraltar and refers to the species’ exclusive distribution along the Atlantic coast of Portugal.

Pelodytes hespericus sp. nov. 

Etymology. The specific name is a latinized adjective derived from the name Hesperides (Ἑσπερίδες), Nymphs of the fading sun and daughters of the Titan Atlas, in allusion to an Iberian mythological garden. The Hesperian Massif also takes its name from the same etymology, meaning “western” in ancient greek, referring to its position in the Mediterranean sea.

FIGURE 12. Dorsal view of living Pelodytes hespericus sp. nov., male paratype JDR 2012-2. 

Díaz-Rodríguez, Jesús, Marcelo Gehara, Roberto Márquez, Miguel Vences, Helena Gonçalves, Fernando Sequeira, Iñigo Martínez-Solano & Miguel Tejedo. 2017. Integration of Molecular, Bioacoustical and Morphological Data Reveals Two New Cryptic Species of Pelodytes (Anura, Pelodytidae) from the Iberian Peninsula.
  Zootaxa. 4243(1); 1–41.  DOI: 10.11646/zootaxa.4243.1.1

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