Morphology and DNA barcodes reveal the presence of the non-native land planarian Obama marmorata (Platyhelminthes : Geoplanidae) in Europe

Abstract

We report for the first time the occurrence of Obama marmorata in the Iberian Peninsula as an introduced species from the Neotropical Region. The species is also reported for the first time in Argentina. The identification was made on the basis of morphological evidence. The divergence levels of a fragment of the mitochondrial cytochromec oxidaseI gene from Argentinean and Iberian samples were studied. The morphology of samples from the two regions was the same and matched the original description of the species. A DNA barcoding matrix was constructed using new sequences from O. marmorata and sequences of related species taken from GenBank. Among the Geoplanidae, interspecific divergence ranged between 3.3 and 14.4%, while intraspecific divergence percentages were 0–1.2%, signalling the presence of a DNA barcoding gap. All O. marmorata sequences, irrespective of their geographic origin, form a well supported clade with an intraspecific divergence of 0–0.9 (average = 0.4%). These results indicate the utility of DNA barcoding to discover allochthonous species in this group of organisms.

The true identity ofObama(Platyhelminthes: Geoplanidae) flatworm spreading across Europe

“…The Cox1 + Lago alignment consists of 822 bp and 58 Obama sequences of which 20 come from Lago‐Barcia et al . (). As the sequences of Lago‐Barcia et al .…”

“…As the sequences of Lago‐Barcia et al . () are shorter (323 bp) the alignment was filled with Ns to reach the length of the remaining sequences. However, tests with shorter alignments were made to verify that the missing data did not alter the results.…”

“…Lago‐Barcia et al . () reported the introduction of O. marmorata into Spain and Argentina. They identified specimens from both countries by comparing them with Froehlich's () description, and corroborated their identity by comparing DNA sequences with that of specimens named Obama sp.…”

“…For the phylogenetic analyses we prepared a dataset with all the genes concatenated (concatenated dataset) and another with all the Cox1 sequences from this study and from the study by Lago‐Barcia et al . () (Cox1 + Lago dataset). In the concatenated dataset, incomplete sequences or missing genes were filled with Ns and three species from the genus Cratera Carbayo et al ., were used as the outgroup (Carbayo et al ., ).…”

“…Herein we study the identity of these two molecularly different species and also discuss the identity of some specimens from Argentina and Spain recently identified by Lago‐Barcia et al . () as Obama marmorata .…”