Research Article Speciation in Thaparocleidus (Monogenea: Dactylogyridae)

Copyright © 2013 Andrea Šimkova ́ et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The phylogeny of monogeneans of the genus Thaparocleidus that parasitize the gills of Pangasiidae in Borneo and Sumatra was inferred from molecular data to investigate parasite speciation. The phylogeny of the Pangasiidae was also reconstructed in order to investigate host-parasite coevolutionary history.Themonophyly ofThaparocleidus parasitizing Pangasiidae was confirmed. Low intraspecies molecular variability was observed in three Thaparocleidus species collected from geographically distant localities. However, a high intraspecies molecular variability was observed in two Thaparocleidus species suggesting that these species represent a complex of species highly similar in morphology. Distance-based and tree-based methods revealed a significant global fit between parasite and host phylogenies. Parasite duplication (i.e., intrahost speciation) was recognized as themost common event inThaparocleidus, while the numbers of cospeciation and host switcheswere lower and similar to each other.When collapsing nodes correspond to duplication cases, our results suggest host switches in theThaparocleidus-Pangasiidae system precluding congruenc