The phylogenetics of Anguillicolidae (Nematoda: Anguillicolidea), swimbladder parasites of eels

BACKGROUND: Anguillicolidae Yamaguti, 1935 is a family of nematode parasites infecting fresh-water eels of the genus Anguilla, with five species in the genera Anguillicola and Anguillicoloides. Anguillicolidae is part of Spirurina, a diverse clade made up of only animal parasites. Anguillicoloides crassus is of particular importance, as it has recently spread from its endemic range in the Eastern Pacific to Europe and North America, where it poses a significant threat to new, naïve hosts such as the economic important eel species Anguilla anguilla and Anguilla rostrata. The Anguillicolidae are therefore all potentially invasive taxa, but the relationships of the described species remain unclear. RESULTS: We generated an extensive DNA sequence dataset from three loci (the 5' one-third of the nuclear small subunit ribosomal RNA, the D2-D3 region of the nuclear large subunit ribosomal RNA and the 5' half of the mitochondrial cytochrome c oxidase I gene) for the five species of Anguillicoli...