Mitogenomic phylogenies support the validity of the family Micracanthorhynchinidae (Acanthocephala: Echinorhynchida), with novel gene arrangement in the mitogenomes of Micracanthorhynchina hemirhamphi and Rhadinorhynchus laterospinosus

The mitogenome of M. hemirhamphi represents the largest mitogenome of acanthocephalan reported so far. The mitogenome of R. laterospinosus is the smallest mitogenome of the order Echinorhynchida, which also represents the first mitogenomic data for the genus Rhadinorhynchus and also for the Rhadinorhynchidae sensu stricto. Comparative mitogenomic analyses revealed the gene arrangements of R. laterospinosus and M. hemirhamphi represent two new types of mitochondrial gene arrangement reported in Acanthocephala. Moreover, mitogenomic phylogenies further confirmed the validity of the family Micracanthorhynchinidae and suggested a sister relationship Micracanthorhynchinidae + (Rhadinorhynchidae + Cavisomatidae) within Echinorhynchida.