Inäbnit T., Dennis A.B.

Melampus bidentatus is a complex of three cryptic species that are an important component of the salt marsh communities along the North American east coast and the Gulf of Mexico. We assembled the mitochondrial genome of the cryptic species M. bidentatus “North” and “South” from Illumina short read data using NovoPlasty and from PacBio Hifi data using MitoHifi respectively and annotated them using the MITOS webserver. Both mitochondrial genomes contain 37 genes (13 protein coding, 2 rRNA, 22 tRNA), 24 on the forward strand and 12 on the reverse strand, and have an identical gene order. The pairwise difference between the two mitochondrial genomes is 0.333. Melampus bidentatus North and South are two of four currently known Ellobioidea species (one, Pedipes pedipes, related, the other, Myosotella myosotis, less so) who deviate from the otherwise uniform gene order within the Superfamily (10 sequenced mitochondrial genomes). These four species are also recovered outside the rest of the Ellobioidea in all mitogenome based phylogenies, which is not supported by other phylogenetic or morphological studies. A putative control region was identified for all known mitochondrial genomes within Ellobioidea.