Description of a species of Fabaeformiscandona (Ostracoda, Crustacea) from Kushiro Marsh, Hokkaido, Japan, with the nearly complete mitochondrial genomic sequence

So far, 16 species of non-marine ostracods have been reported from Kushiro Marsh, Kushiro Shitsugen National Park, eastern Hokkaido, Japan (Hiruta and Smith 2001, Smith and Hiruta 2004). Nine of these species are in Candonidae, the second-most diverse family of non-marine ostracods. This family contains ca. 550 species, or around 25% of the total number of non-marine ostracod species (Martens et al. 2008).

We sampled ostracods in Kushiro Marsh on 27 December 2012 and identified an undescribed species in the family Candonidae, herein described as Fabaeformiscandona kushiroensis sp. nov. This species belongs to the F. acuminata species group and is characterized by the shapes of the elongate, dorsally directed medial and outer lobes on the distal end of each hemipenis. We also determined for this species the sequence of the nearly complete mitochondrial genome, the first record from the order Podocopa. The genome (ca. 17 kbp) contains two ribosomal RNA, 22 transfer RNA, and 13 protein-coding genes, as also found in other arthropods for which the mitochondrial genome has been sequenced. The gene arrangement is similar to the pancrustacean ground pattern, except that in the control region there is an approximately 2 kbp tandem repeat region composed of 220-bp motif sequences. We describe the genetic features of the mitochondrial genome, including nucleotide composition and the secondary structures of tRNAs and rRNAs, and compare them with the genome of Vargula hilgendorfii (Myodocopa, Ostracoda).