The complete mitochondrial genome of squat lobster, Munida gregaria (Anomura, Galatheoidea, Munididae).

We determined the mitogenome sequence of Munida gregaria (Fabricius 1793) (Anomura, Galatheoidea, Munididae), which is the first complete mitogenome sequence in the family Munididae Ahyong et al., 2010. The mitogenome of M. gregaria is 16 326 bp in length and contains 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs) and two control regions (CRs). Mitogenome analysis of M. gregaria showed an extra copy of the CR and rearrangements of two PCGs (nad2 and nad3) compared to the arthropod ground pattern. Additionally, it contains a tRNA (trnY) inversion and rearrangements of two PCGs (nad1 and nad3) when compared with that of Neopetrolisthes maculatus and Shinkaia crosnieri, respectively. The phylogenetic tree confirmed that M. gregaria belongs to the superfamily Galatheoidea within Anomura. Our results will be useful for the detailed study of mitogenome evolution and the phylogenetic relationships among the superfamily in the infraorder Anomura.

Munida gregaria (Fabricius 1793) is a benthic squat lobster species of the continental shelf and upper slope off southern South America, New Zealand, and southern Australia (Baba et al. 2008; Schnabel et al. 2011). Of 274 species in the genus Munida, this cold temperate species is suggested to be the only transpacific species in its family on both sides of the East Pacific Barrier, whose dispersal might have occurred by rafting on buoyant macroalgae via the Antarctic Circumpolar Current (Nikula et al. 2010; Perez-Barros et al. 2014; Macpherson 2015). Therefore, M. gregaria and its genetic information have great potential for studies on species expansion, gene exchange, circumpolar dispersal and phylogeography.

Individuals of M. gregaria were collected using hand net from a harbour in Punta Arenas, Chile (53°10′03S, 70°54′30W). Among them, one specimen was deposited in the Korea Polar Research Institute (KOPRI, Incheon, South Korea). Genomic DNA extraction, sequencing and gene annotation were performed according to the methods described by Song et al. (2015). Phylogenetic tree was constructed using MEGA 6.0 (MEGA Inc., Englewood, NJ) (Tamura et al. 2013).

The complete mitogenome of M. gregaria was 16 326 bp in length (GenBank accession number: KU521508; Specimen deposit number: KPIV000001) and contained 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs) and two control regions (CRs).

The superfamily Galatheoidea comprises four families: Galatheidae Samouelle, 1819; Munididae Ahyong et al., 2010; Munidopsidae Ortmann, 1898; Porcellanidae Haworth, 1825. The complete mitogenomes have sequenced from only two families: Shinkaia crosnieri (Family Munidopsidae) and Neopetrolisthes maculatus and Petrolisthes haswelli (Family Porcellanidae) (Yang & Yang 2008; Shen et al. 2013; Tan et al. 2014). Here, we report the first mitogenome sequence of M. gregaria of the family Munididae. The mitogenome of M. gregaria has rearrangements of two PCGs (nad2 and nad3), which is likely a common characteristic feature shared among anomurans, whereas most brachyurans follow the typical arthropod ground pattern. Additionally, the M. gregaria mitogenome contains a tRNA (trnY) inversion and rearrangements of two other PCGs (nad1 and nad3) when compared with that in N. maculatus and S. crosnieri, respectively. Further, it has two CRs (CR1 and CR2) because of the presence of an extra CR (682 bp) between trnS2 and trnP, whereas other anomurans species have only one CR (CR1 or CR2).

To infer the phylogenetic relationship of the M. gregaria mitogenome, we performed the maximum likelihood analysis by using the concatenated sequences of 13 PCGs from 15 selected species of the order Decapoda. Munida gregaria was grouped with S. crosnieri and formed a solid monophyletic group of the superfamily Galatheoidea within Anomura (Figure 1).

Figure 1.

Maximum likelihood (ML) tree based on the mitogenome sequences of Munida gregaria (KU521508; this study) with 15 other selected species was constructed using MEGA 6.0 software. The bootstrap supports are shown on each node. The following mitogenomes were used in this analysis: Clibanarius infraspinatus (NC_025776; Gan et al. 2015), Pagurus longicarpus (NC_003058; Hickerson & Cunningham 2000), Paralithodes brevipes (NC_021458; Yanagimoto & Kobayashi, unpublished), Lithodes nintokuae (NC_024202; Yanagimoto, unpublished), Paralithodes camtschaticus (NC_020029; Kim et al. 2013), Shinkaia crosnieri (NC_011013; Yang & Yang 2008), Neopetrolisthes maculatus (NC_020024; Shen et al. 2013), Petrolisthes haswelli (NC_025572; Tan et al. 2014), Homologenus malayensis (NC_026080; Hui et al. 2014), Umalia orientalis (NC_026688; Shi et al. 2015), Eriocheir japonica (NC_011597; Wang et al. 2014), Ilyoplax deschampsi (NC_020040; Ji et al. 2014), Scylla tranquebarica (NC_012567; Sangthong, unpublished), Pseudocarcinus gigas (NC_006891; Miller et al. 2005), and Acetes chinensis (NC_017600; Kim et al. 2012).

To our knowledge, this is the first report of the complete mitogenome in the family Munididae and will be useful for the detailed study of mitogenome evolution and phylogenetic relationships among the superfamilies in the infraorder Anomura.

Funding information

This study was supported by the basic research program of the Korea Polar Research Institute (PE16020).