The complete mitochondrial genome of Myanmar warty newt <Emphasis Type="Italic">Tylototriton shanorum</Emphasis> (Salamandridae: <Emphasis Type="Italic">Tylototriton</Emphasis>)

Tylototriton shanorum, an endemic species of Myanmar, is threatened by illegal capture and environmental destruction. Here, the complete mitochondrial genome (mitogenome) of T. shanorum is described. The entire mitogenome sequence of T. shanorum is 17,096 bp long, containing 13 protein coding genes, two ribosomal RNA, 22 transfer RNA genes, one control region. In addition, two additional 3′ Cytb like sequences and two complete tRNA^Thr genes, one pseudo tRNA^Thr, and three noncoding sequences (NC1, NC1′ and NC2) were situated between Cytb and tRNA^Pro genes. The new complete mitogenome sequence of T. shanorum will be useful for conservation genetics, evolutionary biology, phylogeography, as well as phylogenetic relationships studies of this threatened species.     

The complete mitochondrial genome sequence of <Emphasis Type="Italic">Buceros bicornis</Emphasis> (Bucerotiformes: Bucerotidae)

Buceros bicornis (Bucerotiformes: Bucerotidae) has been listed as a near threatened species by the International Union for Conservation of Nature and Natural Resources (IUCN) due to over-hunting and habitat loss. Thus, it is a great challenge for us to efficiently protect the Buceros bicornis resource from extinct. Molecular biology research can provide the scientific basis for the conservation of key endangered species. In this work, we first reported the complete mitochondrial genome (mitogenome) sequence of Buceros bicornis by next-generation sequencing (NGS). The total length of the complete mitogenome was 17,117 bp and its overall base composition was estimated to be 30.2% for A, 23.5% for T, 32.3% for C and 14.0% for G, indicating an A?+?T (53.7%)-rich feature in the Buceros bicornis complete mitogenome. In addition, it contained the typical structure of 13 protein-coding genes (PCGs), 2 ribosomal RNA genes, 22 transfer RNA genes (tRNAs) and a non-coding control region (D-loop region). The newly obtained mitogenome sequence seems to be useful for conservation biology and evolutionary studies on hornbill bird species, which would contribute to enrich the Buceros bicornis mitogenome resource and promote its biological research.     

Characterization of the complete mitochondrial genome sequence of the Asiatic toad <Emphasis Type="Italic">Bufo gargarizans</Emphasis> (Amphibia,Anura, Bufonidae) with phylogenetic analysis

The Asiatic toad Bufo gargarizans belongs to Bufonidae. This species is known from the Russian Far East, central, northern and north-eastern China, the Democratic People’s Republic of Korea and Japan. In this study, the complete mitochondrial genome of B. gargarizans was sequenced. The mitogenome was 17,407 bp in length, consisting of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes, and a non-coding control region. As in other vertebrates, most mitochondrial genes are encoded on the heavy strand, except for ND6 and eight tRNA genes which are encoded on the light strand. The overall base composition of the B. gargarizans is 28.9% A, 28.2% T, 27.5% C and 15.3% G. Phylogenetic analysis showed B. gargarizans was closely related to B. bankorensis and B. tuberculatus. The complete mitogenome of B. gargarizans can provide an important data for the studies on phylogenetic relationship and population genetics to further explore the taxonomic status of this species.     

The complete mitochondrial genome of <Emphasis Type="Italic">Indirana semipalmata</Emphasis> (Amphibia: Anura)

The complete mitochondrial genome of the endemic frog Indirana semipalmata was sequenced. The mitogenome is a circular molecule of 17,052 bp in length, containing 13 protein-coding genes (PCGs), two ribosomal RNA (r RNA) genes, 21 transfer RNA (tRNA) genes and a non-coding D-loop region (control region). Its gene arrangements are similar to the typical neobatrachian-type except for the loss of tRNA ^Asn gene. Our data, which represent the first mitogenome for the genus, will serve as a reference for further studies on the conservation genetics of the endemic amphibian fauna of the Western Ghats.     

The complete mitochondrial genome of the scaleshell <Emphasis Type="Italic">Leptodea leptodon</Emphasis> (Bivalvia: Unionidae)

The Leptodea leptodon (Bivalvia: Unionidae) is native to the United States, it is threatened by human activities and habitat destruction. In the present study, it’s complete mitochondrial genome was reconstructed from whole-genome Illumina sequencing data with an average coverage of 1213X. The total length of mitogenome is 16,133 bp, which consists of 37 typical animal mitochondrial genes, including 22 transfer RNAs (tRNAs), 13 protein-coding genes (PCGs) and two ribosomal RNAs. The putative control region (329 bp) is located between ND5 and tRNA-Gln, with an A + T content of 67.4 %. The base composition of the genome is A (38.7 %), C (26.7 %), G (10.8 %) and C (26.7 %) with an overall GC content of 37.5 %. Phylogenetic analysis suggests that L. leptodon is closely related to its confamilial counterparts than to the other taxa.     

The complete mitochondrial genome of the long-lived Greenland shark (<Emphasis Type="Italic">Somniosus microcephalus</Emphasis>): characterization and phylogenetic position

The Greenland shark (Somniosus microcephalus) has recently been identified as the world’s longest-living vertebrate animal, which raises conservational concern in light of recently high bycatch. We report the complete mitochondrial genome of S. microcephalus to be 16,730 bp and composed by 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and a control region. The overall nucleotide composition was 30.8% A, 29.9% T, 14.5% G, and 24.9% C, with a total of 39.4% GC content. Phylogenetic analysis confirmed the position of S. microcephalus in the traditional tree of sharks. The availability of the S. microcephalus mitogenome will contribute to further conservational genetic studies of a unique species, listed as ‘data deficient’ on the Norwegian Red List and ‘near threatened’ on the IUCN Red list.     

The complete mitochondrial genome of Chinese <Emphasis Type="Italic">Sarcocheilichthys kiangsiensis</Emphasis> (Cypriniformes: Cyprinidae: <Emphasis Type="Italic">Sarcocheilichthys</Emphasis>)

Sarcocheilichthys kiangsiensis: is a threatened (IUCN: Least Concern) and native fish in China. This study deals with the complete mitochondrial genome of Sarcocheilichthys kiangsiensis by using next-generation sequencing. The full length of the circular genome is 16,672 bp. It consists of 37 typical animal mitochondrial genes including 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes and 2 ribosomal RNA (rRNA) genes and a control region. The overall nucleotide composition is: 29.7% A, 25.7% T, 27.4% C, and 17.2% G, with a total A?+?T content of 55.4%.     

The complete mitochondrial genome of a threatened loach (<Emphasis Type="Italic">Beaufortia kweichowensis)</Emphasis> and its phylogeny

The Beaufortia kweichowensis is a threatened and native fish in China. In present study, the complete mitochondrial genome of B. kweichowensis was determined using the next-generation sequencing. The circular mitochondrial genome was 16543 bp in length, and contained 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, a putative displacement loop locus and an origin of replication on the light-strand. The overall nucleotide composition was 29.1% A, 25.0% T, 28.7% C, 17.2% G, with 54.1% AT, respectively. Phylogenetic analyses using a nucleotide dataset of cytochrome c oxidase subunit I gene with two different methods (Maximum likelihood and Bayesian analysis) both highly supported the close relationship of B. kweichowensis, Beaufortia szechuanensis and Beaufortia liui, consistent with previous classifications based on morphological and molecular studies. Furthermore, the topology demonstrated that the Balitoridae can be classified into two subfamilies, and the B. kweichowensis belongs to the subfamily Gastromyzoninae. These data provide useful information for a better understanding of the mitochondrial genomic diversities and evolution in fish as well as novel genetic markers for studying population genetics and species identification.     

The complete mitochondrial genome of the vulnerable megophryid frog <Emphasis Type="Italic">Oreolalax rhodostigmatus</Emphasis> (Anura,Megophryidae)

Oreolalax rhodostigmatus Hu and Fei, 1979 is a rare and threatened frog, which is mainly distributed in the caves or underground waters in karst regions of southwest China. The International Union for Conservation of Nature (2017) categorized this endemic species as vulnerable. In this study, we reported the first complete mitochondrial genome of O. rhodostigmatus. The circular double-strand genome was 18,676 bp in size and contained 13 protein-coding genes, 23 transfer RNA genes, 2 ribosomal RNA genes, and a putative control region. The overall nucleotide composition was: 28.0% A, 32.4% T, 24.9% C, and 14.7% G, with a total A+T content of 60.4%. The common genomic features including genome content, gene order, and composition were similar to those of other Oreolalax species. Phylogenetic analysis of 17 Megophryidae species indicated that O. rhodostigmatus was located in the basal clade of Oreolalax.     

The complete mitochondrial genome of <Emphasis Type="Italic">Triplophysa brevibarba</Emphasis> with phylogenetic consideration

Triplophysa brevibarba is distributed in the upstream of Ya-lung River. The conservation status of this fish has been assessed as near threatened due to overfishing and habitat destruction. In the present study, we determined the first complete mitochondrial genome of T. brevibarba. This genome was 16,570 bp in size and contained 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a typical control region. The overall nucleotide composition was: 28.2% A, 28.5% T, 25.3% C, and 18.0% G, with a total A?+?T content of 56.7%. The genome size, gene arrangement, and composition were similar to those of other Triplophysa species. Phylogenetic analysis of all 42 Nemacheilidae species showed that Triplophysa is a monophyletic group and T. brevibarba was clustered with Triplophysa minxiannesis and Triplophysa robusta located in the basal clade of Triplophysa.     

Characterization of the complete mitochondrial genome for the <Emphasis Type="Italic">Euphractus sexcinctus flavimanus</Emphasis> (Mammalia,Xenarthra) subspecies

We are reporting the complete mitochondrial genome for the Euphractus sexcinctus flavimanus, a subspecies from South America, who is also known as yellow armadillo and six-banded armadillo. The de novo short read assembly was obtained from a west-central Brazil specimen. A typical mammalian mitogenome, containing 37 genes and one non-coding region (D-loop) was found. The total length was 16,805 base pairs and differences were observed among the E. s. flavimanus mitogenome described here and that previously reported for an E. sexcinctus unknown subspecies. Such difference was mainly due to the variation in the non-coding region. The complete mitochondrial genome described for the E. s. flavimanus is an important data source for comparative approaches, including genetic diversity studies among armadillo species and subspecies.     

The complete mitochondrial genome of <Emphasis Type="Italic">Ovis ammon darwini</Emphasis> (Artiodactyla: Bovidae)

Ovis ammon darwini: has been listed as a near-threatened species by IUCN-World Conservation Union due to over-hunting and poaching, competition with domestic livestock, and habitat destruction. Study on molecular biology research provides the scientific basis for the protection and sustainable utilization of key endangered species. Mitochondrial genome is very useful for researches in ecology, systematics and conservation biology. In this study, the complete mitochondrial genome sequence of O. a. darwini was determined by next-generation sequencing data, which is 16,618 bp in length and contains 13 protein-coding genes(PCGs), 2 rRNAs genes, 22 tRNAs genes and a non-coding control region. Base composition of genome is A(33.7?%), C(25.8?%), G(13.1?%), T(27.4?%) with an A?+?T content of 61.1?%. Phylogenetic analysis suggested that the systematic status of O. a. darwini was more closed related to O. a. hodgsoni clustered with O. ammon. The mitogenome of O. a. darwini offered significant information for molecular genetic research of O. ammon.     

The complete mitochondrial genome sequence of spotted linsang (<Emphasis Type="Italic">Prionodon pardicolor pardicolor</Emphasis>)

In this study, the complete mitochondrial genome sequence of Prionodon pardicolor pardicolor has been reported for the first time in China. The total length of the mitogenome was 16,689 bp. It contained the typical structure, including 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and 1 control region (D-loop). tRNA^Ser lost the stem of DHC loop and failed to form a typical cloverleaf secondary structure. Mitochondrial control region of P. p. pardicolor was 1242 bp long, laying between the tRNA^Pro and tRNA^Phe genes. Based on the 13 PCG sequences, homology and single-nucleotide mutation loci were performed between P. p. pardicolor and P. pardicolor. As a result, the homology between two species was 99.6% on average, and Nucleotide mutation loci was 41. Also, in view of their mitochondrial control region comparison, P. p. pardicolor drop 28 bp nucleotides.     

The complete mitochondrial genome of Chinese Shrew, <Emphasis Type="Italic">Sorex sinalis</Emphasis> (Soricidae)

The complete mitogenome sequence of Chinese Shrew (Sorex sinalis) was determined in this study. The mitogenome is a circular molecule of 17,216 bp in length, containing 13 protein-coding genes, two ribosome RNA genes, 22 transfer RNA genes and two non-coding regions. Recently, Chinese Shrew has been listed as Data Deficient by the IUCN red list of threatened animals and Near Threatened by the red list of China’s vertebrates. The new sequenced complete mitogenome of S. sinalis would provide useful information for application in conservation genetics and evolution for the endemic species of China.     

The complete mitochondrial genome of goby <Emphasis Type="Italic">Acentrogobius viridipunctatus</Emphasis>

In this study, we first determined and described the complete mitochondrial genome of Acentrogobius viridipunctatus, a member of the Family Gobiidae. The complete mitogenome sequence was 16,507 bp in length containing 13 protein-coding genes, two rRNA genes, 22 tRNA genes, one non-coding control region (D-loop). We identified genome-wide variations among mitochondrial genomes of different Acentrogobius species and found that the D-loop regions harbored most of the sequence variations, which would further provide valuable genome variation information for the conservation and utilization of A. viridipunctatus.     

The complete mitogenome of the winged argonaut <Emphasis Type="Italic">Argonauta hians</Emphasis> and its phylogenetic relationships in Octopoda

The mitogenome of the winged argonaut Argonauta hians (Argonautidae) was decoded using next generation sequencing. The de novo assembled mitogenome consists of 16,130 bp, including 13 protein coding genes, 2 ribosomal RNAs and 22 transfer RNA genes. The gene arrangement is identical to the other available Octopodidae octopus sequences submitted to NCBI. The overall base composition of the A. hians mitogenome is 29.1% A, 6.9% C, 13.2% G and 40.9% T. The phylogenetic analysis of the A. hians mitogenome suggests an ancestral position in the order Octopoda, compared to species in the Amphioctopus, Cistopus and Octopus (Octopodidae) genera. The decoding of the A. hians mitogenome provides insight into the evolutionary history and rises the concern of conservation on this uncommon and ancestral Octopoda species.     

Characterization of an endangered marine strombid gastropod <Emphasis Type="Italic">Strombus luhuanus</Emphasis> complete mitochondrial genome

In this study, we first determined the complete mitochondrial genome of the endangered marine strombid gastropod Strombus luhuanus, an important shellfish traditionally distributed around Hainan island of China and parts of Papua New Guinea. The complete mitogenome sequence was 15,799 bp in length containing 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and one non-coding control region (D-loop). We further compared the mtDNA sequences of S. luhuanus and S. gigas, and calculated the moderate sequence variations in their protein coding regions, which would further provide valuable genome variation information for conservative studies of S. luhuanus.     

The complete mitogenome of sea slug, <Emphasis Type="Italic">Nembrotha kubaryana</Emphasis> (Mollusca: Polyceridae)

In this study, the complete mitogenome sequence of sea slug, Nembrotha kubaryana (Mollusca: Polyceridae), has been decoded for the first time by low coverage whole genome sequencing method. The overall base composition of N. kubaryana mitogenome is 31.5% for A, 14.0% for C, 16.4% for G and 38.0% for T, and has low GC content of 30.5%. The assembled mitogenome, consisting of 14,598 bp, has unique 13 protein coding genes (PCGs), 22 transfer RNAs and two ribosomal RNAs genes. The N. kubaryana has the common mitogenome gene organization and feature of Nudipleura (a clade of sea slugs and sea snails). The complete mitogenome of N. kubaryana provides essential and important DNA molecular data for further phylogenetic and evolutionary analysis for sea slugs and sea snails.     

The complete mitochondrial genome sequence of <Emphasis Type="Italic">Rusa unicolor dejeani</Emphasis> (Artiodactyla: Cervidae)

Rusa unicolor has been listed as a vulnerable species by the International Union for Conservation of Nature and Natural Resources (IUCN) because of overexploitation for subsistence and markets in meat and antlers. Mitochondrial DNA has been used to differentiate R. unicolor from other ungulates and sympatric species. In this study, we determined the complete mitochondrial DNA genome of Rusa unicolor dejeani. The circle genome (16,437 bp in length) contained 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and one D-loop region. All the PCGs in R. u. dejeani were distributed on the H-strand, except for the ND6 gene and eight tRNA genes which were encoded on the L-strand. We expect that the complete mitogenome of R. u. dejeani could provide a molecular data for species identification, phylogeography analysis, population genetics research and evolutionary studies.     

Mitochondrial genome of the sand goby <Emphasis Type="Italic">Acentrogobius caninus</Emphasis> (<Emphasis Type="Italic">Acentrogobius</Emphasis>, Gobiidae)

In this study, we first determined and described the complete mitochondrial genome of Acentrogobius caninus, a member of the Family Gobiidae. The complete mitogenome sequence is 16,616 bp in length containing 13 protein-coding genes, two rRNA genes, 22 tRNA genes, a putative control region (CR), and a light-strand replication origin (OL). Phylogenetic analysis suggests that A. caninus boasts a close relationship with other two species of the genus Acentrogobius. Our results are expected to provide useful molecular information for species identification and further phylogenetic studies of the Gobiiformes family.