The higher-level taxonomy of the stingrays (Dasyatidae) has never been comprehensively reviewed. Recent phylogenetic studies, supported by morphological data, have provided evidence that the group is monophyletic and consists of four major subgroups, the subfamilies Dasyatinae, Neotrygoninae, Urogymninae and Hypolophinae. A morphologically based review of 89 currently recognised species, undertaken for a guide to the world's rays, indicated that most of the currently recognised dasyatid genera are not monophyletic groups. These findings were supported by molecular analyses using the NADH2 gene for about 77 of these species, and this topology is supported by preliminary analyses base on whole mitochondrial genome comparisons. These molecular analyses, based on data generated from the Chondrichthyan Tree of Life project, are the most taxon-rich data available for this family. Material from all of the presently recognised genera (Dasyatis, Pteroplatytrygon and Taeniurops [Dasyatinae]; Neotrygon and Taeniura [Neotrygoninae]; Himantura and Urogymnus [Urogymninae]; and Makararaja and Pastinachus [Hypolophinae]), are included and their validity largely supported. Urogymnus and the two most species rich genera, Dasyatis and Himantura, are not considered to be monophyletic and were redefined based on external morphology. Seven new genus-level taxa are erected (Megatrygon and Telatrygon [Dasyatinae]; Brevitrygon, Fluvitrygon, Fontitrygon, Maculabatis and Pateobatis [Urogymninae], and an additional three (Bathytoshia, Hemitrygon and Hypanus [Dasyatinae]) are resurrected from the synonymy of Dasyatis. The monotypic genus Megatrygon clustered with 'amphi-American Himantura' outside the Dasyatidae, and instead as the sister group of the Potamotrygonidae and Urotrygonidae. Megatrygon is provisionally retained in the Dasyatinae pending further investigation of its internal anatomy. The morphologically divergent groups, Bathytoshia and Pteroplatytrygon, possibly form a single monophyletic group so further investigation is needed to confirm the validity of Pteroplatytrygon. A reclassification of the family Dasyatidae is provided and the above taxa are defined based on new morphological data.
In this study, the complete mitogenome sequence of two moray eels of Gymnothorax formosus and Scuticaria tigrina (Anguilliformes: Muraenidae) has been sequenced by the next-generation sequencing method. The assembled mitogenome, with the length of 16,558 bp for G. formosus and 16,521 bp for S. tigrina, shows 78% identity to each other. Both mitogenomes follow the typical vertebrate arrangement, including 13 protein coding genes, 22 transfer RNAs, two ribosomal RNAs genes, and a non-coding control region of D-loop. The length of D-loop is 927 bp (G. formosus) and 850 bp (S. tigrina), which is located between tRNA-Pro and tRNA-Phe. The overall GC content is 45.5% for G. formosus and 47.9% for S. tigrina. Complete mitogenomes of G. formosus and S. tigrina provide essential and important DNA molecular data for further phylogenetic and evolutionary analysis for moray eel.
In this study, the complete mitogenome sequence of the longfang moray, Enchelynassa canina (Anguilliformes: Muraenidae) has been sequenced by the next-generation sequencing method. The length of the assembled mitogenome is 16,592 bp, which includes 13 protein coding genes, 22 transfer RNAs, and 2 ribosomal RNAs genes. The overall base composition of longfang moray is 28.4% for A, 28.0% for C, 18.4% for G, 25.1% for T, and show 82% identities to Kidako moray, Gymnothorax kidako. The complete mitogenome of the longfang moray provides an essential and important DNA molecular data for further phylogeography and evolutionary analysis for moray eel phylogeny.
The complete mitochondrial genomes of two jungle crows (Corvus macrorhynchos) were sequenced. DNA was extracted from tissue samples obtained from shed feathers collected in the field in Sri Lanka and sequenced using the Illumina MiSeq Personal Sequencer. Jungle crow mitogenomes have a structural organization typical of the genus Corvus and are 16,927 bp and 17,066 bp in length, both comprising 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal subunit genes, and a non-coding control region. In addition, we complement already available house crow (Corvus spelendens) mitogenome resources by sequencing an individual from Singapore. A phylogenetic tree constructed from Corvidae family mitogenome sequences available on GenBank is presented. We confirm the monophyly of the genus Corvus and propose to use complete mitogenome resources for further intra- and interspecies genetic studies.
Here we report the complete mitochondrial genome of the Bornean banteng Bos javanicus lowi (Cetartiodactyla, Bovidae), which was determined using next-generation sequencing. The mitochondrial genome is 16,344 bp in length containing 13 protein-coding genes, 21 tRNAs and 2 rRNAs. It shows the typical pattern of bovine mitochondrial arrangement. Phylogenetic tree analysis of complete mtDNA sequences showed that Bornean banteng is more closely related to gaur than to other banteng subspecies. Divergence dating indicated that Bornean banteng and gaur diverged from their common ancestor approximately 5.03 million years ago. These results suggest that Bornean banteng might be a distinct species in need of conservation.
Climatic differences across a taxon's range may be associated with specific bioenergetic demands and may result in genetics-based metabolic adaptation, particularly in aquatic ectothermic organisms that rely on heat exchange with the environment to regulate key physiological processes. Extending down the east coast of Australia, the Great Dividing Range (GDR) has a strong influence on climate and the evolutionary history of freshwater fish species. Despite the GDR acting as a strong contemporary barrier to fish movement, many species, and species with shared ancestries, are found on both sides of the GDR, indicative of historical dispersal events. We sequenced complete mitogenomes from the four extant species of the freshwater cod genus Maccullochella, two of which occur on the semi-arid, inland side of the GDR, and two on the mesic coastal side. We constructed a dated phylogeny and explored the relative influences of purifying and positive selection in the evolution of mitogenome divergence among species. Results supported mid- to late-Pleistocene divergence of Maccullochella across the GDR (220-710 thousand years ago), bringing forward previously reported dates. Against a background of pervasive purifying selection, we detected potentially functionally relevant fixed amino acid differences across the GDR. Although many amino acid differences between inland and coastal species may have become fixed under relaxed purifying selection in coastal environments rather than positive selection, there was evidence of episodic positive selection acting on specific codons in the Mary River coastal lineage, which has consistently experienced the warmest and least extreme climate in the genus.
Angiostrongylus malaysiensis is a nematode parasite of various rat species. When first documented in Malaysia, it was referred to as A. cantonensis. Unlike A. cantonensis, the complete mitochondrial genome of A. malaysiensis has not been documented. We report here its complete mitogenome, its differentiation from A. cantonensis, and the phylogenetic relationships with its congeners and other Metastrongyloid taxa. The whole mitogenome of A. malaysiensis had a total length of 13,516bp, comprising 36 genes (12 PCGs, 2 rRNA and 22 tRNA genes) and a control region. It is longer than that of A. cantonensis (13,509bp). Its control region had a long poly T-stretch of 12bp which was not present in A. cantonensis. A. malaysiensis and A. cantonensis had identical start codon for the 12 PCGs, but four PCGs (atp6, cob, nad2, nad6) had different stop codon. The cloverleaf structure for the 22 tRNAs was similar in A. malaysiensis and A. cantonensis except the TΨC-arm was absent in trnV for A. malaysiensis but present in A. cantonensis. The Angiostrongylus genus was monophyletic, with A. malaysiensis and A. cantonensis forming a distinct lineage from that of A. costaricensis and A. vasorum. The genetic distance between A. malaysiensis and A. cantonensis was p=11.9% based on 12 PCGs, p=9.5% based on 2 rRNA genes, and p=11.6% based on 14 mt-genes. The mitogenome will prove useful for studies on phylogenetics and systematics of Angiostrongylus lungworms and other Metastrongyloid nematodes.
We describe the characteristics of complete mitogenome of C. brachyotis in this article. The complete mitogenome of C. brachyotis is 16,701 bp long with a total base composition of 32.4% A, 25.7% T, 27.7% C and 14.2% G. The mitogenome consists of 13 protein-coding genes (11,408 bp), (KM659865) two rRNA (12S rRNA and 16S rRNA) genes (2,539 bp), 22 tRNA genes (1518 bp) and one control region (1239 bp).
The mitochondrial genome sequence of the ghost crab, Ocypode ceratophthalmus, is documented (GenBank accession number: LN611669) in this article. This is the first mitogenome for the family Ocypodidae and the second for the order Ocypodoidea. Ocypode ceratophthalmus has a mitogenome of 15,564 base pairs consisting of 13 protein-coding genes, two ribosomal subunit genes, 22 transfer RNAs and a non-coding AT-rich region. The base composition of the O. ceratophthalmus mitogenome is 35.78% for T, 19.36% for C, 33.73% for A and 11.13% for G, with an AT bias of 69.51% and the gene order is the typical arrangement for brachyuran crabs.
The Mictyris longicarpus (soldier crab) complete mitochondrial genome sequence is reported making it the first for the family Mictyridae and the second for the superfamily Ocypodoidea. The mitogenome is 15,548 base pairs made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs and a non-coding AT-rich region. The soldier crab mitogenome gene order is characteristic of brachyuran crabs with a base composition of 36.58% for T, 19.15% for C, 32.43% for A and 11.83% for G, with an AT bias of 69.01%.
This is the first study to identify and determine the phylogenetics of neritids found in Malaysia. In total, twelve species from the family Neritidae were recorded. Ten species were from the genus Nerita and two species were from the genus Neritina. DNA barcodes were successfully assigned to each species. Although some of these species were previously reported in the region, three are only presently reported in this study. The dendrogram showed Nerita and Neritina strongly supported in their respective monophyletic clades. Phylogenetic positions of some species appeared unstable in the trees. This could be due to the differences in a small number of nucleotides, thus minimizing genetic variation between each specimen and species.
The mitogenome of the Australian freshwater blackfish, Gadopsis marmoratus was recovered coverage by genome skimming using the MiSeq sequencer (GenBank Accession Number: NC_024436). The blackfish mitogenome has 16,407 base pairs made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a 819 bp non-coding AT-rich region. This is the 5th mitogenome sequence to be reported for the family Percichthyidae.
The mitochondrial genome sequence of the Australian tadpole shrimp, Triops australiensis is presented (GenBank Accession Number: NC_024439) and compared with other Triops species. Triops australiensis has a mitochondrial genome of 15,125 base pairs consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a non-coding AT-rich region. The T. australiensis mitogenome is composed of 36.4% A, 16.1% C, 12.3% G and 35.1% T. The mitogenome gene order conforms to the primitive arrangement for Branchiopod crustaceans, which is also conserved within the Pancrustacean.
The mitochondrial genome sequence of the Australian crayfish, Euastacus yarraensis, is documented and compared with other Australian crayfish genera. Euastacus yarraensis has a mitogenome of 15,548 base pairs consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a non-coding AT-rich region. The base composition of E. yarraensis mitogenome is 32.39% for T, 22.45% for C, 34.43% for A, and 10.73% for G, with an AT bias of 66.82%. The mitogenome gene order conforms to what is considered the primitive arrangement for parastacid crayfish.
The mitochondrial genome sequence of the stone crab, Myomenippe fornasinii, second of the superfamily Eriphioidea is documented. Myomenippe fornasinii has a mitogenome of 15,658 base pairs consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs and a non-coding AT-rich region. The base composition of the M. fornasinii mitogenome is 36.10% for T, 18.52% for C, 35.48% for A, and 9.90% for G, with an AT bias of 71.58%. The mitogenome gene order conforms to what is the standard arrangement for brachyuran crabs.
The mitochondrial genome sequence of the Morton Bay bug, Thenus orientalis, is documented, which makes it the second mitogenome for species of the family Scyllaridae and the ninth for members of the superfamily Palinuroidae. Thenus orientalis has a mitogenome of 16,826 base pairs consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 23 transfer RNAs, and a non-coding AT-rich region. The base composition of the T. orientalis mitogenome is 31.31% for T, 23.77% for C, 31.05% for A, and 13.87% for G, with an AT bias of 62.36%. In addition to a duplicated trnS1 and several other tRNA gene rearrangements, the mitogenome gene order has novel protein coding gene order with the nad6 and cob genes translocated as a block to a location downstream of the nad3 gene.
The complete mitogenome of the ray Pastinachus atrus was recovered from a partial genome scan using the HiSeq sequencing system. The P. atrus mitogenome has 18,162 base pairs (61% A + T content) made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a 2516 bp non-coding AT-rich region. This mitogenome sequence is the first for a ray from Australian waters, the first for the Genus Pastinachus, and the 6th for the family Dasyatidae.
The complete mitochondrial genome of the swimming crab Thalamita crenata was obtained from a partial genome scan using the MiSeq sequencing system. The Thalamita crenata mitogenome has 15,787 base pairs (70% A+T content) made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a putative 897 bp non-coding AT-rich region. This Thalamita mitogenome sequence is the first for the genus and the eighth for the family Portunidae.
The complete mitochondrial genome of the moon crab Ashtoret lunaris was obtained from a partial genome scan using the MiSeq sequencing system. The Ashtoret lunaris mitogenome is 15,807 base pairs in length (70% A + T content) and made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a putative 956 bp non-coding AT-rich region. This A. lunaris mitogenome sequence is the first for the genus, as well as the family Matutidae and superfamily Calappoidea.
The complete mitochondrial genome of the enigmatic freshwater crayfish Engaeus lyelli was sequenced using the MiSeq Personal Sequencer (Illumina, San Diego, CA). The mitogenome has 16,027 bp consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 23 transfer RNAs, and a non-coding AT-rich region. The base composition of E. lyelli is 29.01% for T, 27.13% for C, 31.43% for A, and 12.44% for G, with an AT bias of 60.44%. The species has the distinctive gene order characteristic of parastacid crayfish with the exception of some minor rearrangements involving the tRNA genes.