Sedimentary Vibrio Blooms in the Xisha Islands May Associate with the 2020 Coral Bleaching Event.

Coral reefs are among the most biodiverse ecosystems, providing habitats for various organisms. Studies on coral bleaching have been increasing recently, but little is known about the distribution and community assembly of coral pathogenic bacteria (e.g., several Vibrio species). We elucidated the distribution pattern and interaction relationships of total bacteria and Vibrio spp. in sediments from the Xisha Islands, which are characterized by their high coverage and diversity of coral resources. Vibrio spp. showed significantly higher relative abundance values in the Xisha Islands (1.00 × 108 copies/g) than in other areas (approximately 1 × 104 to 9.04 × 105 copies/g), indicating that the coral bleaching event of 2020 may have promoted the bloom of vibrios. A spatial shift in community composition was observed between the northern (Photobacterium rosenbergii and Vibrio ponticus) and southern (Vibrio ishigakensis and Vibrio natriegens) sites, accompanied by a clear distance-decay pattern. The spatial distance and coral species (e.g., Acroporidae and Fungiidae) had much greater correlations with the Vibrio community than did environmental factors. However, complex mechanisms may exist in the community assembly of Vibrio spp. due to the large proportion of unexplained variation. Stochastic processes may play an important role, as shown by the neutral model. Vibrio harveyi had the highest relative abundance (77.56%) and niche breadth, compared to other species, and it was negatively correlated with Acroporidae, likely reflecting its strong competitive ability and adverse effects on specific corals. Our study provides insights into the bloom and underlying assembly mechanisms of sedimentary vibrios in the Xisha Islands, thereby contributing to identify the potential indicator of coral bleaching and provide inspiration for the environmental management of coral reef areas. IMPORTANCE Coral reefs exert important roles in maintaining the sustainability of marine ecosystems but decline worldwide due to various drivers, especially pathogenic microorganisms. Here, we investigated the distribution pattern and interactions of total bacteria and Vibrio spp. in the sediments from Xisha Islands during the coral bleaching event of 2020. Our results showed that the abundances of Vibrio (1.00 × 108 copies/g) were high across the whole sites, indicating the bloom of sedimentary Vibrio spp. Coral pathogenic Vibrio species were abundant in the sediments, likely reflecting adverse effects on several kinds of corals. The compositions of the Vibrio spp. were separated by geographical location, which was mainly attributable to the spatial distance and coral species. Overall, this work contributes by providing evidence for the outbreak of coral pathogenic vibrios. The pathogenic mechanism of the dominant species (especially V. harveyi) should be comprehensively considered by laboratory infection experiments in the future.

Vibrio sinus sp. nov., a marine bacterium isolated from coastal seawater.

A Gram-straining-negative, facultatively anaerobic, motile by means of a polar flagellum and rod-shaped marine bacterium, designated S4M6T, was isolated from surface seawater collected in Dongshan Bay (Fujian, PR China). Phylogenetic analysis based on 16S rRNA genes, phylogenomic analysis of single-copy gene families and whole genome data indicated that S4M6T represented a member of the genus Vibrio. The closest phylogenetic relatives of S4M6T were Vibrio marisflavi CGMCC 1.8994T (97.8 % 16S rRNA gene sequence pairwise similarity), Vibrio variabilis LMG 25438T (96.9 %), Vibrio gangliei SZDIS-1T (96.2 %) and Vibrio aestivus M22T (96.1 %). The growth of S4M6T occurred at 15-35 °C (optimum 28 °C), pH 4.0-9.0 (optimum 5.0-7.0) and in the presence of 2-5 % (w/v) NaCl (optimum 3 %). The predominant fatty acids (>10 %) are C16 : 0, summed feature 3 (C16 : 1ω7c and/or C16 :  1ω6c) and summed feature 8 (C18 : 1ω7c and/or C18 :  1ω6c). The DNA G+C content of the assembled genomic sequences was 43.4 % for S4M6T. Average nucleotide identity (ANI) values between S4M6T and the reference species were lower than the threshold for species delineation (95-96 %); in silico DNA-DNA hybridization further indicated that S4M6T had less than 70 % similarity to its relatives. On the basis of the polyphasic evidence, strain S4M6T is proposed to represent a novel species of the genus Vibrio, for which the name Vibrio sinus sp. nov. is proposed. The type strain is S4M6T (= KCTC 92312T= MCCC 1K06167T).

Vibrio methylphosphonaticus sp. nov., a methylphosphonate-decomposing bacterium isolated from surface seawater in the Xisha Islands, PR China.

A Gram-stain-negative, facultative anaerobic, methylphosphonate-decomposing, motile by a polar flagellum and rod-shaped marine bacterium, designated S4B1T, was isolated from the surface seawater collected from the Yongle Atoll (Xisha Islands, PR China). The pairwise alignment showed the highest sequence similarity of 97.5 and 96.6 % to Vibrio aestuarianus subsp. cardii 12_122_3T3T and Vibrio atypicus HHS02T, respectively. Phylogenetic analysis based on 16S rRNA gene and the phylogenomic analysis of single-copy genes showed that strain S4B1T belonged to the genus Vibrio and formed a close branch with Vibrio qingdaonensis ZSDZ65T. Growth of strain S4B1T occurred at 4-30 °C (optimum, 28 °C), at pH 6.0-8.0 (optimum, pH 7.0) and in the presence of 2-7 % (w/v) NaCl (optimum, 3 %). The predominant fatty acids (>10 %) were C16 : 0, iso-C16 : 0 and summed feature 3 (C16 : 1 ω7c or/and C16 : 1 ω6c). The DNA G+C content of the assembled genomic sequence was 44.3 mol%. Average nucleotide identity (ANI) values between S4B1T and its reference species were lower than the threshold for species delineation (95-96 %), in which its highest ANI value with V. qingdaonensis ZSDZ65T was 87.0 %. In silico DNA-DNA hybridization further showed that strain S4B1T had less than 70 % similarity to its relatives. On the basis of the polyphasic evidence, strain S4B1T is proposed to represent a novel species of the genus Vibrio, for which the name Vibrio methylphosphonaticus sp. nov. is proposed. The type strain is S4B1T (=KCTC 92311T=MCCC 1K06168T).

Vibrio agarilyticus sp. nov., an agar-digesting marine bacterium isolated from coastal seawater in Daya Bay (Guangdong, China).

A Gram-strain-negative, facultatively anaerobic, motile, rod-shaped and flagellated marine bacterium, designated SM6T, was isolated from surface seawater collected in Daya Bay (Guangdong, China). Phylogenetic analysis based on 16S rRNA gene sequences, multilocus sequence analysis, phylogenomic analysis of single-copy gene families and whole genome data showed that strain SM6T belonged to the genus Vibrio. The closest phylogenetic relatives of SM6T were Vibrio plantisponsor MSSRF60T (97.38 % 16S rRNA gene sequence pairwise similarity), Vibrio variabilis R-40492T (97.27 %), Vibrio aestuarianus ATCC 35048T (97.21 %) and Vibrio sagamiensis LC2-047T (97.3 %). Growth of strain SM6T occurred at 10-45 °C (optimum 30 °C), at pH 6.0-9.0 (optimum 6.0) and in the presence of 0-10 % (w/v) NaCl (optimum 3-8 %). The predominant fatty acids (>10 %) were summed feature 3 (C16 : 1 ω7c or/and C16 : 1 ω6c), C16 : 0 and summed feature 8 (C18 : 1 ω7c or/and C18 : 1 ω6c). The DNA G+C content of the assembled genomic sequences was 47.37 % for strain SM6T. Average nucleotide identity values between SM6T and its reference species were lower than the threshold for species delineation (95-96 %); in silico DNA-DNA hybridization further showed that the strains shared less than 70 % similarity. On the basis of evidence from the present polyphasic study, strain SM6T is considered to represent a novel species of the genus Vibrio, for which the name Vibrio agarilyticus sp. nov. is proposed. The type strain is SM6T (=KCTC 82076T=MCCC 1K04327 T).

Flammeovirga agarivorans sp. nov., an agar-digesting marine bacterium isolated from surface seawater.

A Gram-stain-negative, aerobic, gliding, reddish-orange-coloured, rod-shaped strain, designated SR4T, was isolated from surface seawater sampled at Luhuitou fringing reef (South China Sea). Phylogenetic analyses based on the 16S rRNA gene, phylogenomic analysis of single-copy gene families and whole genome data affiliated it to the genus Flammeovirga. It was most closely related to Flammeovirga yaeyamensis NBRC 100898T (97.99 % 16S rRNA gene similarity). The genome average nucleotide identity and DNA-DNA relatedness values between strain SR4T and its reference strains were less than 74.2 and 16.3 %, respectively. Growth occurred at 20-35 °C (optimum, 28 °C), pH 6.0-9.0 (optimum, pH 7.0) and in the presence of 1-6 % (w/v) NaCl (optimum, 2-4 %). The dominant fatty acids were C16 : 0, iso-C15 : 0 and C20 : 4 ω6,9,12,15c. The polar lipid profile of strain SR4T comprised phosphatidylethanolamine, two glycolipids, two aminophospholipids and three unidentified lipids. The major respiratory quinone was MK-7. The DNA G+C content of strain SR4T was 34.20 mol%. On the basis of the polyphasic evidence, strain SR4T is proposed as representing a novel species of the genus Flammeovirga, for which the name Flammeovirga agarivorans sp. nov. is proposed. The type strain is SR4T (=KCTC 82075T=MCCC 1A17137T).

Diversity of Culturable Bacteria from the Coral Reef Areas in the South China Sea and Their Agar-Degrading Abilities.

The South China Sea (SCS) is abundant in marine microbial resources with high primary productivity, which is crucial for sustaining the coral reef ecosystem and the carbon cycle. Currently, research on the diversity of culturable bacteria in the SCS is relatively extensive, yet the culturable bacteria in coral reefs has been poorly understood. In this study, we analyzed the bacterial community structure of seawater samples among Daya Bay (Fujian Province), Qionghai (Hainan Province), Xisha Islands, and the southern South China Sea based on culturable methods and detected their abilities for agar degradation. There were 441 bacterial strains, belonging to three phyla, five classes, 43 genera, and 101 species, which were isolated by marine agar 2216E (MA; Becton Dickinson). Strains within Gammaproteobacteria were the dominant group, accounting for 89.6% of the total bacterial isolates. To investigate vibrios, which usually correlated with coral health, 348 isolates were obtained from TCBS agar, and all isolates were identified into three phylum, three classes, 14 orders, 25 families, and 48 genera. Strains belonging to the genus Vibrio had the greatest number (294 strains), indicating the high selectivity of TCBS agar for vibrios. Furthermore, nineteen strains were identified as potentially novel species according to the low 16S rRNA gene similarity (<98.65%), and 28 strains (15 species) had agar-degrading ability. These results indicate a high diversity of culturable bacteria in the SCS and a huge possibility to find novel and agar-degrading species. Our study provides valuable microbial resources to maintain the stability of coral ecosystems and investigate their roles in the marine carbon cycle.

Comparative Mitogenomics Reveals Cryptic Species in Sillago ingenuua McKay, 1985 (Perciformes: Sillaginidae).

It is unreliable to identify marine fishes only by external morphological features. Species misidentification brings great challenges to fishery research, resource monitoring and ecomanagement. Sillago ingenuua is an important part of commercial marine fishes, and in which, the morphological differences between different groups are not obvious. Here, we compared different geographical groups of S. ingenuua which were collected from Xiamen, Dongshan, Keelung, Songkhla and Java. The results showed that all samples of S. ingenuua were similar in external morphological characteristics and the shape of the swim bladder, but there were two distinctive lineages which were flagged as cryptic species based on DNA barcoding. The comparative mitogenomic results showed that S. ingenuua A and S. ingenuua B were identical in structural organization and gene arrangement. Their nucleotide composition and codon usage were also similar. A phylogenetic analysis was performed based on 13 concatenated PCGs from eight Sillago species. The results showed that the genetic distance between S. ingenuua A and S. ingenuua B was large (D = 0.069), and this genetic distance was large enough to reveal that S. ingenuua A and S. ingenuua B might be different species.

The Complete Mitochondrial Genome of Homophyllia bowerbanki (Scleractinia, Lobophylliidae): The First Sequence for the Genus Homophyllia.

Reef-building coral species of the order Scleractinia play an important role in shallow tropical seas by providing an environmental base for the ecosystem. The molecular data of complete mitochondrial genome have become an important source for evaluating phylogenetic and evolutionary studies of Scleractinia. Here, the complete mitogenome of Homophyllia bowerbanki (Milne Edwards and Haime, 1857), collected from Nansha Islands of the South China Sea, was sequenced for the first time through a next-generation sequencing method. H. bowerbanki is the first species of its genus for which the mitogenome was sequenced. This mitogenome was 18,154 bp in size and included two transfer RNA genes (tRNAs), 13 protein-coding genes (PCGs), and two ribosomal RNA genes (rRNAs). It showed a similar gene structure and gene order to the other typical scleractinians. All 17 genes were encoded on the H strand and the total GC content was 33.86% in mitogenome. Phylogenetic analysis (maximum likelihood tree method) showed that H. bowerbanki belonged to the "Robust" clade and clustered together with other two species in the family Lobophylliidae based on 13 PCGs. The mitogenome can provide significant molecular information to clarify the evolutionary and phylogenetic relationships between stony corals and to facilitate their taxonomic classification; it can also support coral species monitoring and conservation efforts.

Recent deterioration of coral reefs in the South China Sea due to multiple disturbances.

More frequent global warming events, biological disasters, and anthropogenic activities have caused extensive damage to coral reefs around the world. Coral reefs in the Xisha Islands (also known as the Paracel Islands) have been damaged following rounds of heatwaves and crown-of-thorns starfish (CoTS) outbreaks over recent decades. Based on a comprehensive community survey in 2020, we determined a diagnosis for the present state of six coral regions in the Xisha Islands. The findings suggested that these regions had a total of 213 species of scleractinian corals belonging to 43 genera and 16 families. Living coral coverage across sites was widely divergent and ranged from 0.40% (IQR: 7.74-0.27%) in Panshi Yu to 38.20% (IQR: 43.00-35.90%) in Bei Jiao. Coral bleaching prevalence was 23.90% (IQR: 41.60-13.30%) overall and topped out at 49.30% (IQR: 50.60-48.10%) in Bei Jiao. Five of the coral regions (all but Yongxing Dao) were under threat of CoTS outbreaks. High mortality combined with excellent recruitment rates suggested potential rehabilitation after recent deterioration. We employed a quantifiable Deterioration Index (DI) to evaluate the intensity of deterioration of coral reefs in the Xisha Islands. The results showed that Yongxing Dao and Langhua Jiao had low recent deterioration (DIrecent = 0.05, IQR: 0.07-0.02 and 0.04, IQR: 0.11-0.01, respectively), while Bei Jiao, Yongle Atoll, Yuzhuo Jiao, and Panshi Yu had high recent deterioration (DIrecent > 0.16). Different monitoring sites within the same coral region were heterogeneous with regards to all above indexes. Moreover, we reviewed and discussed potential disturbances that threaten the health of the Xisha Islands' corals. It is crucial to identify severely afflicted areas and find successful methods to better manage coral reef health in this region.

The complete mitochondrial genome of Montiporavietnamensis (Scleractinia, Acroporidae).

Montiporavietnamensis Veron, 2000 (Cnidaria, Anthozoa, Scleractinia, Acroporidae) is an uncommon, but distinctive species of stony coral. The complete mitochondrial genome of M.vietnamensis was sequenced in this study for the first time, based on 32 pairs of primers newly designed according to seven species in the family Acroporidae. The mitogenome of M.vietnamensis has a circular form and is 17,885 bp long, including 13 protein-coding genes (PCGs), 2 tRNA (tRNAMet, tRNATrp), 2 rRNA genes and a putative control-region. The base composition of the complete mitogenome was 24.8% A, 14.2% C, 24.2% G and 36.8% T, with a higher AT content (61.6%) than GC content (38.4%). Based on 13 protein-coding genes, a Maximum Likelihood phylogenetic analysis showed that M.vietnamensis is clustered in the genus Montipora which belongs to the family Acroporidae. More stony coral species should be sequenced for basic molecular information and to help confirm the taxonomic status and evolutionary relationships of Scleractinia in the future.

Complete mitochondrial genome sequences of Physogyralichtensteini (Milne Edwards & Haime, 1851) and Plerogyrasinuosa (Dana, 1846) (Scleractinia, Plerogyridae): characterisation and phylogenetic analysis.

In this study, the whole mitochondrial genomes of Physogyralichtensteini and Plerogyrasinuosa have been sequenced for the first time. The length of their assembled mitogenome sequences were 17,286 bp and 17,586 bp, respectively, both including 13 protein-coding genes, two tRNAs, and two rRNAs. Their mitogenomes offered no distinct structure and their gene order were the same as other typical scleractinians. Based on 13 protein-coding genes, a maximum likelihood phylogenetic analysis showed that Physogyralichtensteini and Plerogyrasinuosa are clustered in the family Plerogyridae, which belongs to the "Robust" clade. The 13 tandem mitogenome PCG sequences used in this research can provide important molecular information to clarify the evolutionary relationships amongst stony corals, especially at the family level. On the other hand, more advanced markers and more species need to be used in the future to confirm the evolutionary relationships of all the scleractinians.

Description of a new species, Sillago nigrofasciata sp. nov. (Perciformes, Sillaginidae) from the southern coast of China.

A new Sillago species, the black-banded sillago, Sillago nigrofasciata sp. nov., is described based on 302 specimens sampled from the southern coast of China. Morphological comparisons have been conducted between the new species and ten other Sillago species. The results show that the new species is characterized by a black mid-lateral band below the lateral line when fresh; other characteristics are similar to those of Sillago sihama but subtle differences exist on the swim bladder between Sillago nigrofasciata sp. nov. and S. sihama. A detailed description and illustrations are provided for the new species. The validity of this new species is also supported by a genetic comparison using sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene.

Characterization of the complete mitochondrial genome of Diploastrea heliopora and phylogeny of the scleractinia species which have group I introns in their COI genes.

Mitochondrial genome DNA is a powerful marker for resolving phylogenetic relationships among scleractinian corals. Here, we decode the complete mitochondrial genome of Diploastrea heliopora (Lamarck, 1816) for the first time. The general features are 18 363 bp in length, and conventionally, with 13 protein coding genes, two ribosomal RNAs, and two transfer RNAs. Gene arrangement and distribution are similar to other scleractinian corals. Moreover, the COI gene of D. heliopora is broken up into two parts by a complex group I intron. This intron is 1076 bases in length and contains helical structures (P1-P10, except P2) and four conserved regions (P, Q, R, and S). The mitochondrial genome of D. heliopora has asymmetric base composition (13.03% C, 20.29% G, 25.91% A, and 40.77% for T). Based on concatenated protein coding genes, ML and BI trees show similar phylogenetic relationship: D. heliopora clustered closely with Sclerophyllia maxima and Echinophyllia aspera into the robust branch. The data and conclusion in this study are reference for further phylogenetic studies of corals.

Complete mitochondrial genome of the Turbinaria bifrons (Scleractinia, Dendrophylliidae).

In this study, the complete mitogenome sequence of the stony coral, Turbinaria bifrons Brüggemann, 1877, has been decoded for the first time by next-generation sequencing (NGS) and genome assembly. The assembled mitogenome was 18,880 bp in length, contained 13 protein coding genes, 2 transfer RNAs, and 2 ribosomal RNAs. The complete mitogenome of T. bifrons showing 97.09% identities to Tubastraea tagusensis. The complete mitogenome provides essential and important DNA molecular data for further phylogenetic and evolutionary analysis for coral phylogeny.

Complete mitochondrial DNA sequence of the Psammocora profundacella (Scleractinia, Psammocoridae): mitogenome characterisation and phylogenetic implications.

Complete mitochondrial DNA sequence data have played a significant role in phylogenetic and evolutionary studies of scleractinian corals. In this study, the complete mitogenome of Psammocora profundacella Gardiner, 1898, collected from Guangdong Province, China, was sequenced by next-generation sequencing for the first time. Psammocora profundacella is the first species for which a mitogenome has been sequenced in the family Psammocoridae. The length of its assembled mitogenome sequence was 16,274 bp, including 13 protein-coding genes, two tRNAs and two rRNAs. Its gene content and gene order were consistent with the other Scleractinia species. All genes were encoded on the H strand and the GC content of the mitochondrial genome was 30.49%. Gene content and order were consistent with the other Scleractinia species. Based on 13 protein-coding genes, Maximum Likelihood phylogenetic analysis showed that P. profundacella belongs to the "Robust" clade. Mitochondrial genome data provide important molecular information for understanding the phylogeny of stony corals. More variable markers and additional species should be sequenced to confirm the evolutionary relationships of Scleractinia in the future.

The complete mitochondrial genome of Plesiastrea versipora (Scleractinia, Plesiastreidae) sheds light on its phylogeny and taxonomy of the family Plesiastreidae.

The genus Plesiastrea used to be a member of the traditional family Faviidae, falling into the challenging 'Bigmessidae' clade, and was re-established until recent molecular phylogenies published. The entire mitogenome of the symbiotic coral Plesiastrea versipora (Lamarck, 1816), the type species of the family Plesiastreidae, was sequenced. The length of the mitochondrial genome is 15,320 bp and it includes thirteen protein-coding genes (PCGs), two rRNAs and two tRNAs. The nucleotide composition of GC is 32%. We perform phylogenetic reconstruction based on maximum likelihood (ML) and Bayesian analysis(BI) using all PCGs. Our result indicates that P. versipora clusters closely with species which belong to Mussidae, Merulinidae and Lobophylliidae. Our phylogenetic analyses provide solid evidence for phylogenetic placement of P. versipora and the evolutionary relationships among different families within the traditional robust clade of Scleractinia. In addition, the mitogenome data provide useful information for further molecular systematic investigations on Plesiastreidae as well as conservation biology research of P. versipora.

Pleistocene isolation caused by sea-level fluctuations shaped genetic characterization of Pampus minor over a large-scale geographical distribution.

The southern lesser pomfret (Pampus minor) is an economically important fish, and its numbers are declining because of overfishing and environmental pollution. In addition, owing to the similarities of its external morphological characteristics to other species in the genus Pampus, it is often mistaken for grey pomfret (P. cinereus) or silver pomfret (P. argenteus) juveniles. In this study, the genetic diversity and structure of 264 P. minor individuals from 11 populations in China and Malaysia coastal waters were evaluated for the first time, to the best of our knowledge, using mitochondrial cytochrome b fragments. The results showed that P. minor had moderate haplotype diversity and low nucleotide diversity. Furthermore, two divergent lineages were detected within the populations, but the phylogenetic structure corresponded imperfectly with geographical location; thus, the populations may have diverged in different glacial refugia during the Pleistocene low sea levels. Analysis of molecular variation (AMOVA) showed that genetic variation originated primarily from individuals within the population. Pairwise F ST results showed significant differentiation between the Chinese and Malaysian populations. Except for the Xiamen population, which was classified as a marginal population, the genetic differentiation among the other Chinese populations was not significant. During the Late Pleistocene, P. minor experienced a population expansion event starting from the South China Sea refugium that expanded outward, and derivative populations quickly occupied and adapted to the new habitat. The results of this study will provide genetic information for the scientific conservation and management of P. minor resources.

Characterization of the complete mitochondrial genome sequences of three Merulinidae corals and novel insights into the phylogenetics.

Over the past few decades, modern coral taxonomy, combining morphology and molecular sequence data, has resolved many long-standing questions about scleractinian corals. In this study, we sequenced the complete mitochondrial genomes of three Merulinidae corals (Dipsastraea rotumana, Favites pentagona, and Hydnophora exesa) for the first time using next-generation sequencing. The obtained mitogenome sequences ranged from 16,466 bp (D. rotumana) to 18,006 bp (F. pentagona) in length, and included 13 unique protein-coding genes (PCGs), two transfer RNA genes, and two ribosomal RNA genes . Gene arrangement, nucleotide composition, and nucleotide bias of the three Merulinidae corals were canonically identical to each other and consistent with other scleractinian corals. We performed a Bayesian phylogenetic reconstruction based on 13 protein-coding sequences of 86 Scleractinia species. The results showed that the family Merulinidae was conventionally nested within the robust branch, with H. exesa clustered closely with F. pentagona and D. rotumana clustered closely with Favites abdita. This study provides novel insight into the phylogenetics of species within the family Merulinidae and the evolutionary relationships among different Scleractinia genera.

Complete mitochondrial genome of Echinophylliaaspera (Scleractinia, Lobophylliidae): Mitogenome characterization and phylogenetic positioning.

Lack of mitochondrial genome data of Scleractinia is hampering progress across genetic, systematic, phylogenetic, and evolutionary studies concerning this taxon. Therefore, in this study, the complete mitogenome sequence of the stony coral Echinophylliaaspera (Ellis & Solander, 1786), has been decoded for the first time by next generation sequencing and genome assembly. The assembled mitogenome is 17,697 bp in length, containing 13 protein coding genes (PCGs), two transfer RNAs and two ribosomal RNAs. It has the same gene content and gene arrangement as in other Scleractinia. All genes are encoded on the same strand. Most of the PCGs use ATG as the start codon except for ND2, which uses ATT as the start codon. The A+T content of the mitochondrial genome is 65.92% (25.35% A, 40.57% T, 20.65% G, and 13.43% for C). Bayesian and maximum likelihood phylogenetic analysis have been performed using PCGs, and the result shows that E.aspera clustered closely with Sclerophylliamaxima (Sheppard & Salm, 1988), both of which belong to Lobophylliidae, when compared with species belonging to Merulinidae and other scleractinian taxa used as outgroups. The complete mitogenome of E.aspera provides essential and important DNA molecular data for further phylogenetic and evolutionary analyses of corals.

The complete mitochondrial genome of Sillago indica (Perciformes: Sillaginidae).

In this study, the complete mitochondrial genome (mitogenome) sequence of Sillago indica has been determined by long polymerase chain reaction and primer walking methods. The complete mitochondrial genome is a circular molecule of 16,647 bp in length and contains 37 mitochondrial genes (13 protein-coding genes, 2 ribosomal RNA (rRNA), 22 transfer RNA (tRNA)), and a control region as other bony fishes. Within the control region, we identified the termination-associated sequence domain (TAS), the central conserved sequence block domains (CSB-F, CSB-E, CSB-D and CSB-C), and the conserved sequence block domains (CSB-1, CSB-2 and CSB-3).