A Gram-stain-negative and facultatively anaerobic bacterial strain, designated GUOT, was isolated from surface water collected from the South China Sea. Cells were non-flagellate, yellow, non-spore-forming and rod-shaped. The 16S rRNA gene sequence comparisons with species in the genus Arenibacter showed that strain GUOT shares the highest similarity of 97.5 % with Arenibacter echinorum and Arenibacter palladensis . Average nucleotide identity and digital DNA–DNA hybridization values between strain GUOT and its related type strains were 77.1–78.4% and 20.8–26.2 % respectively. Growth of strain GUOT occurred at 15–50°C (optimum, 20–25°C), pH 5–7.5 (pH 6) and in media containing 0–7 % NaCl (optimum, 0–1 %). Cells contained methanol-soluble yellow-coloured pigments but flexirubin-type pigments were absent. The major fatty acids (>5 %) were iso-C17 : 0 3-OH, iso-C15 : 0, anteiso-C15 : 0, C16 : 0, summed feature 3, iso-C15 : 1 G and iso-C15 : 0 3-OH. The dominant polar lipids comprised phosphatidylethanolamine and some unidentified polar lipids. The main respiratory quinone was menaquinone-6. The DNA G+C content of strain GUOT was 40.1 %. Based on the presented data, we consider strain GUOT to represent a novel species of the genus Arenibacter , for which the name Arenibacter aquaticus sp. nov. is proposed. The type strain is GUOT (=KCTC 62629T=MCCC 1K03559T)

2020) Complete mitochondrial genome and the phylogenetic position of a new species, Johnius taiwanensis (Perciformes: Sciaenidae) from Chinese waters, Mitochondrial DNA Part B, 5:1, 920-921, ABSTRACTIn this study, the complete mitogenome of a new species, Johnius taiwanensis (Chao et al. 2019) was obtained. Its mitogenome is 18,451 bp in length, consisting of 37 genes with the typical gene order and direction of transcription in vertebrates. Gene rearrangement was found in J. taiwanensis. The overall nucleotide composition is: 24.2% A; 18.0% C; 21.1% G, and 36.7% T. Sizes of the 22 tRNA genes range from 66 to 75 bp. Two start codons (ATG and GTG) and three stop codons (TAG, AGA and TAA/TA/T) were detected in 13 protein-coding genes. In the Bayesian tree based on the complete mitogenomes of 26 species (including J. taiwanensis) from the family Sciaenidae, all nodes were strongly supported. The result shows that J. taiwanensis was placed as sister to the Trewavas croaker J. trewavasae of the same genus. The mechanism of gene rearrangement in the genus Johnius merits further investigation. ARTICLE HISTORY

Reproductive dynamics of three important clupeiform food fishes (Gray's Grenadier Anchovy Coilia grayii, Osbeck's Grenadier Anchovy Coilia mystus, and Chinese Gizzard Shad Clupanodon thrissa) were studied in the largest estuary of Fujian Province, China: the Min River estuary and its adjacent nearshore waters. Samples were collected from May 2017 through July 2020 using trammel nets and trawlers. Females were observed to be significantly larger than males for Gray's and Osbeck's grenadier anchovies but not for Chinese Gizzard Shad. The overall sex ratios of all three species showed a significant female bias. Gonad histology was applied to determine spawning season, peak spawning season, and length at 50% maturity for females and males. The spawning season of females lasted from April to September (peak spawning season in April-July) for Gray's Grenadier Anchovy, from March to September (peak in March-June) for Osbeck's Grenadier Anchovy, and from April to July (peak in May-July) for Chinese Gizzard Shad. Spawning seasons of males were similar to those of females. The estimated SLs at 50% maturity for females and males, respectively, were 11.3 and 9.4 cm for Gray's Grenadier Anchovy, 12.7 and 10.4 cm for Osbeck's Grenadier Anchovy, and 12.7 and 11.6 cm for Chinese Gizzard Shad. The spawning grounds for these species were located for the first time: in the Min River estuary for Gray's Grenadier Anchovy, mainly in the adjacent nearshore waters and extending to the estuary for Osbeck's Grenadier Anchovy, and mainly in the lower reaches of the Min River and extending to the estuary for Chinese Gizzard Shad. As important food fishes in the region, stocks of these three species have shown certain degrees of overexploitation; therefore, stock assessments and management plans are necessary to achieve their sustainable fisheries.

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