Characterization of the Complete Mitochondrial Genome Sequences of Three Croakers (Perciformes, Sciaenidae) and Novel Insights into the Phylogenetics.

The three croakers (Nibea coibor, Protonibea diacanthus and Argyrosomus amoyensis, Perciformes, Sciaenidae) are important commercial species inhabiting the Eastern Indian Ocean and Western Pacific. Molecular data employed in previous research on phylogenetic reconstruction have not been adequate and complete, and systematic and comprehensive phylogenetic relationships for these fish are unresolved. We sequenced the complete mitochondrial genomes of the three croakers using next-generation sequencing for the first time. We analyzed the composition and phylogenies between 19 species in the family Sciaenidae using the mitochondrial protein coding sequences of 204 species in the Series Eupercaria. We present the characterization of the complete mitochondrial genome sequences of the three croakers. Gene arrangement and distribution of the three croakers are canonically identical and consistent with other vertebrates. We found that the family Sciaenidae is an independent branch that is isolated from the order Perciformes and does not belong to any extant classification. Therefore, this family is expected to belong to a new classification at the order level and needs further analysis. The evolution of Sciaenidae has lagged far behind the Perciformes differentiation. This study presents a novel insight into the phylogenetics of the family Sciaenidae from the order Perciformes and facilitates additional studies on the evolution and phylogeny of Series Eupercaria.

A morphological and genetic description of pentastomid infective nymphs belonging to the family Sebekidae Sambon, 1922 in fish in Australian waters.

Infective nymphal stages of the family Sebekidae Sambon, 1922 are reported from four species of fish in Australian waters for the first time. Infected fish were collected from locations in Western Australia, the Northern Territory and north Queensland. The infective nymphs of Alofia merki Giglioli in Sambon, 1922 and Sebekia purdieae Riley, Spratt et Winch, 1990 are reported and described for the first time. The remaining specimens were identified as belonging to the genus Sebekia Sambon, 1922 based on the combination of buccal cadre shape, shape and size of hooks, and overall body size, but could not be attributed to any of the other species of Sebekia already reported due to missing required morphological features. DNA sequences of members of the family Sebekidae are presented for the first time. The lack of knowledge on the pentastome fauna of wild crocodiles, and any potential intermediate hosts, in northern Australia, is also outlined.

The complete mitochondrial genome of the black jewfish Protonibea diacanthus (Perciformes: Sciaenidae).

We describe the complete mitochondrial genome of the black Jewfish Protonibea diacanthus. It was assembled from approximately 1.6 million reads produced by Ion Torrent next generation sequencing. The complete genome was 16,521 bp in length consisting of 13 protein-coding regions, 22 tRNA, 12S and 16S rRNA as well as two non-coding regions. The A+T base content (52.8%) is similar to other teleosts.

The complete mitochondrial genome of the blackspotted croaker Protonibea diacanthus (Perciformes, Sciaenidae).

We present the complete mitochondrial genome of Protonibea diacanthus in this study. The mitochondrial genome is 16,535 bp in length, containing 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and a control region. All of them are encoded on the heavy strand except ND6 and 8 tRNA genes on the light strand. The nucleotide compositions of the light strand are 31.09% of G, 27.54% of T, 25.34% of A and 16.03% of C. All the protein-coding genes start with ATG initiation codon except ATP6 with GTG, and 5 types of inferred termination codons are AGA (COXI and COXII), T (ND3, ND4, Cytb), TA (ND2, COXIII and ATP6), TAA (ND1, ATP8 and ND4L) and TAG (DN5 and ND6). There are 14 intergenic spacers and 7 gene overlaps. The tandem repeat sequence is observed in 12S-rRNA, 16S-rRNA, tRNA(Trp), tRNA(Ala), COXIII, ND4L and ND4 genes. Gene arrangement and distribution are consistent with the typical vertebrates.

Characterization, development and multiplexing of microsatellite markers in three commercially exploited reef fish and their application for stock identification.

Thirty-four microsatellite loci were isolated from three reef fish species; golden snapper Lutjanus johnii, blackspotted croaker Protonibea diacanthus and grass emperor Lethrinus laticaudis using a next generation sequencing approach. Both IonTorrent single reads and Illumina MiSeq paired-end reads were used, with the latter demonstrating a higher quality of reads than the IonTorrent. From the 1-1.5 million raw reads per species, we successfully obtained 10-13 polymorphic loci for each species, which satisfied stringent design criteria. We developed multiplex panels for the amplification of the golden snapper and the blackspotted croaker loci, as well as post-amplification pooling panels for the grass emperor loci. The microsatellites characterized in this work were tested across three locations of northern Australia. The microsatellites we developed can detect population differentiation across northern Australia and may be used for genetic structure studies and stock identification.