Stable isotope analysis reveals ontogenetic feeding shifts in Pacific blue marlin (Makaira nigricans) off eastern Taiwan.

To gain a better understanding of the trophic ecology of Pacific blue marlin Makaira nigricans off eastern Taiwan, nitrogen and carbon stable isotopes (δ15 N and δ13 C) and Bayesian mixing models were used to explore trophic dynamics and potential ontogenetic feeding shifts across M. nigricans of different size classes. Makaira nigricans samples from east of Taiwan (n = 213) and Palau (n = 37), as well as their prey (n = 70), were collected during 2012 and 2013. Results indicated increases in δ15 N with size, with values of larger size classes (> 200 cm eye-to-fork length; LEF ) significantly higher than those < 200 cm LEF . Values of δ13 C were negatively correlated with size. Makaira nigricans > 200 cm LEF had the highest estimated trophic position (4.44) and also exhibited ontogenetic changes in trophic position. Large M. nigricans fed more on dolphinfish Coryphaena hippurus and hairtail Trichiurus lepturus, while smaller M. nigricans consumed smaller forage fish (e.g., moonfish Mene maculata) and cephalopods. These changes may relate to greater swimming speeds and vertical habitat use in larger M. nigricans, allowing capture and consumption of larger prey items at higher trophic positions. The high trophic level of M. nigricans east of Taiwan confirms its important role as an apex predator in marine food webs and how ecological role changes with size.

Complete mitochondrial genome of the palemargin grouper Epinephelus bontoides (Pisces: Perciformes).

The complete mitogenome of the palemargin grouper, Epinephelus bontoides, was presented in this study. This mitochondrial genome consists of 16 903 bp, follow the typical gene arrangement with 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and a non-coding control region (CR). The overall base composition was A, 28.7%; G, 16.1%; C, 28.0%; and T, 27.2%. The control region was 1200 bp in length, which located between tRNAPro and tRNAPhe, rich in A + T (69.2%) content. Based on the Neighbor-Joining (NJ) tree, E. bontoides was grouped with E. trimaculatus, E. quoyanus, E. areolatus, and E. bleekeri, and then combined with E. merra formed a clade. This complete mitogenome of E. bontoides can provide essential phylogenetic information of Epinephelus.

The complete mitochondrial genome of Babylonia borneensis (Gastropoda: Neogastropoda: Buccinidae).

The complete mitochondrial genome sequence of the Babylonia borneensis is reported for the first time in this study. The length of genome was 15 556 bp, including 13 protein-coding genes, 2 ribosomal RNA genes and 22 transfer RNA genes. The nucleotide composition of the mitogenome showed AT-rich feature, with the AT content of 68.2%. Comparison of the identity of the B. borneensis mitogenome with B. areolata, B. lani and B. lutosa was 87.5%, 87.4% and 86.9%, respectively. The construction of phylogenetic tree showed high bootstrap support value. Babylonia borneensis grouped together with other Babylons and the lineages of Buccinidae was strongly supported. In this study, our results could provide a further understanding in the phylogenetic relationships of the Neogastropoda.

Complete mitochondrial genome of the sixblotch hind Cephalopholis sexmaculata (Pisces: Perciformes).

The complete mitogenome of the sixblotch hind, Cephalopholis sexmaculata was presented in this study. This mitochondrial genome consists of 16,589 bp, with 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and a noncoding control region (CR), and its gene arrangement is identical to most vertebrates. The overall base composition of the heavy strand is A, 29.35%; G, 16.08%; C, 28.56%; and T, 26.01%. The COI gene started with GTG codon and the ATP6 gene started with CTG codon. The complete mitogenomic data may provide informative for further phylogenetic approach of species of Cephalopholis and related genera belong to the Epinephelidae groupers.

Mitochondrial DNA sequence of Conus textile (Neogastropoda: Conidae).

The cone snail Conus textile belongs to the family Conidae. It is a kind of molluscivorous species. The complete mitochondrial DNA sequence was constructed by next-generation sequencing in this study. The mitogenome of C. textile is 15,765 bp in length, including 13 protein-coding genes, 22 tRNA genes, 2 ribosomal RNA genes and 1 control region. The base composition was 27.3% A, 37.9% T, 15.7% C and 19.1% G. The phylogenetic tree of C. textile with the other 6 Conus species and 15 Neogastropoda sea snails was built. It provides fundamental data for further research of phylogeny and biogeography with this genus.

The complete mitochondrial genome of Conus capitaneus (Neogastropoda: Conidae).

The complete mitochondrial genome sequence of cone snail Conus capitaneus, a kind of worm-hunting sea snails, was performed by next-generation sequencing. The mitogenome is 15,829 bp in length, including 13 protein-coding genes, 22 tRNA genes, 2 ribosomal RNA genes (12S and 16S rRNA) and 1 control region. It has an overall base composition of A (25.6%), T (36.6%), C (16.3%) and G (21.5%). It shows 79.8% identity with C. tribblei, which also belongs to worm-hunting sea snail. The phylogenetic analysis was conducted with 21 closely related species to assess their phylogenetic relationship. The complete mitogenome of the C. capitaneus provides important DNA molecular data for further phylogeography.

The complete mitochondrial genome of Conus striatus (Neogastropoda: Conidae).

Conus striatus is a kind of piscivorous cone snail. We have sequenced it by next generation sequencing method. We used de novo assembly and reference mapping methods to assemble mitogenome. The mitochondrial genome is 15,738 bp, containing 13 protein coding genes, 22 transfer RNAs and 2 ribosomal RNAs genes. The overall base composition of C. striatus is 25.9% for A, 16.3% for C, 20.8% for G and 38.6% for T. The phylogenetic analysis was conducted with 18 related species and confirmed the classification status. The complete mitogenome of the C. striatus provides an essential and important DNA molecular data for further phylogeography and evolutionary analysis for cone snail phylogeny.

The complete mitochondrial genome of Conus tulipa (Neogastropoda: Conidae).

The complete mitogenome sequence of the cone snail Conus tulipa (Linnaeus, 1758) has been sequenced by next-generation sequencing method. The assembled mitogenome is 16,599 bp in length, including 13 protein-coding genes, 22 transfer RNA genes and 2 ribosomal RNA genes. The overall base composition of C. tulipa is 28.7% A, 15.2% C, 18.4% G and 37.7% T. It shows 81.1% identity to the cone snail C. consors, 78.5% to C. borgesi and 77.5% to C. textile. Using the 13 protein-coding genes and 2 ribosomal RNA genes of C. tulipa in this study, together with 18 other closely species, we constructed the species phylogenetic tree to verify the accuracy and utility of new determined mitogenome sequence. The complete mitogenome of the C. tulipa provides an essential and important DNA molecular data for further phylogeography and evolutionary analysis for cone snail phylogeny.

The complete mitochondrial genome of Poecilia formosa (Actinopterygii: Cyprinodontiformes: Poeciliidae).

The complete mitochondrial genome sequence of the Poecilia formosa is first reported in this study. The length of genome is 16 550 bp, including 13 protein-coding genes, 2 ribosomal RNA genes and 22 transfer RNA genes. Congeneric mitogenome sequence identity is 87.7% with P. reticulate and 93.1% with P. sphenops. The reconstructed phylogenetic relationships of 16 Cyprinodontiformes species based on 13 protein-coding genes were highly supported and the clade of all Poecilia fishes included had a support value of 100%. Our results shall provide a better understanding in the evolutionary histories of the Cyprinodontiformes.