Phylogenetic relationships of some common Indo-Pacific snappers (Perciformes: Lutjanidae) based on mitochondrial DNA sequences, with comments on the taxonomic position of the Caesioninae

Abstract

The phylogenetic relationships of 27 species of common Indo-Pacific snappers (Lutjanidae) were explored using the 16S ribosomal RNA and cytochrome b mitochondrial genes with minimum evolution, maximum parsimony, maximum likelihood and Bayesian inference analyses. Included were species representing four subfamilies, the Caesioninae, Etelinae, Paradicichthyinae, and Lutjaninae. Members of the closely related families Haemulidae, Lethrinidae, Nemipteridae and Sparidae, were included for outgroup comparisons and to explore the relationships between the Haemuloidea, Lutjanoidea and Sparoidea. Monophyly of the Lutjanidae was resolved. The Caesioninae was nested within the Lutjaninae, supporting the recent view that the Caesionidae should be treated as a synonym of the Lutjanidae. The subfamilies Etelinae and Paradicichthyinae were resolved as sister taxa to the remainder of the Lutjanidae, which corroborates previous cladistic analyses conducted to determine relationships of lutjanid subfamilies. Bayesian inference and maximum likelihood analyses suggest that Macolor is the sister taxon to the Caesioninae and may represent a transitional form between the Lutjaninae and Caesioninae. Three species of Western Atlantic lutjanids, Lutjanus campechanus, L. synagris, and Rhomboplites aurorubens, were included in the analyses to examine their relationships to Indo-Pacific species; they formed a well-supported clade nested within Pacific lutjanines suggesting that Atlantic species of Lutjaninae are derived from an Indo-Pacific lineage. Results of our molecular phylogenetic analyses are congruent with the general morphology and external colouration of the resolved groups of species of Lutjanus. The "black spot" complex containing L. fulviflamma, L. monostigma, and L. russelli was resolved with strong support, and had L. carponotatus nested within. The morphology of L. carponotatus suggests a close relationship to this group, and the lack of the black spot near the lateral line below the soft dorsal fin is possibly a secondary loss. As expected, the "blue-lined" species, L. kasmira and L. quinquelineatus, formed a strongly supported clade. Lutjanus bohar and L. gibbus, both distinctly red, long-lived fish that often accumulate large quantities of ciguatera toxin in their tissues, were resolved as sister taxa.