The Phylogenetic Relationships of Lampridiform Fishes (Teleostei: Acanthomorpha), Based on a Total-Evidence Analysis of Morphological and Molecular Data

Abstract

We investigated the phylogenetic relationships among five species of lampridiform fishes, three basal outgroup species (two aulopiforms and one myctophiform), and two species of non-lampridiform acanthomorphs (PolymixiaandPercopsis) using a combined parsimony analysis of morphological and molecular data. Morphological characters included 28 transformation series obtained from the literature. Molecular characters included 223 informative transformation series from an aligned 854-base pair fragment of 12S mtDNA and 139 informative transformation series from an aligned 561-base pair fragment of 16S mtDNA. A total-evidence analysis using the aulopiformsSynodusandAulopusand the myctophiformHygophumas outgroups corroborates the monophyly of Lampridiformes and unitesPolymixiawithPercopsis.Among the lampridiform fishes we examined,Metaveliferis basal, followed in ascending order byLampris, Lophotus, Regalecus,andTrachipterus.This hypothesis is congruent with the most recent morphological analysis of the Lampridiformes and rejects a diphyletic origin of elongate body form within the clade. Analysis of a combined matrix of 12S and 16S mtDNA data yielded a phylogenetic hypothesis isomorphic with the total-evidence phylogeny. Analyses of partitioned DNA data sets reveals that single gene regions are poor predictors of the total-evidence phylogeny while combined analyses of both DNA data sets are good predictors of the total-evidence phylogeny.