Evolutionary Relationships of the Enigmatic Anglerfishes (Teleostei: Lophiiformes): Can Nuclear DNA Provide Resolution for Conflicting Morphological and Mitochondrial Phylogenies?

Abstract

Anglerfishes, order Lophiiformes, are among the most spectacular fishes living today and are widely known for their modified first dorsal-fin spine that serves as a luring apparatus. They comprise 351 living species placed in 73 genera, 18 families, and five suborders found world-wide from tropical near-shore habitats to the deep ocean. Previous studies using mitogenomes and morphological characters conflict, especially within the deep-sea suborder Ceratioidei, requiring that an independent line of evidence be examined to estimate the species tree. To this end, fragments from the protein coding nuclear loci ENC1, Glyt, myh6, and zic1 were analyzed from 68 species of lophiiforms representing all five suborders and 17 of the 18 families. Partitioned Bayesian and maximum likelihood analyses recovered monophyly for the order and all suborders. The concatenated nuclear genes strongly support the most basal position of the Lophiidae, supporting previous morphological and mitogenome studies. In addition, strong support for a clade comprising Chaunacoidei + Ceratioidei was also recovered, lending support to the previous mitogenome study. An unexpected relationship was recovered with regard to the Ogcocephaloidei, being recovered for the first time as basal to a clade comprising Antennarioidei + (Chaunacoidei + Ceratioidei). In addition, novel relationships were recovered within the Antennarioidei, rendering the family Antennariidae paraphyletic. While these relationships have not been recovered in previous morphological studies, some life history characters appear to lend support to these relationships. Relationships recovered within the Ceratioidei in this study conflict with both morphological and mitogenome studies and highlight the need for faster evolving nuclear loci to be analyzed to better understand these relationships. Additionally, evidence is presented to support at least three species within the Antennarias striatus complex. The results of this study are presented in a revised classification of the Lophiiformes.