Phylogeny Reconciles Classification in Antarctic Plunderfishes
The resolution of phylogenetic relationships within rapid radiations poses a significant challenge in systematic biology. However, the integration of genome-scale DNA data with multispecies coalescent-based tree inference methods offers a strategy to resolve historically recalcitrant nodes within radiations of closely related species. Here, we analyze a dataset of over 60,000 loci captured via double digest restriction site-associated DNA sequencing (ddRADseq) using both concatenation- and coalescent-based approaches to infer the phylogenetic relationships of the Antarctic notothenioid lineage Artedidraconinae. Previous studies identify artedidraconines as the most rapidly diversifying subclade of notothenioids, but evolutionary studies of the clade are stymied by pervasive phylogenetic and taxonomic uncertainty. The results of our phylogenomic analyses provide clarity to several long-standing challenges in the systematics of artedidraconines, including the deep paraphyly of Artedidraco. Our findings enable the construction of a classification that reflects phylogenetic relationships, including the description of a new genus and the resurrection of a classification of Notothenioidei that places Artedidraconinae as a subfamily of Harpagiferidae. This work provides a phylogenetic perspective for investigations of the tempo and mode of diversification in artedidraconines, which is likely to provide new insights on the dynamics of the notothenioid adaptive radiation as a whole.
Neodraco skottsbergi from the South Orkney Islands (–61.213304, –45.935358), 7.1 cm standard length. YPM ICH 022463.
Phylogenetic relationships of Artedidraconinae based on maximum likelihood analyses of concatenated ddRAD datasets using IQ-TREE. Bootstrap support values for nodes less than 100% are shown. (A) Phylogeny resulting from analysis of the dataset that includes 64,980 ddRAD loci. The DNA sequence alignments include data for at least 84 of the 168 sampled specimens (min84). The sectors of the Southern Ocean where specimens were collected are indicated with colored circles at the tips of the phylogeny. (B) Phylogeny resulting from analysis of the dataset that includes 19,042 ddRAD loci. The DNA sequence alignments include data for at least 126 of the 168 sampled specimens (min126). (C) Phylogeny resulting from analysis of the dataset that includes 1,331 ddRAD loci. The DNA sequence alignments include data for at least 144 of the 168 sampled specimens (min144). See Data Accessibility for tree file.
Phylogenetic relationships of Artedidraconinae based on multispecies coalescent analyses of SNPs extracted from ddRAD datasets using tetrad. Bootstrap support values for nodes less than 100% are shown. (A) Phylogeny resulting from analysis of the dataset that includes 64,980 ddRAD loci. The DNA sequence alignments include data for at least 84 of the 168 sampled specimens (min84). The sectors of the Southern Ocean where specimens were collected are indicated with colored circles at the tips of the phylogeny. (B) Phylogeny resulting from analysis of the dataset that includes 19,042 ddRAD loci. The DNA sequence alignments include data for at least 126 of the 168 sampled specimens (min126). (C) Phylogeny resulting from analysis of the dataset that includes 1,331 ddRAD loci. The DNA sequence alignments include data for at least 144 of the 168 sampled specimens (min144). See Data Accessibility for tree file.
Results of principal component analysis (PCA) of meristic trait data for five species of Artedidraco and two species of Neodraco. (A) Biplot visualization of PC axes 1 and 2. (B) Visualization of variable loadings for all PC axes 1, 2, and 3. Points and convex hulls in biplots are colored according to species. In panel B, D1 = first dorsal-fin spines, D2 = second dorsal-fin rays, A = anal-fin rays, P = pectoral-fin rays, and ULL = tubular scales in upper lateral line.
Contributor Notes
Associate Editor: M. P. Davis.