Diet-driven ecological radiation and allopatric speciation result in high species diversity in a temperate-cold water marine genus Dendronotus (Gastropoda: Nudibranchia)

• Published in: Molecular phylogenetics and evolution Vol. 141; p. 106609
• Main Authors: Ekimova, Irina, Valdés, Ángel, Chichvarkhin, Anton, Antokhina, Tatiana, Lindsay, Tabitha, Schepetov, Dimitry
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-12-2019
• Subjects: Adaptive radiation; Algorithms; Animals; Arctic; Arctic Regions; Bering strait; Biodiversity; Biological Evolution; Character evolution; Diet; DNA, Mitochondrial; Evolution, Molecular; Gastropoda - genetics; Gastropoda - physiology; Genetic Speciation; Likelihood Functions; Molecular phylogenetics; Phylogeny; Species Specificity; Time Factors; Arctic Regions; Adaptive radiation; Bering strait; Molecular phylogenetics; Arctic; Character evolution
• ISSN: 1055-7903; 1095-9513
• DOI: 10.1016/j.ympev.2019.106609

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•Dendronotus shows strong correlation between radular morphology, diet and phylogeny.•Ancestral area reconstruction suggests Pacific origin of Dendronotus.•Diet-driven adaptive radiation occurred in the North Pacific during Miocene-Pliocene.•Dendronotus lineages dispersed to the Atlantic following historical climate changes.
While the majority nudibranch clades are more species rich in the tropics, the genus Dendronotus is mainly represented in Arctic and boreal regions. This distribution pattern remains poorly understood. An integrative approach and novel data provided valuable insights into processes driving Dendronotus radiation and speciation. We propose an evolutionary scenario based on molecular phylogenetics and morphological, ecological, ontogenetic data, combined with data on complex geology and paleoclimatology of this region. Estimated phylogenetic relationships based on four molecular markers (COI, 16S, H3 and 28S) shows strong correlation with radular morphology, diet and biogeographical pattern. Ancestral area reconstruction (AAR) provides evidence for a tropical Pacific origin of the genus. Based on AAR and divergence time estimates we conclude that the evolution of Dendronotus has been shaped by different processes: initial migration out of the tropics, diet-driven adaptive radiation in the North Pacific influenced by Miocene climate change, and subsequent allopatric speciation resulting from successive closings of the Bering strait and cooling of the Arctic Ocean during the Pliocene-Pleistocene. At the same time, contemporary amphiboreal species appear to have dispersed into the Atlantic fairly recently.